Minimal Depth Below Railroad Siding Minimal Depth Below Railroad Siding chicopee (Mechanical) (OP) 11 Apr 15 01:12 I am just curious about the recommended minimum depth of a liquid propane pipe run (8" Sch 40) under railroad siding. RE: Minimal Depth Below Railroad Siding davidbeach (Electrical) 11 Apr 15 01:25 Best to ask the railroad. They all have their specific requirements. RE: Minimal Depth Below Railroad Siding chicopee (Mechanical) (OP) 17 May 15 14:12 Actually, I was referred to AREMA Chapter1, Section1, however, I have no real need for this expensive manual, except for the subject matter which I am interested for verification only. I have come across links from railroad companies and it appears that 5-1/2' for propane lines within casings is suggested without referring to AREMA. If there is an excerpt in a particular link, I would appreciate that reference.