Okay guys, I’ve got a question about whistle signals. We know that 2 shorts is forward and 3 shorts are backing up, but is it direction specific or direction of engine specific?

As an example let’s take an engine that would always face the same direction, like the ET&WNC, but is assigned for the day to run eastbound. This would make eastbound, a totally backing move, since the engine is always faceing west. So when heading east and the engineer releases the brakes, is it 2 whistles or 3? Seems that it would be which way the engine is facing, especially a steam engine. But with a small diesel, like a 44 tonnner, they look close to the same on both ends, so is the whistle signals dependent on which end has the assigned “F” on it? It may be very obvious to the engine crew, as they sit in the cab. But to the outside observer, the 44 tonner could spend all day running backwards, heading east, and yet be at the head of an eastbound train, giving backing signals everytime they release the brakes?

Cold day, too much time on my hands.