Nice little earner or shortcut to court?

Steve Kemp

Member
Join Date
Nov 2003
Posts
122
One for the safety gurus...
I've been asked to design and build the controls for a hydraulic shear. It's a floor-mounted, foot-pedal operated machine using a cylinder to operate a single (upper) pivoted blade downward past a stationary lower blade. So it's a big scissors, with the point nearest the operator, who holds the part to be cut with a hand at each end. The cut speed is to be in the order of 2s from top to bottom. So long as the footswitch is pressed, the cycle will continue (down/up). If the footswitch is released, the blade returns to the top. I've found a footswitch by Bernstein that incorporates an E-stop function (push past detent), but even so, the whole thing looks like a can of the proverbials. Any thoughts?
 
Hi Steve

The machine MUST be designed so that the operator cannot get his hands near the cutter when the machine is operating. You may be able to add a safety curtain or they may have to re-think the machine operation so that the operator no longer has to hold the item to be cut. You need to have a meeting with the client where you discuss the safety issues and for your own safety that meeting should be recorded.

Regards

Bryan
 
The meeting does not have to be recorded.
If you do record it, then it is unlikely to be any defence in court.
The best thing to do is to design your machine safely.
There are published standards for all types of machinery. In Australia, we have copied the European standard on this and re-named it AS4024. Unfortunately I can't remember the correct European standard number, and I am at home so do not have my references handy. This standard has design rules for safety for the machine you are referring to. I would suggest strongly to proceed only once you know the rules. The cost of the standard and the hours spent studying it are well worth what it would save you in criminal or civil penalties (not counting knowing you cost someone their fingers).

This knowledge can then be applied to other jobs, turning it into a nice little earner.
 
There will be a british european standard for this machine, get a copy of it and follow the safety requirements to the letter.

Also you will need BSEN 60204 - Safety of Machinery - Electrical equipment of machines.

BSEN 12100 parts 1 and 2 - Safety of Machinery Basic concepts
BSen 954 Safety of machinery - Safety related parts of control systems
BSEN 294 Safety of Machinery - Safety distances to prevent danger zones being reached by upper limbs

You may want to consider turning this job down if you dont have much experience with safety systems for this sort of machinery.

If you are automating a manual machine then it will need to be CE marked and it probably is an annex 4 machine which means that it has to be approved by a notified body.

The operator need to be kept away from the cutters and also you will need to fit a cat 4 e-stop unless you can install fixed guarding. The distance between the guard and the cutter must be such that the gap will not allow any part of the body to reach the blades.
 
Last edited:
For Europe

Machines and their control systems are governed by the following standards:

EN 292-1/2 SAFETY OF MACHINERY
EN 1050 SAFETY OF MACHINERY
EN 60204 ELECTRICAL EQUIPMENT
EN 954-1 SAFETY RELATED CONTROL SYSTEMS
EN 418 SAFETY STOP
EN 574 SPECIFIC PROTECTION STANDARDS
TYPE C STANDARDS FOR MACHINES

THE DESIGNER MUST DO A RISK ASSESSMENT PER EN 1050 BEFORE ANY DESIGN WORK.
 
Steve.

I agree with John that your machine will probably be considered an Annex 4 machine and will need to comply with the extra regulations associated with this. The machinery safety regulations are designed for new "stand alone" machines and can be difficult to apply to machinery in automated processes and retrofits. The most important document for most such purposes is the Provision and Use of Work Equipment Regulations (PUWER) which is very similar to the machinery safety regs but is more apropriate if you are not supplying the complete machine. PUWER is an HSE document and is easily obtainable.
Andybr
 
Everyone may be getting ahead of theirselves, there has not been enough information provided to say how it needs to be done.

Much of it depends on the shear design. If this is for smaller pieces the shear itself may have a metal guard in place that just allows for the thickness of the plate i.e. the opening may be less than an inch.

I am basing that it will not be too large a system because he stated it used a pivoted cutter and in my experience these type are usually for small piece work. Something along this line:
http://www.edwardsironworkers.com/bar.html

There are numerous types of shears with design and operational difference, most are built thees days with physical guards in place to make it difficult for an operator to insert body parts.

I agree, get the standards, but most of all learn how it is physically designed to operate and what safeguards will be in place.
 
I would also look into changing the design so that the operator doesn't have to hold the part. Can clamps be used? The further the operator is from the process the better.

I have a similar application and use permanent mounted guards that cannot allow a finger to pass through. The shear also has a clamp that holds the material to the table as it shears. No hands or fingers can get near the blades while in operation.
 
The standard you probably need is BSEN 13985:2003

Apart from PUWER you also need to meet the Essential health and safety requirements as laid down in the Supply of Machinery (Safety) REgulations
 
I stick with what I said about recording the meeting. I didn't say tape record or video record, I mean you write it down and keep a record. Perhaps because I am older the term 'record' has a different connotation. Keeping good records shows a machines development and the considerations made in terms of safety. It also shows when 'production' decided to bypass the safety you designed in order to boost productivity.

Bryan
 
You could also phone the HSE at East Grinsted and ask for an expert in that particular field, they will phone you back and give you all the relevant reg numbers you need, they will also suggest what they would prefer. We did this recently on a press job and they were very helpful.
 
I think you are definitely on the hook for the safety of the modified machine... "modified" being the hook. Even if the machine is "unsafe" under current standards, that is often allowed if the machine met standards when new. Once you modify it, however, it must meet current standards when returned to service.

I want to say that even moving the machine from the original location to a new location requires that current safety standards be satisfied when the machine returns to service... but I might be imaginging that one.

In any event, best practice is certainly to ensure that the machine meets current standards, and the owner should know this and budget for it before making any modifications.
 

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