worker protection at crocodile (alligator) shears

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Health and Safety Executive

Worker protection at crocodile (alligator) shearsGuidance Note PM 65

This is a free-to-download, web-friendly version of PM 65 (First edition, published 1986). This version has been adapted for online use from HSE’s current printed version.

You can buy the document at www.hsebooks.co.uk and most good bookshops.

ISBN 978 0 1188 3935 8Price £2.50

This guidance gives advice to users of crocodile shears – sometimes called ‘alligator’ shears – and recommends how this machinery should be set up correctly to minimise the risk of accidents occurring.

It is aimed at those who would use this equipment in the workplace and will be of use to factory managers/owners in order to assist worker protection and to comply with the legal position.

HSE Books

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© Crown copyright 1986

First published 1986

ISBN 978 0 1188 3935 8

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

Applications for reproduction should be made in writing to: The Office of Public Sector Information, Information Policy Team, Kew, Richmond, Surrey TW9 4DU or e-mail: [email protected]

This guidance is issued by the Health and Safety Executive. Following the guidance is not compulsory and you are free to take other action. But if you do follow the guidance you will normally be doing enough to comply with the law. Health and safety inspectors seek to secure compliance with the law and may refer to this guidance as illustrating good practice.

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ContentsThe machine 4

Accidents 4

Legal position 4

Recommendations 5



The machine1 A crocodile shear is a machine which cuts metal to length. It has a heavy metal fixed lower blade (or section) against which an upper hinged blade continuously operates in a scissor action. Most machines have a heavy hinged metal clamp for holding the scrap metal against the lower blade. The scrap metal is placed under and through the clamp by the operator and then pushed between the two blades. The top blade descends and shears off the metal into sections for sale and reprocessing. Scrap material is usually fed by hand into the machine as automatic feeding is impractical for most machines. This of course means that the operator’s hands are close to the continuously moving blade and the lower (anvil-type) section of the machine. (These machines should not be confused with the smaller type shear which is used to clean and separate non-ferrous scrap material).

Accidents2 These machines have caused many serious accidents to operators and to others. Injuries have included (a) amputation of fingers, amputation of hands and (b) severe crush injuries to hands from trapping between the scrap metal and the clamp when the material has ‘kicked up’. All these accidents have occurred during:

(a) the operator feeding material into the machine; or (b) by operators and others tripping or falling over material, etc and coming into contact with the descending blade.

Legal position 3 Section 14(1) Factories Act and Sections 2 and 6 Health and Safety at Work etc Act 1974 (HSW Act) apply to these machines.

Figure 1 Unprotected crocodile shear



Figure 2 Fixed extension fitted to lower blade

Recommendations4 The lower blade should be fitted with a fixed extension on the edge away from the moving top blade. This should extend beyond the leading edge of the clamp by a minimum of 5.08 cm (2 inches) and provide a level surface on which material being cut may be rested.

The purpose of this fixed extension is two-fold:

(a) it provides a firmer and more stable base for the material; and (b) it removes the operator’s hand from the vicinity of the clamp and thus reduces the risk of the crushing of the hand against the clamp by the material ‘kick up’.

5 A strong rigidly fixed mesh guard should be mounted around the operating parts of the machine. This guard can either be fastened to the machine frame or alternatively fixed to a rigid frame, the legs of which could be embedded in concrete. The guard should be designed to prevent access to the continuously acting blade at the feed side except to the extent necessary to allow the material to be fed into the machine. The guard should also be designed to prevent access at the front and at the rear (delivery) side of the machine. This guarding system should limit operator access to the danger area and also prevent inadvertent contact by a person falling or tripping into the machine. For machines not fitted with a clamp the guarding system will need to be designed to take into account the trapping risk created by the material kicking up against the lower edge of the guard. Please see Fig 3.


Figure 3 Addition to guarding for crocodile shears without a clamp. The measures illustrated above are considered to be appropriate for machines not fitted with a clamp

Figure 4 Strong guard at feed side with extension to lower blade


Movingblade

Fixed blade

Guard

Front view

77mm x 77mm x 10mm angle, bolted or welded to outside edge of guard in position shown (for full length of opening)

Lower blade extension

or75mm x 15mmsteel stripwelded to guard

Close-ups of modification at A

A



6 A suitable chute should, where reasonably practicable, be fitted to the discharge side of the machine (See figure 5). This is to allow the removal of the material after shearing and should be incorporated in the guarding enclosure mentioned in paragraph 5. It also maximises the protection afforded by this guarding system.

Figure 5 Chute at delivery side of machine

7 Where practicable, the machine should be located in an elevated position (eg on an embankment or other structure). This makes access from the discharge side of the machine more difficult, allows the grading and removal of the finished scrap metal and improves the layout of the yard (See figure 6).

Figure 6 Machines in an elevated position



8 The cutting of large section scrap metal at the front of the machine (eg to cut into plate) should be discontinued. Where large metal plate (ie plate wider than the maximum width of the machine) has to be cut, it should first be cut by oxy-acetylene torch into suitable widths for feeding into the machine.

9 A safe system of work should be formulated for people operating and maintaining the crocodile shear(s). The system of work should pay particular attention to the following matters:

(a) the maximum thickness of scrap material which can be cut should be clearly marked on the frame of the shearing machine (b) the proper use of the safety devices (c) the provision and maintenance of clear and unrestricted space around the machine(s) (d) the proper storage of scrap prior to shearing (e) the electrical isolation of shears before maintenance work begins (f) the replacement of all safety devices before work at the shears recommences (g) the minimum age of operators should be marked on the machine

10 People should not be permitted to operate crocodile shears unless:

(a) they are over eighteen years old and (b) they have been carefully instructed of the dangers arising from the use of the machine and have received adequate training by a suitably experienced person.

Published by HSE 03/10 of 9


Further information

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