AFAIK, nobody ever out axle weighted the C&O H8. I'm guessing that this was an insurance policy over the fact that she's a six coupled design, and hence more likely to bust loose on the same TE as an eight coupled machine. If Chessie had upped the boiler pressure and run these big girls in flatter country by policy, they'd have done much better, cost wise. In the real world, N&W laughs all the way to the bank!
Dr. Huddleston died believing that the boiler pressure of the H8 could be raised to 300 pounds from its designed 260.
A Lima calculating engineer named James Cunningham retired to St. Louis, where he was interviewed by a friend of mine named Ray Curl, who had been Chief Draftsman for the C&EI at Danville, Ill. and who had moved to St. Louis after the MoP took the C&EI over.
Curl asked Cunningham the question directly: "Was the H8 designed so that its pressure could be raised from 260 to 300 pounds?"
Cunningham replied "absolutely not."
Dr, Huddleston believed that it was possible because the H8's boiler plates were thicker than those of the N&W A (this was in part a lot of the weight difference between the two locomotives). But he made no mention of firebox sheets, flue sheets, staybolting or any other item subjected to full boiler pressure.
But Cunningham knew, and through him and Ray Curl we know the truth.
EdKing
