Fabulous coverage as usual! Having done this on a much smaller scale I am trying to get a scale perspective. Assume the ties are 8 x 8 and the outriggers are 4 x 8. The outriggers are pre-assembled to the tie with the j-bolts. This would put the ties @ 12" on center and the outrigger which supports the walkway is sandwiched between the j-bolt tie and the next one.

Now I assume that the guardrail which appears to be 4 x 6 (by scale of the ties) is pre-drilled once up on the bridge deck with a jig that centers the J-bolt holes and spaces them @ 36" then placed over the J-bolts which are driven up from below. Question; how do they make sure the hook stays square to the beam flange when the bolts are tightened?

Now if the ties and outriggers are a different size my assumed spacings are wrong but the same question on the guardrail still applies.

Thanks Howard...you're the MAN!

Dick Samuels
Oregon Pacific Railroad