The Railway inspector asked Evan, "What would you do if you realised there were two trains heading for each other on the same piece of track?"
Evan answers, "I'd switch one of the points for one of the trains."
"What if the lever broke?" asked the inspector.
Well, then I'd dash down out of the signal box," said Evan, "and I'd use the manual lever over there"
"What if that had been struck by lightning?"
"Then," Evan answers, "I'd run back into the signal box and phone the next signal box."
"What if the phone was engaged?"
"Well in that case, I'd rush down out of the box and use the public emergency phone by the level crossing up there."
"What if it was vandalised?"
"Oh, well, then I'd run into the village and get my uncle Tom."
This puzzles the inspector, so he asks: "Why would you do that?"
Came the answer, "My uncle Tom has never seen a train crash."