Health and Safety
Executive
Worker protection at crocodile
(alligator) shears
Guidance 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 8
Price £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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Health and Safety
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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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Contents
The machine 4
Accidents 4
Legal position 4
Recommendations 5
Worker protection at crocodile (alligator) shears
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The machine
1 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).
Accidents
2 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
Worker protection at crocodile (alligator) shears
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Health and Safety
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Figure 2 Fixed extension fitted to lower blade
Recommendations
4 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.
Worker protection at crocodile (alligator) shears
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77mm x 77mm x 10mm
angle, bolted or welded to
outside edge of guard in
position shown
(for full length of opening)
Guard
Moving
blade
A
or
75mm x 15mm
steel strip
welded to guard
Lower blade
extension
Fixed blade
Close-ups of
modification at A
Front view
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
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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
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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 oxyacetylene 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)
(b)
(c)
(d)
(e)
(f)
(g)
the maximum thickness of scrap material which can be cut should be clearly
marked on the frame of the shearing machine
the proper use of the safety devices
the provision and maintenance of clear and unrestricted space around the
machine(s)
the proper storage of scrap prior to shearing
the electrical isolation of shears before maintenance work begins
the replacement of all safety devices before work at the shears recommences
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.
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Further information
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www.hse.gov.uk or contact HSE Books, PO Box 1999, Sudbury, Suffolk
CO10 2WA Tel: 01787 881165 Fax: 01787 313995. HSE priced publications
are also available from bookshops.
For information about health and safety ring HSE’s Infoline Tel: 0845 345 0055
Fax: 0845 408 9566 Textphone: 0845 408 9577 e-mail: [email protected] or
write to HSE Information Services, Caerphilly Business Park, Caerphilly CF83 3GG.
Published by HSE
03/10
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