Fall protection for tools?

[StructureMan44]

Have any of you encountered or utilized a net or something similar that can provide protection from falling tools? We have an open area 30ft by 30ft between steel beams that we would like to put in place some sort of net or temporary barrier to stop the fall of up to a 70lb tool from a fall of about 50ft.

 

[JStephen]

I've seen construction areas where they had covered walkways, I assume partly for this reason- but I think those were plywood covers or something similar, not net. I don't know if they were designed or just built.
One problem with a net would be defining the load- if you know what you're going to drop, you can work with that, but not knowing the size of the falling object, you'd just about need a solid cover.

 

[MotorCity]

This is one of the functions of a toe kick on industrial platforms. If you are concerned that the tools project above the toe kick, I would simply use a larger toe kick or perhaps a screen or mesh around any elevated platforms or catwalks

 

[IRstuff]

I would think that this is typically not considered, because any group of workers that prone to dropping things are going to be dropping more than just tools.

TTFN
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[Lesali]

Ah fall protection! This is may not be an OSHA requirement but you feel it is needful. I'm not aware of toe kicks being install for use during construction but a temporary toe kick as suggested is an option. But, if you are serious about netting, then you might look at the netting used at driving ranges as they come in large expanses of materials, are woven tight enough to stop a golf ball and are designed to carry the tension from all that wind.

 

[Archie264]

Stopping a 70lb tool that has fallen from 50ft is no trivial matter. Or to put it another way, 70# is a heavy tool and 50' is a long way to fall.

I can provide follow up information later but I believe the following is correct:

For 50' time of fall = 1.762 seconds at which time the velocity will be 56.745 ft/sec = 38.68 mph.

Mass = wt/g = 70/32.2 = 2.174 pounds mass

E = .5mv^ = (.5)(2.174)(56.75^2) = 3,500 ft-lbs

Set Energy = Work = Fd and solve for d. And "d" is your proposed stopping distance. If you have in mind, say, 6" = .5', then F = 7,000#...no trivial matter. If you have in mind 1"...well you do the math. Stopping distance and/or strong members are your friends. Aircraft carrier arresting gear works better for it's task then steel beams but in this case it's not the tool that's to be preserved so steel beams and/or heavy timber might be preferred.

 

[BigH]

Can you tie off your tool so that it doesn't fall?

 

[ACtrafficengr]

What about the nets they used for fall protection in bridge work? If it will catch a 200lb ironworker, it should work for a 70lb tool. They usually were a lot less than 50 ft below the work area, though.

Last year, a truck driver was killed by a steel tape dropped from a hi-rise.

http://www.nydailynews.com/new-york/delivery-man-killed-freak-job-site-accident-article-1.1997887

 

[Canuck67]

If you are considering a net, I would suggest layering two nets with a separation between them. The reasons for this are that if a single net is 'tight', the tool will tend to bounce off the net like a trampoline. Set the first one 'loose' to absorb as much energy as possible. If for some reason the first net lets go, a significant percentage of the energy will hopefully be dissipated and the second net will arrest the tool. I would look towards cargo netting or possibly the mesh they use in NHL hockey arena's to protect the attendees from errant pucks in the end zones.

The fun part will be setting up a test area of netting and dropping a tool from height. I have done this with layered plexiglass panels intended for protective canopies at building entrances.

 

[BUGGAR]

After I dropped my third $20 Stanley tape in San Pablo Bay from the new Dumbarton Bridge, I learned the value of a lanyard.

I thought safety lanyards for tools were mandatory.

 

[TehMightyEngineer]

They make nets specifically for this, you see them in construction sites that takes place over active sidewalks in urban areas. I've used them in an industrial facility that had a spalling elevated slab and they needed a bandaid until they could fix it.

Maine Professional and Structural Engineer.

http://www.fepc.us

 

[MikeHalloran]

A net is not likely to stop a spud wrench.


Mike Halloran
Pembroke Pines, FL, USA

 

[TehMightyEngineer]

Here you go:

http://www.incord.com/construction/vertical-debris-nets.htm

http://www.incord.com/construction/perimeter.htm

Grabbed the first link off of Google, I'm sure there are other suppliers as well.

Maine Professional and Structural Engineer.

http://www.fepc.us