Functional Safety and a legacy system (1975)

[mad4x4]

We have a legacy winch system that was built back in 1975, we are looking to replace all the controls (electrical) on this and bring it up to a more modern standard. Mainly due to all the control being obsolete.

Do we have to fully look at the functional safety of the complete winch (electrical & hydraulic) to bring it into line fully with IEC61508 / IEC61511 , or can we just look at it from the Electrical side only and use the ALARP priniciple to say its to expensive to replace all the hydrailics as well?

 

[janner_10]

https://www.safemachine.co.uk/scenarios/

Scroll to the very bottom. I interpret it as requiring a new assessment in your case, others may disagree.

 

[James Mcquade]

when I worked for a British company we were told the following.
a grandfathered system could be modified using the existing controls (Note what I said, modified), BUT, when upgrading the controls, you had to meet all current EU safety standards and codes (again, note the word upgrading).

the rules may have changed since 2004.
I would have your company safety manager / local rules official confirm what we said.
NOTE - this is our opinions and they do not matter ! YOU must confirm what is required !

regards,
james

 

[JesperMP]

If the machine functionality and operation stays exactly the same, and it stays in the same location, basically replacing old parts for new parts 1-to-1 then you do not have to bring it uptodate.

 

[jraef]

But from an ethical perspective, wouldn't it be prudent to update machinery to make it safer? This is that opportunity.

And if that alone is not enough for someone, imagine an unfortunate situation wherein someone is injured after the changes and it comes out that this opportunity was eschewed for financial considerations. Any decent lawyer would be on that like stink on you-know-what.

 

[James Mcquade]

Jraef,
I agree and so did the EU. When I joined that company in late 1997, the ruling just came out, when you upgrade the controls on a grandfathered machine, you must meet all the current EU and safety requirements.
This is what the company president told us in the engineering meeting and that's is what I am relaying to everyone.

james

 

[Jeev]

You need to get your local (State) legislation. In my experience the local legislation can vary between states and certainly between countries. If we were doing the same thing in any state in Australia, we would be looking at bringing the whole system to a current and compliant level. This is actually not part of the AS/ISO/EN standard, but part of the WorkPlace Health & Safety Act that makes reference to the Machine Safety Standard (AS4024 here). In our case what it says is that any modification made by the OEM/machine builder/SI makes that person liable.


I think realistically that comes back to the need to have completed risk assessments through various stages of the project.

 

[mad4x4]

Thanks for the input, My take on this is that a significant change has taken place so a Process Hazard Analysis has to be conducted.

So basically treat as a new build

 

[lanester]

Assuming you are in the UK, the PUWER (Provision and Use of Work Equipment Regulations) apply as well as the EU's Machinery Directive. PUWER places a duty on employers to ensure the work equipment they own, operate, and have control over is safe to use at all times. This is regardless of machinery age! So in a court of law, if there was an injury whilst operating the equipment your company would have to prove that they have done enough to prevent the incident occurring in the first place.

So as others had said just doing a controls upgrade is not sufficient.