AS 1755—1986

Australian Standard

Conveyors—Design,construction, installation, andoperation—Safety requirements

This Australian standard was prepared by Committee SF/25, Guarding of Conveyors.It was approved on behalf of the Council of the Standards Association of Australia on25 November 1985 and published on 3 March 1986.

The following interests are represented on Committee SF/25:

Australian Conveyor Manufacturers AssociationBureau of Steel Manufacturers of AustraliaConfederation of Australian IndustryDepartment of Employment and Industrial Affairs, QldDepartment of Employment and Industrial Affairs, Vic.Department of Industrial Relations, N.S.W.Department of Labour S.A.Electricity Commission of New South WalesMelbourne Chamber of CommerceMetal Trades Industry Association of AustraliaNational Safety Council of AustraliaSafety Institute of Australia (Incorporated)State Electricity Commission of Victoria

Review of Australian Standards.To keep abreast of progress in industry, Australian Standards are subjectto periodic review and are kept up to date by the issue of amendments or new editions as necessary. It isimportant therefore that Standards users ensure that they are in possession of the latest edition, and anyamendments thereto.

Full details of all Australian Standards and related publications wil l be found in the Standards AustraliaCatalogue of Publications; this information is supplemented each month by the magazine ‘The AustralianStandard’, which subscribing members receive, and which gives details of new publications, new editionsand amendments, and of withdrawn Standards.

Suggestions for improvements to Australian Standards, addressed to the head office of Standards Australia,are welcomed. Noti fication of any inaccuracy or ambiguity found in an Australian Standard should be madewithout delay in order that the matter may be investigated and appropriate action taken.

This Standard was issued in draft form for comment as DR 84171.

AS 1755—1986

Australian Standard

CONVEYORS —DESIGN,CONSTRUCTION,INSTALLATION, ANDOPERATION — SAFETYREQUIREMENTS

First published (as AS CZ15) . . . . . . . . . . . . . . 1971AS 1755 fi rst published . . . . . . . . . . . . . . . . . . 1975Second edition . . . . . . . . . . . . . . . . . . . . . . . . 1986

Incorporating:Amdt 1 — 1995

PUBLISHED BY STANDARDS AUSTRALIA(STANDARDS ASSOCIATION OF AUSTRALIA)1 THE CRESCENT, HOMEBUSH, NSW 2140

ISBN 0 7262 4012 5

AS 1755—1986 2

PREFACE

This edition of this standard was prepared by the Association’s Committee onGuarding of Conveyors, to supersede AS 1755-1975, SAA Conveyor Safety Code. Itcontains the safety measures to be implemented for the installation and operation ofconveyors and conveyor systems, and sets out the necessary personal protectivemeasures against hazards experienced by operators of such plant.

The text of this standard has been modified in accordance with the appropriaterecommended modifications received in response to a request for the review ofAS 1755-1975.

The recommended changes included in this standard cover the general safetyrequirements for large and small conveyors and conveyor systems, and in particularthe details for conveyor control and motor drive isolation. Technical and editorialamendments have been incorporated in line with available ISO documentation formechanical handling equipment, andAppendix A has been expanded to includeconveying equipment not covered in the previous edition.

Copyright STANDARDS AUSTRALIA

Users of Standards are reminded that copyright subsists in all Standards Australia publications and software. Except where theCopyright Act allows and except where provided for below no publications or software produced by Standards Australia may bereproduced, stored in a retrieval system in any form or transmitted by any means without prior permission in wri ting fromStandards Australia. Permission may be conditional on an appropriate royalty payment. Requests for permission and information oncommercial software royalties should be directed to the head off ice of Standards Australia.

Standards Australia wil l permit up to 10 percent of the technical content pages of a Standard to be copied for useexclusively in-house by purchasers of the Standard without payment of a royalty or advice to Standards Australia.

Standards Australia wil l also permit the inclusion of its copyright material in computer software programs for no royaltypayment provided such programs are used exclusively in-house by the creators of the programs.

Care should be taken to ensure that material used is from the current edition of the Standard and that it is updated whenever theStandard is amended or revised. The number and date of the Standard should therefore be clearly identif ied.

The use of material in print form or in computer software programs to be used commercially, with or without payment, or incommercial contracts is subject to the payment of a royalty. This policy may be varied by Standards Australia at any time.

3 AS 1755—1986

CONTENTS

Page

SECTION 1. SCOPE AND GENERAL

1.1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51.2 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51.3 Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51.4 Referenced Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51.5 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

SECTION 2. MATERIALS

2.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72.2 Material Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

SECTION 3. DESIGN AND CONSTRUCTION

3.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83.2 Design and Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

SECTION 4. INSTALLATION

4.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94.2 Access to Conveyors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94.3 Crossovers for Aisles and Passageways . . . . . . . . . . . . . . . . . . . . . . 94.4 Conveyors Installed in Tunnels or Pits . . . . . . . . . . . . . . . . . . . . . . 94.5 Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94.6 Electrical Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94.7 Protective Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94.8 Conveyor Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104.9 Fire Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

SECTION 5. GUARDING5.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125.2 Design and Construction of Guards . . . . . . . . . . . . . . . . . . . . . . . 125.3 Dangerous Parts Requiring Guarding . . . . . . . . . . . . . . . . . . . . . . 155.4 Removal of Guards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155.5 Guarding of Other Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

SECTION 6. SPECIFIC REQUIREMENTS FOR UNIT-HANDLINGCONVEYORS

6.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216.2 Slat Conveyors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216.3 Towing Conveyors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216.4 Roller Flight Conveyors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236.5 Flat Belt Conveyors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236.6 Overhead Chain or Cable Conveyors . . . . . . . . . . . . . . . . . . . . . . 236.7 Overhead Chain or Cable Conveyor

(Power and Free Type) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236.8 Swing Tray Conveyors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236.9 Vertical Chain Conveyors (Opposed Shelf Type) . . . . . . . . . . . . . . 24

SECTION 7. SPECIFIC REQUIREMENTS FOR BULK-HANDLINGCONVEYORS

7.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257.2 Safe Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257.3 Belt Conveyors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257.4 Screw Conveyors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257.5 En Masse and Bucket Conveyors . . . . . . . . . . . . . . . . . . . . . . . . . 257.6 Vibrating and Oscillating Conveyors . . . . . . . . . . . . . . . . . . . . . . 257.7 Drag Chain Conveyors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

AS 1755—1986 4

Page

SECTION 8. SPECIFIC REQUIREMENTS FOR MOBILE ANDPORTABLE CONVEYORS

8.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268.2 Design and Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268.3 Stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268.4 Attachment Points for Towing . . . . . . . . . . . . . . . . . . . . . . . . . 268.5 Boom Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268.6 Locking Against Creep . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268.7 Pneumatic Tyres . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268.8 Loss of Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268.9 Wire Rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268.10 Boom or Trunking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268.11 Conveyor Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268.12 Control of Motor Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268.13 Guarding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278.14 Safe Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

SECTION 9 INSPECTION AND MAINTENANCE

9.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289.2 Regular Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289.3 Removal of Guards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289.4 Safety of Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

SECTION 10 INSTRUCTIONS FOR OPERATING AND MAINTENANCE

10.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2810.2 Synopsis of Plant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2810.3 Operating Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2810.4 Maintenance Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2810.5 Spare parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

SECTION 11 TRAINING AND SUPERVISION OF OPERATORS

11.1 Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2911.2 Safe Operating Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2911.3 Safe Working Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

SECTION 12. MARKING AND IDENTIFICATION

12.1 Marking of Conveyors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3012.2 Nameplates and Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3012.3 Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3012.4 Load Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3012.5 Marking of Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3012.6 Location of Signs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

APPENDICES

A Glossary of Conveyor Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31B Example of a Work Permit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

ANNEX. LIST OF REFERENCED DOCUMENTS . . . . . . . . . . . . . . . . . . 64

5 AS 1755—1986

STANDARDS ASSOCIATION OF AUSTRALIA

Australian Standard

for

CONVEYORS — DESIGN, CONSTRUCTION, INSTALLATION, ANDOPERATION — SAFETY REQUIREMENTS

SECTION 1. SCOPE AND GENERAL

1.1 SCOPE. This standard applies to the design,construction, installation, and guarding of conveyorsand conveyor systems, whether of a temporary orpermanent nature, for the conveyance of materials.

It sets out requirements for materials of construction,mechanical design, general safety requirements,specific requirements for unit and bulk handlingconveyors, t raining and supervision ofoperators,inspection and maintenance, and operatingand maintenance instructions.

The standard is not intended to apply to industrialtrucks, tractors or trailers, prime movers coupled withmonorails, tiering machines, cranes, hoists, skiphoists, monorails, power shovels, power scoops,bucket drag lines, platform elevators designed tocarry passengers or the elevator operator, movingstairways and highway or rail vehicles, or conveyorsspecifically designed for the conveyance ofpassengers.

This standard does not cover individually powered orline shaft powered rollers, which are used in otherthan continuous manufacturing industries (see alsoClause 1.5.4.2).

A glossary of conveyor terms is provided inAppendix A.

1.2 PURPOSE.The purpose of this standard is toestablish uniformity in engineering practice withrespect to conveyors throughout the Commonwealthof Australia. The requirements have been drafted toprovide conveyors and conveyor systems withpractical and adequate safety features and to stipulateconditions for safety in operation and maintenance.

Attention is particularly drawn to the requirements ofthe Regulatory Authority specific to equipmentsafety.

1.3 APPLICATION. This standard shall apply to allnew conveyors and new conveyor systems and anyaddition or amendment to the standard shall beapplied in a similar manner.

The term ‘new conveyor’ is not intended to apply toa conveyor or conveyor system in connection withwhich a contract for supply and installation had beenentered into prior to the date on which the standardand its amendments came into operation.

1.4 REFERENCED DOCUMENTS. A list withtitles of the documents referred to in this standard isgiven in theAnnex.

1.5 DEFINITIONS. For the purpose of thisstandard, the following definitions apply:

1.5.1 Accompanying documents— documentsaccompanying the equipment containing all importantinformation for the user, in particular that relevant tosafety.

1.5.2 Controls.

1.5.2.1 Emergency stop control— a device whichstops a conveyor system(s) in the shortest practicabletime .

1.5.2.2 Start control — a device for starting up aconveyor system situated appropriately for the localor remote starting of the system. (See alsoClause 4.8.7).

1.5.2.3 Stop control— a normal stop control whichis electrically wired directly in the circuit or in thestarting control circuitry, resulting in a fail safeimmediate or sequence stopping of the conveyorsystem.

1.5.3 Control circuit isolation — the interruption ofthe control circuitry of the drive motor(s) of aconveyor system(s).

1.5.4 Equipment and parts.

1.5.4.1 Bulk-handling conveyor— a conveyordesigned for moving loose material from one locationto another.

1.5.4.2 Conveyor— apparatus or equipment workedby any power other than manual, by which loads areraised, lowered or transported or are capable of beingraised, lowered, transported, or continuously drivenby —

(a) an endless belt, rope or chain or other similarmeans;

(b) buckets, trays or other containers or fittingsmoved by an endless belt, rope, chain or othersimilar means;

(c) a rotating screw;

(d) a vibration or walking beam; or

(e) a powered roller conveyor where the rolls aredriven by an endless belt, rope, or chain,

and including the supporting structure, auxiliaryequipment and gear used in connection with theconveyor.

1.5.4.3 Conveyor system— an installation of one ormore conveyor(s) which transport or transfer loadsfrom one conveyor to another and whose control isintegrated .

1.5.4.4 Unit-handling conveyor — a conveyordesigned for moving individual components or groups

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AS 1755—1986 6

of components either directly or within a containerfrom one location to another.

1.5.5 Fail safe — the feature of a conveyor orconveyor system which minimizes any hazard topersonnel and equipment in the event of powerfailure, malfunction of the conveyor or conveyorsystem or the like.

1.5.6 Guards.

1.5.6.1 Guarded — shielded, fenced, enclosed orotherwise protected by means of suitable enclosure,covers, casing, shield guards, trough guards, railingguards, or by nature of location or position so as toremove foreseeable risk of personal injury beingcaused by accidental contact or approach, and for anunderguard so as to remove any additionalforeseeable risk of personal injury being caused bycontact with or spillage of material from theconveyor.

1.5.6.2 Guarded by location or position— themoving parts are protected by their remoteness fromthe floor, platform, walkway or other working level,or by their location with reference to frame,foundation, or structure so as to remove theforeseeable risk of accidental contact by persons orobjects. Remoteness from foreseeable regular orfrequent presence of public or employed personnelmay in reasonable circumstances constitute guardingby location.

1.5.6.3 Underguard— a stationary device of suffi-cient strength and capacity to catch, retain, andcontain any foreseeable spillage which might causepersonal injury from a conveyor passing over aroadway, walkway, work space, or like area, for thepurpose of protecting persons in that area.

1.5.7 Nip point — that point at which a machineelement moving in line meets a rotating element sothat it is possible to nip, pinch, squeeze, or entrapobjects coming into contact with one of the twomembers. The term also applies to the similar pointwith respect to two rotating parts or two convergingparts in linear movement.

1.5.8 Power isolation— the physical separation ofequipment or circuits from all power sources.

1.5.9 Regulatory Authority — a Minister of theCrown, a government department or other publicauthority having power to issue regulations, orders orother instructions having the force of law in respectof any subject covered by this standard.

1.5.10 Shall and should— the word ‘shall’ is to beunderstood as mandatory, and the word ‘should’ asnon-mandatory, advisory or recommended.

1.5.11 Shear point— the point at which or the linealong which a moving part meets or passes closeenough to a stationary part or object so that parts ofthe human body can be caught, trapped, or pinchedbetween them.

1.5.12 Whole current isolation — the physicallyopening of the power supply conductors to the drivemotor(s) of a conveyor system(s).

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7 AS 1755—1986

SECTION 2. MATERIALS

2.1 GENERAL. All materials shall comply with therelevant Australian standards or with otherspecifications acceptable to the Regulatory Authority.

2.2 MATERIAL SPECIFICATIONS. The followingstandards specify the material requirements forconveyors and supporting structures:

(a) Bolts — AS 1110, AS 1111, AS 1112, AS 1252,AS 2451, and AS 2465.

(b) Concrete — AS 1379 and AS 1480.

(c) Conveyor belts — AS 1332, AS 1333, andAS 1669.

(d) Forgings and castings — AS 1448, AS 1734,AS 1830, AS 1831, AS 1832, AS 1866, AS1874, and AS 2074.

(e) Gears — AS B61, AS B66, and AS 1565.

(f) Rivets — AS A34.

(g) Roller chain — AS 1532 and AS 2152.

(h) Structural steel — AS 1074, AS 1131, AS 1163,AS 1204, and AS 1444.

(j) Wire rope — AS 1656 and AS 2759.

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AS 1755—1986 8

SECTION 3. DESIGN AND CONSTRUCTION

3.1 GENERAL. Conveyors and conveyor systems shall bedesigned, manufactured and installed consistent with—

(a) the appropriate requirements of this standard;

(b) the requirements of the Regulatory Authority; and

(c) the accepted principles of safe engineering practiceand workmanship.

3.2 DESIGN AND CONSTRUCTION.

3.2.1 General. Safety features necessary for the safeoperation of conveyors and conveying machinery shall beincorporated at the design stage.

3.2.2 Design requirements.The design and constructionof a conveyor shall take into full account the magnitude,incidence, conditions and manner of all loading and forceslikely to be applied to the conveyor.

The design and construction of a conveyor shall, whereapplicable, comply with the relevant standards.

The slope and characteristics of the conveying device shallbe designed so as to prevent unintentional sliding of theproduct or object being conveyed under normal workingconditions.

3.2.3 Brakes and brake devices.

3.2.3.1 Safe stopping.Every conveyor shall be designed soas to ensure that it will stop in the shortest practicable timeconsistent with safety when the driving power isdisconnected, and remain stopped until the power isrestored.

3.2.3.2 Anti-runaway or anti-runback devices. Everyconveyor which can run away or run back shall beprovided with ‘anti-runaway’ or ‘anti-runback’ devices.Where a belt or chain drive is interposed between themotor and the driving shaft, a device shall be provided onthe driving shaft to sustain the load in the event of failureof such drive.

3.2.3.3 Prevention of movement. Where an electro-mechanical brake is provided on an inclined conveyorwhich may run away or run back, and a positive drive isnot used, e.g. a fluid coupling is used, means shall beprovided to prevent movement of the conveyor until suchtime as positive drive is established.

Brakes shall not be released until the torque has beenapplied to the main driving shaft of the conveyor, and shallbe applied automatically if the power fails or the operatingcontrol is returned to the off or stopped position.

3.2.3.4 Controlled speed of descent.Brakes which aremanually released and applied by the movement ofoperating devices shall be designed so that, if the power isinterrupted with the brakes in the release position, the loadcan descend only at a controlled speed.

3.2.3.5 Sustained load. Where a brake is used as ananti-runaway or anti-runback device, it shall be rated tosustain 150 percent of the runaway load of the conveyorwhen applied.

3.2.4 Lubrication of bearings. Where bearings areinaccessible or are in hazardous locations and requirelubrication, the means of lubrication shall be located in anaccessible and safe position and the lubricant piped to thebearings. The lubrication points should be located outsidethe alignment of the carrying mechanism of the conveyorand should be accessible without the removal of any guard.

3.2.5 Take-ups and counterweights.

3.2.5.1Gravity take-up.Where take-ups have suspendedcounterweights, suitable precautions shall be takenagainst the danger of the counterweight falling. Thecounterweight shall be enclosed in a suitable enclosureequipped with guides and stops which shall extend to afloor of sufficient strength to withstand the fallingweight.

Where counterweights are attached to lever arms, asafety device shall ensure that the weights cannotbecome detached if the device used for the adjustmentof the weight becomes loose.

3.2.5.2 Wire ropes for take-ups and counterweights.All wire ropes used for take-ups and counterweights ofconveyors shall have a minimum safety factor of 4.5.

3.2.5.3 Spring take-ups. Where spring and screwtake-ups are used and adjustment is required when theplant is in operation, the means of adjustment shall bereadily accessible. Guards shall be provided to protectpersonnel from contact with moving parts.

Where spring and screw take-ups are remote or on adifferent level from the main drive, a stop controlcomplying withClause 4.8.7shall be provided.

3.2.6 Wire ropes. All wire ropes used on a conveyoror conveyor system, other than for take-ups andcounterweights, shall comply with the appropriaterequirements of the relevant standards (seeClause 1.4).

3.2.7 Hinged sections.

3.2.7.1 General. Hinged sections of a conveyor orconveyor system used for the purpose of creating apassageway shall be designed so that when the hingedsection is opened while the conveyor is in operation itneed only stop the adjacent upstream conveyor. Theconveyor may be restarted automatically upon closure ofthe hinged section provided that the requirements ofClause 4.8.7.5are complied with.

3.2.7.2 Manually operated.Manually operated hingedsections shall be self-locking in the open position orcounterbalanced, and shall be designed so that themaximum effort required to open or close the hingedsection does not exceed 150 N.

3.2.7.3 Power operated. Power-operated hingedsections shall be provided with mechanical safetydevices which restrict their closing to a safe speed andprevent them from falling in event of power failure.

3.2.8 Raising and lowering systems.Fixed or mobileconveyors including an articulated or mobile part in avertical plane, actuated manually or by a motor, shallhave a safety device for immobilizing the articulated partin the event of voluntary or accidental stopping of themotive power.

A raising and lowering system shall be fitted with anappropriate device which prevents the accidentalmovement or kickback of a manually operated crank.

The raising and lowering system shall be located so thatit is unnecessary for any person to be under theconveyor. The movement shall be limited at the extremepositions by appropriate stops or limiting devices.

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9 AS 1755—1986

SECTION 4. INSTALLATION

4.1 GENERAL. In areas where a conveyor or conveyorsystem is installed, safe access platforms and safeservicing facilities shall be provided for the purpose ofloading, unloading, operation, maintenance andinspection. The design, construction, and installation offixed platforms, walkways, underpasses, crossovers,stairways, and ladders shall be in accordance withAS 1657.

4.2 ACCESS TO CONVEYORS.

4.2.1 Platforms to be provided. Permanent platformsnot less than 600 mm wide shall be provided to enableall parts of the plant which need to be reached forpurposes of operation and regular maintenance to bereadily and safely accessible. A clear access platform orfloor space of at least 600 mm wide shall be providedfor maintenance purposes. The minimum platform sizeshall be 600 mm square. Platforms at different levelsshall be adequately and conveniently connected.

4.2.2 Use of ladders.Access to plant for purposes ofoperation shall be from floors or platforms and not fromstairways or fixed ladders. Portable ladders shall not beused as places from which operation or regular mainten-ance may be carried out.

4.2.3 Crossovers.Where walkways are provided onboth sides of a conveyor, and where convenient accessto either side of the conveyor may be required byemployees who regularly work in the area, crossovers orunderpasses with safe means of access thereto should beprovided at appropriate intervals, and at the head and tailends of conveyors where no other crossing is available.

4.3 CROSSOVERS FOR AISLES AND PASSAGE-WAYS. Where a conveyor crosses a walkway, aisle orpassageway and the lowest part of the conveyor ormaterial or attachment is less than 2 m from the floor orwalkway surface, a crossover or underpass shall beprovided.

4.4 CONVEYORS INSTALLED IN TUNNELS ORPITS.

4.4.1 Working clearance. Where it is necessary towork from within a tunnel or pit, e.g. for maintenancepurposes, a minimum working clearance of 600 mmcoupled with a minimum headroom of 2 m shall beprovided .

4.4.2 Ventilation and drainage. Tunnels and pitsshould be designed for proper ventilation and drainage.If necessary sump holes should be provided, and anysuch sump holes shall be covered. Where pumps areprovided, the controls shall be located in an accessibleand safe position outside any area that may be flooded.

4.4.3 Depth indication. Visual indications shall beprovided to indicate the depth of water and to guardagainst the possibility of persons stepping into deepwater in the event of the tunnel or pit becoming flooded.

4.4.4 Alternative egress.Provision shall be made foralternative means of egress from tunnels and pits wherethere might be a danger to persons. Normal accessshould be reasonably remote from possible overflowsand other sources of danger.

4.4.5 Use of covers for headroom.Where the depthof a pit is less than 2 m, the headroom may be achievedby the removal of covers. Where covers are provided,they shall be hinged or otherwise secured to preventtheir displacement through the opening, and the exposedopening shall be provided with a suitable guard rail ofadequate strength which can be readily and convenientlyerected but not removed. Access to the opening shall berestricted until the guards, which shall be on at leastthree sides, are in position.

4.4.6 Removal of accumulated material. Pits shallhave adequate space for the accumulation of spilledmaterial and means for the ready removal of suchaccumulation.

4.5 LIGHTING. Suitable permanent or mobile lightingshall be provided for conveyors or conveyor systemsappropriate to their location. The level of illuminationshall provide safe access to conveyors or conveyorsystems and create safe working conditions foroperation, inspection, and maintenance purposes (seeAS 1680). Provision should be made for access to lightfittings for ease of servicing.

Permanent lighting shall be provided in tunnels and pitsand areas where natural light is not available. Inaddition, permanent lighting and/or power outlets forconnecting hand-held lamps shall be provided in areasrequiring maintenance and inspection.

NOTE: Hand-held fittings should beone of the extra-low voltagetype.

4.6 ELECTRICAL REQUIREMENTS. The electricalinstal-lation, components and associated equipment ofconveyors or conveyor systems shall comply withAS 3000 and other relevant standards.

4.7 PROTECTIVE DEVICES.

4.7.1 General. Where personal safety is involved, allprotective devices shall be hard-wired external toelectronic control equipment of conveyors or conveyorsystems.

4.7.2 Overload protection. Every conveyor where themaximum torque developed by a motor will producestress in excess of safe working stresses and wherefailure may cause a hazardous situation shall have, inaddition to the overload protection provided to protectthe motor overload devices to protect the conveyor andmechanical drive parts. Such devices shall be designedto quickly disconnect the conveyor or drive parts fromthe motive power in the event of overload.

4.7.3 Types of device.The overload devices may bespeed-responsive switches, shear pins, torque limitingcouplings, or any other devices designed for the purposeof quickly disconnecting the motive power or limitingapplied torque. Shear pin failure on any one drive unitshall stop all drive units on that conveyor and any otherpreceding synchronized conveyor or material feeder.Where a shear pin is used, a description of the propersize and material of the shear pin shall be placed at anappropriate point on the conveyor so that the operatorscan readily see it when replacement is being made.

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4.7.4 Speed control. Where the operation of theoverload device would permit overspeeding in eitherdirection with consequent hazard to persons, a speedcontrol device shall be provided.

4.8 CONVEYOR CONTROL.

4.8.1 General. Conveyors and conveyor systems shallbe provided with appropriate drive power isolation,whether electrical, hydraulic, pneumatic, or mechanical.

4.8.2 Drive power isolation. Drive power isolationshall be obtained by mains supply isolating switches ordevices capable of being secured in the isolatingposition. Resetting of mains supply isolating switches ordevices shall be by manual operation only.

The securing method shall be by means of a key-operated lock, danger tag (as approved), or other methodacceptable to the Regulatory Authority. Features shall beincorporated which positively indicate the isolating andoperating conditions of the isolating device and alsoprovide a method of preventing unauthorized orinadvertent operation.

Power-isolating switches or devices shall not be capableof being locked in the supply mode.

4.8.3 Motor isolation. Motor isolation shall beobtained by either one of the following means:

(a) A full current isolator connected in series with thedrive motor and mounted adjacent to the drive.

(b) A control circuit isolating switch mounted adjacentto the drive motor the operation of which shallcomply with Clause 4.8.4.

Whole current switches and control circuit isolatingswitches shall comply withClause 4.8.2and shall beclearly identified.

4.8.4 Control circuit isolation. Where control circuitisolation is used, such isolation shall be used only asmotor isolation for the purpose of test and inspectionservices. Operation of the control circuit isolator shallopen the main supply to the drive motor.

The control circuit isolator, at the drive, shall bear anotice worded as follows:

CAUTION — For testing/inspection purposes only. Forservicing and maintenance access, isolate the drive power at themain supply isolator.

4.8.5 Whole current isolation. Where access to theconveyor is required whole current isolation shall beimplemented to isolate the drive functions of theconveyor controls. Operation of the whole current switchshall open the supply to the drive motor and to allauxiliary drives, operation of which could cause theconveyor belt to move.

4.8.6 Starting controls.4.8.6.1 General. At each conveyor start location, aclearly labelled stop control shall be provided.4.8.6.2 Remote control. Conveyors or conveyorsystems equipped with remote control shall comply withthe following:(a) Where the start control is in a position from which

the whole of the conveyor’s operation cannot beviewed and the possibility exists of accidentsarising from the starting of the equipment, anautomatic visible and/or audible signal shall beprovided to warn persons in the vicinity of theconveyor or conveyor system prior to the starting

up of the conveyor or system. There shall be asuitable time delay between the beginning of thesignal and the starting of the conveyor or conveyorsystem.

(b) Where conveyors or conveyor systems are equippedwith remote control and separate local manualcontrol switches for any conveyor in a system,these controls shall be clearly marked andinterlocked so that the remote control cannotoverride the local control. Starting interlocks orcontacts from remote controls shall be physicallydisconnected by the selection of local control.

(c) The local/remote control selector switch shall besuitably protected or located to prevent operation byother than authorized persons. The selectedcondition shall be displayed at the local startlocation and may also be displayed at both theremote and local control locations.

(d) An appropriate warning sign shall be displayed.

4.8.7 Stop controls.4.8.7.1 General. All conveyors and conveyor systemsshall be provided with manual emergency-stop controls.Where a conveyor is not electrically powered, provisionshall be made for an appropriate stopping device. Inaddition, conveyors may be equipped with manualnormal-stop controls for the purpose of production orother stopping functions (see alsoClause 4.8.7.4).Field-mounted manual stop controls, whether foremergency or normal stop functions, shall be of theknock-off, automatic lock-off, manual reset type.Lanyards are considered to comply with thisrequirement.

4.8.7.2 Emergency stopping of conveyors.The stoppingfunction of an emergency-stop control shall, uponactivation, open the mains supply and lock itselfsimultaneously in the off position. It shall prevent thestarting of the conveyor from any position until suchtime that the stopping control has been manually reset.It shall not be possible to restart the conveyor after themanual reset operation without the activating of thenormal start control.4.8.7.3 Emergency-stop controls. Provisions foremergency stopping of conveyors and conveyor systemsby means of emergency-stop controls shall be asfollows:(a) Conveyors positioned within 2.5 m from the floor

or normally accessible walkways or platforms shallhave emergency-stop controls located at intervalsnot exceeding 30 m.

(b) Readily accessible conveyors shall have emergency-stop controls located at intervals not exceeding30 m. Accessible points along the pull wire of alanyard type stop control shall be considered asbeing emergency-stop controls.

(c) Where conveyors pass through storage areas andovens or other areas not considered readilyaccessible, emergency-stop controls at the entry andexits of these areas shall be provided.

(d) Emergency-stop controls shall be wired directly intothe conveyor control circuit and where activated,shall isolate the power supply to the conveyor byelectromechanical means.

(e) Where the conveyor is controlled by electronicequipment, emergency-stop controls shall be hard-wired external to the electronic equipment so that

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electronic circuit malfunction shall not inhibit thefunction of the stopping device.Inaccessible conveyors supported on trestles exceeding2.5 m in height, or conveyors not accessible other thanby a ladder or mobile platform, should haveemergency-stop controls located at the base of thetrestles at intervals not exceeding 100 m.

Operation of a local emergency-stop control in aconveyor system should be arranged so that it stops theassociated conveyor and its feeding conveyors, exceptwhere the control is located at a transfer point and itmay be necessary to also stop the downstream conveyor.Where emergency stopping of the total conveyor systemis required, the system should be provided with a singleor multipositioned group of emergency-stop controls.Operation of the emergency-stop controls should resultin the stopping of the total system. These emergency-stop controls shall be either at the main control point, orat suitable positions which permit the operator a clearview of the total system.

Where access is provided on each side of the conveyor,local emergency-stop controls shall be provided on bothsides.

Emergency-stop control systems shall be uniformthroughout the installation.4.8.7.4 Normal-stop controls. Where normal-stopcontrols are provided in addition to emergency-stopcontrols, the normal-stop controls may be wired intoelectronic control equipment for sequence controlpurposes. Interlocking should be arranged so that thesequencing control cannot be initiated before the manualresetting of the stopping mechanism and the start controlhas been activated. Where this type of conveyor controlhas been incorporated appropriate warning signals (seeClause 4.8.6.2) and warning signs shall be provided.4.8.7.5 Automatic stop controls. Automatic stopcontrols provided for conveyor systems for other thansafety purposes, e.g. overdimensional load, tensionmechanism overtravel, and temperature limit controls,should not prevent the restarting of the system afterresetting, provided that —

(a) the stopping device is labelled to indicate that theconveyor will restart upon resetting the device; and

(b) where this control is in a position from which thewhole of the system cannot be viewed and there isa possibility of accidents arising from the startingof the conveyor, a warning signal in accordancewith Clause 4.8.6shall be provided.NOTE: This stop control may be wired into electronic controlequipment.

4.8.7.6 Lanyard or pull wire. Automatic lock-outmanual reset stop controls which are operated by alanyard or pull wire shall comply with the following:

(a) They shall be installed within reach of the operatoror other person engaged in the near vicinity of theconveyor.

(b) Where emergency-stop controls are not provided atthe head or tail end of the conveyor, lanyardswitches shall be installed.

(c) Breaking, slackening or removal of the lanyard orpull wire shall automatically stop the conveyor.

(d) The force required to operate the lanyard or pullwire stop control shall not exceed the following:(i) Where applied midway between the lanyard or

pull wire supports and at right angles to theaxis of the lanyard or pull wire . . . . 70 N.

(ii) Where applied along the axis of the lanyardor pull wire in either direction . . . 230 N.

(e) Supports for lanyards or pull wires shall beprovided at intervals not exceeding 4.5 m.

A cross lanyard or pull wire or equivalent type of stopsystem may be installed above approaches to certainpoints, e.g. crushers, transfers and chutes.

Lanyards or pull wires should be stranded galvanized orplastics-covered wire or be of similar material notaffected by atmospheric or environmental conditions.

NOTE: The application of lanyards to long overland conveyorsis subject to approval by Regulatory Authorities.

4.8.7.7 Interlocking devices. Except where theconveyor at the loading and unloading point isoperationally visible to and under the control of anoperator, an electrical or mechanical device shall beprovided on all sequence type conveyor systems toautomatically stop the conveyor or the load when aconveyor, bin, hopper, or chute to which it feeds has notbeen started, has been stopped, or has been blocked withloads so that it cannot receive additional loads ormaterial (see alsoClause 4.8.7.5).

4.8.7.8 Location of signs. Each stop control shall bereadily accessible and shall be indicated by safety signserected in suitably conspicuous positions. Such signsshall comply with AS 1319, and shall have letters notless than 15 mm high.For lanyard controls, signs shall be erected at suitableand clearly visible positions along the length of theconveyor, or at any other position where lanyard isinstalled, at intervals not greater than 30 m.

4.9 FIRE PROTECTION. In the design of ‘aconveyor or conveyor system and of the situation intowhich it is to be installed, consideration should be givento the materials of construction, the materials beinghandled, and the operating conditions to assess the extentto which the installation may be a fire hazard.Firefighting facilities should be provided consistent withthe assessment of the fire hazard.In the design of the access provided for the operationand maintenance of the conveyor or conveyor system,safe alternative means of exit shall be provided forpersonnel in case of fire.

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SECTION 5. GUARDING

5.1 GENERAL. Guards shall be designed to preventinjury to persons and shall be provided at everydangerous part of a conveyor normally accessible topersonnel.Guards should be planned into the design of theconveyor or conveyor system and should not inthemselves create a hazard.Guards shall be provided to prevent accidental contactby persons or parts of clothing being caught, e.g.between belt and pulley, chain and sprocket, cable andsheave, or drum and block. Where removal of a guard isnot required for inspection or maintenance purposes, theguard shall be secured in position so that it cannotreadily be removed without the use of tools.Fixed guards shall be provided where the conveyor canbe serviced without the removal of the guards (e.g. foradjustments, cleaning or lubrication).Removable guards shall be installed in a manneracceptable to the Regulatory Authority in positionswhere normal maintenance or cleaning is carried outregularly .

5.2 DESIGN AND CONSTRUCTIONOF GUARDS.5.2.1 General. Guards shall be made of solid material,mesh, or equivalent construction, and shall be designedto prevent persons reaching into the danger area (seeFig. 5.1).

Sheet metal guards shall be not less than 1.5 mm thick.For mesh guards, 9 mm mesh shall be not less than1.5 mm thick; 50 mm mesh shall be of not less than3 mm wire thickness.Guards shall not deflect more than 12 mm under a forceof 450 N applied at any point on the guard over a squarearea of 50 mm side.These requirements are not intended to exclude othermethods of construction provided that they comply withthe requirements for prevention of access.Where a guard is situated so that a person may climb orrest upon it, such guard shall be capable of sustaining amass of 75 kg placed in any position upon it, togetherwith a simultaneous force of 220 N applied horizontallyin the same or any other position. The guard shallmaintain the required safe clearances.

Fig. 5.1. USE OF MESH FOR GUARDS

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5.2.2 Reach dimensions (SeeFigs 5.2and 5.3). Thedesign and construction of guards and their subsequentlocation shall be such that the distance of any nip pointor shear hazard and the nearest point of access isrestricted as follows:

(a) Arm reach . .. . . . 1000 mm from under arm tofingertips.

(b) Elbow reach . . . . . 500 mm from the inside elbowto fingertips.

(c) Wrist reach . . . . . 280 mm from wrist to tip ofmiddle finger.

(d) Finger reach . . . . 150 mm(e) Vertical reach . . . . 2500 mm maximum when

standing on toes.The above dimensions include an allowance made toobtain clearance from the danger areas.

5.2.3 Guard placement. The size of mesh or otheropenings in the guard and the distance of the guard fromthe danger point shall be as follows:

(a) Size of mesh of opening up to and including 9 mm.... Distance of guard from danger point virtuallysame as sheetmetal, working clearance onlyrequired.

(b) Above 9 mm up to 50 mm square ...Guard at least150 mm from danger point.

(c) All types of guards ....Distance between theunderside of the guard and the floor not to exceed250 mm.

Where complete enclosure with a guard is not provided,fence type guards shall be used and the height of theguard and the distance of the guard from the dangerpoint shall be in accordance withFig. 5.4. The size ofmesh or other openings shall be not greater than 9 mmwhere the nip point is up to and including 150 mm fromthe guard, and not greater than 50 mm square where thenip point is in excess of 150 mm from the guard.

(a) Reaching over a barrier

(b) Reaching around a barrier

Fig. 5.2. REACHING OVER AND AROUND A BARRIER

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millimetres

Height of nip point fromfloor or working surface

(a)

Distance from nip point to guard (c)Height of guard from floor or working surface ( b)

2290 2130 1980 1830 1680 1520 1380 1220 10002500 — — — — — — — — —2360 75 150 230 230 230 230 230 230 2302290 75 150 230 300 380 380 380 380 —

2210 — 200 300 380 450 530 530 530 6002130 — 200 300 450 530 600 600 600 —2050 — 150 300 450 600 600 600 680 1100

1980 — 150 300 450 600 680 680 750 —1900 — — 230 450 600 680 680 840 —1830 — — — 450 600 680 750 840 1200

1750 — — — 450 600 750 840 920 —1680 — — — 380 600 750 840 920 —1600 — — — 380 530 750 840 920 1300

1520 — — — 230 530 750 840 920 —1450 — — — — 530 750 840 920 —1380 — — — — 450 750 840 920 —

1300 — — — — 380 750 840 920 13501220 — — — — — 750 840 920 —1150 — — — — — 680 840 920 —

1050 — — — — — 680 750 840 —1000 — — — — — 680 680 840 1400920 — — — — — 300 680 840 —

840 — — — — — — 600 840 —750 — — — — — — 380 750 —680 — — — — — — 300 600 1200

600 — — — — — — — 530 —530 — — — — — — — 380 —

NOTES:1. For intermediate measurements use next higher scale.2. Measurements shown allow 75 mm over average reach.

Fig. 5.4. GUARDING DISTANCES

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5.3 DANGEROUS PARTS REQUIRINGGUARDING (See alsoFigs 5.5 to 5.12).5.3.1 Minimum clearance of moving parts. Wherethere is a risk of personal injury from any nip pointor shear hazard, between any moving part of carryingmechanism of the conveyor and any attachment fixedthereto, and any fixed portion of the conveyorstructure and any other equipment, the clearance shallbe not less than 90 mm. Where this minimumclearance is not practicable, the clearance may bereduced provided that the nip point or shear hazard iseffectively guarded.

As an alternative, pop-out rollers or dead plateswhich, when operating, allow a minimum clearanceof 90 mm to be maintained, may be provided. Theforce required to operate such devices shall notexceed 110 N.Where the surface of the moving part of the conveyoris provided with projections exceeding 6 mm inheight, or where there is any type of attachment tothe moving part, the minimum clearance of 90 mmshall be maintained between the highest point of theprojection and the adjacent structure.

5.3.2 Nip points and shear hazards.Guards shallbe provided to prevent accidental contact with nippoints or shear hazards where the nip point or shearhazard exists up to a height of 2.5 m above any floor,platform level, or stored goods or materials.

5.3.3 Rotating parts. The use of exposedprojecting parts such as keys, bolts and set-screwheads on rotating members should be avoided wherepossible. Where this is not possible, such projectingparts shall be provided with guards. Guards shall beprovided for all exposed shaft couplings and collars.

Sheet metal guards shall be provided for all fluidcouplings which are provided with fusible plugs.

5.3.4 Hoppers and chutes.All openings to hoppersand chutes shall be suitably protected where there isdanger of personnel falling into the opening.Hoppers or chutes shall be provided with accessopening so that, as far as possible, any necessarycleaning inspection may be carried out from outsidethe hopper or chute.

The sides of open hoppers or chutes shall be highenough to prevent material falling into working areasbelow and to prevent injury to personnel by contactwith moving parts in the conveyor. Open chutesshould be provided with front plates at the pointwhere conveyors discharge into them to preventmaterials from bouncing out of the chute.Chute doors shall be located so that when open theydo not create a hazard to personnel during normaloperation of the plant. When the chute doors areopen, there shall be a minimum headroom of not lessthan 2 m .

5.4 REMOVAL OF GUARDS.5.4.1 Fixed guards. Where required for inspection,maintenance, or operational purposes, hingedinspection doors may be provided in a fixed guard,but such inspection doors shall comply withClause 5.4.2.

5.4.2 Removable guards and covers. Liftinghandles or lugs shall be provided where required forthe safe removal or opening of guards or covers.Removable guards and covers shall be clearlylabelled ‘DANGER — Isolate drive before removingguard’.

5.5 GUARDING OF OTHER AREAS.5.5.1 Loading, unloading, and discharge points.Wherever a person is employed at a loading,unloading, work station, transfer, or discharge point,adequate safeguards in the form of guard rails,fences, or close fitting guards shall be installed toprevent injury to personnel.

5.5.2 Guarding of openings in floors. In locationswhere conveyors pass through a floor or where it ispossible to inadvertently step upon moving plant,hand railing and toe boards shall be provided inaccordance withAS 1657. Provision should be madefor a height gauge at the loading end where aconveyor passes through a floor to ensure sufficientclearance between the load and the floor.

5.5.3 Restricted areas. Where conveyors areinstalled in restricted access areas, they may beconsidered as being partially for fully guarded at thediscretion of the Regulatory Authority.

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Fig. 5.5 TYPICAL GUARDS FOR HEAD PULLEY

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Fig. 5.7 TYPICAL GUARD AT THE TAIL END OF THE CONVEYOR

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Fig. 5.8. TYPICAL GUARD FOR A CHUTE

Fig. 5.9. TYPICAL GUARD AT BEND OF CONVEYOR

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Fig. 5.10. TYPICAL GUARD FOR A TRAVELLING TRIPPER

Fig. 5.11. TYPICAL GUARD FOR GRAVITY TAKE-UP AT FLOOR LEVEL

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Fig. 5.12. TYPICAL GUARD FOR ACCESS UNDER A CONVEYOR

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SECTION 6. SPECIFIC REQUIREMENTSFOR UNIT-HANDLING CONVEYORS

6.1 GENERAL. Conveyors designed for unit loadsshall comply with the requirements of this Sectiontogether with the appropriate and applicablerequirements specified in other Sections.

Where routine operations, maintenance, andreplacement of parts is necessary and such parts arenot readily accessible, access and platforms shall beprovided in accordance withAS 1657.

6.2 SLAT CONVEYORS. Unless deemed safe bylocation and position, the sides and undersides of slatconveyors shall be appropriately guarded (seeFig. 6.1). All slats shall be designed for live load andshall include an allowance for wear. The hazardwhich may be caused by the space between slats orvariation in such space as they move along theconveyor track shall be eliminated as follows:(a) Slats travelling in a straight line. The space

between slats travelling in a straight line shouldbe 25 mm; however, where the slats have a clearspace between of more than 25 mm, the entirespace under the top or carrying rung of slatsshall have a solid, smooth bed to prevent ashearing hazard between the moving slats andany structure or return run.

(b) Change of direction. Where the minimumdistance between slats is less than 20 mm ormore than 30 mm when passing around the endshaft sprockets or where changes of directionoccur, the slats shall be guarded in a manner toprevent any person from receiving injury fromthe closing slats.

6.3 TOWING CONVEYORS (See Fig. 6.2).Underfloor or overhead truck towing conveyors shallbe provided with means to release the truck from thetow chain in the event of the truck or load meetingan obstruction.

There shall be at least 600 mm clear space betweenany two trucks and their loads on parallel lines orbetween any two trucks, including loads and a fixedobject.Tow truck wheels shall be guarded by one of thefollowing methods:

(a) By providing guards on the wheels to within20 mm of the floor.

(b) By providing a skirt guard on the truck to within20 mm of the floor.

(c) By any other method which provides equivalentsafety to personnel.

Fig. 6.1. SLAT CONVEYOR

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Fig. 6.2. TRUCK TOWING CONVEYOR

Fig. 6.3. POSITION OF PROTECTIVE PLATE

Fig. 6.4. PROVISION OF POP-OUT ROLLERS

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6.4 ROLLER FLIGHT CONVEYORS. Where therollers of roller flight conveyors are arranged toprovide a clear space of more than 25 mm and thereare structural members under the rollers whichpresent a shear hazard, and the conveyor is not safeby virtue of its position, the entire space under thetop or carrying run of rollers shall have a solidsmooth bed to prevent a shearing hazard between themoving rollers and the structure.

Where the rollers are not mounted on the centrelineof the chain and where the minimum clearancebetween the rollers is less than 25 mm, the closingroller shall be guarded externally at the closing point.

6.5 FLAT BELT CONVEYORS.6.5.1 Protective plate. A table or a suitable flatprotective plate used in conjunction with side platesor side guards shall be provided under the belt to thetangent line of the pulley to minimize the possibilityof accidents between the nip point of the belt and thepulley (seeFig. 6.3).6.5.2 Transfer points. At transfer points, where abelt conveyor discharges onto a roller conveyor,means shall be provided to ensure a minimumclearance between the conveyors of 90 mm exceptwhere guards are provided (seeClause 5.3).

This minimum clearance may be reduced by usingpop-out type rollers or dead plates, provided that theroller substructure or support does not encroach onthis clearance (seeFig. 6.4).

6.5.3 Return idler guarding. On any exposedsection of a conveyor which is not safe by virtue ofits location or position, the return idler rollers shallbe provided with guards to prevent accidental contactwith nip points of any return idler and belt where thenip points are between 0.6 m and 2.5 m above anyfloor, platform or level.

6.6 OVERHEAD CHAIN OR CABLE CONVEY-ORS. That portion of an overhead chain or cableconveyor which travels so that the lowest point of theconveyor or its load is more than 2.5 m above groundlevel shall be provided with underguarding to sustainany object which may fall from the conveyor and infalling cause injury to persons underneath.

Where traction wheels or roller turns are installed ata height of less than 2.5 m from the ground level, thenip points between the chain and the wheel or rollershall

be guarded. Traction wheels or roller turns shall bedesigned so that their fall due to failure of bearingsor shafts is minimized.

6.7 OVERHEAD CHAIN OR CABLE CON-VEYOR (POWER AND FREE TYPE). Where theunderside of the free track of an overhead chain orcable conveyor is within 2.5 m of the floor level, thepower chain and trolley shall be suitably guardedwhere they pass through the yokes. Where, however,access to the trolley is from walkways provided formaintenance, yokes need not be specifically guardedprovided that the clearance between the trolleybracket and the yoke is not less than 30 mm.

Where drop sections are used, suitable means shall beprovided to prevent the following free trolley fromentering the open section of the track, and the freetrolley in the dropped section shall be positivelyretained on its track.Means shall be provided to stop the descent of anydrop section or to control its speed to not more than125 percent of its normal operation; in any case, itsspeed shall not exceed 500 mm/s.

6.8 SWING TRAY CONVEYORS (See Figs 6.5and 6.6).6.8.1 Fork tray type. Where there is more than oneloading point, a fork tray type conveyor or itscontrols shall be designed so as to ensure that theloading forks or fingers can be in the loadingposition at only one level at any one time while theconveyor is in motion.

Where the discharge is automatic, means shall beprovided to ensure that the conveyor will stop shouldthe receiving area be unable to take the dischargeload.

Loading and unloading points shall be guarded byfixed guards extending a distance of at least 1 mfrom the sill line of the loading or unloading point.

6.8.2 Solid tray type. Where the discharge fromsolid tray type conveyors is not automatic, theloading and unloading point shall be provided withdoors electrically interlocked to prevent movement ofthe conveyor while any door is open.

Fig. 6.5 SWING TRAY CONVEYOR (DETAIL)

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6.9 VERTICAL CHAIN CONVEYORS (OP-POSED SHELF TYPE) (SeeFig. 6.7). Means shallbe provided on vertical chain conveyors to stop the

conveyor in the event of any portions of the loadprojecting beyond the door head or still line.

Fig. 6.6. SOLID TRAY CONVEYOR

Fig. 6.7. VERTICAL CHAIN CONVEYOR

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SECTION 7. SPECIFIC REQUIREMENTSFOR BULK-HANDLING CONVEYORS

7.1 GENERAL. Conveyors designed for bulk hand-ling shall comply with the requirements of thisSection together with the appropriate and applicablerequirements specified in other Sections.

7.2 SAFE ACCESS.7.2.1 Walkways (SeeClause 4.2). Where appro-priate, a walkway complying withAS 1657should heprovided on at least one side of bulk handlingconveyors. Where inspection, maintenance, andreplacement of parts of a conveyor remote from suchwalkways is necessary and such parts are not readilyaccessible, an additional walkway should beprovided.The provision of an additional walkway is notnecessary where safe access is available and can beprovided on the conveyor structure.7.2.2 Crossovers and underpasses.Where accessis required for operational purposes, crossovers, orunderpasses shall be provided. A suitable crossoveror underpass attached to a mobile tripper will satisfythe requirement. Where appropriate, suitable boardingswitches shall be provided to isolate the travel drive.

7.2.3 Access to drive unit.Access to the drive unitand tail pulleys shall be provided for all bulkhandling conveyors whether of the fixed or shuttletype.7.2.4 Nip points. Unless deemed safe by position orlocation, guards shall be provided to preventaccidental contact with nip points where the nippoints are between 0.6 m and 2.5 m above any floor,platform or level (seeFig. 5.4). Guarding of nippoints shall comply withSection 5.

7.3 BELT CONVEYORS.7.3.1 Danger points. The most important dangerpoints on belt conveyors are shown inFig. 7.1 and

marked with arrows. These are at the nip (wrapping)points of the belt with the pulley. (See alsoFigs 5.5to 5. 12.)7.4 SCREW CONVEYORS.All casings and load-ing, delivery, drainage, and inspection apertures orchutes of screw conveyors shall be guarded orinterlocked to prevent contact with the screw and nippoint.

7.5 EN MASSE AND BUCKET CONVEYORS.Access to the driving machinery or head of en masseand bucket conveyors shall be provided from aplatform of such dimensions as will allow thereplacement of any machinery. Access to and theguarding of the platform shall comply withAS 1657.

7.6 VIBRATING AND OSCILLATING CON-VEYORS. Where access walkway or platform isprovided past or at the end of a vibrating oroscillating conveyor, the requirements ofSection 5shall apply.7.7 DRAG CHAIN CONVEYORS. Where inspec-tion panels are used in the top of the trunking whichencloses the drag chain, a wire mesh screen shall beprovided under the door or panel; such screen shallbe designed and constructed so as to withstand aforce of 750 N in any position upon it and maintainthe required safe clearances at all points of guarding.All loading, delivery, drainage, and inspectionapertures or chutes in the trunking shall be guardedto prevent contact with the ’flights’ or nip points.Such guarding shall be securely bolted and/or weldedin position. Where guards or covers are to be openedfor cleaning the conveyor, they shall be hinged andinterlocked electrically or mechanically with thedriving means by positive non-interference devices soas to prevent movement of the conveyor while theguard or cover is in the open position or is removed.The guarding shall comply withSection 5.

NOTE: Nip points are indicated by arrows.

Fig. 7.1. DANGER POINTS OF BELT CONVEYORS

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SECTION 8. SPECIFIC REQUIREMENTSFOR MOBILE AND PORTABLE CONVEYORS

8.1 GENERAL. Mobile and portable conveyorsshall comply with the requirements of this Sectiontogether with the appropriate and applicablerequirements specified in other Sections.

8.2 DESIGN AND CONSTRUCTION. Mobile andportable conveyors shall be designed and constructedso as to remain stable under normal loading andtransporting conditions. The design and constructionof mobile and portable conveyors shall take intoaccount the magnitude, incidence, conditions andmanner of loading and all forces likely to apply tothe conveyors.

8.3 STABILITY. The margin for stability formobile conveyors and conveyor structures shall bedetermined under the combined effects of —

(a) wind loading;(b) design live and dead loads; and

(c) design live load and dynamic effects.The design margin of stability expressed as apercentage shall be calculated from the followingequation:

where the stabilizing moment is the moment of theconveyor mass about its axis of tipping, and theoverturning moment is the moment of the designloads about the conveyor axis of tipping.The margin of stability for a mobile conveyor shallbe not less than 50 percent.

8.4 ATTACHMENT POINTS FOR TOWING.Suitably designed points of attachment shall beprovided for the towing of mobile conveyors.

NOTE: Reference should be made to the rules for towingmobile conveyors issued by the local traffic authori ties.

8.5 BOOM MOUNTING. The boom or trunkingshall be mounted on a chassis, base or wheels. Theplan distance at right angles to the boom or trunkingbetween the chassis, base, or wheels shall be not lessthan 25 percent of the elevated height of the boom ortrunking.

8.6 LOCKING AGAINST CREEP. Suitablelocking devices shall be provided to prevent creepwhile the conveyor is in use.

8.7 PNEUMATIC TYRES. Where pneumatic tyredwheels are used, stability shall be maintained inconditions of under-inflation or loss of air in any onewheel.

8.8 LOSS OF POWER. Suitable means shall beprovided to automatically sustain the boom in anyposition when power is removed from the raising orlowering medium. A screw or helix type brake fulfilsthis purpose. Pawl and ratchet type winches withoutbrakes shall not be used.

8.9 WIRE ROPE.8.9.1 Safety factors and diameter ratios.Wirerope, where used for elevating booms, shall complywith the appropriate requirements of AS 1656 and AS2759 with respect to minimum factor of safety andratio of rope diameter to drum and sheave diameter.

8.9.2 Attachment. Attachment of the ropes shall bemade in such a manner as will ensure that thestrength of the rope is maintained in the connection.

8.9.3 Minimum diameter. Ropes of less than 6 mmdiameter shall not be used.8.9.4 Load equalizing.Where more than one ropeor fall is used, automatic static means of equalizingthe load on each rope shall be provided.8.9.5 Anchorages.Rope anchorages shall have aminimum safety factor of 4.5.8.10 BOOM OR TRUNKING.8.10.1 Minimum approach.The boom or trunkingshall be designed so that it cannot approach closerthan 1 m to the ground or floor level unless measuresare taken to ensure that the elevated boom ortrunking has its descent controlled to a safe regulatedspeed. The boom raising frame shall not becomedetached from the boom, trunking, or base.

8.10.2 Separation from drive. The boom ortrunking shall be attached and supported so that whenat its lowest elevation or while being transported itcannot rest upon the conveyor drive.

8.10.3 Warning notice.A permanent notice shall beattached in a conspicuous position adjacent to theprime mover (seeFig. 8.1).

The notice shall comply with AS 1319 (see Section4 therein) and shall be displayed on all conveyors onwhich the boom or trunking can be raised in excessof 2 m.8.11 CONVEYOR DRIVE. Where an internalcombustion engine is used as the conveyor powerdrive, the following applies:(a) The speed control should have a positive

shut-off of the power source to prevent speeds inexcess of the designed maximum.

(b) The conveyor should be equipped with a fireextinguisher of sufficient capacity to extinguisha fire arising from the loss of total fuel capacityof the fuel storage tank.

(c) An appropriate cautionary sign should beattached to the conveyor prohibiting its use inconfined spaces because of the toxic hazard ofthe exhaust fumes.

(d) Due consideration should be given to the controlof static electricity (see AS 1020).

8.12 CONTROL OF MOTOR DRIVE.8.12.1 General.An automatic lock-out manual resettype switch shall be provided in an accessibleposition at each end of the conveyor. Drive powerisolation shall comply withClause 4.8.

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8.12.2 Electric power supply. Flexible conductorsproviding power to the conveyor drive shall be —

(a) protected to prevent mechanical damage; and(b) attached to the conveyor in a manner that

prevents strain on the electrical connections.

Core-balance earth-leakage devices should beprovided to circuits feeding mobile conveyors (seeAS 3190).

8.12.3 Clutches.Where toothed or dog type clutchesare used, they shall have not less than four teeth orfour dogs. The teeth or dogs and their matingrecesses shall be undercut sufficiently to preventinadvertent disengagement of clutches.

8.13 GUARDING. The guarding of mobile convey-ors shall comply withSection 5. Guards shall also beprovided as follows:

(a) On return side idlers less than 2.5 m from theground or floor level or at any position that canbe reached by a person while the conveyor isoperable.

(b) On flywheels, couplings, and starter mechanismsof petrol engines.NOTE: It is recommended that impulse, spring, orpermanently attached cord type starters be used to eliminateexposed ir regular surfaces or start ing pulleys.

(c) On exposed or extended shafting of crank typestarting mechanisms.

(d) On bag and bale conveyors to preventdislodgment of the load. Such side guards oraprons shall have an effective height of 100 mmwhether splayed or vertical.

(e) On exposed screws, chains, or flights in hoppers.The design shall be such as will prevent personalcontact with the moving parts.

(f) On return side chains with pusher attachment.Such chains shall be positioned to preventcontact by persons or shall run in protectiveducts or a similar method of guarding.

8.14 SAFE ACCESS.Where appropriate, a meansof safe access shall be provided on the conveyor.

Fig. 8.1 WARNING NOTICE

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SECTION 9. INSPECTION AND MAINTENANCE

9.1 GENERAL. An inspection and maintenanceprogram shall be organized to keep the conveyormechanism in a safe operating condition.

9.2 REGULAR CHECKS. Persons responsible forthe operation, inspection and maintenance ofconveyors and conveyor systems, shall be familiarwith the operational and safety requirements of theequipment. These requirements include the following:(a) Instructions and recommendations provided by

the manufacturer of the equipment.(b) Regular inspection of the relevant parts of the

equipment for abnormal wear.

(c) Implementation of a preventive maintenanceprogram.

(d) Details of maintenance and regular checksappropriately recorded and kept for futurereference.

9.3 REMOVAL OF GUARDS. Where inspectionor maintenance work entails the removal of guardsdrive power shall be disconnected from the conveyor(seeClause 4.8.2).9.4 SAFETY OF PERSONNEL. Where inspectionand maintenance personnel are required to work insituations where there is a risk of falling,consideration should be given to the use of safetybelts and harness assemblies (see AS 1891 andAS 2626).

All persons working on a conveyor or conveyorsystem shall be provided with individual locks andkeys or danger tags for personal safety (seeClause 4.8.2). Where appropriate, a work permitmay be provided (seeAppendix B).Under normal circumstances, where a person hastagged or locked out a conveyor, it is theresponsibility of that person to remove the tag orlock and to reset the control.

SECTION 10. INSTRUCTIONS FOR OPERATINGAND MAINTENANCE

10.1 GENERAL. Operation and maintenanceinstructions should be supplied with all conveyorsand conveyor systems and should be subdivided intofour parts in accordance with Clauses 10.2 to 10.5.

10.2 SYNOPSIS OF PLANT. This part should bea book type reference to all component parts of theconveyor or conveyor plant with machine capacities,speed, serial numbers, and order numbers, and shouldinclude reduced scale general arrangement drawingsof all mechanical and electrical equipment.

10.3 OPERATING INSTRUCTIONS. This partshould give clear instructions on the operation of theconveyor and/or conveyor plant from ‘Start Up’ to

‘Close Down’ including all possible sequences ofcontrol and operation.

10.4 MAINTENANCE INSTRUCTIONS. Thispart should give clear instruction on completeroutines for lubrication and maintenance of theconveyor and/or conveyor plant, and should besupported by arrangement drawings showing the partsrequiring routine lubrication and maintenance.

10.5 SPARE PARTS. This part should compriselists of recommended spares together with serialnumbers, order numbers, and any other details thatwould be necessary in obtaining spares, all of whichshould be illustrated by suitable arrangementdrawings indicating the location of the various partsin question.

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SECTION 11. TRAINING AND SUPERVISION OF OPERATORS

11.1 TRAINING. During the training of conveyoroperators, particular care should be taken to ensurethat each operator understands the safe operation ofthe conveyor and the following safety precautions:(a) The method of stopping and starting the

conveyor.

(b) The hazards which are known to arise in thecourse of normal working.

(c) The hazards liable to arise from bad practices,inattention, and misuse.

(d) The purpose of the guard or safety device, andhow the guard or device may fail.

(e) The necessity for immediately informing theperson in charge if any faults or defects arise,and the danger to the operator in attempting tocorrect any faults.

(f) The ability to recognize overloading or abnormalloading conditions.

Instructions shall be given that guards or safetydevices shall not be tampered with, removed, oraltered in any way, and that adjustable guards shallbe readjusted only by an authorized person. Theoperator’s knowledge on the use of the conveyor orconveyors and the precautions to be taken should beregularly checkedA conveyor operator should be closely supervised bya person with a thorough knowledge of the conveyoror conveyors during the training period.11.2 SAFE OPERATING PROCEDURES. Thefollowing operating procedures apply to all conveyorinstallations:(a) All starting and stopping controls shall be kept

clearly marked. The area around these devicesshall be kept free from obstructions to permitready access to them and a clear view of them atall times.

(b) The area around all loading and unloading pointson the conveyors shall be kept free fromobstructions at all times.

(c) Manual cleaning of belts, pulleys, or drums shallnot be carried out while the conveyor is inmotion.

(d) No person shall be permitted to travel on amoving conveyor at any time, unless anexemption is granted by the RegulatoryAuthority.

(e) Maintenance or repair work shall not be carriedout while a conveyor is in operation. In everycase the power shall be disconnected and thestopping control shall be positively locked in theopen or stop position before such work iscommenced. Where it is not practicable to carryout adjustment of a conveyor while it is stopped,a qualified operator shall be in attendance whilesuch adjustment is being made.

(f) Before a conveyor that has stopped because ofan overload is restarted, the reason shall beascertained and the stoppage cleared. Thestopping control shall be locked out before anyattempt is made to remove the cause of anoverload.

(g) No overload or safety control shall be removedfrom the conveyor. Precautions should be takento prevent unauthorized persons from adjustingor tampering with the adjustment of any suchcontrol. Where adjustments are to be made, theyshall be carried out by a competent authorizedperson.

(h) All persons working on or near a conveyor shallbe instructed in the location and operation ofstopping controls.

(j) At no time should a conveyor be used for apurpose other than one for which it wasdesigned, unless such design has been provedsatisfactory for the new conditions of use andload, nor should it be loaded in excess of its safeworking load.

(k) Good housekeeping shall be maintained at alltimes.

(l) Operators should not wear loose clothing whichmay become entrapped in a conveyor.

11.3 SAFE WORKING METHODS. Operatorsshall be trained in safe working methods (seeAS 1470).

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SECTION 12. MARKING AND IDENTIFICATION

12.1 MARKING OF CONVEYORS. The follow-ing information shall be marked on the conveyor oron labels permanently attached thereto:

(a) The manufacturer’s name, trade name or mark.(b) An identification number or code.

12.2 NAMEPLATES AND LABELS. Nameplatesand labels shall be durable, corrosion resistant andpermanently attached and shall be clearly visible.

12.3 IDENTIFICATION. The identification numbershall be in raised or indented letters or figures of aminimum height of 15 mm complying with AS 1319.

12.4 LOAD CAPACITY. The load capacity for aunit handling conveyor (SWL) should be exhibitedadjacent to or on the conveyor at each loadingposition.The load capacity for a bulk handling conveyor shallbe exhibited on the conveyor; it is acceptable on adata plate or on the driving unit.

Unit handling conveyors of the overhead chain typeshall have its SWL exhibited as mass per attachment,and total load per structure.

12.5 MARKING OF CONTROLS.12.5.1 Start and stop controls. All conveyorcontrols shall be marked with the words appropriateto their function, e.g. stop, start, forward, reverse,raise, or lower. Arrows indicating the direction oftravel shall be provided at forward and reversecontrols. The identification colours used shall be inaccordance with AS 1318.

12.5.2 Emergency stop control. All emergencystop controls including the central emergency stopcontrol shall be clearly marked with their function.

12.6 LOCATION OF SIGNS. Care should beexercised in the choosing of sign mounting locationsto ensure that the possibility of the signs becomingobscured by stacked materials is prevented (see alsoAS 1319).

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APPENDIX A

GLOSSARY OF CONVEYOR TERMS

NOTE: The terms and definitions applicable to conveying systems set out in this Appendix are accompanied by typicalconfigurations for the purpose of clari ty; however, this does not exclude other arrangements that achieve the same effect.

A1 ANTI-RUNBACK DEVICES.A1.1 Anti-runback device for belt conveyors — consists of a full complement of shaped steel spragsor wedges, located in the annular space between concentric inner and outer races. Power is transmittedfrom one race to the other by the wedging action of the sprags between them. Rotation of one race in the‘driving’ direction causes the sprags to tilt, thus transmitting the torque in full from one race to the other.Conversely, rotation of the race in the other direction frees the sprags and permits overrunning betweenthe races.

A1.2 Anti-runback device for overhead chain conveyor— a mechanical device to prevent reversal ofa loaded conveyor under action of gravity when forward travel is interrupted.

UPHILL SAFETY STOP

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A1.3 Anti-runaway device for overhead chain conveyor— a mechanical safety device to lock or catchthe conveyor and prevent running away in the direction of travel in the case of failure.

DOWNHILL RUNAWAY STOP

A2 APRON CONVEYORS.A2.1 Apron conveyor — a conveyor composed of interlocking or overlapping, flat or shaped plates,carried on chains and running on tracks.

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A2.2 Apron conveyor with pans — an apron conveyor in which the sides and ends of the plates areturned upwards to form open pans.

A3 BELT CONVEYORS.A3.1 Belt conveyor— a conveyor using a moving belt for the conveying medium. The belt is usuallydriven by a drum at one end, passing over a free-running drum at the other end. The upper portion of thebelt may be supported by free-running idlers or suitable flat surfaces. This type of conveyor can bearranged for horizontal or inclined travel, the angle of slope depending on the character of the goodsconveyed and the type of belt surface.

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A3.2 Fixed belt conveyor — a stationary mechanical item of plant designed for the conveying ofmaterials and fitted with an endless of fabric, rubber, plastics, leather, or metal.

A3.3 Mobile belt conveyor — a mobile conveyor on wheels which is not self-propelled, carryingcontinuous handling equipment, with either adjustable or non-adjustable heights.

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A3.4 Portable belt conveyor— a portable conveyor on stands, carrying continuous handling equipment,with adjustable heights.

A3.5 Belts conveyor, thrower or spreader— a short high speed belt conveyor, capable of throwingloose bulk material into otherwise inaccessible areas.

A3.6 Blanket, or twin band conveyor — a conveyor composed of two moving belts working in unison,the carrying surfaces being in or near contact. The load is carried between the two belts. This conveyorcan be used up and down steep inclines.

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A3.7 Closed belt conveyor— a conveyor composed of a moving belt capable of being formed into aclosed tubular shape. While in motion the belt opens to receive the load, closes to convey it, and opensto discharge it.

A3.8 Flat belt conveyor — a conveyor composed of a moving flat belt carried on free-running rollersor sliding on a suitable surface.

A3.9 Sloping belt conveyor— a horizontally or vertically tensioned belt conveyor with or without aloading tail unit.

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A3.10 Telescopic belt conveyor— a continuous belt consisting of a series of pulleys which permitsextension or retraction of the conveyor length.

A3.11 Troughed belt conveyor— a conveyor composed of a moving belt carried on horizontal centreand inclined side rollers that imparts a transverse curvature to the belt.

A4 BARREL OR DRUM CONVEYOR — a conveyor with arms fixed to the chains which may be setat a moderate angle to the vertical. Loading can occur at any intermediate floor but unloading can onlyoccur as the arms pass over the top of the chain sprockets and discharge the load.

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A5 BUCKET CONVEYORS.A5.1 Bucket conveyor— any type of conveyor in which the materials are carried in a series of bucketsattached to chains, ropes or belts.

A5.2 Bucket elevator — a conveyor for loose bulk materials with buckets as the carrying mediumattached to the belt or chains as the driving medium.

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A5.3 Continuous bucket conveyor— a belt and bucket or chain and bucket conveyor where the bucketsare set at close pitch. The sides of the buckets are made to overlap thus forming a continuous trough.

A5.4 Gravity bucket conveyor — a conveyor consisting of freely swinging buckets carried betweenparallel endless chains, the buckets being tipped to discharge contents. The centre of gravity of the bucketis below the centre line of the chain pivot and thus the chain may follow any path from horizontal tovertical with the buckets continuing to hang vertically. Feeding of the buckets may either by gravity orby means of a suitable rotary feeder.

Drive corner

A5.5 Inclined belt and bucket conveyor — a conveyor generally total ly enclosed for powderedor granular material, consisting of suitably shaped buckets mounted at predeterminedpitches onan endless belt, but inclined at a slight angle to the vertical. (Similar to vertical belt and bucketconveyor.)

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A5.6 Pivoted bucket conveyor— a conveyor using pivoted buckets attached between two endless chains.The buckets remain in a carrying position until tipped or inverted to discharge.

A5.7 Vertical belt and bucket conveyor— a conveyor generally totally enclosed for powder or granularmaterial consisting of suitably shaped buckets mounted at predetermined pitches on an endless belt. Thebelt obtains its motion from a powdered head pulley and is returned over a tail pulley, adjustment beingprovided to accommodate belt stretch. Material is picked up either by buckets dredging out the bottomof the conveyor or by feeding the material into the passing buckets and then discharged by centrifugalaction while passing over the head.

A5.8 Vertical internal discharge chain and bucket conveyor— a totally enclosed continuous bucketconveyor with the bucket carried between two chains and having inner openings. The material is fed inat the foot of the conveyor and discharge occurs when the buckets are inverted while passing over the headsprockets, the material being delivered by means of a chute passing through a conveyor casing.

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A6 CHAIN CONVEYORS.A6.1 Chain conveyor— a conveyor for unit loads, with an endless driving medium, e.g. chain or cable,and a series of trolleys supported by an overhead track.A6.2 Chain conveyor with driving dogs — a chain conveyor with pusher dogs driving load-carryingtrucks on separate track or floor.

A6.3 Chain or wire rope belt conveyor — a conveyor composed of a belt secured to transverse supportscarried by moving chains or wire ropes. The chains or wire ropes transmit the driving force, the beltforming the load-carrying medium.

A6.4 Drag chain conveyor— a conveyor having one or more endless chains which drag bulk materialsin a through.

A6.5 Overhead chain conveyor (open track type)— a conveyor which uses a bi-planar chain suspendedby wheeled trolleys which run on an overhead track.

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A6.6 Overhead chain conveyor (enclosed track)— a chain conveyor which uses a bi-planar articulatedchain which serves to transmit driving tension and carries the weight of the load. It has rollers disposedin the vertical and horizontal planes running in an enclosed track.

A6.7 Overhead chain or cable conveyor (power and free type)— an overhead chain conveyor withpusher dogs attached to an endless chain or cable driving load-carrying trolleys running on a separate trackfrom which trolleys can be diverted away from the driving chain by means of switches. These conveyorsmay be designed for single plane or multiple plane operations.

A6.8 Positive discharge type chain and bucket conveyor— a conveyor similar to the vertical belt andbucket conveyor but normally operating at slow speeds, and arranged for the buckets to up-end whenapproaching the discharge point by means of deflecting sprockets.

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A6.9 Raised link or offset roller chain conveyor — a conveyor consisting of two or more strands ofchain running in parallel tracks with the loads carried directly on the chains.

A6.10 Single chain or crate conveyor— a conveyor with a centrally located chain as the drivingmedium.

A6.11 Sliding chain conveyor— a conveyor assembled with one or more endless chains sliding on trackson which objects are carried.

A6.12 Swing chain conveyor— a single chain type conveyor assembled with finger trays.

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A6.13 Swing chain conveyor, fork tray type— a conveyor consisting of freely swinging finger typetrays carried between parallel endless chains which swing at the change of direction to pick up on the feedside and discharge the feed on the downward side. The drive is generally at the head of the conveyor, thechains passing over sprockets of considerable diameter. Loading or unloading can be made automatic andcan occur at any intermediate floor level.

A6.14 Swing tray conveyor, solid tray type— a vertical conveyor having one or more endless chainswith suitable pendant trays, or carries which receive and deliver packages or objects at one or moreelevations.

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A6.15 Twin rail conveyor (Power and free type)— an overhead twin rail conveyor of the chain or cabletype.

A6.16 Twin chain type, swing tray — a conveyor with two endless chains and swing trays.

A6.17 Vertical bag or bale conveyor— a conveyor comprising two endless chain connected togetherby flight bars set at suitable interval. The bag or bale is lifted by flight bars and slides up a smoothbacking surface and is ejected by hinged deflectors.

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A6.18 Vertical chain conveyor, opposed shelf type— two or more elevating conveying units opposedto each other. Each unit consists of one or more endless chains whose adjacent facing runs operate inparallel paths so that pairs of opposing shelves or brackets are synchronized to receive packages or traysand deliver them at any number of elevations. (The auto-unload type is illustrated.)

A7 CROSS-BAR CONVEYOR — a conveyor consisting of two strands of chain connected together byfixed bars from which unit loads are suspended.

A8 DISC OR BUTTON CONVEYOR — a conveyor composed of a wire rope or chain carrying discsor buttons and operating in a V-shaped trough.

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A9 EN MASSE CONVEYOR — a conveyor composed of an endless chain built up from shaped flightmoving through an enclosed duct.

A10 FLIGHT CONVEYORSA10.1 Flight conveyor (push-type)— a conveyor comprising one or more endless chains or links towhich flights are attached.

A10.2 Flight conveyor (reciprocating) — a conveyor consisting of a reciprocating beam with attachedhinged flights.

A11 PALLET TYPE CONVEYOR — a conveyor assembled from a series of flat or shaped wheellesscarriers propelled by and attached to one or more endless chains or other linkage.

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A12 POCKET CONVEYOR — a conveyor consisting of a series of pocket made of flexible materialsand festooned between cross-rods carried by two endless chains or other linkage.

A13 PUSHER BAR CONVEYOR — a conveyor assembled from two endless chains, or other linkage,connected at intervals by bars which propel the load.

A14 TRUCK-TOWING CONVEYORS.A14.1 Floor truck-towing conveyor — a moving endless chain or wire rope carried in a trench andmounted above or below floor level, to which is attached by means of a retractable pin, load-carrying towtrucks.

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A14.2 Single strand floor-mounted truck conveyor— a conveyor for unit loads with a single strandchain or wire rope under or above floor level as the driving medium.

A14.3 Over and under single strand floor truck conveyor— a conveyor for unit loads with a singlestrand chain or wire rope just under or above floor level as the driving medium.

A14.4 Overhead monorail chain conveyor— a conveyor for units loads, with an endless chain or cableas the driving medium for a series of trolleys.

A15 GRAVITY CHUTE — a straight, curved, or spiral smooth trough by which bulk materials or unitsloads are directed and lowered by gravity.

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A16 HYDRAULIC CONVEYORSA16.1 Hydraulic conveyor — a conveyor transporting materials by means of a moving stream of wateror other liquid.

A16.2 Open type hydraulic conveyor— a hydraulic conveyor of the open type for loose bulk materials.

A16.3 Tube type I hydraulic conveyor — a hydraulic conveyor of the tube type suitable for unit loads.

A16.4 Tube type II hydraulic conveyor — a hydraulic conveyor of the tube type suitable for loose bulkmaterials.

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A17 INCLINED BAG CONVEYOR — a conveyor set at an inclination to the vertical, composed of twoparallel endless chains connected together by flight bars set at suitable intervals. The bag or bale is liftedby the flight bars and slides up a smooth surface, discharging when it falls forward after passing over thetop sprocket.

A18 MAGNETIC CONVEYOR — a conveyor having a flexible rubber or canvas belt moving adjacentto a static magnetic field which imparts a retaining influence or pull to any magnetizable article and soallows the belt to move the article through vertical and/or horizontal planes.

A19 OSCILLATING CONVEYOR — a conveyor similar to a vibrating conveyor but of the slow-speedtype, using an eccentric crankshaft to move the trough or tube.

A20 PLATE CONVEYOR — a continuous conveyor for loose bulk materials or unit loads.

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A21 POWDERED ROLLER CONVEYOR — a series of rollers over which packages or objects aremoved by the application of suitable power means to all or a part of the rollers.

A22 RECIPROCATING BEAM CONVEYOR — a conveyor assembled with one or more reciprocatingbeams with tilting dogs or pushers.

A23 ROLLER CONVEYOR — a series of rollers supported in a frame over which objects are advancedmanually, by gravity, or by power.

A24 SCRAPER DRAG BAR OR DRAG LINK CONVEYOR — a conveyor having one or more chainsequipped with scraper bars and operating in a trough.

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A25 SCREW CONVEYORS.A25.1 Screw conveyors— a conveyor for loose bulk materials with a trough or tube as the carryingmedium, the material being transported by the action of a rotating helix or broken screw (paddle type.)A25.2 Screw tube conveyor— a screw conveyor for transporting bulk materials by means of a close-bladed screw.

A25.3 Vertical screw tube conveyor— a screw conveyor for transporting bulk material vertically.

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A25.4 Screw auger conveyor— a screw conveyor in which the conveying element is in the form of asolid helix attached to a central rotating shaft working within a tube normally inclined at angle to thehorizontal. The shaft normally rotates at a relatively high speed. The conveyor is generally used forintermittent light duties and for free flowing non-abrasive material.

A25.5 Screw conveyor, trough type— a revolving pipe or shaft on which is mounted helically shapedflighting which serves to convey bulk materials along the trough or a defined path.

A25.6 Screw conveyor, full-bladed type— a screw conveyor in which the conveying element is in theform of a solid helix with either constant or varying pitch, attached to a central rotating shaft the wholebeing enclosed in a ‘U’ trough or tube, the material being moved along by the action of the helix.

A25.7 Screw conveyor, paddle type— a screw conveyor which is similar to the full bladed type, butthe conveying elements are in the form of separate paddles of various shapes attached to the central shaftin the helical pattern, allowing mixing of the material during conveying.

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A25.8 Screw conveyor, ribbon type— a screw conveyor which is similar to the full-bladed type exceptthat the helix is in the form of a ribbon attached to the central shaft by ‘palm-bolts’.

A25.9 Screw tube conveyor— a screw conveyor in which the conveying element is in the form of aribbon helix attached to the inside of a revolving tube.

A26 SHUTTLE CONVEYOR — any conveyor such as a belt, chain, pan, apron, screw, etc, in a self-contained structure movable in a defined path parallel to the flow of the material.

A27 SLATE CONVEYORS.A27.1 Slat conveyors— one or more endless chains to which non-overlapping non-interlocking spacedslats are attached to form a moving support for the packages or objects being conveyed.

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A27.2 Slat conveyor with pushers— a slat conveyor for loose bulk materials or unit loads with slatsand pushers as the carrying medium and with chains as the driving medium.

A27.3 Slat band conveyor— a light duty flat top conveyor in which small hinged plates serve as boththe chain and the work carrying plates. This conveyor provides a flat, smooth, and level surface commonlyused to transport cans and bottles.

A28 SLING OR POCKET CONVEYOR — a conveyor in which the conveying medium consists offlexible fabric pockets, e.g. canvas, each suspended between two cross-bars supported at their ends fromtwo endless chains.

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A29 STEEL BAND CONVEYOR — a belt conveyor in which the carrying medium is a thin flexiblesteel band.

A30 THROWING MACHINE, VANE TYPE — a high speed rotating drum with vanes or paddlescapable of throwing loose bulk material into otherwise inaccessible areas.

A31 TWIN FLAT TOP CONVEYOR — a conveyor which utilizes two heavy duty flat top linescommonly set flush in the floor and driven by a single head shaft to transport large, heavy, or wide objectssuch as a complete motor vehicle, rolls of paper or sheet steel.

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A32 TRANSFER TABLES.A32.1 Transfer tables— equipment for transferring a load from one conveyor to another.A32.2 Ball transfer table — a table with freely mounted balls proud of its surface used for transferringa load with a suitable base, from one roller conveyor to another.

A32.3 Roller conveyor transfer (right angle) — equipment for transferring a load from one rollerconveyor to another running at right angles by means of small manually operated or power-operated liftingrollers. The centreline of the load changes its direction of travel by 90 degrees.

A 32.4 Roller conveyor transfer (straight through) — equipment for transferring a load from one rollerconveyor to others running parallel by means of a roller-topped traversing section. The centreline of theload continues to follow the same direction after transfer.

A32.5 Roller conveyor turntable— equipment for transferring a load from roller conveyor to anotherrunning at angle to it by means of a roller-topped turntable. The centreline of the load does not changeits direction of travel in relation to the centreline of the conveyor.

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59 AS 1755—1986

A32.6 Roller flight conveyor (accumulating)— a conveyor having double strands of chain connectedby spindles supporting freely rotating load-carrying rollers.

A32.7 Roller conveyor — a series of rollers supported in a frame over which packages or objects aremoved manually or by gravity.

A32.8 Hinged section— a hinged section,inserted in a roller conveyor, and counterbalanced to facilitatethe upward tilting of the section to produce a clear way through the conveyor track.

A32.9 Wheel conveyor— a conveyor consisting of a framework and spindles carrying small free runningwheels for the movement of loads having suitable flat bases.

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A33 TRIMMER CONVEYOR — a self-contained, lightweight portable conveyor of the belt type fortransporting bulk materials.

A34 TRIPPER — a conveyor, on wheels, for transporting and discharging bulk materials.

A35 TROLLEY CONVEYOR — a conveyor consisting of a series of trolleys supported from or withinan overhead track connected by an endless chain, cable, or other linkage with loads suspended from thetrolleys.

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61 AS 1755—1986

A36 VIBRATING CONVEYOR — a trough or tube flexibly supported and vibrated to convey bulkmaterial or objects.

A37 WALLED BELT CONVEYOR — a conveyor consisting of a moving belt having a flat carryingface extended to form side walls of limited height.

A38 WIRE MESH BELT CONVEYOR — a conveyor in which the carrying medium is of meshconstruction, either flat or troughed, the conveyor may be straight or curved.

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APPENDIX B

EXAMPLE OF A WORK PERMIT

Conveyor identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Date: . . . . . .

System isolating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Time: . . . . . .

Work to be done . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

PREPARATION

Fuses out Danger tagged Locked out

Switches out Danger tagged Locked out

Isolator out Danger tagged Locked out

Control circuit out Danger tagged Locked out

Flame/Welding: Not permittedPermitted

Protective Equipment Breathing apparatus Type . . . . . . . . . . . . . .

Safety belt and lifeline

Air supply

Low voltage electric tools

Protective clothing Type . . . . . . . . . . . . .

Rescue equipment

Have operators been trained and rehearsed on the use of the equipment?

(continued)

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63 AS 1755—1986

AUTHORIZATION

Permit to . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Time: .. . . . . . . . . . . . . . . . Date: . . . . . .(Maintenance Supervisor)

Authorized by . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . for: . . . . . . . . . . . . . . . . . . . . . . . . . . . . .(Manager, Engineer, Supervisor) (Period)

Persons authorized to enter . . . . . . . . . . . . . . . . . .

Assistant(s) . . . . . . . . . . . . . . . . . . . . . . .

I/We agree to observe the safety precautions and to use the protective clothing and equipment providedabove:

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

RETURN TO SERVICE

Work completed/not completed Time: . . . . . . . . . . . . . . Date: . . . . . . . . . . . . . . . . . . . . . .

Remarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

System handed back. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . to: . . . . . . . . . . . . . . . . . . . . . . . . . .(Maintenance Supervisor) (Manager, Engineer, Supervisor)

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ANNEXLIST OF REFERENCED DOCUMENTS

AS 1020 The Control of Undesirable Static ElectricityAS 1074 Steel Tubes and Tubulars Threaded or Suitable for Threading with Pipe Threads of Whitworth

FormAS 1110 ISO Metric Hexagon Precision Bolts and ScrewsAS 1111 ISO Metric Hexagon Commercial Bolts and ScrewsAS 1112 ISO Metric Hexagon Nuts, Including Thin Nuts, Slotted Nuts and Castle NutsAS 1131 Dimensions of Hot-rolled Structural Steel SectionsAS 1163 Structural Steel Hollow SectionsAS 1204 Structural Steels — Ordinary Weldable GradesAS 1252 High Strength Steel Bolts With Associated Nuts and Washers for Structural EngineeringAS 1318 SAA Industrial Safety Colour CodeAS 1319 Safety Signs for the Occupational EnvironmentAS 1332 Conveyor Belting with Textile ReinforcementAS 1333 Conveyor Belting of Elastomeric and Steel Cord ConstructionAS 1379 Ready-mixed ConcreteAS 1444 Wrought Alloy Steels — AISI-SAE Standard, Hardenability (H) and Stainless SeriesAS 1448 Carbon Steel and Carbon-manganese Steels — Forgings (Ruling Section 300 mm Maximum)AS 1470 Code of General Principles for Safe Working in IndustryAS 1480 SAA Concrete Structures CodeAS 1532 Short Pitch Transmission Precision Roller Chains and Chain WheelsAS 1565 Copper and Copper Alloys — Ingots and CastingsAS 1656 Steel Wire Ropes (Other than for Mining Purposes)AS 1657 SAA Code for Fixed Platforms, Walkways, Stairways and LaddersAS 1669 Friction-surface Rubber Transmission BeltingAS 1680 Code of Practice for Interior Lighting and the Visual EnvironmentAS 1734 Wrought Aluminium and Aluminium Alloy Flat Sheet, Coiled Sheet and Plate for General

Engineering PurposesAS 1830 Grey Iron CastingsAS 1831 Iron Castings — Spheroidal or Nodular Graphite Cast IronAS 1832 Iron Castings — Malleable Cast IronAS 1866 Wrought Aluminium and Aluminium Alloy Extruded Rod, Bar, Solid and Hollow Shapes for

General Engineering PurposesAS 1874 Aluminium Ingots and Aluminium Alloy Ingots and CastingsAS 1891 Industrial Safety Belts and HarnessesAS 2074 Steel CastingsAS 2152 Rivetless Chain, Trolleys and Trolley AttachmentsAS 2451 Bolts, Screws and Nuts with British Standard Whitworth ThreadsAS 2465 Unified Hexagon Bolts, Screws and Nuts (UNC and UNF Threads)AS 2626 Industrial Safety Belts and Harnesses — Selection, Use and MaintenanceAS 2759 Steel Wire Rope — Application GuideAS 3000 SAA Wiring RulesAS 3190 Approval and Test Specification for Current-operated (Core Balance) Earth-leakage DevicesAS A34 Dimensions of Rivets from1/2 Inch to 13/4 Inches Diameter (Excluding Rivets for Boilers)AS B61 Spur and Helical GearsAS B66 Worm Gearing (Inch Series)

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