NES 309 Requirements for Gas Turbines Category 2

Requirements for Gas Turbines

Ministry of Defence Defence Standard 02-309

Issue 2 Publication Date 10 October 2002

Category 2

AMENDMENTS ISSUED SINCE PUBLICATION

AMD NO DATE OFISSUE

TEXT AFFECTED SIGNATURE &DATE

Revision Note

This Issue of this Standard has been prepared to incorporate changes to text and presentation.The technical content has been updated in line with current practice.

Historical Record

Def Stan 02-309 Issue 1 1 April 2000NES 309 Issue 3 January 1989NES 309 Issue 2 July 1985NES309 Issue 1 1981

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DEFENCE STANDARD 02309 (NES 309)

REQUIREMENTS FOR GAS TURBINES

ISSUE 2

This Defence Standard is

authorized for use in MOD contracts

by the Defence Procurement Agency and

the Defence Logistics Organisation

Published by:

Defence Procurement Agency,An Executive Agency of The Ministry of Defence,UK Defence Standardization,Kentigern House,65 Brown Street,Glasgow, G2 8EX.

DEF STAN 02309 / ISSUE 2(NES 309)

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SCOPE

1. This Defence Standard specifies the general requirements for, and gives guidance on theprocurement of Gas Turbines for installation in HM Surface Ships as either propulsion primemovers or for use with suitably rated alternators.

2. This Def Stan includes the minimum requirements for the following:

a. Operating conditions and operating environment;

b. Inspection, Quality Assurance and Testing;

c. Guidance material intended to assist the manufacturer or system designer, and to ensurecommon ground between him and all involved in procurement.

3. Gas Turbines and their associated systems shall comply with the requirements of all relevantstandards whether national, international, military or naval.

4. The manufacturer shall describe any hazard that may exist during the operation or maintenanceof the equipment. Precautions necessary to remove the hazard shall be detailed. If a hazard cannotbe completely eliminated the manufacturer shall state the possible consequences to personnel andequipment.

5. This Standard has been written and shall be used taking into account the policy stipulated in JSP430 Ship Safety Management System Handbook. Equipment new to service shall have a fullsafety case developed for it. Equipment repaired, modified and/or currently in-service shallrequire a safety assessment.

FOREWORD

Sponsorship

1. This Defence Standard is sponsored by the Warship Support Agency (WSA), Ministry of Defence(MOD).

2. Any user of this Def Stan either within MOD or in industry may propose an amendment to it.Proposals for amendments that are not directly applicable to a particular contract are to be madeto the publishing authority identified on Page (1), and those directly applicable to a particularcontract are to be dealt with using existing departmental procedures.

3. If it is found to be unsuitable for any particular requirement, MOD is to be informed in writingof the circumstances.

4. No alteration is to be made to this standard except by the issue of an authorized amendment.

5. Unless otherwise stated, reference in this standard to approval, approved, authorized and similarterms means by the MOD in writing.

6. Any significant amendments that may be made to this standard at a later date will be indicated bya vertical sideline. Deletions will be indicated by 000 appearing at the end of the line interval.

7. Extracts from British Standards quoted within this Def Stan have been included with thepermission of the British Standards Institution.

8. This standard specifies substances contained within the Montreal Protocol which are identified ashaving ozone depleting potential. Our aim is to eliminate the use of these substances as soon asa practicable alternative becomes available.


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9. This Def Stan has been reissued because of technical update.

Conditions of Release

General

10. This Def Stan has been devised solely for the use of the MOD, and its contractors in the executionof contracts for the MOD. To the extent permitted by law, the MOD hereby excludes all liabilitywhatsoever and howsoever arising (including but without limitation, liability resulting fromnegligence) for any loss or damage however caused when the standard is used for any otherpurpose.

11. This document is Crown Copyright and the information herein may be subject to Crown or thirdparty rights. It is not to be released, reproduced or published without written permission of theMOD.

12. The Crown reserves the right to amend or modify the contents of this standard without consultingor informing any holder.

MOD Tender or Contract Process

13. This Def Stan is the property of the Crown. Unless otherwise authorized in writing by the MODit must be returned on completion of the contract, or submission of the tender, in connection withwhich it is issued.

14. When this Def Stan is used in connection with a MOD tender or contract, the user is to ensure thathe is in possession of the appropriate version of each document, including related documents,relevant to each particular tender or contract. Enquiries in this connection may be made to theauthority named in the tender or contract.

15. When Defence Standards are incorporated into MOD contracts, users are responsible for theircorrect application and for complying with contractual and any other statutory requirements.Compliance with a Def Stan does not of itself confer immunity from legal obligations.

Categories of Defence Standard

16. The Category of this Def Stan has been determined using the following criteria:

a. Category 1. If not applied may have a Critical affect on the following:

Safety of the vessel, its complement or third parties.

Operational performance of the vessel, its systems or equipment.

b. Category 2. If not applied may have a Significant affect on the following:

Safety of the vessel, its complement or third parties.

Operational performance of the vessel, its systems or equipment.

Through life costs and support.

c. Category 3. If not applied may have a Minor affect on the following:

MOD best practice and fleet commonality.

Corporate Experience and Knowledge.

Current support practice.


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Related Documents

17. In the tender and procurement processes the related documents listed in each section and AnnexA can be obtained as follows:

a. British Standards British Standards Institution,389 Chiswick High Road,London, W4 4AL.

b. Defence Standards Defence Procurement Agency, An Executive Agency of The Ministry of Defence,

UK Defence Standardization,Kentigern House,65 Brown Street,Glasgow, G2 8EX.

c. Other documents Tender or Contract Sponsor to advise.

18. All applications to Ministry Establishments for related documents are to quote the relevant MODInvitation to Tender or Contract number and date, together with the sponsoring Directorate andthe Tender or Contract Sponsor.

19. Prime Contractors are responsible for supplying their subcontractors with relevantdocumentation, including specifications, standards and drawings.

Health and Safety

Warning

20. This Defence Standard may call for the use of processes, substances and/or procedures that maybe injurious to health if adequate precautions are not taken. It refers only to technical suitabilityand in no way absolves either the supplier or the user from statutory obligations relating to healthand safety at any stage of manufacture or use. Where attention is drawn to hazards, those quotedmay not necessarily be exhaustive.

21. This Def Stan has been written, and is to be used, taking into account the policy stipulated inJSP 430 MOD Ship Safety Management System Handbook.

Additional Information

(There is no relevant information included)

DEF STAN 02309/ ISSUE 2(NES 309)

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CONTENTS

Page No

TITLE PAGE 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SCOPE 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

FOREWORD 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Sponsorship 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Conditions of Release 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Categories of Defence Standard 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Related Documents 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Health and Safety 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Additional Information 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CONTENTS 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 1. PERFORMANCE SPECIFICATION 8. . . . . . . . . . . . . . . . . . . 1.1 Safety 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 Gas Turbines 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3 Gas Turbine Performance 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4 Gas Turbine Alternator Performance 10. . . . . . . . . . . . . . . . . . 1.5 Information Required from the Manufacturer 11. . . . . . . . . . . 1.6 Installation 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 1.1 Conditions of Inclination 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.7 Testing 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8 Commercial Support Issues 13. . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 2. NATIONAL/INTERNATIONAL REGULATIONS 13. . . . . . . 2.1 Relevant Standards 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 3. MILITARY STANDARDS/REQUIREMENTS 14. . . . . . . . . . . 3.1 Relevant Standards 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 4. DESIGN REQUIREMENTS GUIDANCE 15. . . . . . . . . . . . . . 4.1 Definitions 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 Design Requirements 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.1 Gas Turbine Installation/Removal 15. . . . . . . . . . . . . . . . . . . . . 4.2.2 Gas Turbine 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.3 Lubricating Oil System 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.4 Gas Turbine Start Systems 17. . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.5 Combustion and Ignition 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.6 Gas Turbine Surge Margin Control 18. . . . . . . . . . . . . . . . . . . . 4.2.7 Special Service Air 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.8 Air Intake Assembly 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.9 Intercooler (where applicable) 19. . . . . . . . . . . . . . . . . . . . . . . . . 4.2.10 Variable Area Nozzle (where applicable) 19. . . . . . . . . . . . . . . . 4.2.11 Recuperator (where applicable) 20. . . . . . . . . . . . . . . . . . . . . . .


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Page No4.2.12 Gas Turbine Enclosure (where fitted) 20. . . . . . . . . . . . . . . . . . . 4.2.13 Output Shaft 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.14 Exhaust Volute/Uptake 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.15 Base Frame 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.16 Free Power Turbine (where applicable) 23. . . . . . . . . . . . . . . . . 4.2.17 On Engine Fuel Control 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.18 Plant Controls 26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.19 Electrical Supplies 28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.20 Instrumentation 28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3 Auxiliaries and System Interfaces 29. . . . . . . . . . . . . . . . . . . . . 4.3.1 Drains 29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3.2 Ventilation 29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3.3 Compressor Cleaning System 30. . . . . . . . . . . . . . . . . . . . . . . . 4.4 Environmental Conditions and Considerations 31. . . . . . . . . 4.4.1 General Requirements 31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4.2 Emissions 31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4.3 Nuclear Biological and Chemical Defence Precautions 31. . . 4.4.4 Material Specification 32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5 Safety 32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5.1 General Requirements 32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5.2 Gas Turbine Trips 33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6 Fire Prevention 34. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.7 Testing and Trials 35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.8 Installation 35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.9 Painting and Preservation 35. . . . . . . . . . . . . . . . . . . . . . . . . . . 4.10 Maintenance Check 35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.11 Support Issues 36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.11.1 Units 36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.11.2 Drawings 36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.11.3 Spares Requirements 36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.12 Integrated Logistic Support 37. . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 5. CORPORATE KNOWLEDGE AND EXPERIENCE 37. . . . . 5.1 Background 37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2 Technical Issues 37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.1 Water Washing Gas Turbines 37. . . . . . . . . . . . . . . . . . . . . . . . . 5.2.2 Antiicing Systems 38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.3 Engine Health Monitoring 38. . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.4 Gas Turbine Start Systems 38. . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.5 Drains 39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.6 Post Installation Risk Reduction 39. . . . . . . . . . . . . . . . . . . . . . . 5.3 Component Issues 39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3.1 Oil Coolers 39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3.2 Bleed Air Systems 39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3.3 Intercoolers 39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3.4 Recuperators 40. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


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Page No5.3.5 Variable Area Nozzle 40. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3.6 Free Power Turbines 40. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3.7 Enclosures 40. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4 Support Issues 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4.1 Removal Routes 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4.2 Modularity 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4.3 Painting 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 Control Systems 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5.1 On Engine Fuel Control Systems 41. . . . . . . . . . . . . . . . . . . . . .

ANNEX A. RELATED DOCUMENTS 43. . . . . . . . . . . . . . . . . . . . . . . . . . .

ANNEX B. ABBREVIATIONS AND DEFINITIONS 47. . . . . . . . . . . . . . .

ANNEX C. PROCUREMENT CHECK LIST 52. . . . . . . . . . . . . . . . . . . . . .

ANNEX D. SHOCK, BLAST AND MOUNTING REQUIREMENTS 55. .

ANNEX E. TESTS AND TRIALS 56. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ANNEX F. CONDITIONAL ASSESSMENT 60. . . . . . . . . . . . . . . . . . . . . .

ANNEX G. INSTALLATION REQUIREMENTS 61. . . . . . . . . . . . . . . . . . .

ANNEX H. PAINTING AND PRESERVATION 64. . . . . . . . . . . . . . . . . . . .

ANNEX I. INFORMATION REQUIRED FROM THE GAS TURBINE MANUFACTURER 66. . . . . . . . . . . . . . . . . . .

ANNEX J. INTEGRATED LOGISTIC SUPPORT 72. . . . . . . . . . . . . . . . .

ALPHABETICAL INDEX 74. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


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1. PERFORMANCE SPECIFICATION

Related Documents: BS MA 100; BS EN 292; BS EN 10204; BS 3135;DEF STAN 00-25; DEF STAN 61-5 Part 4; DEF STAN 91-4; DEF STAN 07220(NES320); DEF STAN 08123 (NES1004); see also Annex A.

1.1 Safety

a . Gas Turbines (GT) shall be designed and manufactured to withstand the loadsassociated with the specified and reasonably foreseeable operating andmaintenance conditions, without endangering the health and safety of exposedpersons.

b . The GT installation shall be designed and manufactured to ensure that there are nocritical speeds within the operating range.

c . Significant hazards associated with GT include:

(1) Blade failure;

(2) Seal failure;

(3) Shaft failure;

(4) Disc burst;

(5) Fuel/oil leaks;

(6) Electric shock from High Energy Ignition systems.

d . Each of the above hazards shall be addressed within the engineering and safetyjustification provided by the manufacturer for the GT.

e . Vibration monitoring shall form an integral part of the GT safety and controlsystem. The vibration monitoring system shall be capable of detecting the out ofbalance of major components and alerting the ships staff in order to allow shuttingdown the GT prior to the occurrence of a critical failure.

f . GT and Power Turbines (PT) shall be designed, manufactured and installed toensure that, so far as practicable, the debris resulting from a rotor blade failure iscontained.

g . In ensuring that the GT is safe for its intended use, the designer/manufacturer shalladhere to the guidance in BS EN 292.

h . Material certification documentation shall comply with the requirements ofBS EN 10204.

1.2 Gas Turbines

a . All GT shall be fully automatic in normal operation. The GT shall be capable ofmanual operation in applications which allow for this type of control.

b . A control position shall be provided, which shall be capable of interfacing with thevessels Platform/Power Management Systems (P/PMS). The control position and


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Man Machine Interface (MMI) shall be ergonomically designed to include theHuman Factors (HF) guidance contained in DEF STAN 00-25. Ideally, the controlposition shall be located as close as possible to the GT.

1.3 Gas Turbine Performance

a . The performance of the GT shall be based on the following conditions:

(1) Standard conditions (BS 3135 no loss) of:

(a ) 1.013 bar (101.3 kPa) pressure at the Intake Flare and Exhaust Volute(or if fitted recuperator) exit;

(b ) Ambient temperature of 15C (288 K);

(c ) Relative Humidity (RH) of 60%;

(2) Fuel to DEF STAN 91-4. The GT shall be required to operate withoutrestriction on NATO F76 Dieso and Marine Gas Oil (MGO) toBS MA 100. The GT should be able to operate using NATO F44 Avcat, anyrestrictions on operation must be stated by the manufacturer;

(3) Fuel shall be supplied to the GT by an external system operating inaccordance with DEF STAN 07220;

(4) No external air bleed.

b . For the conditions given in Clause 1.3 (1) to (3) above, the GT shall achieve theperformance specified in the System Requirements Document (SRD) or othervalues of the following agreed with MOD:

(1) Rated power for continuous use, and stable operation over the specifiedpower output range;

(2) Fuel consumption at specified rated powers, for a given propeller law orconstant speed operating regime;

(3) Stable acceleration to the rated power from standstill, within a specified time;

(4) Stable acceleration and deceleration between idle and full power, withinspecified time constraints.

c . In order to minimise corrosion and restore performance levels, means shall beprovided for the periodic removal of salt deposits and atmospheric contaminantsfrom blading and internal surfaces.

d . The GT is required to operate under the following environmental conditions:

(1) The GT shall be capable of operation in extreme tropical and arcticconditions as defined in DEF STAN 08123;

(2) The GT shall be capable of operation at rated performance under the differentship attitudes, while subject to ship motions as defined inDEF STAN 08123;

(3) The GT, its ancillaries and installation, in any application, shall be capable ofsurviving the shock conditions specified in the SRD whilst remaining fullyoperational. Indicative examples are given at Annex D;


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(4) The GT, associated machinery and enclosure (where fitted) shall withstandair blast pressures that enter the platforms intake/uptake and ventilationsystem. These shall be specified in the SRD. Indicative examples areincluded at Annex D;

(5) The GT shall function, preferably without loss of performance, in an Nuclear,Biological and Chemical (NBC) environment. Any operating restriction ordegradation in performance shall be stated by the GT designer/manufacturer.

e . The GT manufacturer is required to provide a statement that the GT is capable ofoperation under the above environmental conditions.

f . The GT shall be deemed acceptable to the purchaser if measured parameters fallwithin the tolerance bands specified in the SRD. Guaranteed parameters andassociated tolerance bands that may be listed in the SRD include, but are not limitedto, the following:

(1) System boundaries/interfaces of the propulsion module;

(2) Operation in all environmental conditions prescribed;

(3) Rated power at ISO conditions;

(4) Performance against specified Intake duct depression and Exhaust duct backpressure loses:

(a ) Typically GT 500 mm WG and 760 mm WG respectively for simplecycle GT;

(b ) Typically 305 mm WG and 508 mm WG respectively for advancedcycle GT;

(5) Performance over range of speeds;

(6) Performance in all modes of operation;

(7) Noise level of the GT;

(8) GT vibration level;

(9) Emissions standards and control;

(10) Interference with other systems.

g . Mean Time Between Failure (MTBF) (or maintenance free operating period) andMean Time To Repair (MTTR).

1.4 Gas Turbine Alternator Performance

a . In addition to the requirements of Clause 1.3, a Gas Turbine Alternator (GTA):

(1) Must provide the quality of electrical power supplies required byDEF STAN 61-5 Part 4;

(2) Ideally, the periodic removal of salt deposits and atmospheric contaminantsfrom the blading and internal surfaces of a GTA should be possible whilst it


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remains on-load, connected to and supplying the platform power system.The manufacturer must state any operational restrictions or impact onauthorised component life, if any, that may result.

1.5 Information Required from the Manufacturer

a . To enable the MOD to make an objective evaluation of available GT, themanufacturer is required to supply an engineering description of the GT, whichshould be sufficient to allow the MOD to assess:

(1) The mechanical integrity of the GT (including the Power Turbine (PT));

(2) Intake filtration, intake and exhaust ducting configuration requirements andconstraints;

(3) Enclosure configuration (where appropriate);

(4) Fuel, lubricating and starting systems;

(5) Control alarm and monitoring systems;

(6) All other critical systems.

b . Guidance on the level of documentation that may be specified to fulfil therequirements of Clause 1.5a is provided at Annex I.

c . Where the GT has already proved satisfactory in service, with a number ofapplications, a reduced level of design, manufacture, and trials information may beacceptable to the MOD.

1.6 Installation

a . The GT and associated machinery shall be supplied on a base frame and may beconsidered one unit for alignment and lifting purposes. If designed as the primemover for an alternator, that too may be included on the base frame. Where the GTmanufacturer identifies an advantage to supply the associated machinery on anadditional base frame such a proposal may be assessed by the MOD.

b . The GT manufacturer shall specify the external mounting arrangements for allcomponents of the GT system. All ships service and control system interfacesshall be specified. These shall be identified with reference to the terminal points assupplied by the GT manufacturer.

c . GT shall operate satisfactorily under the conditions of inclination as shown in Table1.1.


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Engineering Installationsd E i t

Angle of inclination, degrees (see Note 1)and Equipment Athwartship Fore-and-Aft

Static(Heel)

Dynamic(Roll)

Static (Trim) Dynamic(Roll)

Main and auxiliarymachinery essential to thepropulsion and safety of theship including essentialelectrical equipment.

15 22.5 5(see Note 2)

7.5

Emergency machinery andequipment includingelectrical equipment.Switchgear, electrical andelectronic appliances (seeNote 3) and remote controlsystems.

22.5(see

Note 4)

22.5 10 10

NOTE: 1. Athwartships and fore-and-aft inclination may occursimultaneously.

2. Where the length of the ship exceeds 100 m,, the fore-and-aft staticangle of inclination may be taken as 500/L degrees where L = lengthof ship, in meters.

3. Up to an angle of inclination of 45 degrees no undesired switchingoperations or operational changes may occur.

4. A static damaged condition up to a maximum of 30 degrees may berequired by the Naval Authority.

Table 1.1 Conditions of Inclination

d . GT shall be capable of achieving the performance specified in the SRD irrespectiveof the installed orientation (longitudinally or athwartships).

e . Where surfaces of the GT, PT or Exhaust Volute exceed a temperature of 220Cduring operation (or any lower value stated in the SRD), they are to suitablyinsulated and clad to minimise the risk of fire and prevent damage or injury by heatto adjacent components or personnel.

1.7 Testing

a . The GT manufacturers proposals for testing the GT shall be submitted forconsideration and shall include:

(1) Details of rotor balancing techniques;

(2) Methods of determining the integrity of pressure casings;

(3) Heat exchanger trials;

(4) The intended method of demonstration where components have a specifiedlife in terms of operating time or operating cycles.


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b . The SRD for the platform propulsion system will detail or make reference to theintended usage, and therefore define the required operation of the GT in-service.

1.8 Commercial Support Issues

a . In addition to the technical performance of the GT there are commercial issuesinvolved in the acquisition, operation and support of such equipment. The GTmanufacturer should, therefore, make proposals with respect to such subjects as:

(1) Through-life contractual repair (Contractor Logistic Support);

(2) Independent oversight of manufacture/repair;

(3) Warranty and performance guarantees;

(4) Duration of spares availability;

(5) Transfer of intellectual property rights;

(6) Any Type Approvals by Classification Societies.

2. NATIONAL/INTERNATIONAL REGULATIONS

Related Documents: IMO Regulations; BS ISO 11042; BS ISO 11342; BS EN 61032;BS EN ISO 9001/2000; BS EN 953; BS EN 10204; BS EN 60529; BS 4278; BS 6861; seealso Annex A.

2.1 Relevant Standards

a . The design, manufacture and servicing (where specified in the SRD) of any GT orGTA is to conducted in accordance with BS EN ISO 9001/2000 Model for QualityAssurance in Design, Development, Production, Installation and Servicing.

b . The GT manufacturer shall ensure that all suppliers are accredited toBS EN ISO 9001/2000 or shall demonstrate that the quality processes, practicesand procedures in place are equal to or exceed those required byBS EN ISO 9001/2000.

c . Emissions to atmosphere as a result of the products of combustion shall complywith the standards demanded by IMO Regulations (covering Emissions fromVessels) and BS ISO 11042 (covering Exhaust Gas and Emissions).

d . Enclosures, where fitted, shall offer protection as specified in BS EN 60529 and BSEN 61032.

e . Guards shall be designed and constructed to the standards specified inBS EN 953.

f . Rotating assemblies shall be dynamically balanced in accordance with BS 6861and BS ISO 11342, or equivalent company specification.

g . Eyebolts for lifting purposes shall conform to BS 4278.

h . Where appropriate, certification inspection documentation shall be to therequirements of BS EN 10204.


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3. MILITARY STANDARDS/REQUIREMENTS

Related Documents: for a full list of related documents see Annex A.

3.1 Relevant Standards

a . Noise tests shall be as specified in the SRD.

b . Vibration tests shall conform to DEF STAN 07256.

c . Vibration and shock mountings shall conform to DEF STAN 08120, BR 3021, BR8470, BR 8471, BR 8742 and BR 8743.

d . Noise attenuation shall be achieved using the guidance contained in DEF STAN08118, DEF STAN 07254.

e . All labels shall be in accordance with DEF STAN 02723.

f . Safety marking colour coding shall conform to DEF STAN 05-34.

g . The electrical system, terminals and labels shall conform to DEF STAN 08107and DEF STAN 02502, observing the safety requirements of DEF STAN 218.

h . Electrotechnical equipment shall confirm to the requirements for materials andfinishes given in DEF STAN 07224.

i . Limited Fire Hazard (LFH) cables and wiring shall be used as applicable inaccordance with BR 2170(1), BR 2000(52), DEF STAN 02512Pt3 and DEFSTAN 61-12 Part 31.

j . The SRD shall include a requirement that where any oils or greases are used orrequired for any purpose they are, wherever possible, to be specified from thoselisted in DEF STAN 01-5. If this is not possible it is to be brought to the attention ofthe Principle Contract Officer (PCO) and/or the Design Authority, as applicable,for resolution.

k . Lubricating Oil Systems shall comply with the requirements of DEF STAN 02303

l . Packaging shall conform to DEF STAN 02724.

m . Environmental conditions are detailed in DEF STAN 08123.

n . GTA performance in response to electrical load changes and the overall quality ofelectrical supplies shall conform to DEF STAN 02607, DEF STAN 08142, DEFSTAN 07243 and DEF STAN 61-5 Part 4, unless otherwise stated in the SRD.

o . Requirements for removal routes are given in DEF STAN 02302 AND DEFSTAN 08103.

p . External fuel systems shall comply with DEF STAN 07220.

q . Intakes and Uptakes shall comply with the requirements of DEF STAN 07218.


15

4. DESIGN REQUIREMENTS/GUIDANCE

Related Documents: for a full list of related documents see Annex A.

4.1 Definitions

a . Enclosure: When required by and specified in the SRD an enclosure can, whereappropriate, form an acoustic and fire containment barrier around the GT. It mayadditionally be required to provide protection to personnel against NuclearBiological and Chemical (NBC) warfare agents and withstand stated shock and airblast overpressure levels.

b . Gas Turbine Change Unit (GTCU): If the replacement philosophy of the GT isremoval of the complete or almost complete unit, this is termed the GTCU, orwhere more accurate the Gas Generator assembly (GG).

c . Module or Maintenance Assembly Change Unit (MACU): When the replacementphilosophy is based on breaking down the GT into smaller component groups forexchange, these are termed MACU.

4.2 Design Requirements

4.2.1 Gas Turbine Installation/Removal

a . The GT, GTCU/GG and or its constituent MACU shall be designed so that they canbe manoeuvred into or out of the ship without damage, oil seepage or fuel spillagevia the planned removal route. Requirements for removal routes shall comply withClause 3.1o.

b . Any component of the GT, which is designated as a lifed component by themanufacturer and designed for Upkeep by Exchange shall be capable ofreplacement without removal of the GT. The time(s) to replace such item(s) shallbe stated by the GT manufacturer. The maximum time(s) to replace such item(s) atsea shall be specified in the SRD.

c . All pipes and mating connections shall have a suitable standard of identificationand, where necessary, shall be provided with blanks. Flexible pipes connected tothe GG shall be so configured that they can be easily disconnected (with minimumspillage) and safely stowed.

4.2.2 Gas Turbine

a . Vibration pickups shall be provided on the GG casings for use with vibrationmonitoring equipment. The siting and type of vibration pick-up should allow bestdetection characteristics of failures or deterioration of critical components. Thecontractor should specify these components.

b . Inspection facilities shall be provided to enable internal viewing of the GTCU. Thecomponents to be viewed should be those deemed critical, by sound engineeringjudgement, and where visual inspection can aid the assessment of componentdeterioration. The contractor should specify these components.

4.2.3 Lubricating Oil System

a . The GT shall be supplied with its own lubricating system to provide lubrication andcooling to its own and the engine driven auxiliary bearings and gearing. The


16

Lubricating Oil (LO) system shall supply de-aerated oil at appropriatetemperatures, pressures and quantities for all GT powers under all specifiedconditions.

b . In GTA applications, consideration, where appropriate, shall be given to theutilisation of a combined GT and GG lubrication system.

c . Where justified by the manufacturer, LO may be utilised for hydraulic actuation ofGT systems.

d . The type of LO is to be specified by the GT manufacturer and shall comply with therequirements of Clause 3.1j.

e . LO systems shall include pressure and scavenge pumps, as deems necessary by themanufacturer, and must include all requisite filtering arrangements, LO tanks andLO coolers. Separately mounted LO modules may be used. LO systems shallcomply with the requirements of Clause 3.1k.

f . All LO filters shall be readily accessible for ease of examination and replacement.

g . Where it is possible that the GG may be caused to rotate, under shut downconditions (known as windmilling), the design shall prevent excessive oil leakagewithin or outside the engine. Any restrictions on the allowable period ofwindmilling must be stated by the GT manufacturer.

h . LO tanks shall be manufactured from corrosion resistant materials, which includethe following fittings:

(1) Lockable drain cock which is easily visible;

(2) Vent, connected with atmosphere;

(3) Dipstick or Sight Glass and level transmitter;

(4) Air/oil separator;

(5) Filling funnel with lockable/securable lid.

i . All fittings, in particular those not contained within an enclosure, shall beadequately protected from misuse and insulated to prevent injury to personnel.

j . LO tanks shall have sufficient capacity to permit 200 hours engine operationwithout need to inspect or top up levels, or 30 seconds supply for maximum oilpumps delivery, whichever is greater.

k . Inspection of oil level and topping up shall be possible during normal engineoperation.

l . Means shall be provided to detect failures in discrete parts of the equipment. Asuitable Condition Based Monitoring System shall be proposed by themanufacturer. The position of detectors/sensors should be designated by themanufacturer to allow ease of access and to give the best possibleindication/detection of performance/deterioration within the equipment. Thefunctionality to determine the location of the performance/degradation within theGT would be an advantage.


17

m . Where required, oil cooler(s) shall be selected with sufficient heat transfercapability to cool full oil flow to 70C (343) in 35C (308) sea temperature.If required, they shall be fitted with an approved design of temperature controller toadjust cooled oil flow to maintain a mean oil outlet temperature of 70C (343) atsea temperatures from 35C (308) to 2C (271) and ambient airtemperature of up to maximum tropical conditions as defined in DEF STAN08123.

n . If sea water cooling is employed, the cooler(s) shall be suitable for a workingpressure of up to 10.3 bar (1030 kPa) on the sea water side and shall be capable ofpassing a sea water flow of 1.6 times the nominal design value without exceeding atube water speed of 3 metres/second or a pressure drop of 1500 mm WG (14.4 kPa).A sea water cooled fresh water cooling system should be used wherever possible.

o . To ensure water flows through coolers in the correct direction, water inlets andoutlets to coolers shall not be interchangeable.

p . Where a separate Power Turbine (PT) LO system is used, conditions of oil pressureand filtration quality shall be specified by the PT manufacturer, including shortterm minimum values (10 second duration) and necessary sampling pressures andtemperatures.

q . An air and oil separator shall be provided where required.

r . All leads for temperature and pressure sensing elements shall terminate in ajunction box sited externally on the GT or enclosure (where fitted). Each lead shallbe clearly identified at both ends. Terminals in the junction box shall be clearlyidentified in accordance with DEF STAN 08107.

s . All sensing elements shall be easily accessible for replacement.

t . All thermometers and thermocouples measuring oil temperatures and pressuresensing elements shall be secured as follows:

(1) Inside the enclosure locked;

(2) Outside the enclosure fitted in pocket with pocket welded in position.

4.2.4 Gas Turbine Start Systems

a . The starter system shall be required to:

(1) Start the engine at the minimum level of power provision when the GT LOtemperature is 0C;

(2) Wet motor the engine for the purpose of purging air from the fuel system;

(3) Dry motor the engine for the purposes of purging fuel from the gas path. Thepurge cycle shall be of sufficient duration to displace at least three times thevolume of the exhaust system;

(4) Dry motor the engine for the purposes of compressor (and, where necessary,intercooler) washing.

b . The starter system shall be suitable for at least 12 starts in any two hour period andshall be capable of providing, without replenishment, not less than six consecutivestarts (or three per engine for multi engine installations).


18

c . The start system shall be capable of remote operation where required and thecontrols, incorporating safeguards against maloperation of the equipment, shallcomply with the requirements of Clause 4.5.2.

d . If an engaging/disengaging arrangement is employed, the starter system shallprevent crash re-engagements irrespective of engine spool speed.

e . If fitted, the air starter motor shall be capable of self-containment should any failureoccur, and the starter air should not exhaust directly into the machinery space.

f . A means of measuring starter motor speed shall be provided, if required, by theengine manufacturer.

4.2.5 Combustion and Ignition

a . The selected combustion system shall give stable and efficient combustion over theagreed range of fuel specifications and all operating conditions, without theformation of excess deposits within the engine.

b . Each combustion chamber shall have provision for automatic drainage at thelowest possible level and sufficiently adequate to avoid accumulation of fuel duringstarting and when stopped.

c . If the proposed ignition system is of the High-Energy type, the manufacturer shallclearly identify the number of igniters required by the system to achieve thespecified start reliability. The engine manufacturer shall also ensure that adequatesafeguards are taken for the protection of personnel and relevant equipment.

d . The frequency of examination, cleaning or replacement of any component in thecombustion system shall not be greater than that stipulated in the SRD.

4.2.6 Gas Turbine Surge Margin Control

a . The manufacturer shall define the operation and parameters for any air bleedsystem required to maintaining appropriate compressor surge margins.

b . The manufacturer shall define the operation and parameters for any variablegeometry system required to maintaining appropriate compressor surge margins.

c . Indication of position and, where necessary control, of bleed valves and variablegeometry systems shall be incorporated into the GT controls.

d . The GT manufacturer shall, where applicable, state the noise levels produced at thebleed pipework interface.

4.2.7 Special Service Air

a . Where specified in the propulsion system SRD, provision is to be made to supplyship services with air bled from the GT compressor(s). In which case conduit shallbe provided between the air bleed manifold(s) and the platform interface. A locallyoperated isolating valve shall be mounted in a safe access position external to theenclosure (where fitted). The PMS shall control the rate of air bleed demand.


19

4.2.8 Air Intake Assembly

a . Depending on the project specific terms of the contract, the air intake may be theresponsibility of the platform provider or system integrator.

b . The design requirements for Intakes and Uptakes shall comply with therequirements of Clause 3.1q.

c . The air intake shall provide a uniform air velocity distribution at the entry to the GTand minimise flow/pressure distortion at the entry to the compressor blading whileminimising the overall pressure loss in order to optimise engine performance. Flowdistortions shall not exceed 10% under any environmental condition or operationalduty.

d . To minimise overall pressure losses, the air intakes shall avoid protuberances suchas ladders, pipes and wiring. Air intakes shall be as straight and as short as possible,avoiding bends and contractions as far as possible.

e . If specified in the SRD, a suitable means of creating the required air flowdistribution at the engine air intake shall be designed and provided by the enginemanufacturer. This could be a cascade bend or a bellmouth intake assembly.

f . The module design shall assume an intake air quality not worse than 0.01 ppm byweight ingested salt content, as specified within in DEF STAN 07218. The airintake may have a screen to protect the equipment from Foreign Object Damage(FOD), which shall prevent significant objects (e.g. > 6 mm) from entering the GT.

g . The design of the assembly may be required to facilitate the fitting of compressorcleaning equipment as defined by the GT manufacturer. Suitable arrangementsshall be made by the manufacturer in the design of the intake system to allow ease ofaccess for maintenance.

h . The connection between the intake assembly and the intake duct is to incorporate aflexible seal arrangement.

4.2.9 Intercooler (where applicable)

a . Should the manufacturer propose a GT solution incorporating an intercooler, themanufacturer shall demonstrate that the possibility of condensation on the air sideof the intercooler has been considered and mitigated.

b . The GT shall be capable of operation with the intercooler, if fitted, bypassed. Theeffect of operation with the intercooler bypassed shall be fully documented andvalidated. The power output/performance of the GT with the intercooler bypassedshall be specified by the manufacturer.

4.2.10 Variable Area Nozzle (where applicable)

a . Variable Area Nozzle (VAN) control shall be integrated with the engine controlsystem.

b . In the event of a VAN control failure, it is preferable that the engine is capable ofrestricted operation with the VAN locked in position. GT performance under thiscondition shall be specified by the manufacturer.


20

4.2.11 Recuperator (where applicable)

a . Should the manufacturer incorporate a recuperator (an exhaust gas heat recoverydevice) into the proposed GT, then the manufacturer shall provide evidence of itssuitability for operation in a warship. Specific reference shall be made by themanufacturer to material selection, method of manufacture, thermal shocktolerance and expansion and corrosion resistance.

b . The normal operating mode should be with the recuperator on-line. If a bypasssystem is fitted, the manufacturer shall state any limitations on poweroutput/performance or GT operation with the recuperator bypassed.

c . Where a recuperator bypass is fitted, the transition times from recuperator on-lineto recuperator bypassed and vice versa shall be stated. Any limitations on thepower output/performance at which this transition can occur shall be specified bythe manufacturer.

d . Adequate and acceptable access shall be provided to allow condition monitoring ofthe recuperator.

4.2.12 Gas Turbine Enclosure (where fitted)

a . Where an enclosure is specified or recommended by the manufacturer, the SRDshall specify the requirements. The manufcaturer should provide a left and/or rightdressed version and state if both versions are suitable for either direction of rotationof the output shaft. The manufacturer should also state if both version are suitablefor nose up or nose down installation.

b . Where more than one entry is specified, the main entry point to the enclosure shallbe situated to allow ease of access to local controls where fitted (for example theymay be arranged on the same side of the enclosure). If the local control panel,where fitted, is not mounted on the GT module but is available for mounting withinthe machinery space, then suitable access should be provided.

c . The enclosure, including access and control panels, shall conform to HumanFactors (HF) constraints as detailed in DEF STAN 00-25. Where a recuperator isfitted, allowance for access shall be made for maintenance of the recuperator andassociated equipment. Where this is proposed to be via removable side panels, orsimilar, the manufacture shall provide a safety justification and, where appropriate,a panel handling system.

d . The enclosure shall be capable of accepting the design forces imposed by thebellows and seal arrangements and those caused by shock, air blast over pressureand thermal expansion. The movement encountered will be in all planes.

e . The air intake sealing arrangement at the interface between the module and intakeducting shall:

(1) Be resistant to cracking by flexing;

(2) Remain operational through the working temperature range of 40C(233K) to 70C (343K).


21

f . The exhaust flexible sealing arrangement at the interface between the module andexhaust ducting shall:

(1) Be resistant to cracking by flexing;

(2) Maintain flexibility whilst at an internal temperature of up to 550C (823K)with an outside temperature of 40C (233K) to 70C (343K).

g . GTCU/MACU removal routes from the enclosure shall be identified in the SRD.Enclosure design should preferably permit either sideways or forward removal ofthe GTCU/MACU (and the free PT, where applicable).

h . The enclosure shall be supplied complete with fittings, including lifting lugs andbrackets, to facilitate GTCU replacement. Lugs shall conform to BS 4278 with aminimum factor of safety of 5.

i . No equipment shall be positioned on, or in, the enclosure in such a way as to hinderor disrupt the GG removal or impair access for maintenance and inspection.

j . The enclosure shall be sized to contain the maintenance envelope of the GT or shallbe so designed to allow ease of access for maintenance of the GT.

k . The enclosure shall include structural characteristics that permit the noiseattenuation requirements of DEF STAN 08118 and DEF STAN 07254 to beachieved.

l . The enclosure shall be gastight and all penetrations of the walls are to be sealed foracoustic and NBCD purposes.

m . Pipework connecting to or from the enclosure shall be in accordance withDEF STAN 02345, and shall be attached to the enclosure in such a way thatsufficient flexibility exists to allow for acceptable movement.

n . Gastight doors shall be designed/provided to withstand blast conditions asspecified in Annex D.

o . The following warning notice in letters of 10 mm minimum height, shall beprovided on the door:

WARNING

NO ENTRY WITHOUT PERMISSION OF SCC.INHIBIT FIRE EXTINGUISHER ON ENTERING AND RESET ONLEAVING.DANGER FROM TOXIC GAS AFTER OPERATION OF FIREEXTINGUISHER.THE VENT FAN MUST BE SHUT DOWN BEFORE OPENING THEDOOR. (for pressurised enclosures)

p . Observation windows shall be provided which:

(1) Allow a view of the accessory gearbox (where relevant);

(2) Allow a view of all associated fuel system components, including the burnermanifold;


22

(3) One window shall be located on the control side of the enclosure adjacent tothe control panel (if fitted).

q . Compressor-washing connections shall (where fitted) be provided on theenclosure.

r . Where appropriate, provision shall be made for access for removable equipmentand instrumentation, such as portable vibration monitoring. Sealing of the accessaperture shall also be provided. Such provision shall allow for the temporarymounting of a sensor within the enclosure with the associated instrumentelectronics and/or readout being situated outside the enclosure.

s . Where the PT is mounted separately from the GTCU, a flexible seal shall beprovided between the acoustic enclosure and PT. This flexible seal shall;

(1) be resistant to cracking by flexing;

(2) be fire resistant to DEF STAN 02345;

(3) maintain flexibility whilst operating over a specified temperature rangewithin the acoustic enclosure;

(4) sustain NBC protection.

4.2.13 Output Shaft

a . The GT manufacturer shall provide the coupling or output shaft to connect the PTto the ships propulsion Main Reduction Gearbox or other driven equipment, e.g. anAlternator. The flange or adaptor to mate with the driven input flange shall bedefined in the SRD.

b . The output shaft characteristics shall be specified for the particular application.Typically the specification should include:

(1) The desired separation between the GT and the driven equipment;

(2) The required torque capability;

(3) The mounting arrangements for the engine and the driven equipment, i.e.rigidly or flexibly mounted, separate or common base(s).

c . Arrangements shall be made to allow for axial and transverse displacementsbetween the GT and the driven equipment during normal operation and toaccommodate the excursion of the engine or driven equipment under shock. Themanufacturer shall provide alignment procedures and tolerances for MODconsideration and approval.

d . Access to the forward flange or coupling shall be provided for inspection anddetailed alignment checks, as appropriate.

e . A coupling shaft cover between the rear face of the engine and the drivenequipment may be required and shall be supplied by the customer. The functions ofthe cover include the provision of:

(1) Personnel protection;


23

(2) A seal for module ventilation air, if relevant;

(3) Access to the output shaft after coupling, if appropriate.

4.2.14 Exhaust Volute/Uptake

a . The exhaust volute shall normally exhaust upwards, but may be inclined either sideof a vertical plane parallel with the engine axis.

b . The requirements for flexible sealing between the exhaust volute and remainder ofexhaust ducting are as stated in Clause 4.2.12f . These should be made ofappropriate heat resistant materials or should be cooled.

c . The build-up of back pressure should be avoided in order to maximise engineperformance. Exhaust duct design shall avoid protuberances such as ladders, pipesand wiring. Uptakes shall be as straight and as short as possible, avoiding bends andcontractions as far as possible.

4.2.15 Base Frame

a . Typically this supports the air intake assembly, GTCU/GG, enclosure (wherefitted), PT assembly, Exhaust Volute, and Recuperator (where applicable) and shallbe sufficiently substantial to allow it, and all mounted assemblies, to be consideredas one unit for alignment and lifting purposes without creating unacceptable strain.In a GTA application, the generator may also require mounting on the same baseframe. This may be detailed in the SRD and, for larger machines, shall require themanufacturer to provide justification of the structural integrity in the event of worstcase failures.

b . The base shall withstand ship hogging or sagging up to a maximum 2000 m radiusof curvature without imposing unacceptable strain on any component mounted onit.

c . The base frame shall be designed to support items of equipment mounted on it,which are subject to the shock accelerations given in Annex D. BR 3021 providesguidance on how this should be achieved.

d . The base frame shall have suitable, support provision for anti-shock/vibrationmountings to meet the requirements of the SRD.

4.2.16 Free Power Turbine (where applicable)

a . When the design incorporates a Free PT, the designer may intend it to be consideredas part of the GT or as a ship fit item. In the first event it is likely that the PTinspection intervals will be similar to those of the hot section(s) of the GG (in whichcase the remainder of this Clause is not applicable). In the later case the PT shouldbe designed to require intensive inspection at not less than the vessels refitperiodicity.

b . In the case of a ship fit PT, the PT may be lubricated by the main gear LO system ifsufficient spare cooling capacity is available.

c . Two overspeed sensors for detecting PT shaft speed, shall be provided.


24

d . The SRD shall state the required direction of rotation of the PT.

e . The PT shall be designed to allow for reverse rotation for a period specified in theSRD. Typically this shall be with the transmission at up to 50% of the design pointastern speed, with the GG running in its normal rotational direction at up to 25% ofthe design point power.

f . PT design shall permit ready access to bearings, couplings and (where fitted) theVAN assembly for inspection, maintenance and replacement where necessary.

g . Vibration pick-ups shall be provided on the PT for use with monitoring equipment.The position and type of sensor should allow best detection characteristics for allpossible failure modes.

h . The PT shall be designed so that the nozzles, rotors, diaphragms and shaft can beremoved from the ship via the planned removal route detailed in the SRD.

4.2.17 On Engine Fuel Control

a . The engine control system shall include a system that regulates the fuel flow in astable and safe manner over the whole operating regime of the GT. The followingfeatures shall be provided:

(1) Capability, following start initiation, to regulate the fuel flow automaticallyso that the engine accelerates to idling speed in a controlled manner;

(2) Control fuel flow in response to a demand signal to give the desired poweroutput whilst operating between idling speed and the limiting controls of theengine;

(3) Control fuel flow following an increase in demand so that the engineaccelerates to provide adequate response without being subject to unduetemperature, stress, or compressor surge;

(4) Control fuel flow following a decrease in demand so that the enginedecelerates to provide the required response without engine flame out;

(5) Control fuel flow to ensure stable steady-state operation at any desired powerlevel within the specified limits;

(6) Control fuel flow so that the engine is maintained within its safe operatingmargins under all ambient temperature conditions. The following limitersshall be provided:

(a) PT speed;

(b) LP Compressor speed (separate to HP Compressor speed whenappropriate);

(c) HP Compressor speed (separate to LP Compressor speed, whenappropriate);

(d) GG Turbine(s) and/or PT entry temperature.

b . Dedicated lockable switch/switches shall be provided to ensure that equipmentcannot be operated when formal hazard control procedures, such as Man Aloft,are in force (DEF STAN 218, DEF STAN 08132 and DEF STAN 00-56 refer.


25

c . For GTA applications, transient and steady state control criteria may be defined bythe required quality of power supplies, as detailed in the SRD.

d . When either manual or automatic trips shut down an engine, the automatic enginecontrol system shall be reset to the shut down condition.

e . The engine control shall be provided with adjustable datums to cater for tolerancein the fuel system equipment preventing the limiters and schedules from beingpreset or to suit the differing operating conditions likely to be encountered inservice.

f . The engine control shall permit satisfactory start to engine idle conditions onminimum throttle setting and shall be consistent to within 3% of fuel flow demandat other settings (if not over-ridden by another control system).

g . Means shall be provided to isolate the fuel from the burner manifold when the GT isshut down. This shall be possible by both local and remote facilities withoutexternal electrical or pneumatic power supplies. It must always be possible torapidly reduce the fuel flow to the GT by means of a the governor in response to anoverspeed or over temperature trip demand.

h . All components in contact with the fuel shall be capable of continuous operationwith only the lubrication provided by the fuel. In the event of the fuel beingcontaminated by sea water, the materials of all components in contact with the fuelshall be resistant to corrosion.

i . The engine control system shall include full flow filtration upstream of the enginedriven pumps. The contractor shall specify the arrangements for the removal,cleaning, venting, priming, draining and replacement of the filter(s), andpermitting these functions to be undertaken without stopping the engine.

j . An inlet filter shall be provided on the inlet side of the enclosure (where fitted).This should, where applicable, consist of a demembraned polyrethane filter12 pores per lineal cm, in two layers, each 13 mm thick. Cross flow ceramic filtersmay be used as an alternative.

k . Flexible pipes shall be provided in the system, where necessary, to absorb relativemovement of all enclosure components and to facilitate GTCU replacement.

l . In the event of failure of electrical power supplies or part of the equipment whichprevent unsafe automatic operation of the engine, the engine control system shall:

(1) For Mechanical Drive applications - keep the engine at its last demandedpower condition until a lower mode of control is applied and controlregained;

(2) For Electrical Drive applications - return the engine to an idle conditionwhere control to maintain operation is lost.

m . When operating under conditions where the automatic control system has failed set(excluding digitally controlled GT):

(1) Where appropriate, facilities are to be provided to allow a manual device tobe engaged which allows the engine power to be increased or decreased in a


26

safe manner. Where the acceleration and deceleration control functions arebypassed, the mechanical movement of the device is to be such that the fuelflow cannot be changed at a rate which would cause an unacceptable engineor transmission loading condition;

(2) At least one PT facility shall be available to shut down the engine shouldexcessive overspeed occur;

(3) If compatible with the control logic, facilities shall be provided to shut downthe engine manually via a mechanical linkage, when further operation is notrequired.

n . Essential control supplies shall be provided with an Uninterruptible Power Supply(UPS) to ensure continued operation in the event of a failure of the platform powersupplies for a minimum period of 30 minutes. If a battery back-up is used it shallfully recharge within 24 hours.

4.2.18 Plant Controls

a . Unless otherwise agreed with MOD, each production engine shall be fitted withcontrol equipment that provides the following functions (additional andcomplementary to those stated in Clause 4.2.17):

(1) Incorporate the control of intercooler, recuperator, VAN, etc., foradvanced/complex cycle GT;

(2) Receives and responds to signals to start, stop or motor and regulates thepower of the GT from remote operating stations;

(3) Collects, conditions and transmits primary surveillance signals to the remoteoperating stations;

(4) Collects, conditions and transmits secondary surveillance signals to theremote operating stations;

(5) Where specified, provides sufficient control and surveillance facilities at theGT local control position to allow:

(a ) Automatic starting and stopping;

(b ) Power regulation within the safe operating envelope of the enginecontrol system;

(c ) Operation of GT wet and dry motoring and system test facilities;

(d ) Observation of engines operating status via analogue or digitalinstruments, alarm, warning and state indications;

(6) Where appropriate, provide control functions at the component control level,to allow direct manual control of fuel flow and engine shut down in the eventof failure of the electrical power supplies or a critical failure of the enginecontrol system (see Clause 4.5.2). Limited self-powered instrumentation isnecessary to allow operation of the equipment in a safe manner.

b . Each GT shall be provided with a Plant Control Unit (PCU) comprising:


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(1) The minimum instrumentation necessary for satisfactory level of control ofthe machinery available under local operating procedures;

(2) All state indication lamps necessary for the correct operation of the availableplant under local operating procedures;

(3) All surveillance indication necessary for the safe operation of the availableplant under local/remote operating procedures.

c . All controls (including switches, push-buttons, etc.) necessary for the operation ofthe module under both local and remote operating conditions shall, whereappropriate, include:

(1) A control authority selection switch for transference of control to either thelocal or remote operating positions;

(2) Means of starting the GT either by manual (switch control) or automaticmeans;

(3) Any control components necessary to operate the various GG and fuel systemcomponents mounted on the enclosure.

d . Depending on the type of fuel control system used, the PCU may be required toaccommodate any associated electronic units comprising:

(1) All equipment required for controlling the fuel flow to the burners over thewhole operating range;

(2) Continuous control and stable handling;

(3) Limiting (engine parameters);

(4) Engine protection (tripping devices).

e . The PCU shall provide for:

(1) Hard wired and/or ether net links for use with a centralised propulsioncontrol and surveillance system;

(2) The required electronic components for a distributed control system.

f . During enclosure design, ergonomic consideration shall be given to the locationand presentation of the controlling levers, etc., where appropriate. No hazard to theoperator or maintainer shall be present in the positioning of these controls.

g . Control, instrumentation and surveillance systems shall be housed in waterproofenclosures to IP67. Panels may be insulated from vibration emanating from theequipment if the GT manufacturer deems it necessary.

h . The PCU and system shall take full consideration of the variations in environmentalconditions (ambient and atmospheric pressure, RH, etc.). The PCU and systemshall ensure that, for any given power demanded, the same power output, within atolerance of 1.5%, shall be achieved, regardless of environmental conditions.

i . Parameters monitored by the PCU and Surveillance System should be thosedeemed appropriate by the GT manufacturer to ensure the safe and efficientoperation of the equipment.


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j . An equipment diagnostics interface shall be provided at the local operatingposition. A Man Machinery Interface (MMI) with full interrogation of the PCUand Control and Surveillance System may be incorporated if consideredappropriate.

k . Facilities for the monitoring of equipment parameter trends may be required. Suchrequirements shall be detailed in the SRD.

l . Push-buttons shall be shrouded to prevent accidental operation.

m . The movement of all rotating controls, switches, levers, handwheels, etc. shall belimited by mechanical stops to avoid damage to the working parts of the operatinggear.

n . All controls shall be positively secured by keys, splines or flats (not grub screws ortaper pins) and located such that it is impossible to replace in a different positionafter removal.

4.2.19 Electrical Supplies

a . The design of electrical supplies shall be in accordance with the following:

(1) DEF STAN 08107;

(2) DEF STAN 02512 Parts 1 and 3;

(3) DEF STAN 07244;

(4) DEF STAN 61-5 Part 4;

(5) DEF STAN 61-12 Parts 1, 11 and 31.

b . The GT manufacturer shall make clear to the contractor or shipbuilder hisrequirements for electrical supplies. The SRD shall define the agreed conclusions.

c . Lighting shall be provided within the enclosure (where fitted) in accordance withDEF STAN 02587 Part 1 and installed to DEF STAN 02502. Lighting levelsshall be sufficient to enable maintenance operations, as designated by the GTmanufacturer, to be carried out.

d . Power sockets shall be provided inside the enclosures (where fitted), in addition toa light switch located outside the module in accordance with DEF STAN 08109 .

e . Enclosures are to be fully screened and are not to produce any electromagneticfield, as required by DEF STAN 08107 and DEF STAN 59-41.

4.2.20 Instrumentation

a . Where fitted, instrumentation consisting of gauges, indicators and switches shall belocated in a group on, or adjacent to, the enclosure (where fitted). Instrumentationassociated with starting, operating and stopping the machinery shall be locatedadjacent to the manual controls and shall be arranged so as to be clearly visible tothe operator when standing at the normal, or On enclosure, control position.Other instruments shall also be grouped and similarly located.


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b . Gauges shall be calibrated in SI units. The requirements for any particularapplication shall be specified in the SRD.

c . Transducers for operating remote gauges shall be easily removable for repair andcalibration checking.

d . For general information relating to instrumentation, see DEF STAN 02599, DEFSTAN 02604, DEF STAN 02626 and DEF STAN 02627.

4.3 Auxiliaries and System Interfaces

4.3.1 Drains

a . The GT drain systems shall ensure that the removal of fluid waste from theequipment is completely safe and environmentally compliant.

b . Drainage arrangements shall be provided in the base of the enclosure to prevent abuild-up of liquids at all installation attitudes. Provision shall be made toaccommodate sealing arrangements to overcome any enclosure differentialpressure (dP) requirements as appropriate.

c . Drains shall be provided at the lowest points of the Exhaust Volute and Air Intake,and other low points as necessary, to prevent any accumulation of liquids in theengine or enclosure (where fitted).

d . If necessary, drains shall be fitted with automatic valves that shut when all liquidshave been removed from the engine. If required, this feature shall be providedeither by the engine manufacturer or the platforms Prime Contractor.

e . Drains shall be led to appropriate tanks. Mixing of different liquids should beavoided.

f . In the event of tank overflow, or on any other occasion, the contents of the draintank(s) shall enter the engine or enclosure. Drain pipework or tanks shall not beopen to atmosphere within the platform.

g . The GT fuel drains shall be led via flexible pipes to terminate at approved positionson the enclosure exterior (where fitted), or where specified.

h . All drains shall be positioned to take account of a Nose Up or Nose Downattitude. Where the installation requires the Inlet Assembly and/or Exhaust Voluteto be off the vertical, special provisions for drainage shall be specified in the SRD.

4.3.2 Ventilation

a . The enclosure (where fitted) shall be ventilated to maintain the safe workingtemperature of all components within the enclosure, to maintain enclosure surfacemetal temperatures below levels hazardous to personnel and to limit enclosure heatrelease to the machinery space in all environmental conditions and during alloperational duties. Such duties will include maximum rated power, rapid engineshut down (i.e. soak conditions) and situations when the PT is driven backwardsduring manoeuvres.

b . The ventilation air may be drawn and filtered directly from machinery spaceatmosphere or alternatively can be drawn from the engine Air Intake system


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utilising a common set of filters for both air systems. The SRD shall indicate anyrequirement/preference. If a forced draught ventilation fan is employed, the engineshould be capable of restricted operation in the event of a fan failure for a perioddefined in the SRD.

c . The enclosure ventilation system (where fitted) shall be designed to exhaust eitherinto the platforms Main Exhaust system by Ventilation Via Volute (VVV) orthrough separate exhaust ducting.

d . If relevant, the supply and exhaust ducts shall be fitted with flaps, which can beoperated manually and which shut automatically on operation of the firefightingsystem to capture the extinguisher charge. The exhaust duct shall be fitted with aflame trap if required.

e . The ventilation system shall be provided with a flexible sealing arrangement thatshall;

(1) be resistant to cracking by flexing;

(2) be fire resistant to DEF STAN 02345;

(3) maintain flexibility whilst operating within a temperature range of 40C(233K) to 70C (343K);

(4) be positioned such that it will not cause corrosion of the GT outer casing.

f . The ventilation system, including ducting, seals, filters and fan (where fitted), shallbe able to withstand the shock and air blast over pressure conditions specified in theSRD.

4.3.3 Compressor Cleaning System

a . Where required by the GT manufacturer to prevent degradation of performance,provision shall be made for cleaning of the engine compressor blading, by liquidsor solids, and for the injection of inhibiting fluid.

b . Since the aim of compressor cleaning is to restore GT/GTA performance whilstmaximising system availability it is desirable to:

(1) Extend the time between washes;

(2) Wash GT on-line (i.e. without shutting down the GT). This is particularlyimportant when considering GTA;

(3) Minimise any power limitations during the wash;

(4) Minimise any effect on GT life related to washing on-line.

c . The compressor cleaning system shall remove all the salt and dirt deposits from thegas path internal surfaces of the compressors and intercooler (where fitted). Itshall, under no circumstances deposit salt, dirt or cleaning mediums in or on the GThot-end components.

d . Low Pressure (LP) compressed air, if available, may be used to assist in compressorcleaning.


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e . The cleaning system and fluids shall be specified by the GT manufacturer, but shallrequire MOD approval.

f . If a water wash tank is fitted, suitable access for cleaning shall be made available.The tank shall be arranged so that it can be filled from the ships fresh water systemand shall also be fitted with a drain connection.

g . A system shall be provided for the injection of a sprayable inhibiting fluid into theGG.

h . The water wash and the inhibitor spray systems (where fitted) should incorporateautomatic features.

4.4 Environmental Conditions and Considerations

4.4.1 General Requirements

a . In the event of a machinery space fire, the GT shall be capable of withstanding thefire for the time prescribed in the SRD and shall remain operational within thelimits defined in the SRD.

b . The GT shall be capable of operating with floodwater to the level of the undersideof the lowest exposed GT casing.

c . Alternators housed in the same enclosures as the GT are subject to the sameenvironmental conditions, including those specified for material tolerance tocontamination, fire, shock and containment in the event of failure. In suchcircumstances the environmental conditions identified in DEF STAN 08142 andDEF STAN 07243, for 60 Hz and dc generators respectively, are superseded.

4.4.2 Emissions

a . The MOD has a stated policy to meet obligations world-wide with respect toemission levels as defined by the International Maritime Organisation (IMO). Atpresent these levels are defined for Diesels. When of emissions levels for GT havebeen defined, these shall supersede those currently specified.

b . Limits for all emissions shall be related to the engine power and where appropriateto the ambient conditions and shall be indicated in the SRD. Under all conditionsemissions shall be expected to conform to IMO Regulations applicable at the timeof procurement. Lower levels of emissions are most desirable and are to includeconsideration of such constituents as the oxides of Nitrogen and Sulphur (NOx andSOx), Carbon Monoxide (CO) and Unburned Hydrocarbons (UHC).

c . Under the conditions above, in normal operation, visible and measurable smokelevels shall be no greater than those specified in the SRD.

4.4.3 Nuclear Biological and Chemical Defence Precautions

a . The GT shall function without loss of performance in an NBC environment.

b . GT systems shall operate in a segregated environment to protect personnel fromadverse effects of NBC contamination.

c . The enclosed area within the enclosure boundary containing the GG and the intakeand exhaust systems shall be gastight in accordance with BR 2170 Volume 2.


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d . All interior surfaces within the enclosure (where fitted) which are exposed tocontamination shall be treated such that washing down operations do notadversely influence performance or cause corrosion.

4.4.4 Material Specification

a . Materials employed in the construction of the GT and enclosure (where fitted shallbe suitable for all the environmental conditions stated above and shall be capable ofwithstanding emergency conditions (e.g. intake filter bypass doors open).

b . Equipment components shall be coated, as the GT manufacturer deems necessary,to protect them from water and salt contamination and the effects of combustion.

c . The materials employed in the construction of the GT and accessories shall be ableto withstand exposure to contamination from the following:

(1) Fuel and its trace contaminants;

(2) Hydraulic fluids;

(3) Engine oil;

(4) Alkalis, including sea water and its constituent salts;

(5) Water repellent (e.g. WD40 or PX24);

(6) Acids, arising from dillution of exhaust products in water;

(7) Firefighting mediums;

(8) Solvent fluids associated with GT equipment.

d . All surfaces exposed to the inlet airflow shall be of corrosion resistant materials orshall be treated such that deterioration shall not result in FOD or from other solidparticle contamination of the inlet air.

e . The total life of GT natural rubber-based flexible hoses for both HP and LP servicesin ships shall be taken as 10 years in store, which may be followed by a full 16 yearsin-service life. Synthetic rubber-based flexible hoses are not lifed, but are replaceddepending on condition.

f . Corrosion resistant material shall be used in all fuel pipes between the shipsfiltration system and the engine/enclosure (where fitted) interface. Zinc based, zinccoated, cadmium plated or pure copper materials shall not be used.

g . Neither the use of cadmium nor zinc finish is permitted on surfaces in contact withLO. Copper shall not be used for piping related to LO systems.

h . Hazards to personnel as a result of exposure of materials to fire, (i.e. production oftoxic substances) shall be stated by the manufacturer.

4.5 Safety

4.5.1 General Requirements

a . GT design shall minimise the possibility of a fire fed by LO and fuel leaks.Localising potential leaks shall be given special attention.

b . GT design shall avoid electrical hazards illustrated in DEF STAN 08107.


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c . GT design shall ensure protection against both electrical shock and mechanicalhazard when checked by the application of the standard test figures as specified inBS EN 61032:98.

d . Personnel employed on operating and maintaining the GT machinery shall beprovided with instructions concerning safe operations.

e . Where applicable to the enclosure (where fitted), all doors shall be provided with alocking device capable of securing the door in the open and closed positions duringnormal ship movement and shock conditions.

4.5.2 Gas Turbine Trips

a . The contractor should designate trip levels which should ensure that no damageoccurs to any part of the equipment and that there is no compromise to the safety ofpersonnel. The equipment should, pending determination of the reason for theoverspeed, be available for re-starting after a minimum shut down period whichshall be given in the SRD.

b . Means shall be provided to automatically shut down (trip) the engine by rapidlyreducing fuel flow below the flame out level under conditions of excessive:

(1) PT speed;

(2) PT Entry Temperature (PTET);

(3) Temperature spread monitoring if applicable (alarm only).

c . A partial overspeed trip shall be provided which shall:

(1) operate above the 100% full power level but should also operate below thelevel of operation for main trips intended to initiate GT shut down;

(2) initiate a rapid drop off in power;

(3) prevent the GT from falling below idle conditions;

(4) NOT initiate a shut down sequence.

d . Where rapid operating devices are used which do not provide positive fuel cut-offto the engine, the trips signals shall be automatically sent to the fuel shut off valve sothat complete fuel isolation to the burner manifolds is achieved.

e . Where compatible with the control logic of the engine, a manual trip shall beprovided, capable of being operated independently from the local and remotepositions, to positively shut off fuel to the engine.

f . The local manual trip gear (where fitted) shall be located in a readily accessibleposition for speedy operation but which avoids possible inadvertent operation.

g . When remote mechanical operation is specified, the operating linkage shall be intension when tripping. Adequate safeguard against inadvertent operation shall beprovided.

h . The PTET trip shall be fitted with suitable isolation to allow local or remoteinhibiting of the trip. A suitable warning lamp shall be provided at the control


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stations to indicate that this inhibit is in operation. Indication of inhibit should begiven at all positions when inhibited from any position.

i . Spurious trips must be avoided at all times and particular consideration shall begiven to prevent inadvertent trips under the maximum shock conditions imposed onthe GT enclosure (where fitted).

j . Arrangements shall be provided to allow the equipment comprising the tripsystems to be periodically tested in service. The checking of all trip channels shallbe achieved without disconnecting any trip circuits.

k . If required, for complex cycle GT configurations, consideration should be givenfor the inclusion of an over torque trip mechanism. The use of a computed value oftorque for control and alarm may be considered.

4.6 Fire Prevention

a . All non-mobile GT installations installed within an enclosure shall be fitted with afire detection system.

b . When activated, the system shall give warning automatically at local and remotepositions.

c . Local manual, remote manual and automatic facilities for operation of the fireextinguishing system may be required. Details shall be given in the SRD.

d . When initiated, the system shall operate immediately to stop the supply ofventilation air to starve any fire(s).

e . An inhibiting device shall be provided to prevent inadvertent local, remote orautomatic operation, with appropriate indication provided at all positions when inthe inhibited mode.

f . A system of pipework and cylinders containing the fire-extinguishing mediumshall be provided. Where appropriate, containers will be located on the outersurface of the module with ability to remove/replace individual containers withoutentering the enclosure.

g . In the event of a fire in the enclosure (where fitted), an engraved plate givinginstructions for the sequence of operations shall be fitted adjacent to the controlbox. Physical, clear and unambiguous indication of when the system has operatedshall be provided at all operating positions.

h . A means shall be provided for purging the enclosure (where fitted) in the event of afire. A connection may be fitted that enables on-board portable fans to be used.Such a connection should be situated in a position to ensure that all unwantedgasses, including those heavier than air, are removed. Any other options shall bediscussed with the Prime Contractor.

i . The system shall be designed to totally flood the enclosure (where fitted). Theconcentration of the chosen extinguishant, required to extinguish all possible fires,shall be achieved and maintained throughout the entire enclosure (where fitted).Discharge trials shall be required to prove the correct concentration can beachieved.


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j . The extinguishant chosen shall be selected on the basis of that it limits, by thegreatest degree, damage to machinery components and health risks to personnel.The extinguishant chosen shall be fully compliant with the requirements of theMontreal Protocol.

4.7 Testing and Trials

a . The requirement for type testing of the first production or prototype engine may bespecified in the SRD. Annex E. gives guidance on recommended (non-mandatory)items for inclusion.

b . Production/shop tests and inspections and Type Tests shall be carried out inaccordance with DEF STAN 02362.

c . Platform/shipboard trials and inspections are divided into:

(1) Installation tests and checks;

(2) Commissioning tests and checks.

d . In addition to the machinery inspection undertaken after Contractors Sea Trials(CST) in accordance with DEF STAN 02353, a Conditional Assessment (CA)shall be carried out on the GT irrespective of the number of hours run during thetrials period. This CA shall include analysis of all logistic items, such as hydraulicfluids, intercooler fluid, fuel, boroscope inspections, etc. A list of typicaladditional maintenance tasks to be conducted is given at Annex F. GTA shall besubject to a similar material survey that shall be agreed with the Equipment ProjectOfficer (EPO).

4.8 Installation

a . The GT manufacturer shall be responsible for the labels and markings on theenclosure (where fitted). Thermal insulation shall be attached to the hot areas of theGTCU, PT and Exhaust Volute. Insulation or screening shall be provided on anyhot surfaces external to the enclosure (where fitted) sufficient to protect personnel.

b . Prior to installation, the GT manufacturer shall supply the platforms PrimeContractor with information on preparation, installation, maintenance andservicing of the GT, together with a Machinery Installation Guide.

c . More comprehensive installation requirements are given at Annex G.

4.9 Painting and Preservation

a . The GT manufacturer shall specify what items of GT equipment shall be paintedand which items of GT equipment shall not be painted. Typical examples are givenat Annex H.

4.10 Maintenance Check

a . In the case of the first installation only, the manufacturer shall physicallydemonstrate on one engine that the method, maintenance documentation, tools andany specialised support equipment are appropriate and fit for purpose with regardto the specified method of engine removal/replacement.


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b . The format of the demonstration and shall be specified in the SRD.

4.11 Support Issues

4.11.1 Units

a . All data, i.e. dimensions, flow rates, temperatures, pressures, etc., shall beexpressed in SI units.

b . All interfaces with the ship, i.e. flanges, threads, etc., shall be expressed in SI units.

c . The dimensions of threads of tools shall be in SI units, if practical.

d . Any deviations from these requirements shall be clearly identified and agreed wit