That's a cast metal "DO NOT TRESPASS" sign in the yard at the Railroad Museum of Pennsylvania. Can you imagine any railroad official today authorizing such an expenditure of company funds?
Maybe not a sign per se, but a respected marque in railroad cranes was Bucyrus. Built in 1925 with a 160 Ton capacity, this one was in harness at Barrington, IL helping to clean up a wreck just west of town forty-seven summers ago on 07/16/1676. There were no fatalities. A light engine move lead by "Candall Cab" 502 move rear ended a caboose and four ore jennies. At the time, a C&NW spokesman said that a signal gave a "false clear", but I don't know what the formal investigation determined. Amazingly, the 6363 survives at the Illinois Railway Museum.
Those guys really don't want us to have fun... We'll just have to do it the old-fashioned way: drop it in a 45-gallon drum and set it on fire...