Railway sleepers

[shoube]

Why are they called railway sleepers

[Clanad]

Two possible meanings, at least in U.S. A sleeper can be a sleeping car, more popularly known as Pullman cars, after their inventor, in which a small room or even a berth can be purchased for overnight trips.  Additionally, the railroad ties, the wooden support structures on which the rails rest, are also known as sleepers... again, at least in U.S.

[Quizmonster]

And here's the reason why...

As long ago as the 1600s in general building and the 1700s in railways, a strong, horizontal beam or balk of wood has been called a "dormant timber" or "sleeper", probably because it seems rather like a human body laid out for sleep and doesn't appear actually to be doing anything very much.

(There were, of course, "railways" long before Stephenson etc in mines and such like.)