Ladder Design for fall arrest loading 1

[Mohit Jain]

I have generally designed ladders for 300 lbs load acting on rung. I researched a bit. It looks like ladder has to be designed for 2700 lbs (by manufacturer) acting at location of fall arrest system. I wanted to ask do we need to design anchors connected to wall/ nailing connected to wood block which acts as a support for side rails for reaction due to such high load in addition to rung and side rail design?

Also, If my ladder extension is 4.0 ft from the last anchor support. Do, I need to check minor direction bending as well for 100 lbs load and will rung acts as brace for side rails? The rail extension will be 4.0 ft in major direction. Will it be distance of extension from last rung or last anchor support for bending in minor direction check?

 

[TLHS]

What standards and jurisdiction are you looking at? Is this a steel ladder?

If there's a fall arrest point provided, then that load needs to go somewhere. If there's a rated point on the ladder then you have to find out where they're assuming that gets passed to and anchor that.

 

[Richard_Honne]

IBC 2021 requires 3,100 lbs live load for fall arrest system. Point load needs to be transfer to the anchorage and supporting blocking.

 

[Mohit Jain]

The ladder is steel with standard 1" rung diameter with 3/8"x3" side rails with anchorage support at every 4.0 ft. The ultimate load was provided to be 2700 lbs from manufacturer of fall arrest system. I wanted to know about anchorage. Currently, I have lag screws connected to wood blocking. Suppose load transfer on side rail is 1000 lbs and i have 4 supports, Can i divided them into 4 supports? I dont think so as it might happen the fall arrest load is applied to rung just near to one support and total load might act on one anchor support.

 

[human909]

A better solution may be to have a fixed line adjacent to the ladder. There are specific fall arrest solution for this with a travelling fall arrest connection along the line. Then you only need ONE suitably rated point at the top of the line rather than trying to make a ladder work for loads that it was never intended for.