As 1755-1986 Conveyors - Design & Fabrication

AS 1755—1986

Australian Standard® Conveyors—Design, construction, installation, and operation—Safety requirements

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

The following interests are represented on Committee SF/25: Australian Conveyor Manufacturers Association Bureau of Steel Manufacturers of Australia Confederation of Australian Industry Department of Employment and Industrial Affairs, Qld Department of Employment and Industrial Affairs, Vic. Department of Industrial Relations, N.S.W. Department of Labour S.A. Electricity Commission of New South Wales Melbourne Chamber of Commerce Metal Trades Industry Association of Australia National Safety Council of Australia Safety Institute of Australia (Incorporated) State Electricity Commission of Victoria

  Review of Australian Standards. To keep abreast of progress in industry, Australian Standards are subject  to periodic periodic review review and are kept kept up to date by the i ssue ssue of amendment amendmentss or new editions as necessa necessary. ry. It is important important t herefore herefore t hat Standar Standards ds users users ensure ensure that they are in possession possession of the latest edition, and any amendments amendments thereto. Full Full details details of all Australian Australian Standard Standardss and related publications publications wil l be found in t he Standards Standards Australia Australia Catalogue of Publications; this information is supplemented each month by the magazine ‘The Australian Standard’, Standard’, which subscribing subscribing members receive, and which giv es details of new publications, new editi ons and amendments, and of withdrawn Standards. Suggestions for improvements to Australian Standards, addressed to the head office of Standards Australia, are welcomed. Notification of any inaccuracy or ambiguity found in an Australian Standard should be made without 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, AND OPERATION — SAFETY REQUIREMENTS

First published published (as AS CZ15) . . . . . . . . . . . . . . AS 1755 1755 first publi published shed . . . . . . . . . . . . . . . . . . Seco Second nd edition edition . . . . . . . . . . . . . . . . . . . . . . . .

1971 1971 1975 1975 1986 1986

Incorporating: Amdt 1 — 1995

PUBLISHED BY ST AND ANDARDS ARDS AUSTRALIA (STANDARDS (STANDARDS ASSOCIATION ASSOCIATION OF AUSTRALIA) AUSTRALIA) 1 THE CRESCENT, HOMEBUSH, NSW 2140 ISBN 0 7262 4012 5

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PREFACE This edition of this standard was prepared by the Association’s Committee on Guarding of Conveyors, t o supersede AS 1755-1975, SAA Conveyor Safety Code. It contains the safety measures to be implemented for the installation and operation of  conveyors and conveyor systems, and sets out the necessary personal protective measures against hazards experienced by operators of such plant. The text of this standard has been modified in accordance with the appropriate recommended modifications received in response to a request for the review of  AS 1755-1975. The recommended changes included in this standard cover the general safety requirements for large and small conveyors and conveyor systems, and in particular the details for conveyor control and motor drive isolation. Technical and editorial amendments have been incorporated in line with available ISO documentation for mechanical handling equipment, and Appendix A has been expanded to include conveying equipment not covered in the previous edition.

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STANDARDS AUSTRALIA

Users of Standards are reminded that copyright subsists in all Standards Australia publications and software. Except where the Copyright Act allows and except where provided for below no publications o r software produced by Standards Australia may be reproduced, stored in a r etrieval system in any f orm or transmitted by any means without prior permission in writing from Standards Australia. Permission may be conditional on an appropriate royalty payment. Requests for permission and information on commercial software royalties should be directed to the head office of Standards Australia. Standards Australia will permit up to 10 percent of the technical content pages of a Standard to be copied for use exclusively in-house by purchasers of the Standard without payment of a royalty or advice to Standards Australia. Standards Australia will also permit the inclusion of its copyright material in computer software programs for no royalty payment 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 t he Standard and that it i s updated whenever the Standard is amended or revised. The number and date of the Standard should therefore be clearly identified. The use of material in print form or in computer software programs to be used commercially, with or without payment, or in commercial contracts is subject to the payment of a royalty. This policy may be varied by Standards Australia at any time.

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CONTENTS Page

SECTION 1. SCOPE AND GENERAL 1.1 1.2 1.3 1.4 1.5

Scope . . . . . . . . . . . . Purpose . . . . . . . . . . . Application . . . . . . . . Referenced Documents Definitions . . . . . . . .

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2.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 Material Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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SECTION 2. MATERIALS

SECTION 3. DESIGN AND CONSTRUCTION 3.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2 Design and Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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SECTION 4. INSTALLATION 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9

General . . . . . . . . . . . . . . . . . . . . . . . . Access to Conveyors . . . . . . . . . . . . . . Crossovers for Aisles and Passageways . . Conveyors I nstalled in Tunnels or Pits . . Lighting . . . . . . . . . . . . . . . . . . . . . . . Electrical Requirements . . . . . . . . . . . . Protective Devices . . . . . . . . . . . . . . . . Conveyor Control . . . . . . . . . . . . . . . . . Fire Protection . . . . . . . . . . . . . . . . . . .

SECTION 5. GUARDING 5.1 General . . . . . . . . . . . . . . . . . . . . . 5.2 Design and Construction of Guards . 5.3 Dangerous Parts Requiring Guarding 5.4 Removal of Guards . . . . . . . . . . . . . 5.5 Guarding of Other Areas . . . . . . . . .

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SECTION 6. SPECIFIC REQUIREMENTS FOR UNIT-HANDLING CONVEYORS 6.1 6.2 6.3 6.4 6.5 6.6 6.7

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Slat Conveyors . . . . . . . . . . . . . . . . . . . . . . . . Towing Conveyors . . . . . . . . . . . . . . . . . . . . . Roller Flight Conveyors . . . . . . . . . . . . . . . . . Flat Belt Conveyors . . . . . . . . . . . . . . . . . . . . Overhead Chain or Cable Conveyors . . . . . . . . Overhead Chain or Cable Conveyor (Power and Free Type) . . . . . . . . . . . . . . . . . . 6.8 Swing Tray Conveyors . . . . . . . . . . . . . . . . . . 6.9 Vertical Chain Conveyors (Opposed Shelf Type)

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SECTION 7. SPECIFIC REQUIREMENTS FOR BULK-HANDLING CONVEYORS 7.1 7.2 7.3 7.4 7.5 7.6 7.7

General . . . . . . . . . . . . . . . . . . . . . . . . . Safe Access . . . . . . . . . . . . . . . . . . . . . . Belt Conveyors . . . . . . . . . . . . . . . . . . . Screw Conveyors . . . . . . . . . . . . . . . . . . En Masse and Bucket Conveyors . . . . . . . Vibrating and Oscillating Conveyors . . . . Drag Chain Conveyors . . . . . . . . . . . . . .

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SECTION 8. SPECIFIC REQUIREMENTS FOR MOBILE AND PORTABLE CONVEYORS 8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8 8.9 8.10 8.11 8.12 8.13 8.14

General . . . . . . . . . . . . . . . . . . . . . . . . Design and Construction . . . . . . . . . . . . Stability . . . . . . . . . . . . . . . . . . . . . . . . Attachment Points for Towing . . . . . . . . Boom Mounting . . . . . . . . . . . . . . . . . . Locking Against Creep . . . . . . . . . . . . . Pneumatic Tyres . . . . . . . . . . . . . . . . . . Loss of Power . . . . . . . . . . . . . . . . . . . . Wire Rope . . . . . . . . . . . . . . . . . . . . . . Boom or Trunking . . . . . . . . . . . . . . . . . Conveyor Drive . . . . . . . . . . . . . . . . . . Control of Motor Drive . . . . . . . . . . . . . Guarding . . . . . . . . . . . . . . . . . . . . . . . Safe Access . . . . . . . . . . . . . . . . . . . . .

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SECTION 9 INSPECTION AND MAINTENANCE 9.1 9.2 9.3 9.4

General . . . . . . . . Regular Checks . . . Removal of Guards Safety of Personnel

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SECTION 10 INSTRUCTIONS FOR OPERATING AND MAINTENANCE 10.1 10.2 10.3 10.4 10.5

General . . . . . . . . . . . . . Synopsis of Plant . . . . . . Operating Instructions . . . Maintenance Instructions . Spare parts . . . . . . . . . . .

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Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Safe Operating Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . Safe Working Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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SECTION 11 TRAINING AND SUPERVISION OF OPERATORS 11.1 11.2 11.3

SECTION 12. MARKING AND IDENTIFICATION 12.1 12.2 12.3 12.4 12.5 12.6

Marking of Conveyors . Nameplates and Labels Identification . . . . . . . Load Capacity . . . . . . Marking of Controls . . Location of Signs . . . .

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Glossary of Conveyor Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . Example of a Work Permit . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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

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APPENDICES A B

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STANDARDS ASSOCIATION OF AUSTRALIA Australian Standard for CONVEYORS — DESIGN, CONSTRUCTION, INSTALLATION, AND OPERATION — SAFETY REQUIREMENTS SECTION 1. SCOPE AND GENERAL 1.1 SCOPE. This standard applies to the design, construction, installation, and guarding of conveyors and conveyor systems, whether of a temporary or permanent nature, for the conveyance of materials.

1.5.1 Accompanying documents — documents accompanying t he equipment containing all important information f or the user, in particular that rel evant to safety.

It sets out requirements for material s of construction, mechanical design, general safety requirements, specific requirements for unit and bulk handling conveyors, training and supervision of  operators,inspection and maintenance, and operating and maintenance instructions.

1.5.2 Controls.

The standard is not intended to apply to industrial trucks, tractors or trailers, prime movers coupled with monorails, tiering machines, cranes, hoists, skip hoists, monorails, power shovels, power scoops, bucket drag lines, platform elevators designed to carry passengers or the elevator operator, moving stairways and highway or rail vehicles, or conveyors specifically designed for the conveyance of  passengers. This standard does not cover individually powered or line shaft powered rollers, which are used in other than continuous manufacturing industries (see also Clause 1.5.4.2). A glossary of conveyor terms is provided Appendix A.

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1.2 PURPOSE. The purpose of this standard is to establish uniformity in engineering practice with respect to conveyors throughout the Commonwealth of Australia. The requirements have been drafted to provide conveyors and conveyor systems with practical and adequate safety features and t o stipulate conditions for safety in operation and maintenance. Attention is particularly drawn to t he requirements of  the Regulatory Authority specific to equipment safety. 1.3 APPLICATION. This standard shall apply to all new conveyors and new conveyor systems and any addition or amendment to the standard shall be applied in a similar manner. The term ‘new conveyor’ is not intended to apply to a conveyor or conveyor system in connection with which a contract for supply and installation had been entered into prior to the date on which the standard and its amendments came into operation. 1.4 REFERENCED DOCUMENTS. A list with titles of the documents referred to in this standard is given in the Annex. 1.5 DEFINITIONS. For the purpose of this standard, the following definitions apply:

1.5.2.1 Emergency stop control — a device which stops a conveyor system(s) i n the shortest practicable time . 1.5.2.2 Start control — a device for starting up a conveyor system situated appropriately for the local or re mot e st art in g o f t he s yst em . (S ee al so Clause 4.8.7). 1.5.2.3 Stop control — a normal stop control which is electrically wired directly in the circuit or in the starting control circuitry, resulting in a fail safe immediate or sequence stopping of the conveyor system. 1.5.3 Control circuit isolation — the interruption of  the control circuitry of the drive motor(s) of a conveyor system(s). 1.5.4 Equipment and parts. 1.5.4.1   Bulk-handling conveyor  — a conveyor designed for moving loose material from one location to another. 1.5.4.2 Conveyor  — apparatus or equipment worked by any power other than manual, by which loads are raised, lowered or tr ansported or ar e capable of being raised, lowered, transported, or continuously driven by — (a) an endless belt, rope or chain or other similar means; (b) buckets, trays or other containers or fittings moved by an endless belt, rope, chain or other similar means; (c) a rotating screw; (d) a vibration or walking beam; or (e) a powered roller conveyor where the rolls are driven by an endless belt, rope, or chain, and including the supporting structure, auxiliary equipment and gear used in connection with the conveyor. 1.5.4.3 Conveyor system — an installation of one or more conveyor(s) which transport or tr ansfer loads from one conveyor to another and whose control is integrated . 1.5.4.4 Unit-handling conveyor  — a conveyor designed for moving individual components or groups

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of components either directly or within a container from one location to another. 1.5.5 Fail safe — the feature of a conveyor or conveyor system which minimizes any hazard to personnel and equipment in the event of power failure, malfunction of the conveyor or conveyor system or the like. 1.5.6 Guards. 1.5.6.1 Guarded  — shielded, fenced, enclosed or otherwise protected by means of suitable enclosure, covers, casing, shield guards, trough guards, railing guards, or by nature of location or position so as to remove foreseeable risk of personal injury being caused by accidental contact or approach, and for an und er guard s o a s to r emov e an y a ddit i ona l foreseeable risk of personal injury being caused by contact with or spillage of material from the conveyor. 1.5.6.2 Guarded by location or position — the moving parts are protected by their remoteness from the floor, platform, walkway or other working level, or by their location with reference to frame, foundation, or structure so as to remove the foreseeable risk of accidental contact by persons or objects. Remoteness from foreseeable regular or frequent presence of public or employed personnel may in reasonable circ umstances constitute guarding by location.

1.5.6.3 Underguard  — a stationary device of sufficient strength and capacity to catch, retain, and contain any foreseeable spillage which might cause personal injury from a conveyor passing over a roadway, walkway, work space, or like area, for the purpose of protecting persons in that area. 1.5.7 Nip point — that point at which a machine element moving in line meets a rotating element so that it is possible to nip, pinch, squeeze, or entrap objects coming into contact with one of t he two members. The term also applies to the similar point with respect to two rotating parts or two converging parts in linear movement. 1.5.8 Power isolation — the physical separation of  equipment or circuits from all power sources. 1.5.9 Regulatory Authority — a Minister of the Crown, a government department or other public authority having power to issue regulations, orders or other instructions having the force of law in respect of any subject covered by this standard. 1.5.10 Shall and should — the word ‘shall’ is to be understood as mandatory, and the word ‘should’ as non-mandatory, advisory or recommended. 1.5.11 Shear point — the point at which or the line along which a moving part meets or passes close enough to a stationary part or object so that parts of  the human body can be caught, trapped, or pinched between them. 1.5.12 Whole current isolation — the physically opening of the power supply conductors to the drive motor(s) of a conveyor system(s).

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SECTION 2. MATERIALS

2.1 GENERAL. All materials shall comply with the relevant Australian standards or with other specifications acceptable to the Regulatory Authority.

(d) Forgings and castings — AS 1448, AS 1734, AS 1830, AS 1831, AS 1832, AS 1866, AS 1874, and AS 2074.

2.2 MATERIAL SPECIFICATIONS.The following standards specify the material requirements for conveyors and supporting structures:

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

(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, and AS 1669.

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Rivets — AS A34.

(g) Roller chain — A S 1532 and AS 2152. (h) Structural steel — AS 1074, AS 1131, AS 1163, AS 1204, and AS 1444. (j)

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Wire rope — AS 1656 and AS 2759.

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SECTION 3. DESIGN AND CONSTRUCTION 3.1 GENERAL. Conveyors and conveyor systems shall be designed, 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 practice and workmanship. 3.2 DESIGN AND CONSTRUCTION. 3.2.1 General. Safety features necessary for the safe operation of conveyors and conveying machinery shall be incorporated at the design stage. 3.2.2 Design requirements. The design and construction of a conveyor shall take into full account the magnitude, incidence, conditions and manner of all loading and forces likely to be applied to the conveyor. The design and construction of a conveyor shall, where applicable, comply with the relevant standards. The slope and characteristics of the conveying device shall be designed so as to prevent unintentional sliding of the product or object being conveyed under normal working conditions. 3.2.3 Brakes and brake devices. 3.2.3.1 Safe stopping. Every conveyor shall be designed so as to ensure that it will stop in the shortest practicable time consistent with safety when the driving power is disconnected, and remain stopped until the power is restored. 3.2.3.2 Anti-runaway or anti-runback devices. Every conveyor which can run away or run back shall be provided with ‘anti-runaway’ or ‘anti-runback’ devices. Where a belt or chain drive is interposed between the motor and the driving shaft, a device shall be provided on the driving shaft to sustain the load in the event of failure of such drive. 3.2.3.3 Prevention of movement. Where an electromechanical brake is provided on an inclined conveyor which may run away or run back, and a positive drive is not used, e.g. a fluid coupling is used, means shall be provided to prevent movement of the conveyor until such time as positive drive is established. Brakes shall not be released until the torque has been applied to the main driving shaft of the conveyor, and shall be applied automatically if the power fails or the operating control is returned to the off or stopped position. 3.2.3.4 Controlled speed of descent. Brakes which are manually released and applied by the movement of  operating devices shall be designed so that, if the power is interrupted with the brakes in the release position, the load can descend only at a controlled speed. 3.2.3.5 Sustained load. Where a brake is used as an anti-runaway or anti-runback device, it shall be rated to sustain 150 percent of the runaway load of the conveyor when applied. 3.2.4 Lubrication of bearings. Where bearings are inaccessible or are in hazardous locations and require lubrication, the means of lubrication shall be located in an accessible and safe position and the lubricant piped to the bearings. The lubrication points should be located outside the alignment of the carrying mechanism of the conveyor and should be accessible without the removal of any guard.

3.2.5 Take-ups and counterweights. 3.2.5.1 Gravity take-up. Where take-ups have suspended counterweights, suitable precautions shall be taken against the danger of the counterweight falling. The counterweight shall be enclosed in a suitable enclosure equipped with guides and stops which shall extend to a floor of sufficient strength to withstand the falling weight. Where counterweights are attached to lever arms, a safety device shall ensure that the weights cannot become detached if the device used for the adjustment of the weight becomes loose. 3.2.5.2 Wire ropes for take-ups and counterweights. All wire ropes used for take-ups and counterweights of  conveyors shall have a minimum safety factor of 4.5. 3.2.5.3 Spring take-ups. Where spring and screw take-ups are used and adjustment is required when the plant is in operation, the means of adjustment shall be readily accessible. Guards shall be provided to protect personnel from contact with moving parts. Where spring and screw take-ups are remote or on a different level from the main drive, a stop control complying with Clause 4.8.7 shall be provided. 3.2.6 Wire ropes. All wire ropes used on a conveyor or conveyor system, other than for take-ups and counterweights, shall comply with the appropriate requirements of the relevant standards (see Clause 1.4). 3.2.7 Hinged sections. 3.2.7.1 General. Hinged sections of a conveyor or conveyor system used for the purpose of creating a passageway shall be designed so that when the hinged section is opened while the conveyor is in operation it need only stop the adjacent upstream conveyor. The conveyor may be restarted automatically upon closure of  the hinged section provided that the requirements of  Clause 4.8.7.5 are complied with. 3.2.7.2 Manually operated. Manually operated hinged sections shall be self-locking in the open position or counterbalanced, and shall be designed so that the maximum effort required to open or close the hinged section does not exceed 150 N. Power-operated hinged 3.2.7.3 Power operated. sections shall be provided with mechanical safety devices which restrict their closing to a safe speed and prevent them from falling in event of power failure. 3.2.8 Raising and lowering systems. Fixed or mobile conveyors including an articulated or mobile part in a vertical plane, actuated manually or by a motor, shall have a safety device for immobilizing the articulated part in the event of voluntary or accidental stopping of the motive power. A raising and lowering system shall be fitted with an appropriate device which prevents the accidental movement or kickback of a manually operated crank. The raising and lowering system shall be located so that it is unnecessary for any person to be under the conveyor. The movement shall be limited at the extreme positions by appropriate stops or limiting devices.

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SECTION 4. INSTALLATION 4.1 GENERAL. In areas where a conveyor or conveyor system is installed, safe access platforms and safe servicing facilities shall be provided for the purpose of  loading, unloading, operation, maintenance and inspection. The design, construction, and installation of  fixed platforms, walkways, underpasses, crossovers, stairways, and ladders shall be in accordance with AS 1657. 4.2 ACCESS TO CONVEYORS. 4.2.1 Platforms to be provided. Permanent platforms not less than 600 mm wide shall be provided to enable all parts of the plant which need to be reached for purposes of operation and regular maintenance to be readily and safely accessible. A clear access platform or floor space of at least 600 mm wide shall be provided for maintenance purposes. The minimum platform size shall be 600 mm square. Platforms at different levels shall be adequately and conveniently connected. 4.2.2 Use of ladders. Access to plant for purposes of  operation shall be from floors or platforms and not from stairways or fixed ladders. Portable ladders shall not be used as places from which operation or regular maintenance may be carried out. 4.2.3 Crossovers. Where walkways are provided on both sides of a conveyor, and where convenient access to either side of the conveyor may be required by employees who regularly work in the area, crossovers or underpasses with safe means of access thereto should be provided at appropriate intervals, and at the head and tail ends of conveyors where no other crossing is available. 4.3 CROSSOVERS FOR AISLES AND PASSAGEWAYS. Where a conveyor crosses a walkway, aisle or passageway and the lowest part of the conveyor or material or attachment is less than 2 m from the floor or walkway surface, a crossover or underpass shall be provided. 4.4 CONVEYORS INSTALLED IN TUNNELS OR PITS. 4.4.1 Working clearance. Where it is necessary to work from within a tunnel or pit, e.g. for maintenance purposes, a minimum working clearance of 600 mm coupled with a minimum headroom of 2 m shall be provided . 4.4.2 Ventilation and drainage. Tunnels and pits should be designed for proper ventilation and drainage. If necessary sump holes should be provided, and any such sump holes shall be covered. Where pumps are provided, the controls shall be located in an accessible and safe position outside any area that may be flooded. 4.4.3 Depth indication. Visual indications shall be provided to indicate the depth of water and to guard against the possibility of persons stepping into deep water in the event of the tunnel or pit becoming flooded. 4.4.4 Alternative egress. Provision shall be made for alternative means of egress from tunnels and pits where there might be a danger to persons. Normal access should be reasonably remote from possible overflows and other sources of danger.

4.4.5 Use of covers for headroom. Where the depth of a pit is less than 2 m, the headroom may be achieved by the removal of covers. Where covers are provided, they shall be hinged or otherwise secured to prevent their displacement through the opening, and the exposed opening shall be provided with a suitable guard rail of  adequate strength which can be readily and conveniently erected but not removed. Access to the opening shall be restricted until the guards, which shall be on at least three sides, are in position. 4.4.6 Removal of accumulated material. Pits shall have adequate space for the accumulation of spilled material and means for the ready removal of such accumulation. 4.5 LIGHTING. Suitable permanent or mobile lighting shall be provided for conveyors or conveyor systems appropriate to their location. The level of illumination shall provide safe access to conveyors or conveyor systems and create safe working conditions for operation, inspection, and maintenance purposes (see AS 1680). Provision should be made for access to light fittings for ease of servicing. Permanent lighting shall be provided in tunnels and pits and areas where natural light is not available. In addition, permanent lighting and/or power outlets for connecting hand-held lamps shall be provided in areas requiring maintenance and inspection. NOTE: Hand-held fittings should be one of the extra-low voltage type.

4.6 ELECTRICAL REQUIREMENTS. The electrical instal-lation, components and associated equipment of  conveyors or conveyor systems shall comply with AS 3000 and other relevant standards. 4.7 PROTECTIVE DEVICES. 4.7.1 General. Where personal safety is involved, all protective devices shall be hard-wired external to electronic control equipment of conveyors or conveyor systems. 4.7.2 Overload protection. Every conveyor where the maximum torque developed by a motor will produce stress in excess of safe working stresses and where failure may cause a hazardous situation shall have, in addition to the overload protection provided to protect the motor overload devices to protect the conveyor and mechanical drive parts. Such devices shall be designed to quickly disconnect the conveyor or drive parts from the motive power in the event of overload. 4.7.3 Types of device. The overload devices may be speed-responsive switches, shear pins, torque limiting couplings, or any other devices designed for the purpose of quickly disconnecting the motive power or limiting applied torque. Shear pin failure on any one drive unit shall stop all drive units on that conveyor and any other preceding synchronized conveyor or material feeder. Where a shear pin is used, a description of the proper size and material of the shear pin shall be placed at an appropriate point on the conveyor so that the operators can readily see it when replacement is being made.

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4.7.4 Speed control. Where the operation of the overload device would permit overspeeding in either direction with consequent hazard to persons, a speed control device shall be provided. 4.8 CONVEYOR CONTROL. 4.8.1 General. Conveyors and conveyor systems shall be provided with appropriate drive power isolation, whether electrical, hydraulic, pneumatic, or mechanical. 4.8.2 Drive power isolation. Drive power isolation shall be obtained by mains supply isolating switches or devices capable of being secured in the isolating position. Resetting of mains supply isolating switches or devices shall be by manual operation only. The securing method shall be by means of a keyoperated lock, danger tag (as approved), or other method acceptable to the Regulatory Authority. Features shall be incorporated which positively indicate the isolating and operating conditions of the isolating device and also provide a method of preventing unauthorized or inadvertent operation. Power-isolating switches or devices shall not be capable of being locked in the supply mode. 4.8.3 Motor isolation. Motor isolation shall be obtained by either one of the following means: (a) A full current isolator connected in series with the drive motor and mounted adjacent to the drive. (b) A control circuit isolating switch mounted adjacent to the drive motor the operation of which shall comply with Clause 4.8.4. Whole current switches and control circuit isolating switches shall comply with Clause 4.8.2 and shall be clearly identified. 4.8.4 Control circuit isolation. Where control circuit isolation is used, such isolation shall be used only as motor isolation for the purpose of test and inspection services. Operation of the control circuit isolator shall open the main supply to the drive motor. The control circuit isolator, at the drive, shall bear a notice worded as follows: CAUTION — For testing/inspection purposes only. For servicing and maintenance access, isolate the drive power at the main supply isolator.

4.8.5 Whole current isolation. Where access to the conveyor is required whole current isolation shall be implemented to isolate the drive functions of the conveyor controls. Operation of the whole current switch shall open the supply to the drive motor and to all auxiliary drives, operation of which could cause the conveyor belt to move. 4.8.6 Starting controls. 4.8.6.1 General. At each conveyor start location, a clearly labelled stop control shall be provided. 4.8.6.2   Remote control. Conveyors or conveyor systems equipped with remote control shall comply with the following: (a) Where the start control is in a position from which the whole of the conveyor’s operation cannot be viewed and the possibility exists of accidents arising from the starting of the equipment, an automatic visible and/or audible signal shall be provided to warn persons in the vicinity of the conveyor or conveyor system prior to the starting

up of the conveyor or system. There shall be a suitable time delay between the beginning of the signal and the starting of the conveyor or conveyor system. (b) Where conveyors or conveyor systems are equipped with remote control and separate local manual control switches for any conveyor in a system, these controls shall be clearly marked and interlocked so that the remote control cannot override the local control. Starting interlocks or contacts from remote controls shall be physically disconnected by the selection of local control. (c) The local/remote control selector switch shall be suitably protected or located to prevent operation by other than authorized persons. The selected condition shall be displayed at the local start location and may also be displayed at both the remote 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 systems shall be provided with manual emergency-stop controls. Where a conveyor is not electrically powered, provision shall be made for an appropriate stopping device. In addition, conveyors may be equipped with manual normal-stop controls for the purpose of production or other stopping functions (see also Clause 4.8.7.4). Field-mounted manual stop controls, whether for emergency or normal stop functions, shall be of the knock-off, automatic lock-off, manual reset type. Lanyards are considered to comply with this requirement. 4.8.7.2 Emergency stopping of conveyors. The stopping function of an emergency-stop control shall, upon activation, open the mains supply and lock itself  simultaneously in the off position. It shall prevent the starting of the conveyor from any position until such time that the stopping control has been manually reset. It shall not be possible to restart the conveyor after the manual reset operation without the activating of the normal start control. 4.8.7.3   Emergency-stop controls. Provisions for emergency stopping of conveyors and conveyor systems by means of emergency-stop controls shall be as follows: (a) Conveyors positioned within 2.5 m from the floor or normally accessible walkways or platforms shall have emergency-stop controls located at intervals not exceeding 30 m. (b) Readily accessible conveyors shall have emergencystop controls located at intervals not exceeding 30 m. Accessible points along the pull wire of a lanyard type stop control shall be considered as being emergency-stop controls. (c) Where conveyors pass through storage areas and ovens or other areas not considered readily accessible, emergency-stop controls at the entry and exits of these areas shall be provided. (d) Emergency-stop controls shall be wired directly into the conveyor control circuit and where activated, shall isolate the power supply to the conveyor by electromechanical means. (e) Where the conveyor is controlled by electronic equipment, emergency-stop controls shall be hardwired external to the electronic equipment so that

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electronic circuit malfunction shall not inhibit the function of the stopping device. Inaccessible conveyors supported on trestles exceeding 2.5 m in height, or conveyors not accessible other than by a ladder or mobile platform, should have emergency-stop controls located at the base of the trestles at intervals not exceeding 100 m.

(b) Where emergency-stop controls are not provided at the head or tail end of the conveyor, lanyard switches shall be installed. (c) Breaking, slackening or removal of the lanyard or pull wire shall automatically stop the conveyor. (d) The force required to operate the lanyard or pull wire stop control shall not exceed the following:

Operation of a local emergency-stop control in a conveyor system should be arranged so that it stops the associated conveyor and its feeding conveyors, except where the control is located at a transfer point and it may be necessary to also stop the downstream conveyor. Where emergency stopping of the total conveyor system is required, the system should be provided with a single or multipositioned group of emergency-stop controls. Operation of the emergency-stop controls should result in the stopping of the total system. These emergencystop controls shall be either at the main control point, or at suitable positions which permit the operator a clear view of the total system. Where access is provided on each side of the conveyor, local emergency-stop controls shall be provided on both sides. Emergency-stop control systems shall be uniform throughout the installation. 4.8.7.4  Normal-stop controls. Where normal-stop controls are provided in addition to emergency-stop controls, the normal-stop controls may be wired into electronic control equipment for sequence control purposes. Interlocking should be arranged so that the sequencing control cannot be initiated before the manual resetting of the stopping mechanism and the start control has been activated. Where this type of conveyor control has been incorporated appropriate warning signals (see Clause 4.8.6.2) and warning signs shall be provided. 4.8.7.5   Automatic stop controls. Automatic stop controls provided for conveyor systems for other than safety purposes, e.g. overdimensional load, tension mechanism overtravel, and temperature limit controls, should not prevent the restarting of the system after resetting, provided that — (a) the stopping device is labelled to indicate that the conveyor will restart upon resetting the device; and

(e)

(i)

Where applied midway between the lanyard or pull wire supports and at right angles to the axis of the lanyard or pull wire . . . . 70 N.

(ii)

Where applied along the axis of the lanyard or pull wire in either direction . . . 230 N.

Supports for lanyards or pull wires shall be provided at intervals not exceeding 4.5 m.

A cross lanyard or pull wire or equivalent type of stop system may be installed above approaches to certain points, e.g. crushers, transfers and chutes. Lanyards or pull wires should be stranded galvanized or plastics-covered wire or be of similar material not affected by atmospheric or environmental conditions. NOTE: The application of lanyards to long overland conveyors is subject to approval by Regulatory Authorities.

4.8.7.7   Interlocking devices. Except where the conveyor at the loading and unloading point is operationally visible to and under the control of an operator, an electrical or mechanical device shall be provided on all sequence type conveyor systems to automatically stop the conveyor or the load when a conveyor, bin, hopper, or chute to which it feeds has not been started, has been stopped, or has been blocked with loads so that it cannot receive additional loads or material (see also Clause 4.8.7.5). 4.8.7.8 Location of signs. Each stop control shall be readily accessible and shall be indicated by safety signs erected in suitably conspicuous positions. Such signs shall comply with AS 1319, and shall have letters not less than 15 mm high. For lanyard controls, signs shall be erected at suitable and clearly visible positions along the length of the conveyor, or at any other position where lanyard is installed, at intervals not greater than 30 m.

(b) where this control is in a position from which the whole of the system cannot be viewed and there is a possibility of accidents arising from the starting of the conveyor, a warning signal in accordance with Clause 4.8.6 shall be provided.

4.9 FIRE PROTECTION. In the design of ‘a conveyor or conveyor system and of the situation into which it is to be installed, consideration should be given to the materials of construction, the materials being handled, and the operating conditions to assess the extent to which the installation may be a fire hazard.

NOTE: This stop control may be wired into electronic control equipment.

Firefighting facilities should be provided consistent with the assessment of the fire hazard.

4.8.7.6   Lanyard or pull wire. Automatic lock-out manual reset stop controls which are operated by a lanyard or pull wire shall comply with the following:

In the design of the access provided for the operation and maintenance of the conveyor or conveyor system, safe alternative means of exit shall be provided for personnel in case of fire.

(a) They shall be installed within reach of the operator or other person engaged in the near vicinity of the conveyor.

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SECTION 5. GUARDING 5.1 GENERAL. Guards shall be designed to prevent injury to persons and shall be provided at every dangerous part of a conveyor normally accessible to personnel. Guards should be planned into the design of the conveyor or conveyor system and should not in themselves create a hazard. Guards shall be provided to prevent accidental contact by persons or parts of clothing being caught, e.g. between belt and pulley, chain and sprocket, cable and sheave, or drum and block. Where removal of a guard is not required for inspection or maintenance purposes, the guard shall be secured in position so that it cannot readily be removed without the use of tools. Fixed guards shall be provided where the conveyor can be serviced without the removal of the guards (e.g. for adjustments, cleaning or lubrication). Removable guards shall be installed in a manner acceptable to the Regulatory Authority in positions where normal maintenance or cleaning is carried out regularly .

Fig. 5.1.

5.2 DESIGN AND CONSTRUCTION OF GUARDS. 5.2.1 General. Guards shall be made of solid material, mesh, or equivalent construction, and shall be designed to prevent persons reaching into the danger area (see Fig. 5.1). Sheet metal guards shall be not less than 1.5 mm thick. For mesh guards, 9 mm mesh shall be not less than 1.5 mm thick; 50 mm mesh shall be of not less than 3 mm wire thickness. Guards shall not deflect more than 12 mm under a force of 450 N applied at any point on the guard over a square area of 50 mm side. These requirements are not intended to exclude other methods of construction provided that they comply with the requirements for prevention of access. Where a guard is situated so that a person may climb or rest upon it, such guard shall be capable of sustaining a mass of 75 kg placed in any position upon it, together with a simultaneous force of 220 N applied horizontally in the same or any other position. The guard shall maintain the required safe clearances.

USE OF MESH FOR GUARDS

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5.2.2 Reach dimensions (See Figs 5.2 and 5.3). The design and construction of guards and their subsequent location shall be such that the distance of any nip point or shear hazard and the nearest point of access is restricted as follows: (a) Arm reach . . . . . . 1000 mm from under arm to fingertips. (b) Elbow reach . . . . . 500 mm from the inside elbow to fingertips. (c) Wrist reach . . . . . 280 mm from wrist to tip of  middle finger. (d) Finger reach

. . . . 150 mm

(e) Vertical reach . . . . 2500 mm maximum standing on toes.

when

The above dimensions include an allowance made to obtain clearance from the danger areas.

(a) Size of mesh of opening up to and including 9 mm .... Distance of guard from danger point virtually same as sheetmetal, working clearance only required. (b) Above 9 mm up to 50 mm square ...Guard at least 150 mm from danger point. (c) All types of guards ....Distance between the underside of the guard and the floor not to exceed 250 mm. Where complete enclosure with a guard is not provided, fence type guards shall be used and the height of the guard and the distance of the guard from the danger point shall be in accordance with Fig. 5.4. The size of  mesh or other openings shall be not greater than 9 mm where the nip point is up to and including 150 mm from the guard, and not greater than 50 mm square where the nip point is in excess of 150 mm from the guard.

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

(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 from floor or working surface (a)

Distance from nip point to guard (c) Height of guard from floor or working surface (b ) 1980 1830 1680 1520 1380 — — — — — 230 230 230 230 230 230 300 380 380 380

2500 2360 2290

2290 — 75 75

2130 — 150 150

1220 — 230 380

1000 — 230 —

2210 2130 2050

— — —

200 200 150

300 300 300

380 450 450

450 530 600

530 600 600

530 600 600

530 600 680

600 — 1100

1980 1900 1830

— — —

150 — —

300 230 —

450 450 450

600 600 600

680 680 680

680 680 750

750 840 840

— — 1200

1750 1680 1600

— — —

— — —

— — —

450 380 380

600 600 530

750 750 750

840 840 840

920 920 920

— — 1300

1520 1450 1380

— — —

— — —

— — —

230 — —

530 530 450

750 750 750

840 840 840

920 920 920

— — —

1300 1220 1150

— — —

— — —

— — —

— — —

380 — —

750 750 680

840 840 840

920 920 920

1350 — —

1050 1000 920

— — —

— — —

— — —

— — —

— — —

680 680 300

750 680 680

840 840 840

— 1400 —

840 750 680

— — —

— — —

— — —

— — —

— — —

— — —

600 380 300

840 750 600

— — 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 COPYRIGHT

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5.3 DANGEROUS PART S REQUIRI NG GUARDING (See also Figs 5.5 to 5.12). 5.3.1 Minimum clearance of moving parts. Where there is a risk of personal injury from any nip point or shear hazard, between any moving part of carrying mechanism of the conveyor and any attachment fixed thereto, and any fixed portion of the conveyor structure and any other equipment, the clearance shall be not less than 90 mm. Where this minimum clearance is not practicable, the clearance may be reduced provided that the nip point or shear hazard is effectively guarded. As an alternative, pop-out rollers or dead plates which, when operating, allow a minimum clearance of 90 mm to be maintained, may be provided. The force required to operate such devices shall not exceed 110 N. Where the surface of the moving part of the conveyor is provided with projections exceeding 6 mm in height, or where there is any type of attachment to the moving part, the minimum clearance of 90 mm shall be maintained between the highest point of the projection and the adjacent structure. 5.3.2 Nip points and shear hazards. Guards shall be provided to prevent accidental contact with nip points or shear hazards where the nip point or shear hazard exists up to a height of 2.5 m above any floor, platform level, or stored goods or materials. The use of exposed 5.3.3 Rotating parts. projecting parts such as keys, bolts and set-screw heads on rotating members should be avoided where possible. Where this is not possible, such projecting parts shall be provided with guards. Guards shall be provided for all exposed shaft couplings and collars. Sheet metal guards shall be provided for all fluid couplings which are provided with fusible plugs. 5.3.4 Hoppers and chutes. All openings to hoppers and chutes shall be suitably protected where there is danger of personnel falling into the opening. Hoppers or chutes shall be provided with access opening so that, as far as possible, any necessary cleaning inspection may be carried out from outside the hopper or chute.

The sides of open hoppers or chutes shall be high enough to prevent material fall ing into working areas below and to prevent injury to personnel by contact with moving parts in the conveyor. Open chutes should be provided with front plates at the point where conveyors discharge into them to prevent materials from bouncing out of the chute. Chute doors shall be located so that when open they do not create a hazard to personnel during normal operation of t he plant. When the chute doors are open, there shall be a minimum headroom of not less than 2 m . 5.4 REMOVAL OF GUARDS. 5.4.1 Fixed guards. Where required for inspection, maintenance, or operational purposes, hinged inspection doors may be provided i n a fixed guard, but such inspection doors shall comply with Clause 5.4.2. 5.4.2 Removable guards and covers. Lifting handles or lugs shall be provided where required for the safe removal or opening of guards or covers. Removable guards and covers shall be clearly labelled ‘DANGE R — Isolate drive before removing guard’. 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 to prevent injury to personnel. 5.5.2 Guarding of openings in floors. In locations where conveyors pass through a floor or where it is possible to i nadvertently step upon moving plant, hand railing and toe boards shall be provided in accordance with AS 1657. Provision should be made for a height gauge at the loading end where a conveyor passes through a floor to ensure sufficient clearance between the load and the floor. 5.5.3 Restricted areas. Where conveyors are installed in restricted access areas, they may be considered as being partially for fully guarded at the discretion 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 REQUIREMENTS FOR UNIT-HANDLING CONVEYORS

6.1 GENERAL. Conveyors designed for unit loads shall comply wi th the r equirements of this Section together with the appropriate and applicable requirements specified in other Sections. Where routine operations, maintenance, and replacement of parts is necessary and such parts are not readily accessible, access and platforms shall be provided in accordance with AS 1657. 6.2 SLAT CONVEYORS. Unless deemed safe by location and position, t he sides and undersides of slat conveyors shall be appropriately guarded (see Fig. 6.1). A ll slats shall be designed for live load and shall include an allowance for wear. The hazard which may be caused by the space between sl ats or variation in such space as they move along the conveyor track shall be eliminated as follows: (a) Slats travelling in a straight line. The space between slats travelling in a straight line should be 25 mm; however, where the slats have a clear space between of more than 25 mm, the entire space under the top or carrying rung of slats shall have a solid, smooth bed to prevent a shearing hazard between the moving slats and any structure or return run.

(b) Change of direction. Where the minimum distance between slats is less than 20 mm or more than 30 mm when passing around the end shaft sprockets or where changes of direction occur, the slats shall be guarded in a manner to prevent any person from receiving injury from the closing slats. 6.3 TOWING CONVEYORS (See Fig. 6.2). Underfloor or overhead t ruck towing conveyors shall be provided with means to release the truck from the tow chain in the event of the truck or load meeting an obstruction. There shall be at least 600 mm clear space between any two trucks and their loads on parallel lines or between any two trucks, including loads and a fixed object. Tow truck wheels shall be guarded by one of the following methods: (a) By providing guards on the wheels to within 20 mm of the floor. (b) By providing a skirt guard on the truck to within 20 mm of the floor. (c) By any other method which provides equivalent safety to personnel.

Fig. 6.1. SLAT CONVEYOR

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Fig. Fig. 6.2 6.2.. TRUCK TRUCK TOWING TOWING CONVEYOR

Fig. Fig. 6.3 6.3.. POSITION POSITION OF PROTECTIVE PROTECTIVE PLATE

Fig. Fig. 6.4 6.4.. PROVISION OF POP-OUT ROLLERS ROLLERS

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6.4 ROLLER FLIGHT CONVEYORS. Where the rollers rollers of roller roller flight flight conv conveyo eyors rs are arranged arranged to provide a clear space of more than 25 mm and there are structu structural ral membe members rs under under the rollers rollers which which present a shear hazard, and the conveyor is not safe by virtue of its position, the entire space under the top top or carry carryin ing g run run of roll rollers ers shall shall have have a soli solid d smooth bed to prevent a shearing hazard between the moving rollers and the structure. Where the rollers are not mounted on the centreline of the the chai chain n and and where where the the minimu minimum m clear clearanc ancee between the rollers is less than 25 mm, the closing roller shall be guarded externally at t he closing closing point. 6.5 FLAT FLAT BELT CONVEYOR CONVEYORS. S. 6.5.1 6.5.1 Protec Protective tive plate. plate. A table or a suitable flat protective plate used in conjunction with side plates or side guards shall be provided under the belt to the tangent line of the pulley to minimize the possibility of accidents between the nip point of the belt and the pulley (see Fig. 6.3). 6.3). 6.5.2 6.5.2 Transfer Transfer points. points. At transfer points, where a belt conveyor conveyor discharg discharges es onto a roller conveyor conveyor,, mean meanss shal shalll be prov provid ided ed to ensu ensure re a minim minimum um clearance clearance between the convey conveyors ors of 90 mm except except where guards are provided (see Clause 5.3). 5.3 ). This minimum clearance may be reduced by using pop-out type rollers or dead plates, provided that the roller substructure or support does not encroach on this clearance (see Fig. 6.4). 6.4). On any exposed 6.5.3 Return idler guarding. section of a conveyor which is not safe by virtue of  its location or position, position, the return idler rollers shall shall be provided with guards to prevent accidental contact with nip points of any return i dler and belt where the nip points are between 0.6 m and 2.5 m above any floor, platform or level. 6.6 OVERHEAD CHAIN OR CABLE CONVEYORS. That portion portion of an overhea overhead d chain chain or cable cable conveyor conveyor which travels so that the lowest point of the conveyor or its load is more than 2.5 m above ground level shall be provided wit h underguarding underguarding to sustain any object which may fall from the conveyor and in falling cause injury to persons underneath. Where traction wheels or roller turns are installed at a height of less than 2.5 m from t he ground level, the nip points between the chain and the wheel or roller shall

be guarded. guarded. Traction Traction wheels or roller turns shall shall be designed so that their fall due to failure of bearings or shafts is minimized. 6.7 6.7 OVERH OVERHEAD EAD CHAIN CHAIN OR OR CABLE CABLE CONCONVEYOR (POWER AND FREE TYPE). Where the underside of the free track of an overhead chain or cable conveyor is within 2.5 m of the floor level, the power power chain and trolley shall shall be suitably suitably guarded guarded where they pass t hrough the yokes. Where, however, however, access access to the trolley is from walkways walkways provided provided for maintenance, maintenance, yokes yokes need not be specifically guarded guarded prov provide ided d that that the the cleara clearanc ncee betwee between n the trolley trolley bracket bracket and t he yoke i s not less than 30 mm. Where drop sections are used, s uitable means shall be provided to prevent the following free trolley from entering the open section of the track, and the free trolley trolley in the drop dropped ped sect section ion shal shalll be posit positive ively ly retained on its track. Means shall be provided to stop the descent of any drop section or to control its speed to not more than 125 percent of its normal operation; in any case, its speed shall not exceed 500 mm/s. 6.8 SWING TRAY TRAY CONVEYORS CONVEYORS (See Figs 6.5 and 6.6 6.6). ). 6.8.1 Fork tray type. Where t here is more than one load loading ing point point,, a fork fork tray tray type type conv conveeyor yor or its controls controls shall be designed designed so as to ensure ensure that the load loading ing fork forkss or finge fingers rs can can be in the the load loadin ing g position position at only one level at any one time while while the conveyor is in motion. Where Where the discharge discharge is automatic, automatic, means means shall be provided to ensure ensure that the conveyor conveyor wi ll stop should the receiving area be unable to take the discharge load. Loading Loading and unloading unloading points points shall be guarded by fixed fixed guar guards ds extend extending ing a distan distance ce of at least least 1 m from the sill line of the loading or unloading point. 6.8. 6.8.2 2 Solid tray tray type. type. Where the discharge from solid solid tray tray type type conv convey eyor orss is not not auto automa matic tic,, the loading and unloading point shall be provided with doors electrically interlocked t o prevent movement movement of  the conveyor while any door is open.

Fig. Fig. 6.5 SWING TRAY TRAY CONVEYOR (DETAIL) (DETAIL) COPYRIGHT

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6.9 VERTICAL VERTICAL CHAIN CHAIN CONVEY CONVEYORS ORS (OPPOSED SHELF TYPE) (See Fig. 6.7). 6.7). Means shall be provided on on vertical chain chain conveyors conveyors to stop the

conv convey eyor or in the event event of any any portion portionss of the load projecting beyond the door head or still line.

Fig. Fig. 6.6 6.6.. SOLID TRAY CONVEYOR CONVEYOR

Fig. Fig. 6.7 6.7.. VERTICAL VERTICAL CHAIN CONVEYOR

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SECTION 7. SPECIFIC REQUIREMENTS FOR BULK-HANDLING CONVEYORS

7.1 GENERAL. Conveyors designed for bulk handling shall comply with the requirements of this Section together with the appropriate and applicable requirements specified in other Sections. 7.2 SAFE ACCESS. 7.2.1 Walkways (See Clause 4.2). Where appropriate, a walkway complying with AS 1657 should he provided on at least one side of bulk handling conveyors. Where inspection, maintenance, and replacement of parts of a conveyor remote from such walkways is necessary and such parts are not readily accessible, an additional walkway should be provided. The provision of an additional walkway is not necessary where safe access is available and can be provided on the conveyor structure. 7.2.2 Crossovers and underpasses. Where access is r equired f or operational purposes, crossovers, or underpasses shall be provided. A suitable crossover or underpass attached to a mobile tripper will satisfy the requirement. Where appropriate, suitable boarding switches shall be provided to isolate the travel drive. 7.2.3 Access to drive unit. Access to the drive unit and tail pulleys shall be provided for all bulk  handling conveyors whether of the fixed or shuttle type. 7.2.4 Nip points. Unless deemed safe by position or location, guards shall be provided to prevent accidental contact with nip points where the nip points are between 0.6 m and 2.5 m above any floor, platform or level (see Fig. 5.4). Guarding of nip points shall comply with Section 5. 7.3 BELT CONVEYORS. 7.3.1 Danger points. The most important danger points on belt conveyors are shown in Fig. 7.1 and

marked with arrows. These are at the nip (wrapping) points of the belt with the pulley. (See also Figs 5.5 to 5. 12.) 7.4 SCREW CONVEYORS. All casings and loading, delivery, drainage, and inspection apertures or chutes of screw conveyors shall be guarded or interlocked to prevent contact with the s crew and nip point. 7.5 EN MASSE AND BUCKET CONVEYORS. Access to the driving machinery or head of en masse and bucket conveyors shall be provided from a platform of such dimensions as will allow the replacement of any machinery. Access to and the guarding of the platform shall comply with AS 1657. 7.6 VIBRATING AND OSCILLATING CONVEYORS. Where access walkway or platform is provided past or at the end of a vibrating or oscillating conveyor, the requirements of  Section 5 shall apply. 7.7 DRAG CHAIN CONVEYORS. Where inspection panels are used in the top of the trunking which encloses the drag chain, a wire mesh screen shall be provided under the door or panel; such screen shall be designed and constructed so as to withstand a force of 750 N in any position upon i t and maintain the required safe clearances at all points of guarding. All loading, delivery, drainage, and inspection apertures or chutes in the trunking shall be guarded to prevent contact with the ’flights’ or nip points. Such guarding shall be securely bolted and/or w elded in position. Where guards or covers are to be opened for cleaning the conveyor, they shall be hinged and interlocked electrically or mechanically with the driving means by positive non-interference devices so as t o prevent movement of the conveyor while the guard or cover is in the open position or is removed. The guarding shall comply with Section 5.

NOTE: Nip points are indicated by arrows.

Fig. 7.1. DANGER POINTS OF BELT CONVEYORS

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SECTION 8. SPECIFIC REQUIREMENTS FOR MOBILE AND PORTABLE CONVEYORS 8.1 GENERAL. Mobile and portable c onveyors shall comply wi th the requirements of this Section together with the appropriate and applicable requirements specified in other Sections. 8.2 DESIGN AND CONSTRUCTION. Mobile and portable conveyors shall be designed and constructed so as to remain stable under normal loading and transporting conditions. The design and construction of mobile and portable conveyors shall take into account the magnitude, incidence, conditions and manner of loading and all forces likely to apply to the conveyors. 8.3 STABILITY. The margin for stability for mobile conveyors and conveyor structures shall be determined under the combined effects of — (a) wind loading;

8.9 WIRE ROPE. 8.9.1 Safety factors and diameter ratios. Wire rope, where used for elevating booms, shall comply with the appropriate requirements of AS 1656 and AS 2759 with respect to minimum factor of safety and ratio of rope diameter to drum and sheave diameter. 8.9.2 Attachment. Attachment of the ropes shall be made in such a manner as will ensure that the strength of the rope is maintained in the connection. 8.9.3 Mini mum diameter. Ropes of less than 6 mm diameter shall not be used. 8.9.4 Load equalizing. Where more than one rope or fall is used, automatic static means of equalizing the load on each rope shall be provided. 8.9.5 Anchorages. Rope anchorages shall have a minimum safety factor of 4.5. 8.10 BOOM OR TRUNKING.

(b) design live and dead loads; and (c) design live load and dynamic effects. The design margin of stability expressed as a percentage shall be calculated from the following equation:

where the stabilizing moment is the moment of the conveyor mass about its axis of tipping, and the overturning moment is the moment of the design loads about the conveyor axis of tipping.

8.10.1 Minimum approach. The boom or trunking shall be designed so that it cannot approach closer than 1 m to the ground or floor level unless measures are taken to ensure that the elevated boom or trunking has i ts descent controlled to a safe regulated speed. The boom raising frame shall not become detached from the boom, trunking, or base. 8.10.2 Separation from drive. The boom or trunking shall be attached and supported so that when at its lowest elevation or while being transported it cannot rest upon the conveyor drive.

The margin of stability for a mobile conveyor shall be not less than 50 percent.

8.10.3 Warning notice. A permanent notice shall be attached in a conspicuous position adjacent to the prime mover (see Fig. 8.1).

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

The notice shall comply with AS 1319 (see Section 4 therein) and shall be displayed on all conveyors on which the boom or trunking can be raised in excess of 2 m.

NOTE: Reference should be made t o the rules for towing mobile conveyors issued by the local tr affic authorities.

8.5 BOOM MOUNTING. The boom or trunking shall be mounted on a chassis, base or wheels. The plan distance at right angles to the boom or trunking between the chassis, base, or wheels shall be not less than 25 percent of t he elevated height of the boom or trunking. 8.6 LOCKING AGAINST CREEP. Suitable locking devices shall be provided to prevent creep while the conveyor is in use. 8.7 PNEUMATIC TYRES. Where pneumatic tyred wheels are used, stability shall be maintained in conditions of under-inflation or l oss of air in any one wheel. 8.8 LOSS OF POWER. Suitable means shall be provided to automatically sustain the boom in any position when power is removed from the raising or lowering medium. A screw or helix type brake fulfils this purpose. Pawl and ratchet type winches without brakes shall not be used.

8.11 CONVEYOR DRIVE. Where an internal combustion engine is used as the conveyor power drive, the following applies: (a) The speed control should have a positive shut-off of the power source t o prevent speeds i n excess of the designed maximum. (b) The conveyor should be equipped with a fire extinguisher of sufficient capacity to extinguish a fire arising from the loss of total fuel capacity of the fuel storage tank. (c) An appropriate cautionary sign should be attached to the conveyor prohibiting its use in confined spaces because of the toxic hazard of  the exhaust fumes. (d) Due consideration should be given to the control of static electricity (see AS 1020). 8.12 CONTROL OF MOTOR DRIVE. 8.12.1 General. An automatic lock-out manual reset type switch shall be provided in an accessible position at each end of the conveyor. Drive power isolation shall comply with Clause 4.8.

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8.12.2 Electric power suppl y. Flexible conductors providing power to the conveyor drive shall be —

(b) On flywheels, couplings, and starter mechanisms of petrol engines. NOTE: It is recommended that impulse, spring, or permanently attached cord type starters be used to eliminate exposed irregular surfaces or starting pulleys.

(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 be provided to circuits feeding mobile conveyors (see AS 3190). 8.12.3 C lutches. Where toothed or dog type clutches are used, they shall have not less than four teeth or four dogs. The teeth or dogs and their mating recesses shall be undercut sufficiently to prevent inadvertent disengagement of clutches. 8.13 GUARDING. The guarding of mobile conveyors shall comply with Section 5. Guards shall also be provided as follows: (a) On return side idlers less than 2.5 m from the ground or floor level or at any position that can be reached by a person while the conveyor is operable.

(c) On exposed or extended shafting of crank type starting mechanisms. (d) On bag and b ale conveyors to prevent dislodgment of the load. S uch side guards or aprons shall have an effective height of 100 mm whether splayed or vertical. (e) On exposed screws, chains, or flights in hoppers. The design shall be such as will prevent personal contact with the moving parts. (f)

On return side chains with pusher attachment. Such chains shall be positioned to prevent contact by persons or shall run in protective ducts or a similar method of guarding.

8.14 SAFE ACCESS. Where appropriate, a means of 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 maintenance program shall be organized to keep the conveyor mechanism in a safe operating condition. 9.2 REGULAR CHECKS. Persons responsible for the operation, inspection and maintenance of  conveyors and conveyor systems, shall be familiar with the operational and safety requirements of the equipment. These requirements include the following: (a) Instructions and r ecommendations 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 maintenance program. (d) Details of maintenance and regular checks appropriately recorded and kept for future reference.

9.3 REMOVAL OF GUARDS. Where inspection or maintenance work entails the removal of guards drive power shall be disconnected from t he conveyor (see Clause 4.8.2). 9.4 SAFETY OF PERSONNEL. Where inspection and maintenance personnel are required to work in situations where there is a risk of falling, consideration should be given to t he use of safety belts and harness assemblies (see AS 1891 and AS 2626). All persons working on a conveyor or conveyor system shall be provided with individual locks and keys or danger tags for personal safety (see Clause 4.8.2). Where appropriate, a work permit may be provided (see Appendix B). Under normal circumstances, where a person has ta gged o r l ocked o ut a con veyor , i t i s t he responsibility of that person to remove the tag or lock and to reset the control.

SECTION 10. INSTRUCTIONS FOR OPERATING AND MAINTENANCE

Operation and maintenance 10.1 GENERAL. instructions should be supplied with all conveyors and conveyor systems and should be subdivided into four parts in accordance with Clauses 10.2 to 10.5. 10.2 SYNOPSIS OF PLANT. This part should be a book type reference to all component parts of the conveyor or conveyor plant with machine capacities, speed, serial numbers, and order numbers, and should include reduced scale general arrangement drawings of all mechanical and electrical equipment. 10.3 OPERATING INSTRUCTIONS. This part should give clear instructions on t he operation of t he conveyor and/or conveyor plant from ‘Start Up’ to

‘Close Down’ including all possible sequences of  control and operation. 10.4 MAINTENANCE INSTRUCTIONS. This part should give clear instruction on complete routines for lubrication and maintenance of the conveyor and/or conveyor plant, and should be supported by arrangement drawings showing the parts requiring routine lubrication and maintenance. 10.5 SPARE PARTS. This part should comprise lists of recommended spares together with serial numbers, order numbers, and any other details that would be necessary in obtaining spares, all of which should be illustrated by suitable arrangement drawings indicating the location of the various parts in question.

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SECTION 11. TRAINING AND SUPERVISION OF OPERATORS 11.1 TRAINING. During the training of conveyor operators, particular care should be taken to ensure that each operator understands the safe operation of  the conveyor and the following safety precautions:

(d) No person shall be permitted to travel on a moving conveyor at any time, unless an exemption is granted by the Regulatory Authority.

(a) The method conveyor.

(e) Maintenance or repair work shall not be carried out while a conveyor is in operation. In every case t he power shall be disconnected and the stopping control shall be positively locked in the open or stop position before such work is commenced. Where it is not practicable to carry out adjustment of a conveyor whil e it is stopped, a qualified operator shall be in attendance while such adjustment is being made.

of stopping

and starting the

(b) The hazards which are known to arise in the course of normal working. (c) The hazards liable to arise from bad practices, inattention, and misuse. (d) The purpose of the guard or safety device, and how the guard or device may fail. (e) The necessity for immediately informing the person in charge if any faults or defects arise, and the danger to the operator in attempting to correct any faults. (f)

The ability to recognize overloading or abnormal loading conditions.

Instructions shall be given that guards or safety devices shall not be tampered with, removed, or altered in any way, and that adjustable guards shall be readjusted only by an authorized person. The operator’s knowledge on the use of the conveyor or conveyors and the precautions to be taken should be regularly checked A conveyor operator should be closely supervised by a person with a thorough knowledge of the conveyor or conveyors during the training period. 11.2 SAFE OPERATING PROCEDURES. The following operating procedures apply to all conveyor installations: (a) All starting and stopping controls shall be kept clearly marked. The area around these devices shall be kept free from obstructions to permit ready access to them and a clear view of them at all times. (b) The area around all loading and unloading points on the conveyors shall be kept free from obstructions at all times. (c) Manual cleaning of belts, pulleys, or drums shall not be carried out while the conveyor is in motion.

(f)

Before a conveyor that has stopped because of  an overload is restarted, the reason shall be ascertained and the stoppage cleared. The stopping control shall be locked out before any attempt is made to remove the cause of an overload.

(g) No overload or safety control shall be removed from the conveyor. Precautions should be taken to prevent unauthorized persons from adjusting or tampering with the adjustment of any such control. Where adjustments are to be made, they shall be carried out by a competent authorized person. (h) All persons working on or near a conveyor shall be instructed in the location and operation of  stopping controls. (j)

At no time should a conveyor be used for a purpose other than one for which it was designed, unless such design has been proved satisfactory for the new conditions of use and load, nor should it be loaded in excess of its safe working load.

(k) Good housekeeping shall be maintained at all times. (l)

Operators should not wear loose clothing which may become entrapped in a conveyor.

11.3 SAFE WORKING METHODS. Operators shall be trained in safe working methods (see AS 1470).

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SECTION 12. MARKING AND IDENTIFICATION 12.1 MARKING OF CONVEYORS. The following information shall be marked on the conveyor or on labels permanently attached thereto: (a) The manufacturer’s name, trade name or mark. (b) An identification number or code. 12.2 NAMEPLATES AND LABELS. Nameplates and labels shall be durable, corrosion resistant and permanently attached and shall be clearly visible. 12.3 IDENTIFICATION. The i dentification number shall be in raised or indented letters or figures of a minimum height of 15 mm complying with AS 1319. 12.4 LOAD CAPACITY. The load capacity for a unit handling conveyor (SWL) should be exhibited adjacent to or on the conveyor at each loading position. The load capacity for a bulk handling conveyor shall be exhibited on the conveyor; it is acceptable on a data plate or on the driving unit.

Unit handling conveyors of the overhead chain type shall have its S WL exhibited as mass per attachment, and total load per structure. 12.5 MARKING OF CONTROLS. All conveyor 12.5.1 Start and stop controls. controls shall be marked with the words appropriate to their function, e.g. stop, start, forward, reverse, raise, or lower. Arrows indicating the direction of  travel shall be provided at forward and reverse controls. The identification colours used shall be in accordance with AS 1318. 12.5.2 Emergency stop control. All emergency stop controls including the central emergency stop control shall be clearly marked with their function. 12.6 LOCATION OF SIGNS. Care should be exercised in the choosing of sign mounting locations to ensure that the possibility of the signs becoming obscured by stacked materials is prevented (see also AS 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 typical configurations for the purpose of clarity; 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 sprags or wedges, located in the annular space between concentric inner and outer races. Power is transmitted from 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 between the races.

A1.2 Anti-runback device for overhead chain conveyor — a mechanical device to prevent reversal of  a 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 t o lock or catch the 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 are turned 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 usually driven by a drum at one end, passing over a free-running drum at the other end. The upper portion of the belt may be supported by free-running idlers or suitable flat surfaces. This type of conveyor can be arranged for horizontal or inclined travel, the angle of slope depending on the character of the goods conveyed and the type of belt surface.

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A3.2 Fixed belt conveyor — a stationary mechanical item of plant designed f or the conveying of  materials 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, carrying continuous 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 throwing loose 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 conveyor can 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 i nto a closed tubular shape. While in motion the belt opens to receive the load, closes to convey it, and opens to discharge it.

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

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

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

A3.11 Troughed belt conveyor — a conveyor composed of a moving belt carried on horizontal centre and 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 set at a moderate angle to the vertical. Loading can occur at any intermediate floor but unloading can only occur 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 buckets attached to chains, ropes or belts.

A5.2 Bucket elevator — a conveyor for loose bulk materials with buckets as the carrying medium attached 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 buckets are 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 between parallel endless chains, the buckets being tipped to discharge contents. The centre of gravity of the bucket is below the centre line of the chain pivot and thus the chain may follow any path from horizontal to vertical with the buckets continuing to hang vertically. Feeding of the buckets may either by gravity or by means of a suitable rotary feeder.

Drive corner

A5.5 Inclined belt and bucket conveyor — a conveyor ge nerally totally enclosed for powdered or granular material, consisting of suitably shaped buckets mounted at predeterminedpi tches on an endless belt, but inclined at a slight angle to the vertical. (Similar to vertical belt and bucket conveyor.)

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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 granular material consisting of suitably shaped buckets mounted at predetermined pitches on an endless belt. The belt obtains its motion from a powdered head pulley and is returned over a tail pulley, adjustment being provided to accommodate belt stret ch. Material is picked up either by buckets dredging out the bottom of the conveyor or by feeding the material into the passing buckets and then discharged by centrifugal action while passing over the head.

A5.8 Vertical internal discharge chain and bucket conveyor — a totally enclosed continuous bucket conveyor with the bucket carried between two chains and having inner openings. The material is fed in at the foot of the conveyor and discharge occurs when the buckets are inverted while passing over the head sprockets, 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-carrying trucks on separate track or floor.

A6.3 Chain or wire rope belt conveyor — a conveyor composed of a belt secured to t ransverse supports carried by moving chains or wire ropes. The chains or wire ropes transmit the driving force, the belt forming the load-carrying medium.

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

A6.5 Overhead chain conveyor (open track type) — a conveyor which uses a bi-planar chain suspended by 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 a rticulated chain which serves to transmit driving tension and carries the weight of the load. It has rollers disposed in 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 with pusher dogs attached to an endless chain or cable driving l oad-carrying trolleys running on a separate tr ack  from which trolleys can be diverted away from the driving chain by means of switches. These conveyors may be designed for single plane or multiple plane operations.

A6.8 Positive di scharge type chain and bucket conveyor — a conveyor similar to the vertical belt and bucket conveyor but normally operating at slow speeds, and arranged for the buckets to up-end when approaching 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 of  chain 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 driving medium.

A6.11 Sliding chain conveyor — a conveyor assembled wit h one or more endless chains sl iding on tracks on 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 type trays carried between parallel endless chains which swing at the change of direction to pick up on the feed side and discharge t he feed on the downward side. The drive is generally at the head of the conveyor, the chains passing over sprockets of considerable diameter. Loading or unloading can be made automatic and can occur at any intermediate floor level.

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

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

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 together by flight bars set at suitable interval. The bag or bale is lifted by flight bars and slides up a smooth backing 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 opposed to each other. Each unit consists of one or more endless chains whose adjacent facing runs operate in parallel paths so that pairs of opposing shelves or brackets are synchronized to receive packages or trays and deliver t hem at any number of elevations. (The auto-unload type i s illustrated.)

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

A8 DISC OR BUTTON CONVEYOR — a conveyor composed of a wire rope or chain carrying discs or 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 flight moving through an enclosed duct.

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

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

A11 PALLET TYPE CONVEYOR — a conveyor assembled from a series of flat or shaped wheelless carriers 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 materials and 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 and mounted above or below floor l evel, to which is attached by means of a retractable pin, load-carrying t ow trucks.

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

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

A14.4 Overhead monorail chain conveyor — a conveyor for units l oads, with an endless chain or cable as the driving medium for a series of trolleys.

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

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A16 HYDRAULIC CONVEYORS A16.1 Hydraulic conveyor — a conveyor transporting materials by means of a moving stream of water or 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 bulk  materials.

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

A18 MAGNETIC CONVEYOR — a conveyor having a flexible rubber or canvas belt moving adjacent to a static magnetic field which imparts a retaining influence or pull to any magnetizable article and so allows 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-speed type, 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 are moved 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 reciprocating beams with tilting dogs or pushers.

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

A24 SCRAPER DRAG BAR OR DRAG LINK CONVEYOR — a conveyor having one or more chains equipped 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 carrying medium, 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 closebladed 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 a solid helix attached to a central rotating shaft working within a tube normally inclined at angle to the horizontal. The shaft normally rotates at a relatively high speed. The conveyor is generally used for intermittent 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 shaped flighting 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 the form of a solid helix with either constant or varying pitch, attached to a central rotating shaft the whole being 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 bl aded type, but the conveying elements are in the form of separate paddles of various shapes attached to the central shaft in 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 except that 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 a ribbon 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 selfcontained 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 spaced slats 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 l oose bulk materials or unit loads with slats and 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 both the chain and the work carrying plates. This conveyor provides a fl at, smooth, and level surface commonly used to transport cans and bottles.

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

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

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

A31 TWIN FLAT TOP CONVEYOR — a conveyor which utilizes two heavy duty flat top lines commonly set flush in the floor and driven by a single head shaft to transport large, heavy, or wide objects such 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 transferring a 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 roller conveyor to another running at right angles by means of small manually operated or power-operated lifting rollers. 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 roller conveyor t o others running parallel by means of a roller-topped t raversing section. The centreline of the load continues to follow the same direction after transfer.

A32.5 Roller conveyor turntable — equipment for transferring a load from roller conveyor to another running at angle to i t by means of a roller-topped t urntable. The centreline of the load does not change its direction of travel in relation to the centreline of the conveyor.

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

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

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

A32.9 Wheel conveyor — a conveyor co nsisting of a framework and spindles carrying small free running wheels 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 for transporting 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 within an overhead track connected by an endless chain, cable, or other linkage with loads suspended from the trolleys.

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

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

A38 WIRE MESH BELT CONVEYOR — a conveyor in which the carrying medium is of mesh construction, 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: Permitted

Not permitted

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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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 provided above: .... ............ .......... ........... ........ ............ ... .......... .... .... ............ .......... ........... ........ ............ ... .......... ....

RETURN TO SERVICE Work completed/not completed Remarks

Time: . . . . . . . . . . . . . . Date:

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

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

.... ............ .......... ........... ........ ............ ... .......... .... System handed back. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . to: . . . . . . . . . . . . . . . . . . . . . . . . . . (Maint enance S uper visor )

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( Manager, E ngineer, S upervi sor )