Well, Folks,
If there was a "Speed record" it is unlikely that it was ever recorded. That sort of "High Spotting" was a firing offense if anything happened.
You keep talking about the K's and I was told by Bob Richardson that one time he was pacing the Shavano and got a ticket from the Colorado Courtesy Patrol (what they USED to be called) for exceeding the 50 mph posted speed limit.
My question, though, is if the 1.1 mph per inch of driver diameter holds true for early locomotives, wouldn't the T-12's have been capable of almost 60 mph??
Rick