Fall Protection 2

[JPAULI167]

designing a monorail beam to hold a trolley as a tie-off point for fall protection. The users will have retractable lanyards when they tie off. Client wants up to 2 users to be able to tie-off. Does the beam need to be capable of supporting just a single 5,000 lb concentrated load?

 

[MiketheEngineer]

Actaully 5,000 lbs. per man. That said OSHA also says that if it is designed for twice the anticipated fall load - it is OK.

Therefore - if the lanyards have been tested and show a "fall force" of only 1,000 lbs - then you can design for 2,000 lbs. times two. Get with your lanyard mfg and see if they have done the tests or buy from someone who has.

The reason you need to design for both "men" falling is that often when one goes - the other either tries to help or is pulled by the other. Therefore - both guys end up "down".

 

[jberg]

As Mike stated, I would also recommend designing for the Max. Arresting Force (MAF) that is listed on the lanyard. MSA, Miller Fall Protection and Capital Safety are some of the major brands that certify the MAF's and I am sure other do too.

The only difference is that I would use that MAF load unfactored and use a F.S. of 2.0 in the steel design. Using the 13th Ed. ASD, the F.S. is the Omega Factor out front.

Normally, I use the number of users * MAF up to 2 persons and then 300# or so for every users over 2. This is similar to the recommendation of "Introduction to Fall Protection" by Nigel Ellis. This is a great read for anyone designing fall protection systems.

JWB