Fixed Ladder Rungs 2

[static12]

For vertical fixed ladder is drilling stringers for setting and welding in place rungs required and if so per what code? Can these rungs just be fillet welded all around to the stringers?
Regards.

 

[SlideRuleEra]

The details of ladder design are covered by ANSI A14
Here is an overview

http://www.labsafety.com/refinfo/ezfacts/ezf132.htm

http://www.SlideRuleEra.net

 

[JStephen]

I am not aware of any standard or code that requires (or even recommends) this. Some specifications require this, most don't.

ANSI A14.3 doesn't seem to cover this detail in the latest version I have. Nor do OSHA requirements, which are currently based on outdated versions of this standard. Note that the link above only addresses portable ladders; it is the A14.3 and OSHA regs that pertain to fixed ladders.

I have assumed that this type of construction dates from the days of riveting, when punching holes every foot along a minor member was just another routine operation, and was probably the easiest way to build the ladder. The older ladders I've seen built like this were welded on the outside, but not on the inside, which leaves a void to collect moisture. Of course, a lot of other features of these old ladders have been rejected, such as 14" width, no cage, etc.

If you'll compare the strength of a fillet weld around the rung to the bending strength of the rung itself, the strength of the weld far exceeds the rung strength. I can see more motivation to increase the rung size than I can to punch the stringers. But realistically, neither seems to be an issue in actual use.

 

[static12]

JStephen:
Thanks for very detailed clarification – From now I will specify just fillet weld all around instead of drilling and welding.

 

[nackra]

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10839

cursory review of OSHA ladder - I didn't see more specifics. I think you've met OSHA requirements...