Pedestrian Handrail Modification

[OSUCivlEng]

I have a question about modifying some existing hand railing. There is about 180 feet of existing hand railing that doesn't meet current code for the opening sizes. I have attached a picture of the handrail in question. The initial idea that was presented to me was to weld some grating between the post and rails. This seems like it could be expensive to buy about 60 panels and weld them to the existing railing.

I wonder if just running cables through holes drilled in the posts wouldn't be a cheaper alternative? The cables would have to be spaced less than six inches apart and they would have to be stretched (like building a barb wire fence), but the material cost would be much less than grating. I would also think drilled the holes would be less expensive than the field welding.

I'm open to any other suggestions as well.

Thanks

 

[bridgebuster]

why not use chain link fence mesh?

 

[bridgebuster]

A few thoughts - hit the submit too quickly - the space between the cables has to be less than 4" for code compliance; with cables, you'll need to pull them tight - how tight? enough to keep a kid from squeezing through.

 

[ACtrafficengr]

On the Lake Champlain Bridge, NYSDOT used galvanized mesh for the pedestrian fencing.

If I recall correctly, the designer said they were standard industrial fence panels. I don't know where they got them. Maybe you could finds a similar bolt-on solution.

 

[OSUCivlEng]

bridgebuster - where are you reading that the space needs to be 4"? Everything I read in Section 13.8 says 6" and even then that is only the lower 27" of the railing.

ACtrafficengr - I like the idea of the fence panels. I'm going to look into that.

 

[bridgebuster]

OSU - the 4" requirement is from IBC 1010.10.1. Granted you're following AASHTO but lawyers are lawyers. One NYC agency has go as far as 3 1/2" max - lawyers are lawyers.

 

[ACtrafficengr]

The chain link would probably be easiest and fastest - it would all clamp on with bolts and straps. You'll want a hand-friendly finish at the top, though.

Also, I think you'll need to add a bottom rail no more than 4" above the ground for ADA compliance.

 

[OSUCivlEng]

I looked into the mesh panels. They use them a lot in stadiums. However they have to be set into a frame made out of a channel to really be installed correctly.

I think you are both right, chain link would be the easiest and fastest to install with bolt on clamps. AC is right I'll have to add a bottom rail/toe kick for ADA compliance, but that will double as a place to secure the bottom of the chain link. I'll have to use 2" mesh to comply with AASHTO. I'm not sure what gauge to use. 6, 9 and 11 look to be common.

Thanks for the help.

 

[bridgebuster]

9 is typically used in my area. Also, save yourself some potential grief - make sure the client is OK with 2" mesh. Some jurisdictions require 1", as it is not considered climbable. Remember - lawyers are lawyers.

 

[OSUCivlEng]

So I'm guessing 3% over stress isn't OK with you either?

 

[bridgebuster]

3%, young man, you must be crazy; never go more than 1%

On a serious note, it's stupid little things like 1" mesh vs. 2"; 4" spacing vs. 6" that can cause trouble. Unfortunately in our work lawyers are very good at convincing juries that we're supposed to anticipate every move that every idiot makes.

 

[OSUCivlEng]

At my first job out of school the owner sent out an email to everyone to instruct them to never let anything be over stressed. His contention was that if something ever happened, even if it wasn't related to the item that was even 0.1% over stressed, a lawyer could depose you and easily convince a jury that it was your fault.

My current boss doesn't share his opinion.