Ya know it just might work to ask permission. The crap shoot there is that if you are told no then you are all done. The biggest issue I feel is the liability that contractors and the railroad are under. It is a way bigger issue for the contractor folks as there are way way more OSHA type inspectors as opposed to FRA types. As another poster stated the proper PPE will go a long way to getting into a place. As far as Sammie's suggestions, carry a grip and unless it is a full scale search no one has the right to snoop inside. There is the place to keep all the "foamer" stuff. Robbie