HSEHealth & Safety

Executive

Bird guano accumulationsand their effect on offshore

helicopter operations

Prepared by BOMEL Ltd/John Burt Associates Ltd

on behalf of BOMEL Consortiumfor the Health and Safety Executive

OFFSHORE TECHNOLOGY REPORT

2000/131

HSEHealth & Safety

Executive

Bird guano accumulationsand their effect on offshore

helicopter operations

BOMEL LtdLedger House

Forest Green RoadFifield, Maidenhead

Berkshire SL6 2NRUnited Kingdom

HSE BOOKS

ii

© Crown copyright 2001Applications for reproduction should be made in writing to:Copyright Unit, Her Majesty’s Stationery Office,St Clements House, 2-16 Colegate, Norwich NR3 1BQ

First published 2001

ISBN 0 7176 2037 9

All rights reserved. No part of this publication may bereproduced, stored in a retrieval system, or transmittedin any form or by any means (electronic, mechanical,photocopying, recording or otherwise) without the priorwritten permission of the copyright owner.

This report is made available by the Health and SafetyExecutive as part of a series of reports of work which hasbeen supported by funds provided by the Executive.Neither the Executive, nor the contractors concernedassume any liability for the reports nor do theynecessarily reflect the views or policy of the Executive.

CONTENTS

644.3 MEASURES USED AND LESSONS LEARNT FROM UK FIXED WING AVIATION

594.2 MEASURES USED AND LESSONS LEARNT BY THE OFFSHORE INDUSTRY TO DATE

554.1 PREVENTION SYSTEMS AND THEIR EFFECTIVENESS

55PART 3 - MITIGATING MEASURES4

493.6 EFFECTS ON MAINTENANCE AND HOUSEKEEPING

443.5 EFFECTS ON PERSONNEL HEALTH AND SAFETY

443.4 THE POTENTIAL HAZARDS FOR HELIDECK OPERATIONS

423.3 EFFECTS ON HELICOPTER FLIGHT OPERATIONS DECISIONMAKING

383.2 THE POTENTIAL HAZARDS TO HELICOPTER FLIGHT OPERATIONS

353.1 LEGAL RESPONSIBILITY - THE OFFSHORE AND AVIATION REGULATORY POSITION

35PART 2 - THE EFFECTS AND CONSEQUENCES FOR OFFSHOREOPERATIONS

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272.3 THE PATTERN AND POSSIBLE REASONS FOR THE GUANO ACCUMULATIONS

32.2 THE EXTENT OF THE PROBLEM

32.1 BACKGROUND TO THE GUANO PROBLEM

3PART 1 - GUANO ACCUMULATION ON INSTALLATIONS2

21.2 SCOPE

11.1 PURPOSE

1INTRODUCTION1

vEXECUTIVE SUMMARY

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CONTENTS CONTINUED

106APPENDIX G - BRISTOW HELICOPTERS WEEKLY REPORT - NUIHELIDECK CONDITION

100APPENDIX F - TOTAL OIL MARINE WATER SPRAY SYSTEM -PHOTOGRAPHS

92APPENDIX E - SEA BIRD SPECIES AROUND UKCS

88APPENDIX D - SEA BIRD ORDERS

85APPENDIX C - UKCS HELIDECK GUANO PROBLEMS - CAA MORANALYSIS

81APPENDIX B - ILLUSTRATIONS OF GUANO ACCUMULATION ANDITS EFFECTS - CAA REPORT

79APPENDIX A - LIST OF CONTRIBUTORS

786.2 BIBLIOGRAPHY

786.1 LIST OF ABBREVIATIONS

78LIST OF ABBREVIATIONS AND REFERENCES6

765.2 RECOMMENDATIONS

735.1 CONCLUSIONS

73CONCLUSIONS AND RECOMMENDATIONS5

674.5 SUMMARY AND CLOSING REMARKS

664.4 MEASURES USED AND LESSONS TO BE LEARNT FROM OTHER INDUSTRIES: IMPLICATIONS FOR OFFSHORE

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HEALTH AND SAFETY EXECUTIVEOFFSHORE DIVISION

BIRD GUANO ACCUMULATIONS AND THEIR EFFECT ON

OFFSHORE HELICOPTER OPERATIONS

EXECUTIVE SUMMARY

This report has been prepared with the help of contributions from several people and companiesworking in the offshore Industry (see Appendix A).

In taking this approach to the subject, a balanced report has been prepared that meets theobjective for obtaining a better appreciation of current bird / guano accumulation problemsencountered on UKCS installations; in particular their effects on safety and health aspects ofoffshore helicopter operations.

Clearly, the long-standing problem with birds / guano on offshore installations has not altered toany extent. This comes as no surprise because it is well known that the forces of nature arealways present and defeating them entirely is often beyond the wit of man. A more pragmaticapproach for duty holder and regulator alike is to simply accept the irresistible forces of natureare at work when an installation is selected and colonised by sea birds. Once this happens theproblem has to be properly managed by the duty holder and helicopter operators to minimisethe effects of the birds on both platform and helicopter operations. Introducing an industry ledhelideck condition monitoring system and focusing on simple solutions for more efficient guanoclean-up are considered to have the greatest potential for gaining real benefits and achievingsome cost savings.

Helicopter bird strikes and interference are always going to be a potential hazard in the offshoreoperating environment. However, evidence suggests that this is a UKCS-wide problem andhelicopter operations to normally unattended installations, where sea birds are known tocongregate, are no more affected or hazardous than elsewhere.

It is apparent that duty holders and helicopter operators are managing the problem in differentways, but levels of success and enthusiasm vary.

There are ways to move forward to make further gains in the quest to reduce operational, safetyand health hazards. Suggested efficiencies for minimising the effects of birds and their guanoaccumulations on NUI’s, are identified in the body of the report and in the recommendations.

Essentially, all sides of the UKCS offshore industry are encouraged to work more closelytogether and to facilitate open dialogue and information exchange to assist all duty holders whoencounter a bird / guano problem on their installations.

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Routine and frequent reporting of helideck condition is fundamental to efficiently managing theguano accumulation and obscured marking and lighting problems. Industry co-operation shouldinclude development of a routine UKCS NUI helideck condition reporting, assessment,recording and publishing system in conjunction with procedures fully owned, sponsored andmanaged by UKOOA / BHAB.

To assist with helideck condition reporting frequency all pilots could be requested to look athelidecks other than the ones they are flying to.

This management approach if used as an ‘early warning system’, offers a good way forhelicopter operators and installation duty holders to jointly discharge their ‘duties of care’ towardensuring that NUI helidecks remain compliant in respect of the ANO and offshore legislation.The procedures could be incorporated into the UKOOA Guidelines for Helicopter Operations toNormally Unattended Installations.

No individual exclusion device has been able to provide the whole solution. It requires acombination of systems to sustain a reasonable degree of freedom from the birds in the mediumterm. This is currently being demonstrated with the Gull Scat / water spray combination onTotal Oil Marine’s MCP-01.

Cleaning and disposal of guano and bird debris from a fouled helideck remains a major task formost NUI duty holders, when they have helidecks that are heavily fouled. It is very unpleasantfor the personnel involved, exposes them to potential health hazards, it is time consuming anddisruptive to routine maintenance operations and is costly. There is much merit in focusingmore attention on finding practical and cost effective solutions to these problems. Solutions thatalso reduce the frequency of repairing helideck surfaces and markings and replacing helidecknets would be an added bonus.

A starting point toward finding a practical solution to disposal and cleaning problems may befound in the ‘tarpaulin’ system currently used, with some success, by ARCO. Arco currentlyemploy a system that achieves bulk guano removal and reduces helideck cleaning effort toquite an extent. It is recommended that industry consider this system as an option thatdeserves further development.

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1. INTRODUCTION

This study report was commissioned by the Health & Safety Executive (HSE),Offshore Division (OD 5.5).

Offshore Technology Report - OTO 98 088, titled “HSE / CAA Inspection ProjectOffshore Helidecks 1991-1995” issued in March 1998 (Reference 1), highlightedconcerns over the long-standing problems of sea birds roosting on NormallyUnattended Installations (NUI’s). The main problem with these sea birds is their habitof leaving guano accumulations, which build up to a point where helideck markingsbecome obscured. This can contribute towards a pilot making a wrong deck landing(Reference 3) and in extreme cases aborting a landing. Equally important is the otherdebris they leave behind (potential FOD, see Section 6 for abbreviations), along withthe general health risks for personnel exposed to guano and increased bird strikepotential for helicopters operating in the local area.

Figures given in the OTO Report suggest that about 30% of helidecks on NUI’s have aconsistent problem with guano accumulation. This figure was given as ‘recent’ in thereport and followed the formation in March 1997 of a Joint Industry Working Group(convened by HSE) to look at the size of the problem posed by colonising seabirds,the range of attendant problems they create and to look for possible solutions. Thisreport continues HSE's aim to facilitate the search for solutions.

The guano problem on NUI helidecks is well illustrated in the photographs reproducedfrom the OTO Report, in Appendix 2.

1.1 PURPOSE

HSE’s primary objective is to obtain a better appreciation of current bird guanoaccumulation problems that are encountered on UKCS installations (manned andunmanned) and their effects on the safety and health aspects of offshore helicopteroperations.

From the findings of this study, a secondary objective is to identify those areas wherefurther productive work could be done to find ways to improve the current situationthrough minimising the effects of guano accumulations.

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1.2 SCOPE

For ease of reference, the study is broken down into three parts that must beaddressed in order to meet the primary and secondary objectives. The topics coveredare:

� Guano accumulation on installations� The effects and consequences for offshore operations� Mitigating measures

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2. PART 1 - GUANO ACCUMULATION ON INSTALLATIONS

2.1 BACKGROUND TO THE GUANO PROBLEM

Since the advent of UKCS oil and gas exploration and production operations, visitingseabirds and other bird species have become part of the natural environment offshore.

Seasonal in their habits (breeding, feeding and migration) a variety of different birdshave been observed on offshore platforms at various times throughout the year.

It is the various species of sea birds that appear to dominate in the helideck guanoaccumulation problem. Manned installations are also affected to some extent butthese tend to be isolated instances and limited in their effect. Normally UnattendedInstallations (NUI’s) are, by far, the most affected. The habitual colonisation, by seabirds, of unmanned installations around the UKCS, particularly during the summer andautumn periods, has given rise to concern over many years for the owners of many ofthe 90 or so NUI’s located around the UKCS. See Figure 2.1 for NUI distributionaround the UKCS.

As has been highlighted in the HSE / CAA Helideck Inspection Project report(Reference 1) and other literature, helideck markings become severely obscured,there are general health risks for personnel exposed to guano and there is always thepotential for aircraft bird strikes.

This report will seek to put these problems into perspective from an operationalviewpoint.

2.2 THE EXTENT OF THE PROBLEM

2.2.1 RESULTS OBTAINED FROM INTERROGATING THE CAA SDDMANDATORY OCCURRENCE REPORTING (MOR) DATABASE

CAA SDD were formally requested to interrogate their MOR Database using a varietyof search parameters such as:

� Guano accumulation on helidecks.� Obscured helideck markings.� Cancelled or aborted sorties due to the above problems.� Bird strikes or near misses around offshore platforms.

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Figure 2.1 - NUI Distribution

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The MOR search yielded just 26 relevant MOR’s. It is significant that only 4 of thesereports actually relate to problems caused by guano accumulations on helidecks.Summaries of the 4 reports are included in Appendix 3.

Considering that MOR record keeping started on 1 January 1976 this is a very lownumber of reports, given that 2,472,129 flight hours and 5,518,748 sectors have beenflown by UKCS offshore helicopters during the period 1973 to 1998.

Simple analysis of the 4 MOR’s shows that 3 were reported during operations in theUKCS Southern Sector. The other location is unknown.

Likewise, 3 of the 4 MOR’s were reported for operations to Normally UnattendedInstallations. The fourth report does not clearly state it was an unmanned platform butthis is probably the case.

The occurrences, all of which affected helideck identification during both day and nightoperations, were noted:

� Two on the approach, and � Two during landing.

One incident was primarily a wrong helideck landing. Amongst other factors (e.g. piloterror and weather) the deck markings were reported to be partially obscured byguano.

There was only one report of the markings being totally obscured by guano.

The very low number of ‘official’ MOR reports submitted by flight crews makes itdifficult to claim there is a significant flight safety problem associated with guanoaccumulations on offshore platforms.

The point to be made here is that it appears guano on helidecks is generally notconsidered a significant enough flight safety problem to prompt ‘flight crews’ to raiseMORs. Yet, from the Regulators, Oil & Gas Industry and the Helicopter Operatorsperspective there is sound evidence of significant problems with guano accumulationson helidecks.

With this apparent contradiction in mind, it is prudent to obtain further evidence toestablish a case for positive action to be taken to reduce guano accumulationproblems. It is probably unproductive to dwell on why the perceptions about helideckguano accumulations might differ. It may simply be a case of “How bad, is badenough to report it on an MOR ?”

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2.2.2 HSE / CAA HELIDECK INSPECTION REPORT CONCLUSIONSIn the HSE / CAA Helideck Inspection Project over 250 helideck inspections werecarried out and 76 of these helidecks were on NUI’s. The report (Reference 1)concluded that at least 30% of Normally Unattended Installations (NUI’s) wereconsistently affected by guano accumulations. This figure is supported by theevidence gathered during the three phases of the inspection programme for HSE, asnoted in the following Table 2.1.

PercentageNumber withGuano Problem

NUI HelidecksInspected

ProjectPhase

201576Total

41717III

13323II Ext.

0015II

24521I

Table 2.1 - CAA Helideck Inspection Project - Guano Problems

It is noted from the table that of the 30% of NUI helidecks that were seen to beconsistently affected by guano, during the period of the CAA inspections, 20% hadbad problems that were caused by the accumulations.

Section 5 of the OTO Report listed five recommendations. Two recommendationsspecifically relate to the substance of this report. They are:

Recommendation 4.“HSE should specifically reinforce the installation owner / operator’s duty of care inrelation to achieving clear and unobscured helideck markings which form the agreedminimum requirements for provision of adequate visual aids for pilots. Thisrecommendation specifically applies to Normally Unattended Installations.”

Recommendation 5.“The HSE should co-ordinate a Research and Development programme into theproblems (visual aids obscuration, general health risks, potential bird strikes)associated with guano. The objectives of the R&D should be to discourage birds fromroosting on Normally Unattended Installations”.

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2.2.3 RESPONSES TO HSE / CAA HELIDECK INSPECTION REPORTRECOMMENDATIONS

2.2.3.1 Joint Industry Work Group ActivitiesOn 24th March 1997 a Joint Industry Working Group meeting was convened by HSE(OD4.6) in their Norwich office. Attendees invited were local Oil & Gas Industry(SACC) and helicopter operator (BHAB) representatives.

The objective of this meeting was to establish if there was an increased or increasingrisk from birds to personnel travelling to and from NUI’s and, if there was an increasedrisk, how this could be reduced to acceptable levels.

HSE (OSD) were keen to take this potential problem forward to promote anindustry-wide solution.

At the meeting, the threat of bird strikes was stated as the major concern for HSE.However, other issues related to the bird problem were included for discussion. Theseincluded guano build up on helidecks, helideck marking obliteration and FOD.Significantly, discussion about health risks were not on the original agenda.

The meeting raised many issues, significant points and a number of actions. Theoutcome is summarised as follows:

� There was no industry awareness of bird strikes.

� Pilot experience suggested that at the low speed of approach to a platform,birds have no problem in manoeuvring out of the way of helicopters.

� Helicopters do not have to get out of the way of birds.

� The hazard of potential bird strikes is not a problem in the low speedscenario. The chances and consequences are less. The hazard hasperhaps been overstated!

� There had been about three occasions when pilots refused to land on NUI’sdue to birds refusing to move off the helideck. One occurred at night.

� Guano builds up very quickly and obscures the helideck markings. This isthe bigger problem and it is always more acute at night. This is primarily dueto pilots seeking good visual cues when changing from forward motion intothe hover and alternating between internal instrument references andexternal landing site references.

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� Duty holders rely on pilots warning them when helideck cleaning is required.Pilots report on a routine basis via ‘voyage logs’.

� The problem is more acute with night flights than in daylight. On someplatforms there is a night flying ban.

� One operator stated their major concern was the health risk to personnelhaving to clean the helidecks.

� After 4 to 5 weeks the guano build-up can be 0.5 to 1 inch thick.

� ‘Gull Scat’ (an audio bird scaring system) had been successfully trialed andwas being fitted to some NUI’s.

� Even with ‘Gull Scat’ fitted the birds, instead of going on the helideck, werenow perching on the helideck support structure.

� It was recognised that scaring devices such as ‘Gull Scat’ may only offershort term, local success. Also the birds may just move to another platformor another part of the same platform.

� A policy of not operating night flights may ease the problem of landing atnight, however by not flying at night pilot competency in this area might bereduced.

� During winter months pilots have to land in the dark in order to maximiseoperator time offshore. In these cases, pilots make a judgement regardingmarking obscuration on the outbound flight. If necessary the helideck can becleaned, if it is not possible to do so then the return flight is brought forward.

� There is a move to do away with helideck nets. The nets can be replacedwith a good friction surface which under normal use will last 3 years.However, guano makes the surface very slippery which in turn can causeproblems for personnel and helicopters. These problems were unquantified.

Following detailed discussions, the main points of which are summarised above, theChairman of the meeting summed up and drew the following conclusions:

� There is a problem and the operators are managing it on an individual basis,not collectively.

� The BHAB / UKOOA and Duty Holders should manage the problem amongthemselves and not the HSE.

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� There appeared to be two common solutions - bird scaring and guanocleaning.

� HSE wanted to know the size of the problem. In 1995 it seemed that at least30% of platforms in the Southern North Sea had a problem. Is this still thecase?

� HSE were very interested to learn that the level of risk of bird strikes was lessthat had first been perceived.

� How should we proceed at this time?

Actions taken away from the meeting were:

� The problem would be raised in UKOOA Aircraft Committee and a requestmade for SACC members to provide information. HSE requested this toinclude health risks as well as the aviation issues.

� Chief Pilots would be asked their views on which platforms had a problem.

� Through BHAB, a request would be made for assistance to collect data onthe number of platforms that have a problem and to raise the profile ofmarkings obscuration. Also, a recommendation that voyage reports beraised whenever possible.

� SACC agreed to collate all the information and to determine if there could bean industry-wide response. This may also involve research, if industry coulddefine the requirements.

� SACC and BHAB to keep HSE informed of actions / issues arising.

Following the meeting the BHAB representative from KLM ERA Helicopters (UK)Limited responded with some statistical data covering the installations serviced byBond and KLM. The data given is as follows:

� Helidecks serviced by Bond and KLM ERA 140

� Helidecks with guano problems 43 (31%)

� Of the 43 helidecks with guano problems 13 generated problems related tobirds roosting on or adjacent to the helideck.

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� Bird strikes amount to no more than 8 or 9 a year.

� No significant damage or bird strike related incident has occurred in recentyears.

� The Bird Strike Avoidance Team at the Central Science Laboratory hasrecords indicating that there were 61 bird strikes in the period 1961 to 1995.

� There is anecdotal evidence to suggest that bird strikes in the low speedenvironment of the helideck area are not a significant safety hazard or asignificant cause of damage to helicopters working offshore.

� Innovations in the form of ‘Gull Scat’ are showing great promise but, theirlong term success will remain in doubt, given the sea bird’s tendency toacclimatise to all preceding “bird scaring” devices.

� The reported drop in overall “problem helidecks” to 31% from the 45% quotedby HSE after the original survey (figure of 45% not substantiated by author),must be encouraging but continuous monitoring of the progress made isjustified.

A second meeting of the Joint Industry Work Group was convened on 24thSeptember 1997. It included representatives from HSE (OSD), CAA, BHAB andUKOOA Aircraft Committee (SACC).

Similar to the first meeting, this occasion also raised several issues, significant pointsand actions and included a review of progress on previous actions. The outcome issummarised as follows:

� The BHAB are to collate a database of platforms with guano problems. Datawill come via pilot voyage reports and the information entered in BHAB’sInstallation / Vessel Limitations List (IVLL).

� The current mechanism of reporting helideck problems relies on pilotsmaking a subjective decision and then reporting back.

� How information regarding helideck problems gets back to the installationoperators and the action the Duty Holder then takes seems to be up to eachindividual.

� There is no formal, uniform system in place to deal with the situation.

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� The BHAB were going to propose a system but it would only have catered forthe needs of the helicopter operators.

� Amoco reported they have, at some time, cancelled all night flights to certainplatforms. Cancelling flights usually resulted in cleaning operations.

� Amoco reported they have fitted ‘Gull Scat’ to all their platforms (quantity 10)with the result that the problem has moved for the time being. Finding a wayto quantify the level of success was very difficult.

� Photographic evidence of two Mobil sister platforms (Camelot ‘A’ and ‘B’)operated by Amoco, one equipped with ‘Gull Scat’ the other not, showedafter 10 months that the one fitted with ‘Gull Scat’ was still clean andmarkings unobscured. Whereas, the other was completely covered withguano and the markings obscured. It was also noted on the ‘clean’ helideckthat guano was deposited around the perimeter but not on the main deck,which was clear. It seemed that the birds, having moved away at first, returnlater as they became habituated.

� Shell reported they look very closely at carrying out night flights.

� HSE observed that from the discussions the problems with guano were stillbeing experienced on a regular basis and that helideck marking obscurationwas the major problem rather than potential problems of bird strikes.

� Shell tabled a description of a device called the “Peaceful Pyramid” whichhad been designed by farmers for use by farmers and growers. It comprisesa rotating, reflecting pyramid which deflects light into the air at the reverseangle of the birds’ approach. It is claimed to have an effective rangecovering 10 acres. Shell had purchased one for trial on the Leman platform.

� HSE tabled details, received from CAA, of another device called the “Duke”.It consists of motion sensors which initiate gulls’ cries of distress. It wasreported that one of these devices was fitted to an Amoco platform in theDutch Sector and was enjoying good success. Shell also reported they hadfitted one on their Leman platform.

The following conclusions and actions were recorded at the meeting:

� There are now three different bird scaring devices being trialed offshore butnot in a co-ordinated way.

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� To respond to the lack of a formal uniform system for pilots to report problemhelidecks it was decided that HSE would draft an Operations Notice inconsultation with the CAA and that it be agreed with BHAB and UKOOA priorto issue to Duty Holders (installation and helicopter operators). The ONwould set down the procedure to enable pilots to formally report a problemwith a helideck. This would enable the installation operator to be informedand take appropriate remedial action. Once the action was complete thehelicopter operator could then be informed thus completing the feedbackloop.

� It was suggested that pilots could also be requested to look at helidecksother than the one they were flying to.

� The procedure could be incorporated into CAP 437 and the UKOOAGuidelines for Helicopter Operations to Normally Unattended Installations.

� The installation operators would continue their bird scaring device trials andreport back to HSE. HSE could then publish the reported findings. CAAsuggested there was scope for a more focused approach.

� It was noted that the trials of the three “bird scaring” devices offshore werenot scientifically based.

� A datum was needed by which effectiveness of the devices can bemeasured. HSE would look into setting up and help to fund a researchproject to review the validity of the methodology being used to test thedevices offshore. The project would not include ecosystem studies. TheHelicopter Safety Research Management Committee (HSRMC) wassuggested as a possible source of funding.

As noted in the above, the Joint Industry Work Group had met twice up to the HSE /CAA Helideck Inspection Project report (Reference 1) publication date. On bothoccasions, the Work Group discussed the size of the problem, possible bird scaringdevices related issues and possible solutions, in detail.

There are no formal records of further Joint Industry Work Group meetings takingplace. However, it is known that routine meetings of the SACC do take place at whichBHAB representatives are present and the guano issue, amongst other topics, is oftendiscussed.

2.2.3.2 Guidelines For the Management of the Offshore Helideck OperationsIn 1996 the Joint Industry Guidelines for the Management of Offshore HelideckOperations were subject to an industry review and update. As part of the updating

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process HSE requested that a section be added to cover the management of birdcontrol.

A section was added which addressed the problems and mitigating measures. Thedocument was reissued (Issue 3) by UKOOA in August 1997.

2.2.3.3 RESEARCH PROJECT PROPOSALSDeveloping an Integrated Bird Management StrategyA meeting took place on 15 November 1995 in the HSE offices in Norwich to discussthe ongoing problems with bird guano on offshore installations, to pursue newinitiatives and to receive a presentation from Dr. John Allan of MAFF. The MAFFpresentation outlined a proposal for the Central Science Laboratory Bird strikeAvoidance Team to undertake a Joint Industry Research Project into the developmentof an integrated bird management strategy for offshore installations.

Subsequent to the meeting (in January 1996) MAFF (CSL - Bird strike AvoidanceTeam) submitted a formal proposal to HSE to undertake the research project.

In order to develop a management strategy the research project would need to gatherdata (by observation and remote monitoring) about sea bird species, feeding, roostinghabits, distribution, etc. There would also be testing of existing scaring and exclusiontechniques.

It was stated by MAFF that information about bird species already available from the observations by the North Sea Bird Club and the Sea Birds at Sea Team weregenerally inadequate and lacked data specific to NUI’s.

It was proposed by MAFF that the work be carried out in three phases, each phasebeing a year duration. The total cost of the project was quoted as £481,054.

After due consideration by industry, the project failed to gain the necessary support.

2.2.3.4 Performance Assessment of Bird Scaring DevicesDetails of various commercially available bird scaring devices have been acquired byHSE over the past few years. Most of these devices have been or are beingdeveloped / trialed by various Duty Holders on the UKCS and in the Dutch Sector.HSE have suggested there is a need for industry to obtain a measure of the trueeffectiveness of these devices. To do so will require an assessment protocol andprocedures for measurement collection, data analysis and reporting.

In October 1998, HSE initiated internal procedures to establish the best way forward toundertake a detailed assessment of bird scaring devices and their effectiveness. Itwas concluded that BOMEL Engineering Consultants, either as a separate research

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project or as part of the Technical Support Services Contract should be invited toperform the work. Subsequently, BOMEL submitted a scope of work for HSEconsideration.

In early 1999 this proposed research project was put on ‘hold’ by HSE OD5.5 pendingthe preparation of a report to obtain an up-to-date status of the whole guano problemon the UKCS.

2.2.3.5 Guano Status Report InitiatedIn September 1999, HSE commissioned this report to obtain an up-to-date status ofthe extent of the helideck guano problem and what effective measures are currentlybeing taken by industry to manage and / or reduce the effects of guano accumulations.An objective of the report is to identify any further practical advances that can bemade to ensure that good management controls and acceptable levels of flight andoffshore operations safety are being maintained.

Also, when considering future R&D projects concerning the offshore ‘bird problem’,HSE OD5.5 has adopted a more pragmatic approach. The priority being to obtaingood ‘operational value’ from any work that is funded from the ‘public purse’.

2.2.4 HELICOPTER OPERATOR EXPERIENCES

2.2.4.1 The BHAB Helideck Administration Office, AberdeenThe BHAB Helideck Administration Office in Aberdeen is not currently in the ‘loop’ forroutine condition reports on helideck degradation due to guano accumulation.Although BHAB have initiated helideck inspections on some NUI’s the OHIR reportshave yet to be received and added to their database.

Therefore, there is no information currently available from the BHAB office aboutguano problems that may affect the currency of Helideck Approval Certificates.

Consistent with current BHAB thinking, a preference has been expressed that thereshould be a single common database for recording helideck condition and restrictions.This applies equally to specific reporting for guano accumulation and obscuredmarkings, etc.

A common database approach would be beneficial in that it removes opportunity forcommercial issues to be raised between helicopter operating companies and platformoperators. It would also be available for reference by all flight crews, irrespectivewhich company is contracted to fly to a particular installation.

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2.2.4.2 Helicopter Operating Bases The helicopter operating bases at Aberdeen, Blackpool, Great Yarmouth andHumberside were contacted via BHAB representatives and they were requested toprovide information on their views, experiences and management of guano problemsin their areas of operation.

The following summarises the information received from each operating area aboutthe extent of the guano problem on NUI’s.

2.2.4.3 AberdeenHelicopter operations out of Aberdeen generally cover the Central and Northern NorthSea areas and the East Shetland Basin.

There are no significant bird populations or guano problems reported that affect themanned installations in these areas.

NUI’s in these areas of the North Sea are few (7). They include Total Oil Marine’sMCP-01, BP Amoco Unity, two Beryl Field SPM’s operated by Mobil North SeaLimited, Shell’s Kittiwake KLB and Shearwater (temporary winching deck) and theBeatrice C in the Moray Firth. They do have some problems.

Generally, there is guano build-up obscuring the helideck names, guano rotting thehelideck nets and accumulations causing slippery surfaces.

However, it is reported that the problems encountered do not significantly affect flightoperations and no flights have been cancelled or restrictions applied to any of thehelidecks.

One bird strike has been reported (happened in the spring - March) but the area wasnot identified. There was no significant damage to the aircraft.

With regard to health concerns or problems it is reported that there is a perception ofpossible health problems by flight crews but mainly, it is just a dislike of the smell andenvironment.

An observation made is that SPM’s and similar unmanned installations do not havewater supplies available at the helidecks therefore cleaning is a major problem.

2.2.4.4 BlackpoolOperating out of Blackpool Airport, Scotia Helicopter Services (Ex: Bond Helicopters)are the only helicopter company currently serving the Liverpool and Morecambe Bayareas.

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There are eight NUI’s in the Liverpool Bay (3) and Morecambe Bay (5) operatingareas.

The general view on the guano problem in this area is that it is not of major concern. Itis reported there are no significant bird populations on either manned installations orNUI’s.

Guano problems are experienced on NUI’s but not on the manned installations.

The guano problem on NUI’s is reported to arise when the interval between visits tothe installations is extended to about 4 weeks.

However, to date, no flight restrictions or flight cancellations have been imposed onthe installations due to guano accumulation problems.

Occasionally, it has been reported that whilst on an approach to a NUI sometimes thebirds are slow to clear away from the helideck, but this has never caused the pilot of ahelicopter to ‘go around’ because of the birds. There have been no reports of birdstrikes.

Significantly, in contrast to Scotia Helicopter Services local report, a BHAB HelideckInspector has recently reported deteriorated markings and guano problems on thehelidecks on two of the installation complexes in the Liverpool Bay area. The problemwas considered sufficient, by the Inspector, to warrant a recommendation that theguano be removed and the markings repaired.

2.2.4.5 Gt. YarmouthBristow Helicopter’s operate from Gt. Yarmouth and cover in the order of 40 NUI’s andseveral manned installations. They report that rarely, if ever, do they have a guanoproblem with manned installations. Primarily, it is a problem that only affects theNUI’s.

The main problems arise from:

� Roosting Birds - occasionally this may require a fly-around to displace thebirds. This may also lead to the birds coming into close proximity with theaircraft which raises the possibility of bird strikes.

� Birds feeding leaving carcasses on the helideck.

� Guano so bad that the stench is very offensive.

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� Guano degrading and obscuring the markings therefore they need regularrepainting and sometimes restricted operations in darkness.

� Guano rotting the helideck net - therefore they require regular replacement.

Bristow’s approach to managing the NUI guano problem is formalised by maintaininga ‘weekly report’ system that tracks the ongoing condition of all the helidecks they arecurrently contracted to serve. See Appendix G for a sample of the Weekly Reportformat (spreadsheet).

The Weekly Report is compiled from inputs taken from Monthly Inspection pro-formaecompleted by flight crews. The flight crews inspect and report using a scale of 1 to 10 for deck condition (see Table 2.2 below). The Weekly Reports are passed on to theinstallation operators for them to plan remedial work, where appropriate.

A general view is that some decks are not inspected as often as Bristows would like.This is because the operators generally make infrequent visits and only fly to the NUI’swhen essential to do so for planned maintenance or unscheduled interventions. Whenvisits are infrequent the guano problem builds up.

Occasionally, operating restrictions are put on platforms when the helideck is badlyaffected with guano build-up. Normally this means “daylight flight operations only” andit restricts helicopter visits for the platform operator until such time as the deck isproperly cleaned to a standard that will lift the restriction.

There have also been occasions where the guano build up has been excessive onNUI’s not fitted with helideck nets such that flight operations have been refused .

Apart from the helicopter operators imposing restricted flight operations on theinstallation operators, some Duty Holders have imposed their own limitations (e.g.Daylight operations only).

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Totally obscured - Daylight cleaning operations ONLY10

No night operations9

Substantial degradation of markings8

Bird usage causing operational problems7

Noticeable degradation of markings6

Obvious bird usage5

Markings beginning to be degraded4

Noticeable, but not operationally significant bird droppings3

Small isolated bird droppings2

Clean1

Table 2.2 - Bristow Scale for Assessing Helideck Condition

NOTE: Inspections are normally carried out MONTHLY but frequency is increased toFORTNIGHTLY for decks classified as 7 or greater.

2.2.4.6 North DenesScotia Helicopter Services (ex. Bond Helicopters) operate out of North Denes insupport of a large number of installations in the Southern sector of the Southern NorthSea (SNS).

Flight operations to the manned installations serviced out of North Denes are reportedto experience no bird / guano problems.

On NUI’s there is a bird / guano problem but there is no set pattern. Some helideckshave their markings completely obliterated. Others are largely unaffected.

The biggest problem areas are:

� North Sea Range� Leman Field� Indefatigable Field

Virtually unaffected are:

� Hewett Field� Laps Field� Viking Field

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Problems directly affecting flight operations are cited as an increased risk of birdstrikes. Actual bird strikes are reported to be approximately one per year.

There are no reported flight restrictions applied as a result of guano accumulations orother related bird problems. Also, it is reported that no flights have been cancelled orsuspended as a result of bird populations or guano problems on the helidecks.

There are no reported health concerns for flight crews from the effects of guano.

Scotia Helicopter Services have no ‘rolling’ system for helideck condition reporting.When there is a problem and the helideck needs to be cleaned, they rely on pilotswriting an operations report which is then sent to the field operator.

2.2.4.7 HumbersideScotia Helicopter Services flight operations out of Humberside to the Northern Sectorof the SNS cover Ravenspurn, West Sole, Rough, Viking and North Valiant. Mannedinstallations are not generally affected by bird / guano problems.

However, the satellite NUI’s in the above fields and those of Boulton and Hyde areaffected by bird / guano problems. The extent varies between moderate to extreme.

Problems encountered by individual crews (some estimated frequencies given) are:

� Obliteration of helideck markings (60%).� Lack of visible deck markings making central deck landing, particularly at

night, more difficult.� Deck markings obliterated sometimes making night landings impossible

(40%).� Having to ‘hold off’ to allow birds to lift prior to landing (30%).� Hovering birds and birds lifting from the helideck on final approach (30%).� Birds attempting to land whilst running on helideck (40%).� Dirt, debris, guano, detritus, dead fish and feathers blowing about in down

draught (30 - 60%).� The debris problem is worst on netted helidecks. Nets can harbour / trap the

debris and also make the decks more difficult to clean. Also the debris rotsthe rope.

� Wet guano being brought into A/C on passenger footwear (40%).� Risk of engine FOD damage from cuttle fish, bones and feathers trapped in

helideck net being lifted in helicopter down wash.� Objects being blown into the face of helideck crew so they look away when

landing and taking-off.

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� BP Operations require an orbit of NUI’s so that the Team Leader can satisfyhimself that it is safe for the helicopter to land. This procedure effectively‘herds’ the birds into the area of the helideck.

Bird strikes and interference by birds have been reported. The problem directly affectsflight operations throughout the year. Actual bird strike numbers are not reported butthey have required aircraft shutdowns. The potential is always there when hovering orcircling to scare the birds away from the helideck.

It is reported that flight restrictions have been applied as a result of guanoaccumulations. Helidecks are declared ‘daylight flights only, until cleaned’ when themarkings become obliterated or difficult to see.

Also, it is reported that some flights have been cancelled or suspended as a result ofguano problems on the helidecks. This has occurred 3 to 4 times a year from Springto Autumn. The problem being obliterated markings which then have to be cleanedduring daylight hours.

In addition, there have been infrequent instances where a landing has been preventedfor fear of a bird strike with rotor blades. The problem being resolved by waiting forthe birds to disperse.

There are no specifically reported health concerns for flight crews from the effects ofguano.

However, there are consistent reports about the unpleasant smell in the aircraft cabinwhen passengers with contaminated footwear and clothing get into the aircraft andleave traces of wet guano, etc. on the cabin floor and seats. The very strong smellalso persists beyond the immediate flight.

Health risks are generally considered by flight crews to be greater for the helideckteams due to airborne debris during take-off and landing and slipping hazards on wetguano.

A particular area of concern about the removal of helideck nets has been raised bysome of the Humberside flight crews.

The following observations have been reported and are relevant to the ‘NUI netremoval debate’:

� FOD and obliterated markings are worst when a helideck net is fitted.� Wheeled aircraft (as opposed to skids) have tyres with good friction quality

and don’t need the helideck nets.

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� Net removal has stopped the collection of guano on the decks.� Net removal has permitted more efficient and easier cleaning / washing

operations to be carried out.� The effect of friction surfaces is quickly lost by having a coating of guano

which also becomes extremely slippery when wet. This is generally not aproblem for the aircraft but makes walking around more difficult.

� Offshore operators used to take time to clean up affected helidecks.However, there has been an improvement, particularly since helicopteroperators banned night landings in the worst affected cases.

� When a helideck is declared ‘day only’ to the oil company, usually the nextworking party (intervention crew) onto the NUI will clean the deck.Occasionally this may take a couple of weeks.

� Removal of a helideck net has not caused too many problems. Althoughthere can be a problem with depth perception, particularly at night. Thishappens mainly on the larger helidecks with a large area of green / grey paintwith very little texture to the surface. With experience this is not too great aproblem. Of course, a helideck contaminated with guano makes obtainingreferences for a night landing more difficult.

Similar to Scotia Helicopter Services at North Denes, Humberside does not have a‘rolling’ system for helideck condition reporting.

However, it has been reported that several years ago an extensive survey wasproposed involving people based offshore gathering daily information on helideckcondition, but it was turned down (by the oil companies?). Flight crews have askedwhether something similar would be relevant again, considering the increasingnumber of NUI’s.

2.2.5 PLATFORM OPERATOR EXPERIENCES

2.2.5.1 UKOOA - Southern Aviation Consultative Committee (SACC)Historically members of the SACC have dealt with the guano problem for UKOOAAircraft Committee. This is because the problem mainly affects installations in theSouthern North Sea Sector (about 80% of the total UKCS NUI’s). It is a regular topicon the agenda at SACC meetings. The current Chairman of SACC is MalcolmHolmes of BP Amoco.

The SACC Chairman is heavily involved in the day-to-day operational problemscaused by ‘unwelcome’ bird populations and guano accumulations affecting helicopteroperations to NUI’s. The SACC Chairman’s opinion is that, in the absence of anoverriding solution to the basic bird problem on NUI’s (and the inevitable guanoaccumulations), the simple and pragmatic answer is to manage the effects onhelidecks and flight operations and employ available solutions in the most

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effective manner possible. He also believes there is merit in widespread adoption ofa formalised BHAB Helideck Condition Reporting system.

Effective management means selecting from the range of available and provenmitigating measures whilst continuing to seek and try new and innovative ideas.

2.2.5.2 Installation OperatorsThe operating bases of the platform operators with NUI’s around the UKCS werecontacted via their UKOOA representatives and were requested to provide informationon their views, experiences and management of guano problems in their areas ofoperation.

The following summarises the operator general experiences and the extent to whichbird / guano problems affect their installations. These operator views arerepresentative of the majority of NUI Duty Holders operating on the UKCS.

Mitigation measures (repellent devices) currently in use and those yet to be tested areaddressed in Section 4. Hazards and health issues are dealt with in Sections 3.4 and3.5 and maintenance issues in Section 3.6.

2.2.5.3 ARCO British LimitedARCO British Limited operate six NUI’s and one manned platform in the SNS. Thereare no major problems on the manned platform but all the NUI’s are badly affected.

In two locations (not specified but thought to be Trent / Tyne) there are severeproblems, mainly because it is isolated and there is abundant food in the area (fishstocks).

Most days personnel go onto the platforms so the helideck condition is constantlymonitored.

Although no flights have been cancelled or aborted due to bird population / guanoproblems, when there is a high guano build-up the helidecks are restricted to dayflights only.

2.2.5.4 BHP PetroleumBHP operate 3 manned and 3 unmanned assets in the Liverpool Bay area. Themanned installations are trouble free from the effects of bird populations and guanoaccumulation.

All three NUI’s are affected but Hamilton North particularly so. At times the helidecksare reported to have 90% guano coverage.

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There are no reported flight restrictions or cancelled or suspended flights. No birdstrikes have been reported.

2.2.5.5 BP AmocoBP Amoco reports that it does not have a bird / guano problem on its fixed SouthernNorth Sea (SNS) manned installations.

The company also owns and operates 26 NUI’s in the SNS (some on behalf of otheroil & gas companies). They are split equally between Northern and Southern sectors.The fields include:

� Southern sector SNS - Leman / Inde assets� Northern sector SNS - Villages, West Sole / Hyde and Amethyst assets

It is mainly in the southern sector where there is a significant problem with birds /guano accumulations on the normally unattended platforms. The problem can bevery bad to the extent that markings quickly become obscured if left untreated. Theproblem also seems to be selective between installations and it differs each year.Low visit ratios may possibly be the reason for this.

Problems generally encountered in both northern and southern sectors as a result ofsignificant roosting / feeding sea bird populations are:

� Helideck net decay� Paint erosion� Cleaning difficulties� Restricted helicopter operations � Dirty footwear, survival suits and helicopter interiors� Foul smell

Occasionally there have been bird strikes (2 in last 5 years). However, neither ofthese incidents occurred whilst helicopters were airborne. They were blade strikeswhilst the helicopter was on the helideck.

Occasionally, aircraft have had to hover to scare birds off the helideck.

There have been ‘daylight operations only’ restrictions imposed on some helidecks inboth the southern and northern sectors.

Whilst it is reported that no flights have been cancelled or suspended in the northernsector, it has happened in the southern sector, but very seldom. For instance, on oneoccasion, a flight to man a NUI had to be postponed because several gulls refused tomove off the helideck, in high wind conditions.

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2.2.5.6 British Gas PlcBritish Gas operate the Rough Field assets out of Humberside. There is one mannedinstallation and one NUI. The NUI was formerly a manned installation.

There are no significant bird populations affecting the platforms, hence, they only havea minor problem with guano accumulations.

There are no problems reported with bird interference / strikes to helicopters and norestrictions imposed on flight operations as a result of bird / guano problems affectingthe helidecks. There have been no flight cancellations due to bird activity.

2.2.5.7 Cal Energy Gas (UK) LtdCal Energy operate the Anglia ‘A’ NUI on Block 48/19B in the SNS. This NUI wasformerly a Ranger Oil asset but was sold to Cal Energy in September 1999. Ex.Ranger staff familiar with the asset have moved to Cal Energy, therefore theirexperience with the guano problem is still readily available.

The Anglia platform does not normally have a large bird population in the vicinity.However, activity did increase this year (1999) over a period of four months during thesummer. By early Autumn the problem has eased again.

There is a high fish population in the area which is cited as the probable reason for thesea bird presence.

It is reported that Anglia has not had any flight restrictions applied as a result of aguano problem. Neither have flights been cancelled or postponed due to birdpopulations / guano accumulations.

2.2.5.8 Centrica HRLCentrica HRL operate one fixed and five NUI’s in the Morecambe Bay area.

There are no problems with sea birds on the fixed installation but there are significantproblems with the NUI’s. The bird populations and guano accumulations build up onall NUI’s and are extensive during the summer months.

There have been isolated instances of bird strikes.

It is reported that no flight restrictions have been imposed on Morecambe Bayoperations and no flights have been cancelled or suspended. However, on the oddoccasion landings have been aborted due to bird populations on the helideck but havebeen successful at the second attempt.

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2.2.5.9 Conoco UK LimitedConoco operate 3 manned production installations and 26 unmanned installations in‘V’ Fields area of the SNS.

There are no sea bird / guano problems on the manned installations.

However, there is a significant sea bird / guano problem which affects all NUI’salthough the worst affected NUI’s are to the North of the gas fields. This is believed tobe linked to fish stocks / breeding in the area.

The extent of bird / guano effects on Conoco NUI operations is helicopter operatorsrestricting flights to ‘daylight only’ if the helideck markings become obscured.

There are no reported flight cancellations, bird strikes or bird interference.

2.2.5.10 Mobil North Sea LimitedMobil operate the Beryl ‘A’ and ‘B’ manned installations and the unmanned BerylSingle Point Moorings (SPM) ‘A’ and ‘B’, in the northern sector of the North Sea. TheSPM’s are classed as NUI’s.

Neither of the manned installations have a major problem with bird populations orguano accumulations.

However, both SPM’s do have a significant bird population / guano problem to theextent of damaging the helideck paint surfaces and helideck netting. Also, there is theproblem of health risks.

There have been no reports of bird strikes associated with the SPM operations.

2.2.5.11 Phillips Petroleum LtdPhillips Petroleum operate the Hewett and LAPS (on behalf of Mobil) fields in theSNS.

There are four manned installations, two on Hewett (48/29Q and 52/5A) and two onLAPS (Lancelot and Excalibar). None of the manned installations suffer from birdpopulations / guano problems.

There are two NUI’s on Hewett (48/29B and 48/29C) and three on LAPS (Guinevere,Galahad and Malory). Both the Hewett NUI’s and Galahad and Malory aresignificantly affected by bird populations and guano accumulations on the helidecks.This is reported to be due to less visits to NUI’s and therefore little disturbance of thesea birds and their feeding habits, etc.

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The main problems encountered are guano build up and the depositing of fish debrison helidecks.

No flights have been cancelled or suspended for Hewett or LAPS operations and therehave been no restrictions applied to any helidecks.

Bird strikes and interference have not been a problem for LAPS and there have beenno recent reports for Hewett.

2.2.5.12 Shell Exploration & ProductionShell operate many manned platforms in the East Shetland Basin, Southern, Centraland Northern North Sea.

It is reported that none of these manned installations has problems with significant birdpopulations or guano.

In the Central North Sea there is one NUI but that is also reported to be trouble free.

However, bird population / guano problems on helidecks and platform structures arereported for all 21 Shell NUI’s in the SNS. These include the installations in the Sole /Silver Pit, Sean, Inde, Corvette and Leman fields. Leman is the least affected.

Apart from the problems of guano accumulations on the helideck and structures thereis the remains of general food and bone debris left on the helideck. Also, on Lemanthere is often a problem with getting the birds off the helideck prior to a helicopterlanding.

There have been no reported bird strikes.

With the exception of Leman, there have been ‘daylight operations only’ flightrestrictions applied to the helidecks.

Corvette being the exception, no flights have been cancelled or suspended due to birdpopulations or guano problems on the Shell NUI’s. On Corvette, suspension of flightoperations occurred due to guano obscured helideck markings and this suspensionremained until the helideck was cleaned.

2.2.5.13 Total Oil MarineTotal Oil Marine operate the Alwyn, Dunbar and Sedco 706 manned installations inthe East Shetland Basin. There have been some reports of significant birdpopulations / guano problems on Dunbar.

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Total also operates the MCP-01 normally unmanned platform in the central sector ofthe North Sea. MCP-01 was originally a manned platform but in 1992 was convertedto NUI status. This arrangement was in fact part of the original design philosophy (circa 1975). The platform is nowadays controlled (by telemetry) from St. FergusTerminal.

There has been a significant bird population / guano problem on MCP-01 since it hasbecome normally unmanned.

Initially, the helideck was consistently and extensively covered with guano and fishdebris. The same problem also affected the stairways and walkways. Helicoptersafety in the landing and take-off phases was also considered a problem with reportsof bird interference with flights and potential for bird strikes.

Whilst no flight restrictions have been imposed on the MCP-01 helicopter operationscrews have been alerted to the problems of potential bird activity. Additionally, therehave been no flight cancellations but, on occasion, helicopters have had to orbit theplatform to ensure that it was safe to make a landing.

The main problems experienced by Total have come from extensive bird roosting /feeding on the helideck and surrounding structures. However, in recent times, theproblem has been successfully managed by employing a combination of mitigatingmeasures which include a water spray system and ‘Gullscat’.

2.3 THE PATTERN AND POSSIBLE REASONS FOR GUANOACCUMULATIONS

2.3.1 GENERALClearly, birds are the principal agents responsible for guano accumulations.Taxonomy is defined as the science of classification of living and extinct organisms.The hierarchy of classification is: Class, Order, Family, Genus, Species, Subspecies.Classes are: mammals, birds, reptiles and amphibians, fish, insects and spiders, andso on. Birds belong to the Aves class.

Birds, like mammals, are warm-blooded, air-breathing vertebrates with afour-chambered heart. A feature unique to birds in the animal kingdom, is that theyare covered with feathers, rather than body hair (as is the case with mammals). Theyall reproduce by laying eggs.

Almost all birds possess the wide range of adaptations which make flight possible.These include a low weight to size ratio combined with the development ofproportionally enlarged limbs, or wings. Light body weight is achieved by thin-walled

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bones with air-filled cavities, and the replacement of heavy jawbones and teeth withlight beaks. Digestion is very rapid, so that food is not stored internally for longperiods. Birds’ wings are a development of the forelimbs and are covered withwater-resistant, lightweight feathers. The power for flight comes from strong muscles(which account for 15% of a bird’s weight), attached to an enlarged breastbone toachieve the muscle length required.

Of some 9700 bird species recognised to date (it should be noted that the process ofclassification is not static and the number of species changes with time), only about300 (around 3%) can (depending on the definition) be considered as seabirds. Thus,while around 97% of species inhabit 30% of the globe (the land), the seabirds (3%)inhabit the remaining 70% (the sea).

Coming to land generally only to breed, seabirds must, for most of the year, derivetheir living from the marine environment.

20% of seabirds have been classified as globally threatened, compared with 12% forall bird species.

2.3.2 SEABIRD ORDERSThe number of bird species are divided into 27 orders. Seabirds are often referred toas pelagic, meaning of, on or in the open sea. The seabirds fall into the orders (fouroff) and families shown in the table in Appendix D. Excluding the Penguins these are:

� Procellariiformes (Petrels, Shearwaters Albatrosses) - 30 species (25%) ofwhich are classified as either critical, endangered, or vulnerable. A further 11species are near-threatened.

� Pelecaniformes (Pelicans, Gannets and Boobies, Tropicbirds, commorantsand shags, frigatebirds) - 11 species (22%) of which are classified as critical(1) or vulnerable (10). A further five are classified as near-threatened.

� Lariformes (Skuas, Gulls, Terns and Noddies, Skimmers, Anks, Guillemotsand Puffins) - one species is critical, one is endangered, seven arevulnerable and seven are near-threatened.

The IUCN classification of endangered species is given in the following table, overleaf.

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Species close to qualifying for any of the above threatened categoriesNear-threatened

10% within100 years

Small or verysmall population(10000 and 1000mature birds,respectively)

Rapid decline(50% over 20years)

Not critical orendangered, butfacing a high riskof extinction in thewild in themedium-termfuture

Vulnerable

20% within 20years

Small or verysmall population(2500 and 250mature birds,respectively)

Rapid decline(50% over 10years)

Not critical, butfacing a very highrisk of extinction inthe wild in the nearfuture

Endangered

50% within 5years

Small or verysmall population(< 250 and < 50mature birds,respectively)

Rapid decline(80% over 10years)

Facing anextremely high riskof extinction in thewild in theimmediate future

Critical (criticallyendangered)

Probability ofExtinction

PopulationDeclineNoteClassification

Table 2.3 - ICUN Criteria for Threatened Species

2.3.3 BIRDS LIKELY TO BE FOUND OFFSHORE UKCSSpecies potentially to be observed on platforms in the UKCS are listed in the table inAppendix E. As can be seen from this list, they comprise: fulmars, shearwaters,petrels, gannets, cormorants, shags, skuas, gulls, kittiwakes, terns, auks, gullemots,razorbills and (possibly) puffins.

To sum up the characteristics of such birds:

� The overwhelming majority of the seabirds cited above can be described asnorthern birds, with their habitat and habits such as to be observable atplatforms both west and east of Great Britain.

� The overwhelming majority of birds are migratory, breeding during the springand summer in the north and wintering south of their breeding grounds; theextent of their southern migration may, however, only be the British Isles insome cases; very few of the species are sedentary.

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� Breeding / nesting habitats tend to be: ledges on coastal and inland cliffs,inshore and offshore islands, beaches, burrows, lakes, estuaries, marshes,peat bogs, sand dunes, scree slopes, sand / rock / coral islands, artificialstructures (roofs etc.), boulder fields; the key features appear to be readyaccess for the birds to food and water, and inaccessibility for potentialpredators.

� The majority food source is the marine environment.

The main reasons why birds migrate are: the seasonal availability of food, the searchfor suitable nest sites, and the need to escape from predators and overcrowding.However, the duration of and distance travelled during migration may varyenormously. Birds that breed in the north of the Northern hemisphere during springand summer, find that when Autumn comes, not only do the days begin to becomeshorter and colder, but plant growth slows down, so that food supplies decline. Thesefactors prompt the birds to head south, often covering huge distances. In the spring,their winter haunts become gradually hotter and drier, so that now the birds’ urge is toreturn somewhere cooler. Having arrived in a place where weather conditions aregood and food plentiful, they will raise a brood before returning south the followingwinter.

As indicated above, for some birds, Britain represents the southern point of theirmigration route. Migrating birds are not exclusive to the Northern Hemisphere, but thefact that there is much less land south of the Equator means that there is much lessbreeding habitat there. In consequence, very few birds breed in the south and winterfurther north.

2.3.4 BIRD LIFE CYCLEThe life cycle of sea birds involves the following:

� egg laying and incubation, birth� fledgling period before ability to fly learnt/develops� period before sexual maturity� breeding adult phase� death.

In the case of a herring gull, for example, the life span is of the order of 30 years. Ofthis, incubation takes about one month and the fledgling period is around 38 days.The time before sexual maturity is about 5 years.

Thus, the bird will spend, on an annual basis, 25 years of its life breeding and for shortperiods within each breeding season feeding itself, two to three chicks and its mate.

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Outside of these periods, it will be migrating and feeding itself. Feeding is, therefore,a principal activity of a sea bird.

2.3.5 MARINE FOOD CHAINDiatoms are numbered among the minute, single-celled plants that had beenobserved floating in sea water since the invention of microscopes in the 17th century.They have an overwhelming importance in the economy of the sea. Diatoms and theirkind are known as phytoplankton, which means “wandering plants”. There are about athousand different species of these simple, unobtrusive plants and modern researchhas shown that the animals of the sea are almost entirely reliant on them (in theirposition low down in the marine food chain) for food.

The various plants of the plankton, like land plants, need light to manufacture food forself-survival. Strong sunlight only reaches the upper layers of the ocean, which is whythe phytoplankton must float on the surface. Species have developed a variety ofways of achieving the required buoyancy.

In addition to light, plants need essential chemical nutrients. These come fromweathered rocks, via river sediments, and are usually extremely plentiful in coastalwaters. Nutrients are also recycled from decaying dead animals or their faecal pellets.The particles that supply the phytoplankton with essential nutrients tend to sink to theocean floor, however, and the limited numbers in the surface water are rapidly usedup. Growth of the phytoplankton can only continue if particles are brought up to thebrightly lit upper layers by strong stirring motions, caused by temperature changes,wind, or upwelling currents.

Thus planktonic plants are most abundant on the east and west coasts ofsouthernmost south America and north America, west Africa, north west Australia, theBlack and Arabian seas, and the east coasts of Asia and Russia. The Atlantic isparticularly rich in planktonic plants in a region bounded at the south by a line joiningthe east coast of the USA to southern Portugal, and at the north by southernGreenland, Iceland and northern Norway. Planktonic plants are particularly abundantin an area circumscribing the British Isles, extending eastwards through the North Seato north west Europe and the Baltic Sea.

The sort of conditions that combine the mix of nutrients and plentiful light only occur atcertain times of the year. At high latitudes, this is limited to a short period in thesummer. In intermediate latitudes, it occurs in spring and again in autumn. Whenthese conditions obtain, the phytoplankton proliferate, creating what is referred to as a“bloom”.

This provides an abundance of food for millions of grazing animals, known aszooplankton. Commonest amongst these are the tiny, one-eyed crustaceans

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(relatives of the shrimps and crabs) known as copepods, which are thought to be themost numerous multicellular animals in the world.

The larvae of fish, barnacles, crabs, sea anemones and many other animals also formpart of the zooplankton, and these are joined by herring-like fish and mid-watershrimps. The plant-eating zooplankton are swallowed up by slightly larger animalsand these small predators in turn provide food for larger fish, whales and seals. Thusthe zooplankton are the first link in the food chain that connects the phytoplankton tothe other larger predators, including fish and, higher up, sea birds.

Fish migrate to find food or breeding sites. Many commute across the oceans tomake the most of the seasonal blooms of plankton, or to prey on smallerplankton-eating fish (“fish fry”). When the breeding season arrives, some speciesmake their way to special spawning grounds to lay their eggs, and these spawninggrounds may be well away from their feeding areas. One reason for this is that youngfish and their parents often have different requirements; another is that separationreduces the risk of adults eating their young.

2.3.6 SEABIRD 2000 PROJECTThere is currently substantial interest and concern in seabird conservation andknowledge of seabird populations in UK areas. In a MAFF news release dated 12April 1999, entitled “Saving seabirds: minister promises action”, the FisheriesMinister Elliot Morley said safeguarding important East Coast seabird colonies, if theyare found to be threatened by industrial fishing, must be a top priority.

Preliminary results from research by international fisheries experts has shown thatseabird colonies on the east Coast of Britain might be affected by fishing for sand eelsin the North Sea. If confirmed, the UK will use the science to press for seasonalclosed areas so that the ecological needs of the bird populations can be protected.Birds, such as Arctic terns, black guillemots, common terns, kittiwakes and puffins relyon the sand eels for their food, especially in the chick-rearing months. At this time MrMorley was launching the “Seabird 2000” project, jointly funded by the Royal Societyfor the Protection of Birds (RSPB) and the Government’s Joint Nature ConservationCommittee. The aim of this project is to discover long-term trends in seabird numbers.

According to the RSPB, more than any other human activity, the fortunes of seabirdstoday are tied up with fisheries. Indeed, globally, fishing has been identified as themost ubiquitous agent of change in marine biodiversity. The pattern of fishing in UKwaters, repeated world-wide, has not proved sustainable for fish stocks, the fishingindustry or the wider marine environment.

Not only has over fishing in the north-east Atlantic run down fish stocks and the fishingindustry but it has also had powerful knock-on effects on seabirds and the rest of the

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marine wildlife. Fisheries also exert more subtle indirect effects on seabirdpopulations, destabilising their community structure through manipulating the foodchain:

� Discards and seabirds: Up to half the fish caught by fishing vessels isroutinely thrown overboard, dead, as 'discards'. This, along with other fishwaste jettisoned, has led to an increase this century in numbers ofscavenging birds, notably fulmars, gannets and gulls which find rich pickingsbehind trawlers.

� A bonanza of fish fry: Fishing has reduced stocks of large fish (such as codand mackerel) which eat smaller fish (such as sprats and sand eels),allowing the latter to multiply. This potentially increases the food supply forseabirds like kittiwakes and puffins.

� Industrial fisheries: Not surprisingly, the fishing industry has responded to thisbonanza of small shoaling fish and is now threatening to over fish them too.The Danish-led 'industrial fishery' for sand eels accounts for about half thefish tonnage landed from the North Sea, much of it from sensitive areas forbreeding seabirds off the east coast of Britain. Industrial fish are not forhuman consumption but are rendered into fishmeal and oil for soft margarineand animal feed.

In light of these concerns, actions taken that attempt to control or otherwise affect,seabird populations are likely to come under close scrutiny.

2.3.7 REASONS FOR BIRDS ON OFFSHORE INSTALLATIONS The question arises as to why the birds are on the platform at all, what are they doingthere?

From the information given above, it is unlikely that the birds are using the helidecks,or other parts of the platforms, as breeding grounds. Whilst many of the birds citedabove breed colonially, the area offered by a helideck may not be enough for some ofthe large colonies and the habitat itself will not provide many of the features required.Moreover, in the case of manned installations, the constant presence of man, alongwith noise and activity would prove too much of a threat and disturbance to broodingbirds.

It is more likely that the birds are resting between feeding and / or searching for food:

� whilst in transit during migration, or � whilst outwith the period of migration, and / or during the breeding season.

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It is well-known that the presence of platforms and associated pipelines tends to warmthe surrounding waters, attracting more fish and other marine creatures to the area,providing rich feeding grounds for the birds. The 500 metre exclusion zone preventscommercial fishing around the installation, thus allowing such fish stocks to thrive.

In the case of manned installations, birds may associate the presence of man withadditional sources of food, experience gained through, say, following fishing vessels.

Additionally, the practice of disposing of certain types of degradable refuse by mannedplatforms may have led the birds to associating the platforms with food. However,since the implementation of MARPOL Annex 5 in 1988 (under the Merchant Shipping(Reception Facilities for Garbage) Regulations), the practice has been banned and allrefuse has now to be containerised for shipment and disposal onshore. Clearly,whilst this food source can be controlled, the natural presence of other nutrients to thebirds cannot.

Whilst the reasons for sea birds congregating around offshore installations are quiteclear and easy to understand, establishing a precise pattern of their activities aroundUKCS offshore installations is difficult to achieve without first undertaking a long anddetailed monitoring program. This is because some of the many factors that typify seabird behaviour can be unpredictable. The behaviour of the birds can change from yearto year, according to their immediate needs.

On some areas of the UKCS the sea bird activity on and around offshore installationswill occur each year, at similar times. Also, it appears that the extent and actuallocations of bird activity is generally recurrent at those installations that have alreadybeen colonised in previous years, unless control measures have been introduced andthey have proved successful. However, apart from the birds responding to the effectsof deterrent systems, there could be any number of other reasons why sea birds quiterandomly move to installations nearby or further away.

It is well known by the offshore installation duty holders and helicopter operators thatmost, if not all, NUI’s are going to be susceptible to sea bird activity at some stage.The simple fact is that once an installation becomes affected by a bird / guanoproblem it then requires control measures to be put in place, regardless of whether thebird problem is persistent or happens randomly.

The foregoing suggests that an intimate knowledge of sea bird behaviour, predictableor otherwise, will be of little help to duty holders toward solving their immediate birdpopulation / guano accumulation management problems.

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3. PART 2 - THE EFFECTS AND CONSEQUENCES FOROFFSHORE OPERATIONS

3.1 LEGAL RESPONSIBILITY - THE OFFSHORE AND AVIATION REGULATORY POSITION

3.1.1 APPLICABLE OFFSHORE SAFETY REGULATIONS ANDINDUSTRY GUIDANCE

3.1.1.1 RegulationsUnder the Health and Safety at Work, etc. Act 1974, there are several pieces ofprimary legislation that should concern Duty Holder’s when discharging their ‘Duty ofCare’, with respect to bird / guano problems arising on their installations. They are:

The Management of Health and Safety at Work Regulations 1992, Regulation 3which requires employers to make a suitable and sufficient assessment of the risks(e.g. from the effects of guano accumulations on helidecks, etc.) to health and safetyof his employees, and of persons not in his employment, to which they are exposedwhilst they are at work and to record the findings of the assessment.

Regulation 5 requires employers to ensure that employees are provided withappropriate health surveillance with regard to the risks to their health and safety whichare identified by the assessment.

The Offshore Installations (Safety Case) Regulations 1992 (SI 1992/2885),Regulation 8 (1) b which requires duty holders to ensure that a Safety ManagementSystem is in place and that it demonstrates that adequate control measures are beingemployed to mitigate attendant risks.

The Personal Protective Equipment at Work Regulations 1992 (SI 1992/2932)which require employers to ensure that suitable personal protective equipment isprovided to employees who may be exposed to a risk to their health and safety (e.g.from the effects of guano accumulations) whilst at work.

The Control of Substances Hazardous to Health Regulations 1994 which requireduty holders to identify, assess, employ appropriate mitigating measures and to keeprecords, where personnel may be exposed to substances harmful to their health (e.g.guano and associated bird debris).

The Offshore Installations and Pipeline Works (Management and Administration)Regulations 1995 (SI 1995/738), Regulation 13 which requires duty holders toestablish procedures and provide plant (i.e. equipment) to secure, so far as is

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reasonably practicable, that helicopter operations, including the landing and taking-offof helicopters, are without risks to health and safety.

Also, Regulation 19 which requires duty holders to clearly display the installationidentification in such a manner as to make the installation readily identifiable from theair.

The Offshore Installations (Design and Construction, etc.) Regulations 1996 (SI1996/913), Regulation 11 which requires the duty holder to ensure that every landingarea forming part of an installation has sufficient clear approach / departure paths toenable any helicopter intended to use the landing area safely, to land and take off inany wind and weather conditions permitting helicopter operations and is of a designand construction adequate for its purpose.

3.1.1.2 GUIDANCEThe above listed Regulations each have their own published (by HSE / HMSO) Codesof Practice or Guidance on Regulations which provide details on practicalinterpretation and application of the Regulations.

Additionally, the subject of managing bird / guano problems on offshore installations isaddressed in the Joint Industry Guidelines for The Management of OffshoreHelideck Operations, Issue No: 3 (Section 4.6 - Management of Bird Control),issued by UKOOA in August 1997.

3.1.2 APPLICABLE AVIATION REGULATIONS

3.1.2.1 RegulationsCAA regulate the use of unlicensed aerodromes (includes offshore helidecks) underthe provisions of The Air Navigation Order 1995 (as amended). This regulatoryinterest is not merely confined to aircraft in flight , but maintenance procedures on theground, etc. Under the ANO, the CAA have powers to provide guidance (usually in theform of CAP’s) where it is considered necessary or appropriate.

3.1.2.2 GUIDANCECAP 393 - Guidance on the Air Navigation Order, defines among other things aPublic Transport Operator’s (Air Operator’s Certificate (AOC) Holder) responsibilities.

Generally stated, this responsibility includes not permitting an aircraft to fly for thepurpose of public transport (offshore flights are classed as public transport - nonscheduled) without first satisfying themselves by every reasonable means that everyplace (whether or not an aerodrome) at which it is intended to take-off or land aremade suitable for the purpose to ensure so far as practicable the safety of the aircraftand its passengers.

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CAP 437 Offshore Helicopter Landing Areas - Guidance on Standards (ThirdEdition - October 1998) sets out the criteria required by the CAA in the assessment ofoffshore landings areas for use by helicopters registered in the UK. It is these criteriathat AOC Holder’s are expected to comply with.

CAP 437 (page 3/17) paragraphs 3.13.2 and 3 specifically address the guano issueon NUI’s.

In addition to other things, it requires helicopter operators to monitor the state of NUIhelidecks and to advise the owner / operator before markings and lighting degradationbecomes a safety concern. It also states that NUI’s should be continuously monitoredfor signs of degradation of visual clues and flights should not be undertaken tohelidecks where essential visual clues for landing are insufficient.

3.1.3 ENFORCEMENT ACTIONCAA actions arising from the four MOR’s (see Appendix C) were not specific in theirdemands for enforcement action. One MOR recommended rig operators regularlyassess the helideck condition. Another, which was mainly about poor helidecklighting, mentioned guano obscuring the lights and among other things, the actionsincluded a request for a Safety Notice.

During the CAA helideck inspection project, enforcement action was taken by HSEOSD following CAA recommendations. One deferred Prohibition Notice and threeImprovement Notices were served on Duty Holders.

It is not clear from the report whether any of these enforcement actions involvedhelidecks with guano accumulation problems.

3.1.4 BHAB OHIR REPORTING AND ACTIONSThe BHAB Offshore Helideck Inspection, reporting and approval scheme covers allUKCS helidecks. At present, the inspection and approval (3 yearly frequency) focusappears to be more on manned installations. However, a BHAB Helideck Inspectorhas recently completed four OHIR’s in Liverpool Bay and has recommended actions toclean off the guano and repair faded helideck markings.

There is no information with respect to any operating restrictions being appliedpending completion of the remedial work arising from these inspection findings. Nor isthere any information with respect to a change to the currency of the HelideckApproval Certificate.

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3.2 THE POTENTIAL HAZARDS TO HELICOPTER FLIGHTOPERATIONS

3.2.1 THE POTENTIAL FOR WRONG DECK LANDINGSIn a recent report (Reference 3), reviewing wrong helideck landings, etc. prepared andissued (in June 1999) by BOMEL Consortium for HSE OD5.5, the obliteration ofhelideck markings, in particular the installation name, was found to be a contributor toflight crews executing wrong deck landings on NUI’s.

Although such events were not found to be frequent, high risk occurrences, it isessential to recognise that the build up of guano can and does cause difficulties forpositive installation identification.

3.2.2 THE BIRD STRIKE POTENTIALCAA Safety Analysis Department issued a Data Plus fact sheet on BIRD STRIKES(Ref: 99/DP1) in June 1999 (Reference 4). Analysis focused on bird strikes recordedon the UK CAA MOR Reporting Scheme database. The database encompasses allevents involving UK registered aircraft world-wide or any aircraft in UK airspace.

Only 17 bird strikes to helicopters were recorded between 1981 and 1998, one a year.However, 11 of these were to the fuselage, with 8 involving collisions with orpenetration of the windscreen or a cabin window. For example, in 1993 a EurocopterSuper Puma (AS 332) was struck by a large bird (species not identified in data sheet)on take off damaging the centre windscreen and sending pieces of glazing into thecockpit. And, in 1998 a large gull penetrated the right hand upper canopy of a Bolkow105.

It was also noted in the analysis that even attempts to avoid bird strikes can lead todamage as in 1995 when a Hiller UH12 struck power cables whilst manoeuvring toavoid birds.

Important to note in the CAA’s report is that none of the recorded bird strike incidentsis reported to involve helicopters on or close to offshore installations.

Notwithstanding the limited offshore helicopter bird strike MOR’s recorded by CAA, itis quite obvious that where there are colonies of birds (in particular the larger specieslike gulls) on or around installations and close to helicopter flight paths. The potentialfor a serious incident involving a bird strike is always present and should not beignored.

For this reason further data was acquired from the CAA in the form of a Bird Strike(Offshore) Statistics Record for the period March 1984 to March 1995. Also, thehelicopter operators were asked to comment on their experiences.

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3.2.2.1 CAA Bird Strike (Offshore) Statistics Record - March 1984 to March1995

A coarse analysis of the CAA bird strike statistics for 1984 - 1995 presents thefollowing picture for offshore operations during this period.

There were 89 recorded events involving various helicopter types and they occurredduring various flight phases, day and night, in various areas of the UKCS. Birdspecies involved ranged from small (starlings) to large (gulls and a goose). Numbersof birds sighted are reported as 1 to 100 plus.

Only two events (2.2%) report that actual damage to the helicopter resulted from thebird collision. One bird (a gull) holed (small area) a main rotor blade. The other, alsoa gull, damaged a windscreen to the extent that, after checks, the aircraft was flownback to base with crew only on board. In several other reports precautionary shutdowns were made and no faults were found.

Significantly, 59 events (66.3%) were recorded during the time helicopters were‘parked’ (rotors turning, etc.) on the helideck.

Distribution of the bird strikes with respect to installation type is reported as:

25.823Not Known (? en-route)

11.310NUI

2.22Jack-up

31.528Semi-sub

29.226Fixed Manned

Percentage of Total

No: ofEvents

InstallationType

Table 3.1 Distribution of Bird Strikes With Respect to Installation Type

The above simple analysis clearly shows that the bird strike problem offshore is notspecific to NUI’s. In fact, apart from Jack-up rigs, helicopter operations on and aroundNUI’s seem have much less of a problem than manned installations and semi-submersibles.

3.2.2.2 Helicopter OperatorsThe helicopter operators currently serving UKCS offshore operations have eachreported bird interference and actual strikes to their helicopters.

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For example, a report from Bristow Helicopters Limited puts another perspective onthe problem. Bristow use the BASIS System (British Airways Data Base) forregistering bird strikes.

For the whole Bristow North Sea helicopter fleet the following record has beenobtained. It covers the last three years (1997-1999) and includes bird strikes on theground, in the air, onshore, en-route and offshore (including those in close proximity tohelidecks).

Occurrences by aircraft type are:

� Eurocopter AS 332 L 10� Sikorsky S 76 4� Sikorsky S 61 4� Bell 212 1� Bell 214 ST 1

Only one of these occurrences is reported to have caused significant damage to theaircraft.

The suggestion here is that whilst the frequency and severity of the bird strikes thathave been encountered have not justified raising an MOR, there is obviously clearevidence that bird strikes can and do occur during offshore helicopter operations.

It is also interesting to note that among the helicopters listed as having experiencedbird strikes only the Sikorsky S 76 is used by Bristow in support of SNS NUIoperations. With 4 occurrences recorded for the whole of their UKCS operations it isnot unreasonable to suggest that NUI’s pose no greater exposure from bird strikesthan elsewhere in the North Sea.

Other types such as the AS 365 and Bo 105 are used for SNS support operations byScotia Helicopter Services. Records have not been acquired for these aircraft.

Further ‘snapshots’ concerning the extent and effects of offshore helicopter birdinterference / strike problems are provided in two papers given in 1995.

The first paper, by Dr John Allan Head of the MAFF (CSL) Bird strike Avoidance Teamwas given to an offshore industry audience on 15 November 1995 at HSE Norwichoffice. The second was presented by Mr. A B Wassell, Chief Airworthiness Engineerof Rolls-Royce Plc at a CAA conference in Birmingham on 6 December 1995, titledAirport Bird Hazard - Your Duty of Care, A Senior Manager’s Perspective.

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Dr. Allan’s paper - Bird Management on Offshore Installations - states that data takenfrom a CAA database (not identified by author) for the period between 1991 and 1993reported 36 bird strikes from around offshore platforms. 18 of these incidents involvedgulls. The rest were smaller species with 4 of them unidentified. Only two incidentsresulted in collisions with more than one bird, both with gulls. The 36 reported birdstrikes resulted in 6 precautionary landings, 2 aborted take-offs, 7 engine shutdowns,2 damaged rotors and one damaged windshield.

Mr. Wassell’s paper - Aero Engine Resistance to Bird Strikes - focuses almost entirelyon fixed wing aeroplanes because of the high accident threat from ‘flocking’ birds,encountered by aircraft during their critical flight phases, at airports.

Significantly, it was stated that whilst current trends in aeroplane design increasesexposure to bird ingestion (the number of birds ingested increases with intake size), helicopter engine installations are significantly less vulnerable and engines can beprotected by design.

More detailed information about the effects of bird collisions with rotor systems has notbe sought.

It is considered sufficient for this report to simply identify the potential for bird strikesaffecting NUI’s and to give an indication of how the problem is reported and viewed bythe aviation industry.

If there is major oil and gas industry concern about the potential for bird strikes on andaround NUI’s then more work will need to be done to acquire complete data, quantifythe risks and assess the consequences.

3.2.3 THE POTENTIAL FOR AN ACCIDENT ON THE HELIDECKCompared with a manned installation with a relatively clean and unencumbered (bybirds) helideck it is probably reasonable to say that there is an increased potential foran accident or serious incident on a helideck where sea birds are present. This isparticularly so when the helideck is accumulated with guano and / or suffering from theadverse effects of guano (e.g. obscured markings, helideck net rotting and unsound,etc.).

Specific scenarios are:

� Aircraft wheels sliding around on wet guano whilst embarking / disembarking.� Aircraft wheels catching in rotten and degrading helideck net mesh.� Deck crew and Passengers slipping on guano when embarking /

disembarking the helicopter.

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The increased potential for a guano related incident on NUI’s is very difficult toquantify.

3.3 EFFECTS ON HELICOPTER FLIGHT OPERATIONS DECISIONMAKING

3.3.1 GENERALThe helicopter operators are well aware of the potential hazards associated withseabirds colonising offshore structures and helideck guano accumulations on NUI’s.This awareness is typified by the importance given to applying flying restrictions to‘errant’ helidecks, when ‘line’ pilots report problems.

The ‘guano’ reporting emphasis appears to be regional in its intensity. This is to someextent expected and is mainly due to the location of most of the normally unattendedinstallations in the southern sector of the North Sea. That is not to say that theproblem is considered less elsewhere around the UKCS. It is simply a matter of thescale of the problem in one particular area.

It can be generally stated that, wherever a guano problem exists on installations itreceives direct attention from the flying point of view.

3.3.2 THE SOUTHERN NORTH SEA SECTOR DATA BASEA measure of the level of reporting designed to encompass the continuing problem ofguano accumulations is the ‘rolling’ database maintained by Bristow HelicoptersLimited at their Gt. Yarmouth operations base. The report is generated from ‘line’ pilotreports which rate helideck deterioration from the effects of guano using ameasurement of 1 to 10 in level of severity.

This Database is unique to Bristows. Scotia Helicopter Services (Bond) have a different approach. They rely on pilots’ voyage reports.

See Section 2.2.5 and Appendix G for more details.

3.3.3 DAYTIME FLIGHTSDaytime helicopter flights are not often adversely affected by sea bird activity or guanoproblems to the extent that offshore operations are seriously interrupted.

Very occasionally it has proved necessary to postpone a landing due to birds refusingto vacate the helideck area.

Similarly, only on rare occasions has a pilot refused to land on a helideck due toexcessive guano accumulation.

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3.3.4 NIGHT TIME FLIGHTSFlights to installations at night or during the hours of darkness (winter period) are anentirely different matter.

At night, in darkness and reduced visibility, it is essential that pilots acquire andmaintain good visual cues of the helideck, its markings and the installation structure inorder to execute safe landings and take-offs. These vital external references need tobe quickly and frequently obtained and alternated with internal reference to the aircraftinstrumentation. Such actions call for clear, unobscured and unambiguous helideckmarkings, lighting, etc.

For the above reason, when guano obscured markings have been reported on voyagereports or by other means and the helideck is deemed to have deteriorated sufficientlyto prevent easy identification, the helidecks will be restricted to “daylight operationsonly” until a cleaning and / or a painting program has been completed.

Fortunately, throughout the year, the bulk of flying to NUI’s is done during daylighthours. However, during winter months it is still essential for intervention crews tomaximise daylight time on the installations for completing scheduled maintenancework. This may therefore mean flying to and from NUI’s in darkness.

By definition, this means that restricting a helideck to ‘daylight operations only ’ shouldnormally not be considered a worthwhile ‘operational’ option by Duty Holders.However, this is for the Duty Holder to decide because it has much to do with theefficiency of his field production operations.

If a Duty Holder plans not to visit a NUI for a significant period of time and a guanoproblem is known to exist then it is assumed that the Duty Holder has already takenthis into account and has procedures in place for employing alternate methods to landan intervention crew on the installation, at night or in darkness, in the event of anemergency.

Also at night there are the potential problems of birds roosting on NUI’s.

During the day, birds are highly visible (in good visibility conditions) to the pilot and willmost times vacate the helideck fairly quickly as a helicopter approaches to land. Atnight and in poor visibility they will be less visible to a pilot and will almost certainly bemuch more reluctant to awake from their slumber and get airborne.

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3.4 THE POTENTIAL HAZARDS FOR HELIDECK OPERATIONS

3.4.1 RISKS TO INTERVENTION HELIDECK CREWS ON UNMANNED INSTALLATIONS

The main risks to intervention helideck crews posed by guano accumulations onhelidecks and surrounding structures are slips, falls and health hazards.

The increased potential for slips and falls is more likely to arise during the initialphases of helideck operations, on arrival at the NUI.

Movements to and from a ‘rotors turning’ helicopter and whilst using the associatedstairs and walkways can be much more precarious if the guano is excessive and wet.Immediately on arrival the appointed OIM / HLO will be required to make installationand helideck safety checks prior to disembarking other personnel. At this time he isprobably at greatest risk.

During helicopter unloading the potential for slips and falls becomes a problem whenthe intervention helideck crews are carrying equipment. This is also the case duringcleaning operations.

Health hazards are dealt with in 3.4.1

3.4.2 THE DISCOVERY OF DEFECTIVE HELIDECK EQUIPMENTOn arrival at a NUI the discovery of defective or unusable helideck equipment causedby the effects of guano is always a possibility. However, operator reports suggest thatfinding unusable helideck equipment is not a commonplace occurrence.

This suggests that routine precautions taken to protect the more vulnerable items ofhelideck equipment are generally proving adequate.

3.5 EFFECTS ON PERSONNEL HEALTH AND SAFETY

3.5.1 POTENTIAL HEALTH EFFECTS FROM GUANOACCUMULATIONS

There are consistent reports from operator personnel and flight crews about theunpleasant odours encountered on helidecks / installations with significant guanoaccumulations. This is not unexpected. However, it is not the odour that is a risk, it isthe source of the odour.

Large and concentrated areas of guano may harbour micro-organisms which can leadto human diseases. This makes exposure to guano potentially hazardous for thepersonnel involved when they come into contact with it.

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In some cases, diseases that may result from prolonged exposure to guano (withoutappropriate protection) can prove fatal, so the potential hazard on helidecks must notbe underestimated. In particular, clearing accumulations of guano off helidecks is notjust unpleasant, time consuming work, it can be harmful to health.

Thus, birds can be a threat to human health. This may be as a source of pathogensand allergens.

3.5.1.1 AllergensProblems can include Allergic Alveolitis, which can lead to lung damage (so called“Bird fancier’s Lung”) as a result of allergic response to bird proteins, or as a source ofdisease organisms, including:

� Chlamydia psittaci - Ornithosis a condition passed directly from bird to mancausing pneumonia.

� Histoplasma capsulatum - Histoplasmosis, from fungi which develop indroppings, and can produce pneumonia

� Cryptococcus neoformans also from fungi which develop in droppings, andcan produce meningitis.

Whether the above disease organisms are common in the bird species to be found onUKCS offshore platforms is unknown.

However, many of these diseases produce flu-like symptoms, and it is important foreveryone concerned to be aware of the risks and to treat such symptoms with caution.

If symptoms persist or are severe, individuals should see their GP and advise him orher of their contact with sea birds and their guano. The same caution should beexercised for family members as well, notwithstanding the low chances of infection forthem.

3.5.1.2 PathogensFood poisoning organisms may also be present, which can be picked up by birds andthen scattered around, contaminating water supplies and human foods directly. Theseinclude:

� Campylobacter spp� Eschericia coli 0157� Listeria spp� Salmonella spp� Vibrio cholerae� Botulina

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Apart from Campylobacter, it is understood that the other organisms normally requirelarge quantities of contaminated food and water to be ingested to cause infection. Onthe other hand, with Campylobacter, a small dose can cause infection and this can betransmitted by contact with droppings.

The above outline of potential health effects from guano exposure should beconsidered sufficient reason for Duty Holders to undertake detailed COSHHAssessments for their NUI operations, in conjunction with professional medical advice.(Note: There have been several papers published by medical and veterinaryspecialists concerning the transmission of diseases by sea birds).

Clearly, there are risks and they are likely to be present as a result of:

� Airborne contaminants (generated by dry guano particles circulated by thehelicopter rotor down wash, during helideck clearing operations and by localwinds).

� Contact with contaminants when handling guano covered equipment andduring the disposal of guano overboard during clearing operations.

� The vulnerability to contamination of water supplies and food containersbrought on board by helicopter for the use of intervention crews.

� Difficulties posed for ensuring personal hygiene on NUI’s (limited facilities).

The following are summary reports received from installation and helicopter operatorsabout their current experience with respect to health issues.

3.5.1.3 Helicopter OperatorsGenerally, there are no reported health issues that arise for the flight crews. However,the main complaint is the smell caused by the guano and, at times when the helicopterstays on the helideck for more than 5 minutes, crews start to feel nauseous.

3.5.1.4 ARCO British LimitedIntervention crews have expressed concern about inhalation of dust during guanocleaning operations.

There is no COSHH assessment in place but personnel directly exposed to the effectsfrom guano cleaning operations are equipped with face masks and ‘wet’ clothing.

3.5.1.5 BHP PetroleumNo health problems or concerns are reported but it is recognised that dried guano dustcan be inhaled.

There is no report of a COSHH program being implemented and the issue of PPE.

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3.5.1.6 BP AmocoIn the southern sector of BP Amoco operations health concerns arise from thepotential for sickness and cross contamination due to poor washing facilities on someNUI’s.

There is a COSHH program in place and personnel are provided with full cover suits,gloves and a mask when directly exposed to guano accumulations or when involvedwith cleanup operations.

3.5.1.7 British Gas PlcThere have been no reported health problems. However, problems with flying debrisis reported during helicopter operations.

A formal COSHH Assessment has not been done but PPE is provided and usedwhen required. This includes waterproof equipment. However, guano clean upoperations on the BGas assets are low frequency and require little effort.

3.5.1.8 Cal Energy Gas (UK) Ltd.No health concerns. The smell is the most common complaint.

No COSHH assessment program in place at present. However, disposable overalls,face masks and gloves are always available.

3.5.1.9 CentricaNo health problems are reported and there is no formal COSHH Assessment programin place. Details on specific PPE provisions have not been provided.

3.5.1.10 Conoco UK LimitedNo health concerns have been reported.

There is a COSHH Assessment in place as part of the Waste Management Process.Masks, plastic disposable coveralls, rubber gloves, rubber boots and goggles areprovided.

3.5.1.11 Mobil North Sea LimitedMain concerns are the smell and some dead birds rotting on the helideck. Alsoslipping.

COSHH program is a part of the overall risk assessment. Disposable coveralls,masks, rubber gloves and boots are provided when personnel are undertakingcleanup operations.

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3.5.1.12 Phillips Petroleum On the Hewett Field NUI’s there have been no reported health problems.

A formal COSHH Assessment program is not in place. However, professional medicaladvice has been taken from the North Sea Medical Centre at Great Yarmouth andSafety Bulletins have been posted to highlight potential dangers from salmonella,Campylobactor and Chlamydia.

Full PPE is available to personnel and it includes protective coveralls, face masks,boots, gloves, etc.

On the LAPS Field NUI’s operated on behalf of Mobil some crews have raisedconcerns about the effects from guano. These concerns are mainly the effects onequipment, work boots and the smell.

There is a formal COSHH Assessment in place and full PPE is available, as definedby the COSHH Assessment.

3.5.1.13 Shell Exploration & ProductionIt is reported that in the Sole / Silver Pit, Sean, Inde and Corvette fields everyone(intervention crews and medics) are generally concerned about the potential healthproblems that can be associated with guano accumulations on the NUI’s. However,similar concerns have not been raised in the Leman area.

Currently, there is no COSHH program in place but a risk assessment is underconsideration.

A high standard of PPE is provided in all areas for personnel working or directlyexposed to the effects of guano. This equipment includes wet suits, goggles, rubbergloves, and masks.

3.5.1.14 Total Oil MarineThere have been no health concerns or potential problems reported by interventioncrews as a direct result of exposure to guano and other bird debris accumulations.

A COSHH assessment has been undertaken and is in place for personnel exposed toguano, etc. Facilities are also provided for washing up.

Personal Protective Equipment includes Slicker Suits, Goggles, Gloves, Rubber Bootsand Face Visors.

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3.5.2 PHYSICAL HAZARDSSimilar to the problems that are likely to be experienced by the intervention helideckcrew (see Section 3.3.1) other personnel will be equally exposed to potential physicalinjury from slips and falls due to loss of non-slip surfaces on helideck, access stairsand walkways.

Additional, but less likely, injury hazards can be present when ‘bird spikes’ areemployed on perimeter and flood lighting.

Where some high intensity sound systems are used for scaring off birds there may bea small risk of sustaining hearing damage, if personnel are exposed to the noise. Thisproblem can be avoided simply by deactivating the system when the installation ismanned.

3.5.3 ADVERSE EFFECTS ON EMERGENCY PREPAREDNESSWhen helidecks are decommissioned for repairs and / or cleaning operations, thehelideck may no longer be immediately available for an emergency evacuation ofpersonnel by helicopter.

Also, where ’daylight only’ flights have been imposed by the helicopter operatorpending remedial work or by the duty holder for operational management reasons, itraises the question about the use of helicopters should a night time intervention benecessary, in the event of a platform / process emergency.

Both the above scenarios could be classed as a foreseeable events. Therefore, botheventualities should be well covered in the Duty Holder’s intervention work plan andoperating / emergency procedures.

3.6 EFFECTS ON MAINTENANCE AND HOUSEKEEPING

3.6.1 HELIDECK SURFACE AND MARKINGSIt is reported that fairly frequent renewal of markings and repairs to the helidecksurface are required on NUI’s affected by guano accumulation.

The following summarises operator current experience.

3.6.1.1 ARCO British LimitedUsing a ‘canvas sheet’ system (with painted markings) under the helideck net hasreduced the deteriorating effect of guano on the helideck surface and markings.

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The effects of guano and the frequency of repairs to the remaining exposed areas ofhelideck surface and markings outwith the area protected by the canvas sheet(helideck net area) have not been reported.

3.6.1.2 BHP PetroleumThere are no reports of repairing helideck surfaces and markings in recent years.

3.6.1.3 BP AmocoIn the southern sector of BP Amoco operations helideck markings and non slipsurfaces are repaired every 2 to 4 years, depending on their condition. Steamcleaning is a problem on wooden helidecks because it can easily lift off the paint.

3.6.1.4 British Gas PlcThe Rough NUI helideck surface and markings are repaired approximately every 5years.

3.6.1.5 Cal Energy Gas (UK) Ltd.Damaged helideck surfaces and markings are repaired yearly but it is suggested theyshould probably be done more often.

3.6.1.6 CentricaFrequency of repairs to helideck surfaces have not been reported.

3.6.1.7 Conoco UK LimitedHelideck surface repairs are done as required.

3.6.1.8 Mobil North Sea LimitedThe helideck markings and non -slip surfaces are repaired / replaced every 2 years.

3.6.1.9 Phillips PetroleumOn the Hewett assets helideck markings and non-slip surfaces are replaced at 3 to 4year intervals.

On the assets operated for Mobil the helideck markings and surface isrepaired/replaced every 3 to 4 years.

3.6.1.10 Shell Exploration and ProductionIt is reported that helideck surfaces and markings are repaired / replaced every 3 to 4years on the Sole / Silver Pit assets, 4 to 5 years on Sean, Inde and Corvette and 5 to6 years on Leman.

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3.6.1.11 Total Oil MarineDamaged helideck markings and the non-slip surface are repaired as part of routinemaintenance but there have not yet been any other helideck equipment replacementsas a result of degradation due to the effects of guano.

3.6.2 HELIDECK NETS AND OTHER EQUIPMENTAs a result of guano damage / deterioration, NUI helideck nets and some helideckequipment require more frequent replacement than normally experienced on mannedinstallations.

The following summarises operator current experience.

3.6.2.1 Arco British LimitedHelideck nets are replaced approximately once a year but other equipmentreplacements due to the effects of guano have not been reported.

3.6.2.2 BHP PetroleumHelidecks nets have been replaced three times in 5 years but other equipmentreplacement due to the effects of guano has not been reported.

3.6.2.3 BP AmocoIn the southern sector of BP Amoco operations helideck nets are replaced every 1 to 3years depending on their condition. Also, there has been early replacement of firefighting equipment due to its deterioration from the effects of guano.

3.6.2.4 British Gas PlcThe NUI helideck net is replaced approximately every 5 years. No other helideck netis replaced as a direct result of bird / guano problems.

3.6.2.5 Cal Energy Gas (UK) Ltd.The helideck net is replaced yearly.

3.6.2.6 CentricaDamaged helideck nets are replaced every two years. Replacement of helideckequipment has not been reported.

3.6.2.7 Conoco UK LimitedHelideck nets are replaced as required. The main items of helideck equipment thatare replaced due the birds is helideck lights.

3.6.2.8 Mobil North Sea LimitedHelideck nets are replaced every 1 to 2 years due to deterioration from the effects ofguano.

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3.6.2.9 Phillips PetroleumOn Hewett assets the helideck nets tend to get replaced as a result of general wearnot due to the deteriorating effects of guano. Other helideck equipment has not beenreplaced solely due to deterioration from guano effects.

On the assets operated for Mobil, helideck nets are changed as required when theyhave deteriorated due to the combined effects of general wear and tear, theenvironment and guano effects. Some helideck fire fighting equipment has beenreplaced as a result of deterioration due to guano effects.

3.6.2.10 Shell Exploration and ProductionShell report that helideck nets are replaced every 6 months on the Sole / Silver Pitassets, annually on Sean, Inde and Corvette and 5 to 6 years on Leman, wherehelideck nets have been fitted.

There are no reports of other equipment replacement due to the effects of guano.

3.6.2.11 Total Oil MarineA helideck net is fitted on MCP-01 and it has required repair on 2 occasions in 2 years.It has been completely replaced in 1999.

3.6.3 HELIDECK CLEANING AND EQUIPMENTRemoving large quantities of guano and bird debris and cleaning helideck surfaces,surrounding structures and equipment is a major part of the routine maintenance forthe large majority of NUI’s. The work falls to intervention crews and it is manpowerintensive, time consuming and therefore costly. Mostly, the work is carried out usingbasic cleaning techniques which have moderate success.

The following summarises operator current experience.

3.6.3.1 Arco British LimitedArco use a tarpaulin system (with helideck markings painted on it) placed beneath thehelideck net. It is removed, with the net, when guano removal and cleaning is requiredand the tarpaulin is lifted by crane and ‘dunked’ in the sea to wash it off. Theperimeter areas of deck are then washed down prior to tarpaulin and net replacement.It is reported that this system has proven successful.

A 200 eco - friendly cleaning chemical called ‘Multiclean’ is used to clean thehelidecks. Applying this chemical helps to break down the guano prior to pressurewashing.

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3.6.3.2 BHP PetroleumBHP use HP water washing to remove and wash away the guano. This has proven tobe very successful.

3.6.3.3 BP AmocoIn the southern sector of BP Amoco operations high pressure water jetting or steamcleaning equipment is used to remove guano and other bird debris. Success ratesvary from limited to high. Guano disposal is as required by COSHH Data Sheet.

3.6.3.4 British Gas PlcThe Rough Field NUI was formerly a manned installation. Helideck cleaning isaccomplished by using fire hoses. This method has proved successful.

3.6.3.5 Cal Energy Gas (UK) Ltd.Guano is removed from the helideck, lighting fixtures and other equipment by using rigwash and general detergents. A special guano cleaner has also been used. Thesemethods are not considered very successful.

The guano is disposed by washing overboard.

3.6.3.6 CentricaPower washing is used for cleaning operations.

3.6.3.7 Conoco UK LimitedConoco assets have a continual cleaning program in place. All NUI’s are cleanedduring each visit.

Pressure washers are used but are not considered to be very successful. Disposalprovisions are in line with the CUKL waste management system.

3.6.3.8 Mobil North Sea LimitedPeriodic removal of guano by high pressure water jetting. Medium levels of successachieved.

3.6.3.9 Phillips PetroleumOn the Hewett assets high pressure wash units and steam cleaning are used but withlimited success. The guano is washed into the drains and discharged to sea.

On Mobil assets operated by Phillips the same cleaning operations take place withsimilar success rates.

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3.6.3.10 Shell Exploration and ProductionA variety of methods are reported to have been used to remove guano, with varyingdegrees of success. They are:

Quite goodHP washer with 'Bioshield'Leman

OK

Very successful

a) Jet wash with / without detergentb) 'Biosol' descaler - Sprayed on

using a garden 'stirrup pump' andleft for the rain and elements toclean

Sean / Inde / Corvette

Not very SuccessfulPressure Washer / ScrubbingSole / Silver Pit

RATINGMETHODASSET

3.6.3.11 TotalPeriodic removal of guano accumulations is required and is done by using a brush anda high pressure water hose. This is fairly successful but requires additional manpowerwhich is costly.

The guano is disposed of by brushing it into the sea.

3.6.4 FITTING BIRD DETERRENT SYSTEMSFitting additional specialised equipment to NUI’s is generally a requirement to combatthe problem of sea birds on NUI helidecks. When the equipment is fitted it needs tobe maintained.

3.6.5 ADDITIONAL MANPOWER AND COSTSGenerally, operators accept that routine guano removal, unscheduled repairs tohelideck markings and surfaces, and more frequent replacement of helideck nets andother equipment, plus extra helicopter trips and personnel to resolve the ongoingproblems simply adds to already high maintenance costs.

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4. PART 3 - MITIGATING MEASURES

4.1 PREVENTION SYSTEMS AND THEIR EFFECTIVENESS

4.1.1 PREAMBLEIn broad terms, bird mitigation measures are classified under the general heading ofpest control. A service industry has grown up onshore for various industry sectorspertaining to:

� Agriculture� Food production� Architecture� Air transport� Waste disposal.

In the agricultural sector there is a need to keep birds away from recently-sowedseeds and young crops, as well as storage facilities.

In terms of food production and storage, birds must be excluded from areas wherefood is present, particularly in large open-plan enclosures.

Architectural requirements are to keep birds off buildings to prevent general nuisance,fouling, damage and unnecessary repair and cleaning costs.

In air transport, there is a necessity to prevent build-up of guano and avoid bird strikeswith aircraft. Waste disposal landfill sites generally attract birds, which become anuisance and hazard for the locality.

In the offshore installations case, guano build-up can obscure helideck markings, andwhere helideck nets are fitted these can quickly rot, reducing their service life,resulting in more frequent replacement and costs.

Guano looks unsightly and can damage the substrate through direct chemical action.

4.1.2 CLASSES OF MITIGATION SYSTEMSFrom inspection of the sales literature of purveyors of onshore mitigation systems,solutions to the bird problem can be classified into three groups:

� proofing� scaring� control.

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Proofing essentially amounts to the application of methods to exclude the birdscompletely from the areas concerned.

Scaring allows birds to visit the areas but provides methods to frighten or startle themaway, hopefully on a permanent basis.

Control relates to catching and selective, or even large-scale, culling.

4.1.3 PROOFINGAs stated above, proofing involves the use of hardware to exclude birds from theareas of concern and to prevent them from landing or settling. A variety of suchhardware is available tailored to suit the particular intended purpose.

For large surface areas, or regions with a large access, netting is used. This is heldtightly in place around and/or slightly away from the area to be protected. The nettingitself can be made from a variety of materials: e.g. UV light-stabilised polyethylene orpolypropylene of various strengths (for extra robustness) at various mesh sizes tocater for different bird types (19 mm for sparrows and small birds, 50 mm for pigeons,100 mm for herring-, lesser- and black-backed gulls). Architectural finishes (includingtranslucent) may be available, along with flame retardent material options. The nettingis held in place by a system of tensioned peripheral steel wires. Eye fixings hold thesteel wire in place to the protected area and it is tensioned with screw-action barreltensioners. The various fixing hardware may be in galvanised or stainless steel. Zipscan be provided to allow human access to the netted-off areas.

Spike systems are designed to be used on relatively small surface areas, both planeor curved. As the name suggests, the hardware consists of upwardly directedradiating or angled spikes made from a variety of materials and supplied in a range ofconfigurations. The upward pointing spikes provide a physical barrier to prevent thebirds from landing and gaining access to the area. The system may comprise a seriesof wires (stainless steel) factory mounted on a basal strip (plastic or stainless steel) ofa fixed length (30 - 33 cm). The wires may be of fixed length (suited to the type of birdto be repelled - 110 or 120 mm for pigeons, or 150 mm for gulls). The wires can bedisposed in alternating patterns of angle and or number (2-1, 2-2, 4-2, and so on) along the length of the strip, or with single wires in a straight or zigzag configurationwith vertical or alternately inclined wires. The strips are mounted to the surface to beprotected by building adhesive or screwing/nailing.

Other systems involve a flat set of radiating spikes that are manually mounted duringinstallation onto the base. Both may be made of UV light-inhibited plastic and can beprovided in a variety of colours, including translucent. The base is mounted onto theprotected surface as suggested above.

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Articulated spikes are a variant on the spike systems outlined above, where the baseon which the spikes are mounted is provided with a series of joints which allow thebase to be folded in a scissors manner. This enables a variety of spike configurationsto be developed using a single strip, from a single line of spikes to an array.Generally, the spikes in such systems are vertically aligned.

Sprung wires are used for areas that are essentially long compared with their width.Stainless steel wires are strung length wise above the area to be protected and sprungagainst a variety of end posts and brackets. The wires may be coated in UVlight-stabilised clear nylon for further weather protection. The end posts and bracketsmay be such as to provide different array configurations of wires and may be securedto the protected area with drive rivets inserted into drilled holes, or withadhesive-mounted bases.

For square or circular areas to be protected, removable wire systems are available.These are suitable in cases where the deterrent has to be placed on a surface thatrequires regular access for maintenance. The system consists of stainless steel,plastic-tipped wires, mounted on a self-lubricating Delron base. The lower part of thebase is fixed to the surface and the upper part, which is detachable and bears thewires, rotates in the wind or when touched by birds. The wires radiate from the upperpart in a fan-shaped pattern and are thus able to cover areas corresponding to 1.25and 2.5m in diameter. Larger areas can be covered by using an array of suchdevices.

The coiled wire system consists of an extendible stainless steel helical coil of about100 mm diameter. Once extended, the coils are secured to the protected area bybrackets screwed or glued into place. Parallel lengths of coil can be disposed toprovide protection to a larger area. It is claimed that the system is easily removed andreplaced; moreover the coils can be temporarily depressed to the surface and whenreleased will spring back into shape.

Finally, humane chemical methods are available. Bird repellent gels may comprise apolybutyl gel, applied by means of a caulking gun, and sealed using a special skinningfluid that is hand-applied with a paintbrush or via an aerosol spray. This latter processis a legal requirement in the UK. In essence the gel forms an unstable, sticky-feeling(although not sticky!) surface for the birds to stand on. As they do not like this feeling,they do not settle. The system has drawbacks, however; it can be broken down bypersistent birds, which can be harmed if the gel skin is broken. The gel can also beabsorbed by a porous substrate unless treated before application. Some purveyors ofthis material offer a two-year guarantee on the product’s effectiveness. In the gelform, small areas would appear to be the most suitable surface. Some USmanufacturers produce a liquid form of the deterrent, suitable for large surface areas.

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It is not clear if, in the US, it is a legal requirement to separate the bird from the gel viaa sealant, as indicated above.

4.1.4 SCARINGBird scaring can be sub-classified into:

� visual scaring� audio scaring� discomfiture.

A variety of visual scaring devices are available. Traditional “scarecrow” typesystems may comprise realistic, life-size models of predators (owls and falcons, in thecase of land-based birds) and balloons. The latter generally have staring “eyes” andother brightly coloured markings on them that signal danger to the birds. They mayalso have foil tails. the balloon is freely suspended by means of a bracket and theconstant motion in the air currents provides a random eye-movement effect.Light-based systems are also available and consist of high-intensity flashing orstroboscopic lights. Holographic, iridescent defecation foil is available in strip form.This is claimed to drive away unwanted birds by producing an optical and aural(rustling) discomfort zone.

A relatively new device called “Scaryman” has been brought to the authors’ attentionbut no details have yet been obtained. The system is described as an ‘inflatable doll’type contraption that is triggered by birds walking on pressure pads.

Audio scaring devices range between the simple to the most sophisticated. At thesimple end, starter pistols with very loud blanks can be used to provide a sudden anddisturbing noise. Ultrasonic systems are available which comprise a series ofloudspeakers and an ultrasonic generator. The latter produces sound that is inaudibleto humans, but with characteristics and at frequencies disturbing to birds. At the hightechnology end, use is made of bird distress call generators. These generally consistof a series of speakers controlled by microprocessor and fed with genuinespecies-specific bird distress or predator calls. The controller usually provides thefacility for randomising the sequence, timing, duration and apparent origin of thesounds. Both portable (land-vehicle mounted and hand-held) and fixed systems areavailable. In some cases, the systems are claimed to be capable of displacing birdsfrom large, remote areas.

Discomfort can be applied to the birds simply by spraying them with water. One suchsystem, designed for domestic gardens, comprises a high-flow instant opening valvein-line with a water supply. The valve is actuated by a high-quality motion sensor(similar to the type used on domestic external lighting), which allows water to pass toan adjustable directional spray jet. Upon detection of bird motion, the device sprays

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for a fixed period of time (say 3 seconds) before the valve is shut and the systemreset.

4.1.5 CONTROLBird control is generally considered to be a “last option” and encumbered with practicaldifficulties. It is more concerned with population management. The birds concernedmay be protected by law and/or endangered. Adverse public reaction may result froma culling exercise; the unaffected public would not regard birds as pests. Birds arevery mobile and some can breed very quickly. Removing part of the population byculling or trapping may simply create a vacuum that is easily filled by replacement.Unless the attractiveness to the birds of the site is removed, they will quickly return.

Nevertheless, control in conjunction with proofing or scaring may be successful due tothe fact that the birds learn about the dangers introduced, but the long-term efficacymay be generational. The main tools used for this mitigation method are:

� air weapons� cage traps.

The use of air weapons may be subject to local laws and animal conservationrestrictions, cannot be carried out remotely, requires a skilled operative on-site anddisposal of the culled birds.

Cage traps appear to be designed for particular species (e.g. feral pigeons, housesparrows and magpies on shore) to cater for size/behavioural differences. Under UKlaw, these traps must be inspected at least once every 24 hours and both food andwater must be present inside the cages. Captured birds which are not pests must bereleased. Those defined as pests must be killed discreetly and humanely. Theapproved method of dispatch in the UK is by neck dislocation. Thus, although cagescan be left, the method is not strictly remote and requires daily maintenance.Operatives would be required to cull and dispose of the pest birds.

4.2 MEASURES USED AND LESSONS LEARNT BY THEOFFSHORE INDUSTRY TO DATE

4.2.1 PREAMBLEThe three classes of mitigation systems for dealing with the bird problem - proofing,scaring and control - have been discussed and exemplified above.

The offshore industry appears to have settled for bird scaring as the principal meansof dealing with the problem.

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4.2.2 AUDIO BIRD SCARING SYSTEMSA number of companies manufacture and/or market audio bird-scaring systems.Largely, as described above, they reproduce bird distress and predator calls throughloudspeaker systems, controlled by microprocessor to randomise variouscharacteristics of the sound. Such an arrangement produces “a constantly changingaudible hostile environment” which, although disliked by the birds, is harmless tothem. Such systems are:

� “Gull Scat” marketed by J B Offshore, based in Norwich in the UK� “Scarecrow Bio-accoustic systems” marketed through Network Pest Control

Systems Limited, based in Warrington in the UK� “Super BirdXPeller PRO” marketed by BIRD-X Inc, based in Chicago in the

USA.

Gull Scat, according to the sales literature, has been adopted by twelve major offshoreoil/gas operators in the North Sea and installed on the helidecks of in excess of 40platforms. Installation dates range from 28 September ‘96 to more recently.

Scarecrow Bio-accoustic Systems manufacture a range of system compilations, asassembled from a series of components, add-ons and accessories. These aresuitable for use as a: small airfields system (portable), large airfield portable system,major civil airport vehicle-mounted system, landfill site vehicle-mounted system,marina system, an unmanned offshore satellite system. The system is reported tohave been installed on BP Amoco’s Harding platform.

Bird-X quote case histories using the Super BirdXPeller in the USA. One was for theLouisiana Land and Exploration Company, who having had unsuccessful experienceusing owl decoys, resorted to the acoustic system. This was reported by themanufacturers to have 100% effectiveness after 3 months.

The second was for the Amerada Hess Corporation and involved the company’s WestCameron offshore platform, located 80 miles south of the Sabine River on the borderbetween Louisiana and Texas. Again the system was reported to be successful overa short time scale. 4.2.3 COMBINED SYSTEMSUnfortunately, birds learn very quickly what is important and what information to ignorethat is not essential for their survival. Thus a threat from which a realistic danger doesnot actually materialise eventually becomes redundant. There is plenty of evidence,for example, that the effect of bird decoys - static models of predators - is veryshort-lived.

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There is also growing evidence regarding the long-term efficacy of the audiobird-scaring devices. It appears that, despite periodic updating of such systems with,for example, louder speakers and a greater range of distress calls, the birds adapt andbecome acclimatised to the noises when it becomes apparent that they are in no realdanger.

It has been judged necessary to augment such systems with additional devices. TheTotal experience on MCP-01, cited earlier, is a good example of this. The introductionof the water spraying set-up appears, in combination with the Gull Scat device, to haveprovided a longer-term solution to the problem.

Information from BIRD-X recommends that the Super BirdXPeller PRO should beused in combination with the “Terror-Eyes” product. The latter is a visual scaringdevice of the brightly coloured/frighteningly marked balloon variety.

4.2.4 UKCS OPERATOR EXPERIENCES

4.2.4.1 Arco British LimitedARCO have not reported on any measures employed to minimise roosting / feedingbirds.

4.2.4.2 BHP PetroleumElectronic bird scarers (Gull Scat ?) and models of owls have been employed butwithout much success.

4.2.4.3 BP AmocoIn the southern sector of their operations BP Amoco have used the following systemswith varying degrees of success / failure.

� ‘Gull Scat’ bird scarer - varying the sounds and sound direction helps.� Plastic Eagle Owls - effective when first used but effect lost after a short time.� Varying helideck coating - effective when newly applied but effect lost as time

progresses.� Varying net design.

4.2.4.4 British Gas Plc‘Gull Scat’ has been installed and initially it worked well. Overall the performance israted as quite good.

4.2.4.5 Cal Energy Gas (UK) LtdSirens have been fitted but have not been successful.

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4.2.4.6 CentricaPlastic owls have been employed but without success. BirdXPeller has also beenused. This system is reported to be effective for a couple of days then the birds return.

4.2.4.7 Conoco UK LimitedUse of scaring or other devices is not reported. Primarily the waste managementsystem is adhered to on all NUI’s with no access to food left on the platforms. Thishas proved fairly successful.

4.2.4.8 Mobil North Sea LtdLifelike owls have been installed at the side of the helideck. At first it appeared towork but now it has no effect.

4.2.4.9 Phillips PetroleumOn Hewett assets bird scare ‘distress call’, stuffed owl, and string wire have beenemployed. All have had a limited effect.

On the Mobil LAPS assets no bird scaring equipment has been installed.

4.2.4.10 Shell Exploration and ProductionOver the years Shell have trialled and employed a number of devices to find a way ofminimise roosting / feeding birds. They have had variable rates of success. Currentlythose devices in use are :

Not at all successfulPlastic OwlsLeman

Not successful at all.Noise scared birds intodepositing more guanobefore flying away.

Not at all successful

a) Gull Scat

b) Plastic bird of prey

Sean / Inde / Corvette

Not at all successful

Not at all successful

Very successful but notintrinsically safe. Usedprior to wells being drilled.

a) Gull Scat

b) Plastic birds of prey

c) Gas Gun

Sole / Silver Pit

RATINGDEVICEASSET

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4.2.4.11 TotalThe problems with unwanted bird populations and guano build-up have largely beenresolved by employing 3 measures. They are:

� Installation of a 'Gull Scat' system.� Installation of a sea water spray system, and� Regular maintenance / housekeeping.

'Gull Scat' was fitted in 1997 and was further improved by modifications in 1998 and1999. Although the system has been modified with more powerful speakers togetherwith additional bird distress calls, the system is judged to have limited success in thelong term. The birds appear to quickly adapt and accept the various noises when itbecomes apparent they are in little or no danger.

As a result of 'Gull Scat’s' limitations, a second method of deterring the birds wassought and a system that had the capability of spraying them with sea water wasinvestigated.

In 1997 a sea water spray system was fitted (See Appendix F for photographs of thesystem components and operation).

The sprinkler system is a simple arrangement that employs 2 industrial sprinklerheads fitted to the helideck guttering and fed from a sea water pump. The jetsdischarge water a distance of 19 metres at a height of 3 metres over the helidecksurface. They are activated remotely by St. Fergus Terminal when bird activity isobserved by a remote camera and relayed to a control room monitor.

The bird population residing on MCP-01 reacted immediately to this new deterrent bymoving off the helideck onto other parts of the installation. However, they have a habitof returning to the helideck to roost when at sunset but are quickly scared off when thewater system is switched on.

In addition, the water jets are activated for one hour morning and evening which hasthe effect of removing any guano build-up during the day.

It is reported the combination of systems has proved very successful and continues tominimise bird activity which ensures the helideck remains fairly clean.

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4.3 MEASURES USED AND LESSONS LEARNT FROM UK FIXEDWING AVIATION

4.3.1 PRINCIPAL FACTORSClearly, fundamental differences exist between the fixed wing situation and helicopteroperations to offshore installations. There are distinct differences between the twotypes of operation.

Airport and airfield take-off, climb, approach and landing areas required for fixed-wingaircraft are clearly much larger than those required by helicopters.

They are invariably on land, largely surrounded by grass, with various buildings,landfill sites, lakes, reservoirs, etc. often situated around the airfield perimeter andbeyond. Sometimes climb and approach sectors can be over the sea.

Many different bird species can be found around airfields, sometimes in large flocks.

Offshore platforms are remote from land, offering the birds the only dry area availablefor perching for many miles around. The species found offshore are predominantlygulls.

Compared with helicopters modern fixed wing aircraft are more vulnerable to birdstrikes that can have catastrophic consequences because:

� Windscreen, aircraft structure, landing gear and control surface impacts tendto occur at much higher airspeeds.

� Large jet engine air intakes are fully exposed to bird ingestion and as aresult, turbine engine failures. As engine thrusts have been increased andthe size of the fan blade increased proportionately, the engine has becomethe most vulnerable component on modern jets.

� Jet aircraft are potentially exposed to multi engine failures from birdingestion.

� Aircraft with propellers powered by reciprocating engines are relativelyimmune to bird strikes.

� Turboprop aircraft suffer as a result of small birds ‘blocking’ the relativelysmall air intake.

� Helicopters operate in the low speed environment and their engine intakesare normally shielded by design or they are fitted with debris guards.However, cases of engine damage have been reported.

� Modern helicopter rotor systems are robustly designed.

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4.3.2 MAIN METHODS USEDThe primary fixed wing focus at airfields and airports is to prevent bird strikesoccurring during critical aircraft flight phases. A fixed wing, jet aircraft is particularlyvulnerable during its take-off and climb when engine power demand is selected atmaximum.

Since the sixties there have numerous serious bird strike incidents recorded atairfields and airports world wide. Several bird strikes have resulted in catastrophiccrashes and others have caused major and costly damage to engines and airframes.

For these reasons, bird hazard control at airports and airfields has been high on theairport management agenda for several years.

Apart from the obvious concerns of airport management toward their ‘duty of care’ toprevent aircraft accidents and potential loss of life, there is always the need for anairport owner to minimise legal exposures. This has led to a significant growth, overthe past decade, in the implementation of comprehensive bird hazard controlprograms as a significant part of Airfield Safety Management Systems.

It is abundantly clear that in the fixed wing aviation industry the major concern is birdstrikes. Guano accumulations are a lesser concern and seem to be confined tobuildings and work places, not the landing areas.

The reverse seems to be the case for the offshore industry.

Fundamental to bird hazard control at airfields are major monitoring programs of thedifferent bird species and their habits, etc. This data is then used to determine whatmitigation measures (proofing, scaring and control methods) can be used to reduce oreliminate bird populations, if possible, and what methods should be used to control thebirds, particularly during periods when aircraft movements are taking place.

Offshore, it is generally accepted that the major problem comes from sea birds andthey are likely to be present on most, if not all, NUI’s. Invariably the majority speciesare gulls and the numbers present at any one time can vary from a few to many.

At this point of discovery the bird / guano problem is normally firmly in place. Offshoreindustry experience over many years has shown that the problem has not beeneliminated or significantly reduced, in the long term, by any of the mitigation methodsused by the fixed wing industry. It should be noted here that some methods used onairfields cannot be reasonably applied on offshore installations.

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4.4 MEASURES USED AND LESSONS TO BE LEARNT FROMOTHER INDUSTRIES: IMPLICATIONS FOR OFFSHORE

4.4.1 PREAMBLEThe three classes of mitigation described above - proofing, scaring and control - arethe principal methods used across sectors of industry onshore. Of these, where it canbe applied, proofing appears to be the favoured option because it physically excludesthe birds from the areas requiring protection. There are no difficulties regarding thebirds reaction to threats that do not subsequently materialise into real dangers. Inwhat are termed “heavy pressure” areas (locations used for nesting and roosting,particularly at night and with heavy fouling), the opinion is that netting (and possiblyheavy-duty spike systems) are the only systems that are likely to be successful.

4.4.2 CONTROL Of the three classes of mitigation system, it is suggested that the class least suitablefor offshore application is control. The use of cage traps would not constitute arealistic method. The traps have been designed with onshore birds specifically inmind: feral pigeons, house sparrows and magpies, and those commercially availablemay not be large enough to cope with the sizes of the majority of bird species seen onoffshore platforms. According to UK legislation, the cages require daily maintenanceand this is certainly out of the question for NUI’s. In the case of manned installations asystem that requires only infrequent intervention without the attendant dispatching anddisposal of birds by operatives would be preferable.

Small and / or large scale culling would also not be a viable option for offshoreplatforms, probably for the same reasons as for trapping. In addition, there may beadverse public reaction and conservation issues to consider.

4.4.3 PROOFINGProofing would, on the face of it, also seem to be unsuitable for the specific applicationin hand here. Methods that exclude birds would also exclude the helicopter from thehelideck. In the case of NUI’s, netting and spike systems are out of the question.Sprung and coiled wires, whilst they could be depressed by the weight of thehelicopter when landing, would present a hazard of catching in the landing gear eitherduring this operation or on take-off. Whilst sprung and coiled wires can be effectiveagainst gulls in urban situations, these tend to be “light pressure” areas which areusually high exposed locations with little fouling to be seen. Chemical methods mayprovide a viable option, but their use is generally for small surface areas compared tothat of a helideck. Furthermore, their long-term durability and effectiveness in ahostile environment like the North Sea has yet to be proven.

Proofing devices, that can be quickly and safely removed upon the approach of ahelicopter, may be feasible options for manned installations. There is nothing

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obviously commercially available. To date, however, this approach has not beenconsidered by the UK offshore industry.

4.4.4 SCARINGScaring appears to be the most viable bird mitigation approach for offshore platforms.It is generally accepted that, onshore, static effigies of predators, for example, havevery little medium or long-term benefit. Audio scaring seems to have a strongfoothold in current practice offshore, systems can be operated automatically on eitherNUI’s or manned installations, or remotely in the case of NUI’s There are concernsthat, unless regular changes are made to the systems (more powerful loudspeakers,changes to the types of sounds made etc.) the birds become acclimatised and tend toignore the threats. The long-term effectiveness of such systems, used alone, is beingcalled into question. There is some evidence that the addition of a second, different,type of scaring system (scarecrow balloons, for example) may prove more effective.However, there is reason to suspect that, with time, the birds will become accustomedto two systems and would that mean the addition of a third and so on?

Providing physical, but harmless, discomfort to the birds seems to suggest itself as asuccessful option, but again the long-term effectiveness needs to be firmlyestablished. Water-jetting (providing that the required pumps and piping can beaccommodated in and around the helideck), being electromechanical, can beoperated either remotely for NUI’s, or automatically for both NUI’s and mannedinstallations through timing devices or motion sensors. It would appear that either nocommercial systems are available, or those that are (motion sensor-based types) aredesigned for domestic gardens and are unlikely to be sufficiently robust for useoffshore. Nevertheless, a suitable remote system has been designed andsuccessfully used for offshore installation helidecks by TOTAL. Water-jetting has theadded advantage of providing a cleaning action.

4.5 SUMMARY AND CLOSING REMARKS

The following tables summarise the systems and equipment that have reportedly beenused by UKCS offshore operators to mitigate bird / guano problems on their NUI’s.Potentially, the lists may be incomplete because records of some methods that mayhave been trialed and discarded in earlier years, could be lost to the personnelcurrently in post. The data also gives some measure of the success rates that havebeen experienced.

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PROOFING

Limited Effect.LowPhillipsStrung wires

Nets and designsnot specified.

LowBP AmocoVarying net design

COMMENTSSUCCESS RATEUSED BYSYSTEM

SCARING

Not intrinsicallysafe

HighShellGas Gun

Bird activitymonitored byCCTV at landbased controlroom. Systemactivated remotelywhen necessary toscatter the birds.

Medium to highTotalWater Spray

Works for a fewdays then birdsbecomehabituated.

LowCentricaBird Expellor

Limited effect.LowPhillipsBird Distress Call-type not identified

Worked for a shorttime until the birdsbecamehabituated.

LowCal EnergySiren - type notidentified

Varying thesounds and sounddirection helps.Birds do becomehabituated to thesounds.

Medium to lowBP Amoco, Total,BGas, BHP, Shell

Gull Scat

Worked for a veryshort time until thebirds becamehabituated

Very Low to NilBP Amoco, Mobil,Centrica, Philips,BHP, Shell

Plastic Eagle Owland other types ofpredator device.

COMMENTSSUCCESS RATEUSED BYSYSTEM

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CONTROL

Ensuring no birdaccess to food lefton NUI's.

MediumConocoEmploying WasteManagementSystem Controls

COMMENTSSUCCESS RATEUSED BYSYSTEM

From the tables it can be seen that several methods have been and are still used byoperators to deal with the bird problem on their NUI’s.

Clearly the long term success rate in removing birds from NUI’s is not high.

It is known that in some instances where devices have been used with immediatesuccess the birds have simply moved to alternate roosting sites (e.g. other NUI’s), onlyto return later. It appears that as more platforms in an area have been equipped withscaring devices (e.g. Gull Scat) the reduction in ‘quiet’ roosting sites has not deterredthe birds from staying in the area. After a period of time they simply becomehabituated.

The proofing devices used to date have had very little effect.

Some scaring devices, notably ‘sound systems’ and water sprays, have beenemployed with a reasonable degree of success, albeit at a moderate level.

Likewise a waste control system that denies birds access to additional food sourceshas proved helpful.

The Gas Gun used by Shell was successful but has limited application because it isnot intrinsically safe.

No individual system has succeeded in removing or reducing the bird / guano problemaltogether.

A combined system of a ‘sound device’ and water spray has met with a fairly highdegree of success but requires constant surveillance and system activation from aremote location to control the problem. It has not been reported that the birds haveentirely abandoned the installation concerned. Nature being what it is, it is unlikelythey will do so!

At the moment there appears to be little in the way of new devices for removing birdsavailable in the marketplace to try out and to have a reasonable expectation of longterm success.

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This apparent lack of new and innovative products suggests that further developmentsto existing ‘bird distress call’ systems and water spray systems may be the onlypractical ways forward available to duty holders to contain bird problems on NUI’s.

Basically, this means that duty holders have no option but to accept that bird / guanoproblems will not go away from NUI’s permanently, now or in the foreseeable future.Therefore, the problem has to be managed by the duty holders (both platform andhelicopter operators) on an ongoing basis, to maintain the helideck facilities in goodoperational condition to ensure that flight and personnel safety is not compromised.

So, are there any other management options that are worth exploring? If so,

� what management options are open that generally accept that sea birds arelikely to be an almost permanent fixture on NUI’s along with their guanoaccumulations, etc.? And,

� what else can be done to limit the cost impacts of maintaining a NUI helideckin good operational condition?

Abundant answers to the above questions do not readily spring to mind. Notsurprising considering that most, if not all, duty holders have been asking themselvesthese questions for several years.

However, to focus on improving maintenance, occupational health aspects andattempting to reduce costs is probably as good a place to start, as any.

The main problems reported that badly affect NUI helicopter operations are guanobuild-up on the helideck and surrounds, deteriorated nets, markings and surfaces.The guano has to be frequently removed and this exposes personnel to health risks. Itis also time consuming and costly to undertake both cleaning operations and full scaleremedial works.

What can reasonably be done to alleviate any of these effects, activities and costburdens?

There is a system worth considering that has potential to reduce maintenance time,personnel health exposure and cost impacts for manpower and equipmentreplacement / repair (e.g. helideck nets, markings, etc.).

The idea is not entirely untried because it is based on one adopted by ARCO for someof their NUI’s.

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In brief, ARCO’s system uses a tarpaulin (same size as helideck net), with helideckmarkings painted on it and placed underneath the helideck net. When the guanobuilds-up and needs to be removed the net and tarpaulin (complete with guano) areremoved and the tarpaulin is hung off the crane to wash it clean, in the sea. Thetarpaulin and net are then replaced after jet washing the remainder of the helideck.

The suggestion for development is as follows:

� A tarpaulin type arrangement, to cover almost the entire helideck surface,could be fabricated from modern, fairly lightweight, highly durable material(similar to a lorry tilt) with all helideck markings permanently imprinted onto it.

� The background and markings could be specified in the correct CAP 437colours.

� Attachments could be fixed to the ‘tarpaulin’ perimeter to pickup and tensiononto existing helideck net fixings. Where the net fixings are not at thehelideck perimeter, modifications may be required.

� The surface of the tarpaulin material could probably be impregnated with anappropriate aggregate to reduce slipping.

� It may be feasible to incorporate into the tarpaulin surface a raised matrix thatappears similar to a helideck net (say, formed by bonding a net system intothe tarpaulin surface). This should provide adequate visual cues and act asa friction mechanism for helicopter wheels. Water drainage may be aproblem that needs further thought.

� Sealed, removable flap apertures could be provided for tie down points.

� Material selection requires easy (non specialist) and economic repair on site.

� Procedures will be required to ensure continued security of the tarpaulinsystem.

If successfully developed, such a device should:

� Largely eliminate the costly and time consuming rework of helideck surfaceand markings, every 2 to 4 years. For a large, 500 sq. metre helideck say, £15,000 for materials and 3 men for 2 weeks labour and transport costs.Also, it is often difficult to reschedule this activity if deteriorated markings andsurface are reported ahead of the planned rework schedule.

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� Largely eliminate the replacement of helideck nets every 1 to 2 years. Cost for a large net say, £4000, plus logistics and manpower to remove old netand replace the new one.

� New ‘tarpaulin’ replacement is estimated as 3 to 4 years. Unit costs willdepend on size, numbers fabricated, etc. They should cost less than the costof materials, etc. for a full helideck surface / markings rework.

� Requires new guano cleanup procedures to undertake releasing 'tarpaulin'fixings, folding and lifting securely by crane to dip into the sea for washing.May require spraying with a detergent prior to washing. Replacement of thetarpaulin should be straight forward. Clear markings would be needed on thetarpaulin and helideck perimeter to ensure positioning accuracy duringreplacement. The manpower and time required for these tasks should be nomore than is currently expended on helideck cleaning operations, maybeless.

NOTE: If a NUI is not equipped with a crane to assist removal and 'seawashing', cleaning can still be accomplished using HP water washingmethod.

� Require jet washing of the perimeter safety net, scuppers, lighting, accessplatforms and other helideck equipment similar to existing procedures. Nogain.

� Personnel exposure to the bulk of guano and debris on the helideck will befor a much shorter period of time during the cleaning operations.

If this suggestion is considered appropriate and of practical value to industry, thesystem will need further development to expand its application and the procedures foruse on any NUI helideck. It would also need to be properly trialed to refine the design.

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5. CONCLUSIONS AND RECOMMENDATIONS

5.1 CONCLUSIONS

Throughout the various sections of this report there are many individual topics thathave been addressed in order to give a complete picture to meet the report objectives.As a result many conclusions concerning the detail can be drawn. However, it isintended to only focus on the main conclusions that arise from the report. They are:

1. The subject of birds and their effects on offshore helicopter operationsproved to have many facets. Each has been identified and addressed to alevel deemed appropriate to meet the study objectives.

2. The bird / guano problem on UKCS offshore installations has existed formany years, in particular on NUI’s. The associated problems are welldocumented and understood by industry and regulators alike. However, longlasting solutions have been very difficult, if not impossible, to find.

3. There are already a large number of NUI’s on the UKCS and there are likelyto be more in the future. Bird / guano problems are unlikely to reduce inscale!

4. Evidence suggests that helicopter bird strikes average about 10 per yearoffshore. These incidents are widely spread on the UKCS and statisticsshow that NUI’s are no more affected than other installations or flightsen-route.

5. Although there have been a number of bird strikes reported over the yearsthey have not resulted in a serious accident, although on 2 occasions therehas been significant damage to the aircraft.

6. Bird strikes on fixed wing aircraft have had catastrophic effects as a result oftheir engine design and operating environment. Helicopters appear to beless exposed to bird strikes by virtue of their engine intake designs androbust rotor systems. They also operate in a low speed environment.

7. The main and more persistent problem for offshore helicopter operations,caused by sea birds, is guano accumulations on NUI helidecks obscuring thehelideck identification, other markings and lighting, thus reducing the visualclues required for making a safe and uneventful landing, particularly at night.

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8. Guano accumulations on NUI helidecks are a persistent problem for the dutyholders. They have to clean the helidecks, repair and replace damaged /faded surfaces and markings and replace helideck nets, etc. more frequently.These additional maintenance activities create scheduling problems andsignificantly increase manpower and other associated expenditures.

9. Permanently removing the birds (mainly gulls) from NUI’s should be regardedas an unrealistic objective. Long established sea bird breeding, feeding androosting habits are the overriding reason for their presence on NUI’s. Theinstallations also offer a relatively safe haven for the birds.

10. Most installations have abundant fish stocks around them or in the local area.This provides a ready source of food for the birds. The bird problem cannotbe permanently solved unless that food chain is broken.

11. From the information gained for this report there does not appear to be areadily identifiable pattern to the bird problem on NUI’s. Some NUI’s arealways affected, some are virtually unaffected and others occasionally getthe problem badly one year then it goes away the next. Only a highlydetailed bird study, across the UKCS, will provide the answers.

12. A proposal by MAFF in 1997 to conduct a 3 year study to formulate anintegrated bird management system failed to gain industry support. Much ofthe research for the study was to be observing birds to establish species,habits and patterns. The value of such a detailed study into sea birds onNUI’s is seriously questioned because if the birds are already present thenthe potential bird strike and guano problem is also there. It is very difficult tosee how establishing the species and observing their habits will providepractical answers for reducing or removing guano accumulations orpreventing bird strikes / interference. It is readily accepted that identifying thespecies of bird colonising platforms will provide the essential data requiredfor setting up audio bird scaring devices (e.g. Gull Scat).

13. A more pragmatic approach for duty holder and regulator alike is to simplyaccept that the irresistible forces of nature are at work when an installation is selected and colonised by sea birds. Once this happens the problem has tobe properly managed by the duty holder and helicopter operators alike tominimise the effects of the birds on both platform and helicopter operations.

14. Routine and frequent reporting of helideck condition is fundamental toefficiently managing the guano accumulation and obscured markingsproblem.

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15. At present helideck condition reporting is done on an individual helicopteroperator basis as a collective, rolling monthly report or by submittingindividual ‘voyage reports’ for specific installations. These reports are thensent to the duty holders to act upon.

16. Helicopter operator responsibilities under the ANO are quite specific forensuring that landing sites are suitable for purpose, etc. Also, CAP 437requires the AOC holder to monitor and advise helideck owners beforemarkings and lighting are degraded and become a safety concern. Inaddition, BHAB are now responsible for the issue and currency of OffshoreHelideck Certificates and placement of restrictions where appropriate.Currently, BHAB do not appear to be ‘in the loop’ for NUI helideck conditionreporting. The offshore Duty Holders also have responsibilities under theoffshore installations regulations to provide facilities and establishprocedures for landing and taking off helicopters, without risks to health andsafety.

17. There is no common UKCS system for routinely observing, rating thecondition, reporting and publishing the information about NUI helidecks.Operationally, there is considerable merit in having such a system which isconsistent and easily accessible to duty holders, helicopter operators and theBHAB. Doing so would greatly assist all parties in meeting their legal ‘dutyof care’ obligations.

18. There does not appear to be an industry agreed, operational protocol thatprovides a consistent approach toward dealing with helideck deteriorationwhen guano accumulation has been reported. A simple and effective systemshould be employed that helicopter operators can embody into theirOperations Manuals and duty holders into their intervention procedures /maintenance programmes and thus provide the required consistency.

19. Over the years much time, effort and money has been spent by offshoreoperators searching out solutions to the bird problem. Many of the ‘pestcontrol’ options open to other industries are simply not suitable for applicationoffshore. However, it appears that most devices that are available andsuitable for offshore application have been tried by the various duty holders.The level of success with most of these devices has been low. However,audio bird scarers (e.g. Gull Scat) and water spray systems have met withsome success.

20. No individual exclusion device has been able to provide the whole solution. Itrequires a combination of systems to sustain a reasonable degree offreedom from the birds in the medium term.

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21. In the longer term, birds become habituated and largely ignore the exclusionsystems employed offshore. This means the bird guano problem becomes apersistent and permanent feature for most NUI helideck operations.

22. Guano removal, disposal and cleaning operations are very unpleasant andexpose personnel to potential health hazards. To date there have been nohealth problems reported by personnel that are related to guano exposureson NUI’s. These potential health hazards are well documented in medicalliterature, etc. and should not be ignored or underestimated by duty holders.

23. Reports suggest that only about half of the NUI duty holders have doneformal COSHH assessments to cover personnel exposure to guano.

24. Guano removal, disposal and cleaning operations are time consuming,disruptive to routine operations, manpower intensive and costly for dutyholders. Jet washing is mainly used for the cleaning job. Depending on thelevels of accumulation, low to moderate success rates are generallyreported.

25. It seems that duty holders could focus more attention on ways to makeguano removal and cleaning operations more efficient and thus attempt toreduce manhours and costs. The solution appears to be linked to an abilityto remove guano in bulk and to reduce the helideck area that needs to becleaned manually.

26. ARCO currently employ a system that achieves bulk guano removal andreduces helideck cleaning to quite an extent. This is done by using a‘tarpaulin’ placed under the helideck net. When the affected area needscleaning the ‘tarpaulin’ is lifted, with the net, by crane and washed in the sea.ARCO report that the ‘tarpaulin’ method is quite successful therefore, theauthors of this report have concluded that this is an option / solution thatdeserves further investigation and development.

5.2 RECOMMENDATIONS

1. UKCS duty holders (installation operators and helicopter operators) shouldcontinue to work together more closely and to openly exchange informationand ideas. This approach should enable all parties to routinely manage thebird / guano problems on offshore installations in the most efficient,consistent and cost effective manner, whilst meeting their ‘Duty of Care’obligations. It would appear the best forum for achieving the high level of

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co-operation required is through a joint industry working group drawntogether from UKOOA Aircraft Committee (led by SACC) and BHABmembers.

2. There should be a UKCS NUI Helideck Condition reporting system put inplace. The system should consistently provide routine monitoring,assessment, reporting and report publication for the benefit of all UKCSinstallation duty holders and helicopter operators. A Bristow Helicoptersmonitoring and reporting system already exists. Ideally, the system andprocedures should be developed to cover all UKCS NUI operations and itshould be jointly sponsored and owned by UKOOA Aircraft Committee andBHAB members. It should also include a simple and consistent operationalprotocol for responding to deteriorating helideck conditions. Industry andhelicopter operations should consider 'night flight ban until helideck clean';'day flight ban if helideck deteriorates further ' as key action requirementwithin the reporting system (CAA report).

3. The search for new and improved devices to deter / exclude bird populationsfrom offshore installations should not cease. However, it is felt that dutyholder time and expenditures should become more focused on findingsolutions and improving the systems for guano removal and cleaningoperations. Efficiencies gained in this area will also reduce personnelexposure to potential health hazards.

4. Industry are being encouraged to look closely at adopting the ‘tarpaulin’system for bulk guano removal and reducing cleaning operations. There ismerit in developing this system if it can be demonstrated that it does notimpair safe helicopter operations, that it substantially reduces cleaningoperations, eliminates the need for repainting helideck surfaces andmarkings and can be achieved at a reasonable cost.

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6. LIST OF ABBREVIATIONS AND REFERENCES

6.1 LIST OF ABBREVIATIONS

ANO Air Navigation OrderBHAB British Helicopter Advisory BoardCAA Civil Aviation AuthorityCOSHH Control of Substances Hazardous to Health - HSE RegulationsCSL Central Science Laboratory (Dept of MAFF)FOD Found on Dispersal - debris on helideckMAFF Ministry of Agriculture, Fisheries and FoodMOR Mandatory Occurrence ReportNUI Normally Unattended InstallationON HSE Operations NoticeOTO HSE OSD Offshore Technology ReportR&D Research and DevelopmentSDD Safety Data Department - CAA componentUKCS United Kingdom Continental ShelfUKOOA United Kingdom Offshore Operators Association

6.2 BIBLIOGRAPHY

1. Offshore Technology Report - OTO 98 088, titled “HSE / CAA InspectionProject Offshore Helidecks 1991-1995”, Issued by HSE OSD March 1998.

2. Operations Notice No: 39 - Guidance on identification of offshoreinstallations, issued by HSE OSD December 1997.

3. A Review of Wrong Deck Landings, Status Lamps and Signalling Devices(HSE Task No: B\0015) - Issued by BOMEL Consortium June 1999.

4. Data Plus fact sheet on BIRD STRIKES (Ref: 99/DP1) - Issued by CAASafety Analysis Department June 1999.

5. CAP 437 - Offshore Helicopter Landing Areas: A Guide to Criteria,Recommended Minimum Standards and Best Practice, Third Edition issuedby CAA October 1998.

6. Guidelines for the Management of Normally Unattended Installations - Issuedby UKOOA.

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APPENDIX A

LIST OF CONTRIBUTORS

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LIST OF CONTRIBUTORS

Arco British LimitedBGas ExplorationBHP PetroleumBP AmocoBristow Helicopters LimitedBritish Helicopter Advisory BoardCal Energy Gas (UK) LimitedCentrica HRLCivil Aviation Authority - Safety Regulation GroupConoco UK LimitedHealth & Safety Executive - Offshore Safety Division OD5.5J B OffshoreMobil North Sea LimitedPhillips Petroleum LimitedScotia Helicopter Services (Ex. Bond Helicopters Limited)Shell UK Exploration & ProductionTotal Oil Marine plc

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APPENDIX B

ILLUSTRATIONS OF GUANO ACCUMULATION AND ITS EFFECTS(COURTESY HSE - OTO REPORT 98 088)

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ILLUSTRATIONS OF GUANO ACCUMULATION AND ITS EFFECTS(COURTESY HSE - OTO REPORT 98 088)

Figure B.1 - Deck markings obscured by guanoFigure B.2 - Deck markings outside net obscured by guanoFigure B.3 - Deck markings obscured by guanoFigure B.4 - Area between net contaminated by regurgitated fish bone

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Figure B.1 Deck Markings Obscured by Guano

Figure B.2 Deck Markings Outside Net Obscured by Guano

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Figure B.3 Deck Marking Obscured by Guano

Figure B.4 Area Between Net Contaminated by Regurgitated Fish Bone

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APPENDIX C

UKCS HELIDECK GUANO PROBLEMS - MOR'S

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UKCS HELIDECK GUANO PROBLEMS - MOR'S

27-Aug-99

Report No: 186 Year: 1989 Incident Type: MORAircraft Type: Bell 212 Flight Phase: ApproachOperating Area: UKCS Region: Southern North SeaHelideck ID: Leman 27H Incident Date: 15 October 1989

Caused By: Helideck Yellow Landing Circle partially obscured by bird droppings. Note: Anumber of unmanned helidecks were being visited to gauge the extent ofguano accumulation problems.

Failure Category: Installation MaintPrimary Cause: Other Secondary Cause: N/A

Comments: Recommend rig operators assess marking obscuration on regular basis.Where markings have deteriorated sufficient to prevent easy identification,deck restricted to 'day use only' until cleaned and/or repainted.

Report ID: 8904169X

Report No: 188 Year: 1990 Incident Type: MORAircraft Type: Bell 212 Flight Phase: ApproachOperating Area: UKCS Region: Southern North SeaHelideck ID: Not Known Incident Date: 25 October 1990

Caused By: Approach/Landing difficulties due to helideck lighting and marking variations.Problem are differences in brightness of lights, marking colour & size,reflections, missing lights, guano obscured markings .

Failure Category: Installation MaintPrimary Cause: Defective Maint Secondary Cause: Other

Comments: CAA helideck lighting review carried out and proposals made to enhance andstandardise deck illumination. Revised CAP437 will include new helidecklighting recommendations. Request for a HSE Safety Notice.

Report ID: 9004835X

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Report No: 190 Year: 1995 Incident Type: MORAircraft Type: Sikorsky S 76 Flight Phase: LandingOperating Area: UKCS Region: Not KnownHelideck ID: Not Known Incident Date: 14 September 1995

Caused By: Offshore platform helideck markings, incl: prohibited landing sector, totallyobscured by bird droppings.

Failure Category: Installation MaintPrimary Cause: Defective Maint Secondary Cause: N/A

Comments: Operator has installed mock 'eagle owls' in an attempt to deter birds. Deckcleaning & painting program planned for Nov 95. Night Ops prohibited untilcomplete.

Report ID: 9504220B

Report No: 175 Year: 1996 Incident Type: MORAircraft Type: Sikorsky S 76 Flight Phase: LandingOperating Area: UKCS Region: Southern North SeaHelideck ID: Not Known Incident Date: 25 November 1996

Caused By: A/C landed on wrong rig. 2 shuttles req'd to ferry all personnel from mannedplatform to NNMI. On 2nd flight A/C entered heavy rain and inadvertentlylanded on a sister satellite 1.5 miles from destination.

Failure Category: A/C OpsPrimary Cause: Pilot Error Secondary Cause: Weather

Comments: Heavy rain reduced visibility and increased cockpit workload. After landingand rain ceased crew realised they were on wrong platform. Deck markingson both platforms partially obscured by guano. Action taken.

Report ID: 9605438G

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APPENDIX D

SEA BIRD ORDERS

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SEA BIRD ORDERS

Auks, Guillemots andPuffins

Alcidae

SkimmersRynchopidae

Gulls, Terns and

Noddies

Laridae

SkuasStercorariidae107Lariformes

FrigatebirdsFregatidae

Cormorants and ShagsPhalacrocoracidae

TropicbirdsPhaethontidae

Gannets and BoobiesSulidae

PelicansPelecanidae50Pelecaniformes

AlbatrossesDiomedeidae

Storm PetrelsHydrobatidae

Diving PetrelsPelecanoididae

Petrels, ShearwatersProcellariidae113Procellariiformes

PenguinsSpheniscidae17Sphenisciformes

ExamplesFamiliesNo of SpeciesOrder

Table D.1 Seabird Orders, Species and Examples

Procellariiformes is a large order of pelagic seabirds divided into four families. Theyare found in all oceans of the world. Their mobility has ensured almost unlimitedradiation, although most are found in the Southern Hemisphere, from where theyoriginated. Some birds undergo vast annual migrations, while others spend manyyears at sea before returning to breed. There is increasing evidence that these birds(which have external and tubular nostrils and large olfactory bulbs in the brain) areable to smell their food from a considerable distance. The feed on fish, squid andplankton, with many feeding adaptations for long-distance foraging. Procellariiformesare generally social and colonial breeders. They do not breed in some cases untilthey are seven to 11 years old, they lay one egg which is not replaced if lost. Somespecies can breed only once every two years, but most birds are long-lived (up to 50years for large Albatrosses). At present, 30 species (25%) of this order are classified

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as either Critical, Endangered, or Vulnerable. A further 11 species areNear-threatened.

Pelecaniformes is a diverse and colourful order of mainly large seabirds consisting ofpelicans, gannets and boobies, tropic birds, cormorant and shags, and frigate birds.Cormorants and frigate birds have a semi-permeable plumage; thus, cormorants haveto dry their wings after swimming, whereas frigate birds simply avoid getting wet.Pelecaniformes are believed to be derived from Procellariiformes stock, with theircentre of origin in the Southern Hemisphere. Cormorants show most adaptiveradiation, being of variable size, extending from the Arctic to the seas of the Antarctic.Pelecaniformes food is mainly fish, with some tropical species additionally takingsquid. Most species are social and colonial breeders, using all breeding habitats andextensively using trees and bushes for nesting. Frigate birds do not breed until sevento 11 years old, then breeding once every two years and having low breeding success,but adults live a long time. The remaining families have a shorter adolescence (two tosix years), lay several eggs in a season, but have relatively higher rates of adultmortality. Eleven species (22%) are classified as Critical (one), or Vulnerable (10),with a further five classified as Near-threatened.

Lariformes is a large and diverse order of birds, comprising skuas, gulls, terns andnoddies, skimmers and auks. The skuas are close relatives of the gulls. They breedin the higher latitudes of both hemispheres and migrate towards and/or across theEquator in the non-breeding season. Skuas are colonial breeders and are fiercelyterritorial; two eggs are laid on the ground. Stercorarius skuas are circumpolar in theNorthern Hemisphere, breeding in the Arctic tundra and feeding on lemmings, youngbirds, insects, berries and carrion. No skuas are classified.

The gulls include 50 species of mainly grey, white and black seabirds of varying sizesand weights. They are essentially birds of the Northern Hemisphere which haveinvaded the South, showing much speciation and adaptive radiation. They occupymany breeding habitats, both natural and man-made. Gulls breed colonially, layingseveral eggs, usually on the ground. Sewage works, landfill sites, reservoirs and fishfactories have encouraged gulls inland in winter, to the point of being a nuisance andeven a danger to human and other bird populations. One species is classified asEndangered, four as Vulnerable and two as Near-threatened.

Terns and noddies are smaller and more slender than gulls, with short legs, a forkedtail and webbed feet (although they are not good swimmers). As a group terns aremore marine than gulls and, while some tropical species are sedentary, most arelong-distance migrants. Terns are social and colonial breeders and feed on fish, smallsquid and crustaceans, which they catch by plunging into the sea. Non-tropicalspecies lay two to three eggs. Unlike gull populations, tern numbers are decreasing.

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Three species are classified as Critical (one) and Vulnerable (two), and two are nearthreatened.

Auks are small black and white diving seabirds that originated in the north Pacific.The conflicting requirements of diving and flying have necessitated a compromise inits wing size; long distance foraging is sacrificed for an almost exclusive occupation ofthe diving niche. One or two eggs are laid by the Auk, and it can breed when two tothree years old. World-wide Auk numbers are now declining. One species isclassified as Vulnerable and three are Near-threatened.

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APPENDIX E

SEA BIRD SPECIES AROUND UKCS

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SEA BIRD SPECIES AROUND UKCS

Bird Species Potentially to be Observed on Platforms in the UKCS. Brief details ofeach of these bird species, in terms of breeding, habitat and migratory habits are givenbelow.

270640Little GullminutusLarus

4001060Mediterranean GullmelanocephalusLarus

3801040Black-headed GullridibundusLarus

5601400Lesser Black-backed GullfuscusLarus

6001500Yellow-legged GullmichahellisLarus

6101470Herring GullargenteusLarus

6101400Iceland GullglaucoidesLarus

7101580Glaucus GullhyperboreusLarus

7501600Great Black-backed GullmarinusLarus

4501240Ring-billed GulldelawarensisLarus

4301200Common GullcanusLarus

5401110Long-tailed SkualongicaudusStercorarius

4501170Arctic SkuaparasicitusStercorarius

5801500Great SkuaskuaCatharacta

720970European ShagaristotelisPhalacrocorax

9001400Great CormorantcarboPhalacrocorax

9301720Northern GannetbassanusMorus

200460Leach's Storm PetrelleucorhoaOceanodroma

150370British Storm PetrelpelagicusHydrobates

340820Manx ShearwaterpuffinusPuffinus

355870Yelkouan ShearwateryelkouanPuffinus

4701090Great ShearwatergravisPuffinus

4601130Cory's ShearwaterdiomedeaCalonectris

4801070Northern FulmarglacialisFulmaris

LENGTH (mm)WINGSPAN

(mm)

COMMON NAMESPECIESGENUS

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320550Atlantic PuffinarcticaFratercula

430640RazorbilltordaAlca

330580Black GuillemotgrylleCepphus

450760Brunnich's GuillemotlomviaUria

420710GuillemotaalgeUria

220320Little AukalleAlle

230660Black TernnigerChlidonias

230520Little TernalbifronsSterna

360800Arctic TernparadisaeaSterna

360800Common TernhirundoSterna

400920Sandwich TernsandvicensisSterna

390780Roseate TerndougalliiSterna

410910Black-legged KittiwaketridactylaRissa

4301100Ivory GulleburneaPagophila

LENGTH (mm)WINGSPAN

(mm)

COMMON NAMESPECIESGENUS

Northern FulmarBreeds in the Atlantic from the Canadian arctic to Britain and France. Typically nestson coastal cliff ledges, but also locally on cliffs and rock faces several kilometresinland. Winters south to Japan and Baja California.

Cory’s ShearwaterBreeds north Atlantic. Transequatorial migrant to south Atlantic and Indian Oceans.In Southern Hemisphere between November and May.

Great ShearwaterAlmost exclusively Atlantic and Indian oceans. Ranges over south Atlantic and southwest Indian Ocean in breeding season (September - May). Dispersal to north AtlanticOcean in May - November.

Yelkouan ShearwaterBreeds France and eastern Algeria eastwards to Aegean Sea and Turkey, Italy formerYugoslavia and Greece. Disperses westwards into Atlantic Ocean, moving generallynorth to Scotland and Scandinavia.

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Manx ShearwaterAtlantic Ocean. Breeds Iceland, France, Wales, England, Faeroes, Ireland andScotland. rare in breeding range (November - January), nests underground.Dispersal southwards in July, returns March; breeding season April to September.Reaches sexual maturity at 5 - 6 years; lays one brood per season (one egg);incubation 47 - 55 days; fledgling period 62 - 76 days. Migratory, pairs for life. Eats:fish, squid and crustaceans. Life span 15 - 30 years.

British Storm PetrelNorth Atlantic. Breeds, April to September, Norway, Faeroes, Iceland, British Isles.Dispersal southwards to seas off Namibia and South Africa.

Leach’s Storm PetrelNorth Pacific and Atlantic Oceans. In Atlantic, breeds Faeroes, Norway and Ireland.Dispersal southwards to tropical and non-tropical waters in non-breeding season.

Northern GannetNorth Atlantic. Breeds colonially Iceland, Faeroes, Norway, British Isles, ChannelIslands and North West France. 60% of breeding pairs in British waters. Dispersalsouth in Winter.

Great CormorantWidely distributed from Scandinavia to British Isles, Iceland and Greenland. Generallyresident. Breeds in colonies at the coast or inland, but generally solitary outside ofthis. Reaches sexual maturity 4 - 5 years; lays 3 - 4 eggs in one brood per breedingseason (March to June); incubation 28 - 31 days; fledgling period 50 days. Eats fish,perching between feeding dives. Life span around 20 years.

European ShagBreeds Iceland, Faeroes and British Isles. Some southwards dispersal from northernareas by young birds.

Great SkuaNorth Atlantic. Breeds loosely colonially Iceland, Scotland, Spitsbergen, Finnmark,Faeroes and Orkney. Disperses south to Mediterranean, north west Africa and eastcoast of USA.

Arctic SkuaCircumpolar in the Arctic from 57o to 80o N. Breeds Aleutians and Scotland.Disperses southwards in winter to pelagic habitat off South America, South Africa andAustralasia.

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Long-tailed SkuaCircumpolar in high Arctic. Breeds further inland than Arctic Skua. Dispersalsouthwards to winter at sea, mainly in Atlantic and Pacific Oceans.

Common GullAlmost circumpolar in Northern Hemisphere. Breeds, usually colonially, near sea andinland in Iceland, north west and central Europe. Dispersal southwards in winter as faras California, north Africa, Persian Gulf, Japan and Taiwan.

Ring-billed GullNorth America. Breeds colonially on islands in freshwater lakes and in meadows.Now recorded annually western Europe, especially Britain and Ireland.

Great Black-backed GullBreeds solitarily or loosely colonially on islands, sand dunes and buildings southernGreenland, Iceland, Faeroes, coastal Europe and Spitsbergen. Winter dispersalsouth, reaching Morroco.

Glaucus GullCircumpolar in Northern Hemisphere. Breeds colonially or solitarily on cliffs andoffshore islands Greenland, Iceland and Spitsbergen. variable dispersal southwardsfrom the ice edge to north west Europe.

Iceland GullNorth Atlantic. Breeds colonially or solitarily on cliffs and offshore islands. Dispersalsouthwards of northern populations, with young birds moving further than adults.Breeds Greenland, some birds resident, but most winter southwards mainly to Icelandand Faeroes, with some reaching north and north west Europe.

Herring GullAlmost circumpolar in northern Hemisphere. Breeds usually colonially in a widevariety of habitats in North America, Europe and north east Asia. Most northernpopulations disperse south in winter, reaching Central America, Iberian peninsula andthe South China sea. Reaches sexual maturity 3 - 7 years; lays 2 - 3 eggs in onebrood per breeding season; incubation 28 - 30 days; fledgling period 35 - 40 days.Sociable, mates for life. Eats fish, shellfish, birds, eggs, chicks, small mammals andedible refuse. Life span over 30 years.

Yellow-legged GullBreeds colonially on islands, beaches, cliffs and occasionally roofs in southernEurope, Mediterranean, western France and Morocco. Disperses north after breeding,regularly reaching North Sea (Britain and English Channel), while some nominatewinter in southern North sea.

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Lesser Black-backed GullBreeds colonially on vegetated sea coasts, cliffs, islands and roofs in the north eastAtlantic from Scandinavia to Spain. Disperses south in winter to western Europe, westAfrica and occasionally southern Africa.

Black-headed GullBreeds colonially mainly inland on freshwater lakes and marshes, moors, sand dunesand beaches in southern Greenland, Iceland and most of Europe. Dispersalsouthwards especially of northern populations wintering west and east Africa(occasionally South Africa), Red Sea and Persian Gulf, India and Indo-China.

Mediterranean GullBreeds colonially in coastal lagoons and salt marshes, steppe lakes and marshes ofthe Black Sea and Aegean, with fewer westwards throughout Mediterranean Europe toSpain and north to southern England and northern Germany.

Little GullBreeds generally colonially mainly inland at freshwater lakes and marshes,occasionally on coastal lagoons in western and central Europe. Dispersal southwardsto winter coastally.

Ivory GullAlmost circumpolar in High Arctic. Breeds usually colonially on sea and inland cliffsand ice fields in Greenland, Spitsbergen. Dispersal southwards usually only to iceedge, occasionally north west Europe.

Black-legged KittiwakeBreeds in large, sometimes huge, colonies, often with Auks, usually on narrow cliffledges in Greenland, west and northern Europe. Dispersal southwards to winterpelagically in north Atlantic and north Pacific.

Roseate TernBreeds colonially, sometimes very densely, on sand, rock or coral islands with orwithout vegetation north west Europe. Northern populations disperse south in winterwest African coast.

Sandwich TernBreeds in dense colonies on low-lying, unvegetated sand mud and gravel in Europeeast to the Caspian Sea. General post-breeding dispersal south to South America,Africa and northern Indian Ocean.

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Common TernWidespread. Breeds colonially and solitarily both coastally and inland on sandybeaches and dunes, islands in lakes and estuaries and artificial rafts in Europe.Disperses to Southern Hemisphere, mostly to west and South Africa. Most first-winterbirds remain in Southern Hemisphere throughout their first summer. Reaches sexualmaturity 2 - 4 years; lays 1 - 3 eggs in one brood per breeding season (May toAugust); incubation 21 - 22 days; fledgling period 22 - 28 days. Eats fish, shrimps andcrabs. Life span up to 25 years.

Arctic TernCircumpolar in arctic and sub arctic regions. Breeds colonially on shingle beaches,tundra, islands in lakes and artificial structures in Greenland, Iceland and Europesouth to France. Long range dispersal south to Antarctic pack ice, usually welloffshore.

Little TernBreeds colonially on beaches, islands and salt marshes in Europe. Northernpopulations disperse southwards.

Black TernNorthern Hemisphere. Breeds colonially on well-vegetated inland lakes, marshes andpeat bogs in Europe from southern Scandinavia to Spain and eastwards acrossEurope and Asia to the Chinese border. Dispersal south to winter at sea on bothcoasts of South American and west Africa. Reaches sexual maturity 2 - 4 years; lays2 - 4 eggs in one brood per breeding season (Spring); incubation 21 - 22 days;fledgling period 19 - 25 days. Eats aquatic insects and larvae, and other small aquaticanimals. Life span up to 17 years.

Little AukHigh Arctic, probably circumpolar in summer. Breeds in huge colonies on screeslopes of coastal cliffs Greenland, Iceland, Spitsbergen, Bear Island, Franz JosefLand, Novaya Zemlya, Severnaya, Zemlya to the Bering Sea. Some birds winterwithin breeding range, most disperse southwards. Lays 1 egg in one brood perbreeding season (late May to August); incubation 24 - 30 days; fledgling period 26 - 30days. Eats plankton, marine worms, molluscs, fish fry.

GuillemotNorth Atlantic and North Pacific. Breeds highly colonially on ledges of steep cliffs andlow flat islands in the Atlantic from eastern North America and Greenland, acrossnorthern Europe to Novaya Zemlya, and south discontinuously and sparsely to theIberian peninsula. Dispersal southwards to the western Mediterranean.

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Brunnich’s GuillemotNorth Atlantic and North Pacific. Breeds highly colonially on ledges of sea cliffs andislands from Greenland and eastwards around the Arctic ocean at many localities toCape Perry in the Amundsen Gulf. Disperses to winter offshore mainly in low-arcticwaters.

Black GuillemotCircumpolar in the Northern Hemisphere. Breeds loosely colonially or solitarily incliffs, scree slopes, and boulder fields Greenland, Iceland, Faeroes, British Isles andScandinavia. Generally sedentary although northern populations move to find ice-freewaters.

RazorbillNorth Atlantic Ocean. Breeds loosely colonially on steep mainland cliffs and rockyoffshore islands in western Greenland and Iceland, Faeroes, British Isles, ChannelIslands, north west France, Denmark, Baltic Sea and Norway. Dispersal southwardsto Iberian peninsula, north west Morocco and western Mediterranean. Reachessexual maturity 3 - 5 years; lays 1 egg in one brood per breeding season (May);incubation 35 days; fledgling period 10 - 18 days. Eats fish.

Atlantic PuffinBreeds highly colonially, mostly in burrows on grassy maritime slopes and sea cliffs,also in boulder field sand scree slopes in Greenland, Iceland, Faeroes, Spitsbergen,Bear Island and Novaya Zemlya and north west Russia, coastally through Norway,Sweden, British Isles, Ireland to the Channel Islands and north west France.Dispersal to sea in winter south to New Jersey, Azores, Canaries, Morocco andwestern Mediterranean. Reaches sexual maturity 4 - 5 years; lays 1 egg per brood inbreeding season (March to April); incubation 39 days; fledgling period 34 - 44 days.Eats sand eels in summer, whitebait or larval fish of many species.

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APPENDIX F

PHOTOGRAPHS OF TOTAL OIL MARINE MCP-01 WATER SPRAY SYSTEM

(Courtesy of Total Oil Marine plc)

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PHOTOGRAPHS OF TOTAL OIL MARINE MCP-01 WATER SPRAYSYSTEM(Courtesy of Total Oil Marine plc)

Figure F.1 - Sprinkler HeadFigure F.2 - Washdown System ConnectionFigure F.3 - Conventional Helideck CleaningFigure F.4 - Installation of Sprinkler HeadsFigure F.5 & F.6 - Sprinklers in Action

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Figure F.1 Sprinkler Head

Figure F.2 Washdown System Connection

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Figure F.3 Conventional Helideck Cleaning

Figure F.4 Installation of 'Sprinkler Heads'

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Figure F.5 Sprinklers in Action

104

Figure F.6 Sprinklers in Action

105

APPENDIX G

EXAMPLE OF BRISTOW HELICOPTERS LTD, NUI HELIDECKCONDITION WEEKLY REPORT

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OWNER LOCATION DATE DUE Reporter Net Scarer HELIDECK CONDITION COMMENTSARCO PICKERILL A 13-Oct MH Y 1 2 3 4 5 6 7 8 9 10ARCO PICKERILL B 21-Aug MH Y 1 2 3 4 5 6 7 8 9 10ARCO TRENT 30-Sep CH Y 1 2 3 4 5 6 7 8 9 10ARCO TYNE 23-aug- DP Y 1 2 3 4 5 6 7 8 9 10ARCO WELLAND 30-Sep DC Y 1 2 3 4 5 6 7 8 9 10ARCO WAVENEY 17-Oct MB Y 1 2 3 4 5 6 7 8 9 10

MOBIL CAMELOT A 4-Oct CH Y 1 2 3 4 5 6 7 8 9 10MOBIL CAMELOT B 7-Aug JS N 1 2 3 4 5 6 7 8 9 10 1 CleanAMOCO BESSEMER 30-Sep AB Y 1 2 3 4 5 6 7 8 9 10 2 Small Isolated Bird DroppingsAMOCO DAVY 30-Sep HM Y 1 2 3 4 5 6 7 8 9 10 No Night Ops 3 Noticeable, but not OperationallyAMOCO Inde 23D 13-Oct PW Y 1 2 3 4 5 6 7 8 9 10 Significant Bird Droppings.AMOCO Leman 27B 27-Aug PC 1 2 3 4 5 6 7 8 9 10 4 Markings Beginning to be DegradedAMOCO Leman 27C 19-Aug RP N 1 2 3 4 5 6 7 8 9 10 5 Obvious Bird UseageAMOCO Leman 27D 27-Aug PC Y 1 2 3 4 5 6 7 8 9 10 6 Noticeable Degredation of MarkingsAMOCO Leman 27E 4-Oct CH 1 2 3 4 5 6 7 8 9 10 7 Bird Useage Causing AMOCO Leman 27F 30-Sep AB Y 1 2 3 4 5 6 7 8 9 10 Operational ProblemsAMOCO Leman 27G 1-Oct RP 1 2 3 4 5 6 7 8 9 10 8 Substantial Degredation of MarkingsAMOCO Leman 27H 6-Oct AB Y 1 2 3 4 5 6 7 8 9 10 AMOCO-DAY ONLY 9 No Night OperationsAMOCO Leman 27J 19-Aug RP N 1 2 3 4 5 6 7 8 9 10 AMOCO-DAY ONLY 10 Totally Obscured -

Daylight Cleaning Operations ONLYRANGER ANGLIA A 17-Aug RW Y 1 2 3 4 5 6 7 8 9 10

SHELL Leman LEB 24-Sep DC 1 2 3 4 5 6 7 8 9 10SHELL Leman LEC 29-Aug PBL Y 1 2 3 4 5 6 7 8 9 10SHELL Leman LED 16-Sep TS Y 1 2 3 4 5 6 7 8 9 10 NOTES :-SHELL Leman LEE 21-Sep HB Y 1 2 3 4 5 6 7 8 9 10SHELL Leman LEF 14-Sep dc 1 2 3 4 5 6 7 8 9 10 1 Date Due is One Month followingSHELL Leman LEG 14-Sep DC 1 2 3 4 5 6 7 8 9 10 the last Inspection.SHELL Leman LET 3-Sep JS N 1 2 3 4 5 6 7 8 9 10 2 The inspection interval should be

reduced to Two Weeks for all decksSHELL Sean SER 1-Oct AB Y 1 2 3 4 5 6 7 8 9 10 Daylight Ops. only classified as 7 or greater.SHELL Inde INJ 14-Sep DC 1 2 3 4 5 6 7 8 9 10SHELL Inde INK 14-Sep AB Y 1 2 3 4 5 6 7 8 9 10SHELL Inde INL 2-Oct HB y 1 2 3 4 5 6 7 8 9 10SHELL Inde INM 15-Sep AB Y 1 2 3 4 5 6 7 8 9 10SHELL Inde INN 30-Sep HB Y 1 2 3 4 5 6 7 8 9 10

SHELL Barque SPB 4-Oct GC Y 1 2 3 4 5 6 7 8 9 10 Daylight Ops. onlySHELL Barque SPL 4-Oct GC Y 1 2 3 4 5 6 7 8 9 10SHELL Galleon SPN 22-Aug HB 1 2 3 4 5 6 7 8 9 10SHELL Galleon SPG 19-Aug AS 1 2 3 4 5 6 7 8 9 10SHELL Schooner SIS 30-Sep AR N 1 2 3 4 5 6 7 8 9 10 Daylight Ops onlySHELL Ketch SIK 1 2 3 4 5 6 7 8 9 10SHELL Corvette CVT 27-Aug JC N 1 2 3 4 5 6 7 8 9 10

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Printed and published by the Health and Safety ExecutiveC0.35 5/01

OTO 2000/071

£30.00 9 780717 620371

ISBN 0-7176-2037-9