Where to put your abutment on railcars

When converting a railroad flat car into a bridge, one thing that you need to determine is where to place your abutment. There are lots of things to consider and our structural engineers (or your structural engineer) will be able to help you determine the most cost effective solution as there is no "one size fits all" answer.

[@Johnintoit]

Do you sell these? I'm looking for one to cross my creek but don't need anything this long, my creek is around 16-17 feet wide but I figured a 20/24 footer would do it depending on where i set the abutment at.