Safety for a motion system that is like 30ft+ in the air and not normally accessible?

[theColonel26]

Safety for a motion system that is like 30ft+ in the air and not normally accessible?

We are looking at designing a sprayer that moves back and forth on a rail, and is driven by a motor or servo. These things will be way up in the air and unless you get on a man lift there is no way you could get hit by it.

I've done some motion before but that was table top stuff that was easily acceptable so everything was guarded.

Anyone have any experience with something like this?

I am wondering if I can forgo physical guarding and light curtains etc. and just have an E-Stop.

 

[JesperMP]

Do a Risk assessment. You need to consider not only the normal operating, but also troubleshooting and maintenance.

I think there needs to be means to attach a safety harness.

If there can be no need for example for troubleshooting when being near the moving parts, then it may be enough to have the means to isolate the rail system from all energy sources.

If you have to be near the moving part but not touch to troubleshoot, it may be enough to have an E-stop.

If it is necessary to touch the moving parts for troubleshooting or adjustment, then it must be guarded or there must be other means, possible a press-to-enable switch that runs the rail at a safe slow speed. If the rail is driven by a VFD or servo, then these often have safety functions built right in, incl. 'Safe Slow Speed' modes, so it is not so esoteric as one might think.

disclaimer: The above is merely loose talk and shall not be taken as expert advice.

 

[arpus4KM]

Entirely depends on the company's own risk assessment as well as osha guidelines for machine guarding.

anything above a certain height (normally reachable from an accessible area) is usually not needing any special guarding. But then things need to be taken into consideration, like what happens if someone walks under it.


I've worked around and seen multiple automated crane type systems. one of them was guarded everywhere that anyone could get near it. but was still accessible with a manlift and nothing to stop it. The other was purely automated to take large, up to 48", diameter ductile iron pipe out of a spincast process in a foundry.

You could walk in the room, under the crane, while in operation. and it would just keep going, nothing on the floor but taking control through the pendant would stop it from running in automatic (except of course at the panel for control switching). But the safety standard for here was to keep your head on a swivel, and don't walk under loads.


A new age type thing you might see, is lots of Lights for anything moving in the overhead, shining on the floor to indicate there is a machine above you working. some have lasers, you get the drift. But this entirely depends on what the standards are. If you get the right place, an overhead automated system would have plenty of floor scanners in place to stop the process if people came into the wrong area too.

 

[James Mcquade]

as mentioned, you need to do a risk assessment.
you may need to put guarding fence around the working area, depending on what the unit is doing during normal operation.
also, if someone in a man life can get to it, a normal e-stop will not work, you will need a loto system for maintenance/troubleshooting.
if the system can move and hit the manlift, you need a safety plan for it.
regards,
james

 

[theColonel26]

as mentioned, you need to do a risk assessment.
you may need to put guarding fence around the working area, depending on what the unit is doing during normal operation.
also, if someone in a man life can get to it, a normal e-stop will not work, you will need a loto system for maintenance/troubleshooting.
if the system can move and hit the manlift, you need a safety plan for it.
regards,
james

Risk Assessment, LOTO device, Safety plan.... that is the end user's problem


Also just for some visualization. This thing is like a big CNC router table on it's side, and it just has a spray nozzle to clean the thing is is permanently mounted too. So it is not like this thing is a crane or anything.

 

[Steve Bailey]

Risk Assessment, LOTO device, Safety plan.... that is the end user's problem

Not if you have anything to do with the design or installation of the equipment.

The dirty little secret of the US Worker's Compensation system is that when a person injured in a workplace accident accepts the Worker's Comp settlement they give up the right to sue the employer. Then their lawyer advises them to sue everybody else who ever had anything to do with the equipment.

 

[theColonel26]

Not if you have anything to do with the design or installation of the equipment.

The dirty little secret of the US Worker's Compensation system is that when a person injured in a workplace accident accepts the Worker's Comp settlement they give up the right to sue the employer. Then their lawyer advises them to sue everybody else who ever had anything to do with the equipment.

Well ****!

 

[arpus4KM]

Well ****!

i've seen a lot of people do a lot of shady ****... and I've only ever heard stories of someone actually being sued by a person who was hurt. doesn't mean it won't happen....

hell, think about it, nothing is stopping a guy from grabbing a manlift and going in the air to check something in the overhead, and then having his head smashed in by a "big *** fan". those things are deadly when people don't pay attention, and your depth perception is messed up when eye level with the blades. never seen or heard of someone suing big *** fans because the fan that runs in the overhead killed a guy.

same for cranes, I heard stories of people who were sued into oblivion because they pencil whipped an inspection... guy runs something, it kills a guy and then the rest is history when the lawyers start asking for questions and paperwork.

but then on the same hand, I've witnessed people pencil whip the **** out of an entire plant worth of crane inspections... marked off the brake as good, never opened the cover. Marked off the rope as good, never ran it all the way up and down to inspect. Marked off the structure as good, only sat in the center of the bay and kind of looked at it from 100 feet away at all corners.