Maybe one of you full-scale engineers can answer this--
When Sam Posey and I were "road testing" the Strasburg Railway's decapod a few years ago, Sam got to run the loco and was told by the hostler to open the dirfting valve (I think that's what it was) before opening the throttle. This was to ???avoid hydraulicing the drive pistons? I don't know, as I was merely the photographer.
Anyway, here on Maui, I've noticed the Sugar Cane Train, which stops right across the street from us, always seems to start up with that valve/device open, so it kinda sounds like, "Ssss, chuf, sss,chuf, sss, chuf..." until it gets up to speed. Is that what the engineer is doing?
I could post a streaming video if someone tells me how to get it on MLS.
When Sam Posey and I were "road testing" the Strasburg Railway's decapod a few years ago, Sam got to run the loco and was told by the hostler to open the dirfting valve (I think that's what it was) before opening the throttle. This was to ???avoid hydraulicing the drive pistons? I don't know, as I was merely the photographer.
Anyway, here on Maui, I've noticed the Sugar Cane Train, which stops right across the street from us, always seems to start up with that valve/device open, so it kinda sounds like, "Ssss, chuf, sss,chuf, sss, chuf..." until it gets up to speed. Is that what the engineer is doing?
I could post a streaming video if someone tells me how to get it on MLS.