OSHA Mobile Platform 1

[FootNMouth]

thread507-103228

We are designing a mobile platform (see attachment). The client has indicated that the platform will be used by maximum of (2) workers at a time. We are intending to use 300 lbs to account for a worker + tools.

OSHA requires we design the platform for 4x the maximum intended load.

For the uniform load, we are considering using 20 psf (similar to roof live load) which then with the 4x safety factor will lead to 80 psf.

In addition, we will design for a concentrated load of 1,200 lbs to account for 4x one worker.

Does anyone see a reason why the loading we are intending to use does not meet the OSHA requirements?

1910.23(e)(1)(iii)
Mobile ladder stands and platforms are capable of supporting at least four times their maximum intended load;

1910.21 (b)
Maximum intended load means the total load (weight and force) of all employees, equipment, vehicles, tools, materials, and other loads the employer reasonably anticipates to be applied to a walking-working surface at any one time.

 

[JStephen]

Sounds reasonable to me.
On a lot of small stuff like this, you'll come up with pretty low stresses anyway, so you may can bump the loading up without affecting the construction.
On the uniform load, you could use the elevated catwalk load from ASCE 7 or something similar, but it likely won't make much difference.
OSHA likes to specify loads and safety factors but doesn't like to specify how they should be applied. So you can take that as "Four times the intended load without failure" or "Four times the intended load without exceeding allowable stresses". This issue has been discussed some in regards to the fall-protection loads on these forums, I believe.