Here is one you don't see everyday, "BRIDGE BEAM: 3RH 34-130, 84'-11" IN LENGTH". This rail is step cut on both ends where it receives the end trucks to optimize hook height. The bridge rail is designed to for 4,000 lb. capacity over an 82' span. It's a 325 series rail with a 3 1/4" riding tread, 34" high by 130 lbs. per foot, and step cut to 14 3/4". Good thing they have extendable bed trailers.