I don't know about a locomotive and a dime, but I've seen a very unlikely object prevent a piece of heavy machinery from moving. In the steel mill where I worked, we had a number of four-wheeled cover trucks for lifting the lids off the soaking pits. These trucks ran on rails, a double-flanged wheel at each corner, about 20' apart. They had an electric motor that powered a pair of wheels at one end, and another motor that lifted the cover. They could be operated remotely from the overhead cranes, or from a floor station, or manually by an operator riding right on them. I don't know what the horsepower of the motor driving the wheels was, but the truck probably weighed 20 or 25 tons, and the pit cover was another 30 or so. One day the crane operator called down on the intercom that the cover truck that he needed to use had stopped. A quick check showed none of the overloads had been tripped, and indeed, it would run in the opposite direction with no trouble. However, going the other way, it ran fine for a short distance, then slowed, and finally stopped. Now, ingots were often placed on the floor between pits for various reasons: these will stop almost anything, but the stop is sudden, loud, and very dusty. The only other thing that we could think of that could do this would be something on one of the rails, like a chunk of scrap, or perhaps some broken firebrick, but usually this stuff is pushed off the rail by a steel plate on the outboard end of each wheel and about 2" above the railhead, installed for just this purpose. A quick check around the wheels revealed the culprit: it was a rolled-up section out of a newspaper, not at all that thick. It could have easily been slipped into a person's back pocket without making it uncomfortable to sit down. I wouldn't have believed it had I not seen it.
Wayne
Strange I remember buying penny candy and 5cent bottles of coke out of those water coolers that were popular when I was a kid. 