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jeppers23  
#1 Posted : 16 May 2022 11:51:19(UTC)
Rank: New forum user
jeppers23

When changing tools or responding to a running problem such as an adjustment.  The person who is operating the machine/line presses the emergency stop and cuts the power at the control panel that he/she has total control over. Would they also be required to lockout / Tagout the machine?  I am trying to put together a procedure that will state that if the person is in control of the power to the machine and there is no risk of anyone turning the power on and resetting the e-stop because the person who is running the machine/line has total control. The need for locking the power of is not required unless the person who has control leaves the work area for whatever reason. If that make sense?  

Edited by user 16 May 2022 11:53:46(UTC)  | Reason: Not specified

HSSnail  
#2 Posted : 16 May 2022 12:27:43(UTC)
Rank: Super forum user
HSSnail

Depends on the risk of someone else turning it back on inadvertantly - without knowing the machine difficult to say (location of stop etc) - but this has been the cause of a number of fatalities over the years. Remeber E stops are what they say - they should not be used as the ordinary way of turning the machine off .

antbruce001  
#3 Posted : 16 May 2022 13:16:59(UTC)
Rank: Forum user
antbruce001

Hi,

As Brian has stated Emergency Stops should not be used to isolate a machine, or used as functional stops either. Under PUWER every machine has to be able to be securely isolated. Either it should have a lockable isolator point installed or it can be 'unpluged' from the power supply. As such, why wouldn't you want to secure the isolation during the maintenace, even if it's just a belt and braces approach.

Roundtuit  
#4 Posted : 16 May 2022 13:17:37(UTC)
Rank: Super forum user
Roundtuit

The use of E-stop was common in an overseas operation until a day the operative was well within the machine. Not seeing anyone present and an idle production line the supervisor presumed the line had stopped whilst the operative had gone for a comfort break promptly re-started the line and immediately killed the worker.

US head office sent teams to train Lock Out Tag Out methodology globally.

In the UK we were used to having Castell keys on the lines power supply - if an operative wanted to enter the danger zones the power was isolated by taking the key and opening a relevant access gate using that same key.

We had to apply an additional operator (single key) pad-lock to keep the power key point cover closed to counter the possibility the gate could be closed and the operator Castell key returned to the power switch whilst the operative remained inside the machine.

Roundtuit  
#5 Posted : 16 May 2022 13:17:37(UTC)
Rank: Super forum user
Roundtuit

The use of E-stop was common in an overseas operation until a day the operative was well within the machine. Not seeing anyone present and an idle production line the supervisor presumed the line had stopped whilst the operative had gone for a comfort break promptly re-started the line and immediately killed the worker.

US head office sent teams to train Lock Out Tag Out methodology globally.

In the UK we were used to having Castell keys on the lines power supply - if an operative wanted to enter the danger zones the power was isolated by taking the key and opening a relevant access gate using that same key.

We had to apply an additional operator (single key) pad-lock to keep the power key point cover closed to counter the possibility the gate could be closed and the operator Castell key returned to the power switch whilst the operative remained inside the machine.

Kate  
#6 Posted : 16 May 2022 13:58:05(UTC)
Rank: Super forum user
Kate

In this scenario, I don't understand the justification that there is no risk of someone else turning the machine back on.  What exactly stops someone else from doing this?

paul.skyrme  
#7 Posted : 16 May 2022 18:12:51(UTC)
Rank: Super forum user
paul.skyrme

It depends on the extent and complexity of the work being done.

If it can be done under functional safety then that is fail-safe, and does not rely on any human input, which LOTO does.

However, that is for limited interventions.

Typically a tip change on a CNC lathe would be undertaken quite safely under functional safety, it would not require full LOTO as the machine is designed with that in mind.

If every intervention is to be done under LOTO then loads of money can be saved by removal of most of the functional safety from machinery and just rely on LOTO.

Without details of the work and machinery, one cannot say whether LOTO is required, or whether functional safety is adequate.

thanks 1 user thanked paul.skyrme for this useful post.
CptBeaky on 17/05/2022(UTC)
stevedm  
#8 Posted : 17 May 2022 07:30:05(UTC)
Rank: Super forum user
stevedm

I think you may have got your terms mixed up here...functional safety is the design safety requirements for the not the premis for isolation  - functional safety is the workings of an emergency stop for example or a light curtain - all in compliance with 13849/ 62061...the use of that to isolate the machine is the same as using the e-stop..which as we know shouldn't be done... 

antbruce001  
#9 Posted : 17 May 2022 08:31:28(UTC)
Rank: Forum user
antbruce001

Going back to the orignal question.

As the existing or intended process is to use the Emergency Stop to isolate the machine (which as detailed above is not good practice) it clearly demostrates a need to isolate the machine for the task to be done safely. As such, that isolation should be secure, which normally means locked in the 'off' position.

The next question, which seems to be the matter of contention is whether or not LOTO is required. I would suggest that if this is 'typical' adjustment etc. and the machine meets the full requirements of PUWER (functional safety requirements - EHSR) then a local procedural control requiring the operator to lock the isolator and hold the key until the adjustments / changes are made may be adequate, without the need for the full application of the LOTO requirements. If however, the work extends beyond the 'limits' of such a procedural control then the full application of LOTO should be applied. This seems to me to be a pragmatic approach, which should be workable without compremising safety.

Edited by user 17 May 2022 09:22:40(UTC)  | Reason: Removal or a contentious statement that was not intended to be so.

thanks 1 user thanked antbruce001 for this useful post.
A Kurdziel on 17/05/2022(UTC)
A Kurdziel  
#10 Posted : 17 May 2022 09:12:59(UTC)
Rank: Super forum user
A Kurdziel

"As a general comment, why do people spend so long trying to justify what they know isn't right, just because operators or managers don't like the required controls?"

Isn't that against at least the spirit of IOSH rules? 

antbruce001  
#11 Posted : 17 May 2022 09:26:40(UTC)
Rank: Forum user
antbruce001

Kurdziel,

Fair comment, it was not my intention to be contentous or cause any offense. I've removed the line. you may wish to do the same so the statement is not made via you constructive feedback.

chris42  
#12 Posted : 17 May 2022 12:25:01(UTC)
Rank: Super forum user
chris42

I agree with Paul above it depends on the complexity of the machine and how automatic it is. The OP talks of tooling change or a setting change. If the machine was say on the less complex side such as a pillar drill then to change the drill bit you would just turn it off as normal and using the E stop or LOTO not required. The operator would be next to the machine and the controls, and I could see no reason that someone would lean over their shoulder and turn it on while the operative has their hands on the chuck /bit.

The other end of the spectrum is some automatic machine with a remotely positioned control that would kill you as soon as look at you given half a chance, that someone else could think should be on. Then there is a whole spectrum in between of machine and controls. A CNC milling machine with interlocked doors, where the machine will not operate when the doors are open to allow removal / insertion of the workpiece, would also allow for changing a damaged / blunt cutter in a carousel perhaps or even just a replaceable carbide tip.

Without seeing the equipment, it is not really possible to comment on the OP’s question IMHO

Chris

A Kurdziel  
#13 Posted : 17 May 2022 12:25:05(UTC)
Rank: Super forum user
A Kurdziel

Sorry Bruce, I think you have misunderstood my comment: I support the line about  “ why do people spend so long trying to justify what they know isn't right”? I agree with that 100%. Often people come on to the forum to basically ask how to get around guidance and safe practice. By the “rules” I mean not the forum rules(for what they are worth) but the IOSH Code of Conduct, Guidance and Disciplinary Procedure which say Para 4.6”  Inform any person overruling or neglecting their professional advice of the potential adverse consequences and keep a written record of the date, time and nature of this action.”

Which would suggest that a H&S professional’s job is not simply to tell their employers simply want to hear but also to explain why certain courses of action are appropriate  and that if they fail to follow that advice, they can’t expect the H&S professional to blindly support them.

Kate  
#14 Posted : 17 May 2022 13:09:11(UTC)
Rank: Super forum user
Kate

I read it the same way, I too thought the criticism was that the comment was offensive to a fellow professional!

A Kurdziel  
#15 Posted : 17 May 2022 15:10:18(UTC)
Rank: Super forum user
A Kurdziel

Sorry I tried to be pithy and ended up just pithing people off!

thanks 1 user thanked A Kurdziel for this useful post.
Kate on 17/05/2022(UTC)
peter gotch  
#16 Posted : 17 May 2022 15:55:41(UTC)
Rank: Super forum user
peter gotch

Firstly, Jeppers, your first posting on these Forums, so welcome.

I think that this thread has veered to the extent where if we had an effective Moderating team, part or all of the thread might have been taken down while some parts were resolved.

I thought about multiple messages via the PM facility but it would take too long.

We have to remember that these are the Public Forums open to people who are NOT members of IOSH (and whilst I see that Jeppers' profile indicates that they are a Member, we don't know what grade or background they have) and so I am not sure that quoting the Code of Conduct is particularly helpful and could easily deter a new visitor from the Forums.

As I see it the original question can be read as looking for informed answers to a reasonable question and NOT looking for an excuse to break some sort of clear rule.

LOTO is not mentioned in UK law and is a non-native invasive species like the American red squirrel or Spanish bluebell. I think that the first time I had every heard the term was probably about 15 years into my career in H&S.

If we look at e.g. the Electricity at Work Regulations 1989 or its predecessor the Electricity (Special Regulations) 1908 as amended in 1944 they don't talk about locking off but rather that work on equipment should be done "dead" unless there are good reasons to do "live" working.

There are lots of machines where LOTO would simply be impossible for the simple reason that there is nowhere to lock off - most things that get plugged into a socket. So whether doing electrical work or other maintenance the usual practice would be for the person doing the work to unplug the machine and be the one who makes sure that it's not plugged back in until all the covers are back in place. 

To ensure an adequate level of safety they might do things like put a barrier around to alert others, but if you bring in an engineer to sort out your washing machine at home, this is very unlikely. 

Then various comments on this thread do illustrate why some work on machines may be permissible with guards open but without isolation - much being down to the nature of the equipment and where anyone at risk may be compared to where the means of restarting is, or where the machine may restart by itself.

So, Jeppers, I think the answer to your question is "it depends", followed by the usual get out clause "and depends on what your risk assessment concludes is appropriate" to ensure safety so far as practicable or so far as reasonably practicable [depending on which specific legislative requirement you are considering].

This question would possibly be easier in the US. OSHA Regulations would probably dictate LOTO. But in the UK it's about working out what to do to comply with the letter of the law and its aims in goal-setting legislation.

BUT, the accident statistics are very clear - the almost entirely prescriptive and proscriptive requirements of OSHA Regulations achieve less than the qualified duties in UK law.

Edited by user 17 May 2022 15:57:17(UTC)  | Reason: Typo

paul.skyrme  
#17 Posted : 18 May 2022 21:56:00(UTC)
Rank: Super forum user
paul.skyrme

Originally Posted by: stevedm Go to Quoted Post

I think you may have got your terms mixed up here...functional safety is the design safety requirements for the not the premis for isolation  - functional safety is the workings of an emergency stop for example or a light curtain - all in compliance with 13849/ 62061...the use of that to isolate the machine is the same as using the e-stop..which as we know shouldn't be done... 

Hello stevedm,

I'm not getting my terms mixed up.

I am not suggesting that functional safety is a replacement for isolation.

What I am saying is that certain interventions on machinery can be undertaken using functional safety, and do not require isolation.

The point at which full isolation of equipment is required is not a definite point, it depends on what the intervention is and the complexity of the work.

This level of detail is not available in the OP.

stevedm  
#18 Posted : 19 May 2022 13:44:42(UTC)
Rank: Super forum user
stevedm

yes I get it and , well to be pedantic you are...functional safety isn't that - the manufacturers guidance in your example for changing parts includes the isolations and guidance that is just the operation of the machine...

the functional safety is the failure rate and assessment of the controls and interlocks that provide that machine to function safety and give the manufacturer the information to be able put that on the market safely...in line with 13849 etc 

you can't rely on those for isolation otherwise we would be using e-stops all the time :)  

I am sure somone will pop up a google example that contradicts that but generally speaking that is how we should separate it...at least that is how I have awlays explained it 

paul.skyrme  
#19 Posted : 23 May 2022 18:33:20(UTC)
Rank: Super forum user
paul.skyrme

I am more familiar with functional safety and validations than I would like to be sometimes, mainly when the client doesn't have all the data for the functions I am expected to validate, or they select parts that are not suitable for use in safety functions.

My point is that not all interventions on machinery require isolation.

Some can be safely undertaken utilising the primary safeguarding and functional safety integrated into the machine controls.

That is why it is termed "functional" safety, it functions to put the machine into a safe state for limited human interactions and interventions.

If this were not the case, then for an automatic CNC lathe, for example, we would have to LOTO every time we took a part out, but we can't do that, because the chuck needs power to open, so we must have power on.  Thus, we must rely on the failsafe design of the guard switches and associated parts in the safety function to achieve the relevant Performance Level (PL), to ensure that we reduce the number of dangerous failures to an acceptable level, based on the harmonised standards, or the PLr assessment undertaken in accordance with ISO 13849 for example.

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