The dead load consists of the estimated weight of the structural members, plus that of
the tracks, ballast and any other railway appendages (signal, electrical, etc.) supported by
the structure. The weight of track material (running rails, guard rails, tie plates, spikes
and rail clips) is taken as 200 pounds per lineal track foot. Ballast is assumed to be 120
lbs per cubic foot. Treated timber is assumed to be 60 lbs per cubic foot.
Waterproofing weight is the actual weight. The designer should allow for additional
ballast depth for future grade or surfacing raises (generally 8 12). On ballasted
deck bridges, the roadbed section is assumed to be full of ballast to the top of tie with
no reduction made for the volume that the tie would include