Okay so i have an old railroad bridge on my property (we own the old abandoned rail road bed. The rail road ties are pretty much all rotted and need to be removed. I was looking to replace with pressure treated lumber. There are two 24" high I-beams that are in great shape, they span 36, and have a 13" wide flange and are spaced 6'-1" from inside flange. I need to know what I could use for the new joist size and spacing to replace the old railroad ties. Most I would have on this bridge would be 5000 pounds (compact tractor). So it wont be as heavy as what use to be on it- +200 tons. Also will be adding a 2x10 decking since it will also be used as a foot bridge and by ATV's.
any info or help would be great!
