A couple of years ago, there was some discussion on this board, as to why PRR (and Porter) went with Left Hand Lead, and most others went with Right Hand. I recently stumbled onto a Q&A in the back of a Locomotive Firemen and Enginemen's magazine, that said, in effect, that a Left-Hand Lead engine would start to pound on the engineer's side first, while a Right-Hand Lead would start pounding on the fireman's side first. For this reason, they suggested that the engineer would attend to the pound on his side first, and therefore the Left-Hand Lead might be slightly more desirable.

Does this make sense?

The magazine issue was May, 1916, and available in Google Books, if interested.

JR

This is an interesting observation. The previous 'wisdom' I have heard regarding 'lead' concerns augment on multiple-track lines, perhaps with different drainage arrangements, that might be susceptible to more damage on one side.

The effect of lead on "hammer blow" augment (which is cross-level lifting of the driver pair) is less if the pedestals are reasonably tight laterally (which would make the axle rise and fall parallel, rather than 'cocking' around the fulcrum of the low contact patch. That would differ by engine and state of maintenance.

If I remember correctly, the infamous problems with the I5 'Shoreliners' and the ACL R1s were on the right-hand rail, so the noise might be expected to be worse on that side. It would be interesting to have someone report on the 1938 AAR testing where the C&NW E4B couldn't get over 100mph without bouncing drivers on camera -- I would suspect this was mains first, and both drivers bounced at the same time.

It was my impression that Voyce Glaze kept all overbalance out of the mains except ~80lb for the vertical component of piston thrust to deal in part with delaying onset of augment, and augment due to the effect of lead with overbalance would be part of that...