Q: What are the Standard tie dimensions and spacing on Narrow Gauge Trestles?
A: According to the Colorado Railroad Museum http://www.crrm.org/index.htm ;
“There is no Standard. It depends on the needs of the Railroad for that particular trestle or Bridge, such as weight of Locomotives, amount of use, curves, walkways and other such variables. Also, each individual Railroad may have it’s own Standards.”
For modeling purposes, a good rule of thumb is, 10’, 8"x8" ties with 8" spaces between ties. A modeler can then determine if these dimensions should to be altered for their need."
Hope this answers some questions. PI