Horizontal (with sag) lifeline
Horizontal (with sag) lifeline
(OP)
I have been asked to review an in-place fall arrest system. It consists of a cable wrapped around a beam (at each end) and secured to itself. From end of cable to end of cable is approx. 200 feet. Notice there is an underdetermined sag (see pic.) as the cable makes its way parallel to the pipes and across the pipe rack beams. This is a pipe rack system undergoing demolition, where the workers (only 1 in this case) will be moving along the top of the pipe with the tie-off below his feet. Folks, I just don't feel right about this, with so many unknowns, and would appreciate any and all comments.






RE: Horizontal (with sag) lifeline
the point of the cable is to stop someone hitting the ground.
i'd model/analyze the problem as though the cable was two straight lines, from an anchor point to the person's attach point. there's another variable, the worker will be tethered to the cable with a sliding loop, yes? so if they fell they wouldn't start fixed to their starting point, but would slide "down-hill" along the cable (tending towards the middle of the cable), yes?
so you might work out how far they could fall, two straight lines L/2 from the anchor points. this sounds like it'll be the worst case, but see how far they'd fall if they were at a 1/4 point ... one line L/4, the other 3L/4.
then there are bunch of other things ... would they hit anything (other piping ?) in their fall ? how fast will they decelerate ? i'd expect the load in the cable to be less of a problem, but still something else to check.
RE: Horizontal (with sag) lifeline
RE: Horizontal (with sag) lifeline
i guess the key issue is would they hurt themself ? (if they fell onto the rack beam)
is there an option ? is this the best that can be reasonably done ??
RE: Horizontal (with sag) lifeline
RE: Horizontal (with sag) lifeline
Richard A. Cornelius, P.E.
WWW.amlinereast.com
RE: Horizontal (with sag) lifeline
rb: I was told by the site safety professional that a similar system was used when the pipe was installed (I know don't make it right), and yes I have a concern with impacting the cross beams before any type of fall is arrested. I envision a type of beam clamp with (tall) stanchion with a lifeline height near the chest of the worker as he stands atop the pipe.
ishvaag: I am with you, quite disgusting.
dicksewerrat: I agree with the OSHA involvement.
Again, thanks all.
RE: Horizontal (with sag) lifeline
Is there a potential for a worker to fall and then swing and hit the structure below or would the worker fall straight down and just hang there until rescued?
RE: Horizontal (with sag) lifeline
RE: Horizontal (with sag) lifeline
Michael.
Timing has a lot to do with the outcome of a rain dance.
RE: Horizontal (with sag) lifeline
I do not think what you have is adequate, it would appear that there is too great a risk of hitting the framing underneath in a fall.
can rou raise the cable?
Here is a link about the osha reg, it is a little vague about a situation like that. http://www.osha.gov/doc/outreachtraining/htmlfiles...
B.E.
The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor
RE: Horizontal (with sag) lifeline
RE: Horizontal (with sag) lifeline
The photo overall looks like its not the best situation with everything below if they did fall. OSHA also has required safety factors and anchorage requirements for a lifeline system of this nature. I don't know what the scope of your work is, I briefly skimmed most of the posts above, but if I had been asked by a contractor verify the safety of the fall protection system I would reference OSHA for the safety factors but in my letter to the contractor very explicitly say that I did not review the fall protection system to be in accordance with OSHA requirements. Safety is the responsibility of the contractor not the structural engineer.
RE: Horizontal (with sag) lifeline
Miller and Web-devicesUSA come to mind. They will help you all the way down the line...
RE: Horizontal (with sag) lifeline
Funny how many places I've been in and used life lines that if I were to fall with a typical lanyard (in place of the proper retractable) you would fall 10-12' and land on equipment or worse, chemical baths.
RE: Horizontal (with sag) lifeline
RE: Horizontal (with sag) lifeline