I believe I read someplace, though I can't find the reference now, that the "standard" for US RR's was to quarter steam loco drivers with "right hand leading". My understanding is that this means the piston/valve event on the right (engineer's) side occurs 90 degrees ahead (in forward rotation of the drivers) of the same event on the left (fireman's) side. Thus when the rods are down on the right side (6:00 position), the crankpins are forward (closest to the cylinders, or 3:00 position as seen from the right side looking at the back of the left side drivers) on the left side. Thus the loco has to move forward 1/4 driver rev before the left side drivers get to the rods down position. I also understand that the Pennsy, the Standard RR of the World, was non-standard and quartered it's loco drivers the other way, with the left side leading. Can someone confirm my understandings and provide a source reference?
Given that my understanding is correct, it is interesting to check the quartering on HO steam locos. In a quick review, I see that my Rivarossi locos are consistently "correct" with right hand lead quartering, and my Bower PRR models are "correct" with left hand lead quartering. I am surprised to find that my old Mantua/Tyco steamers, none of which are PRR prototypes, are all quartered with left hand lead. I'm curious - does anyone have both the BLI C&O and PRR 2-10-4's who can check whether the quartering is reversed on the two models? (Or did the War Production Board, in granting PRR permission to build duplicates of the C&O T-1's, require the PRR to deviate from it's prior quartering practice on the J-1's?) Geezer