Mostly the railways would have been running at relatively low speeds in this period - there was a lot of wartime damage to tracks etc. so relatively few trains went much above say 40-50 MPH on most routes until well after the war. I'm not the person to give a definitive answer on this though, but I'm sure that there are sites that can give you all the information you'd need. The point I want to make though is that there would be very few bodies mutilated beyond all recognition if there was a train crash, the speeds were way too low.
