Re: Mike Allen's observations on speed and engine controls - When I rode engine cabs in 2004 and 2005, the engineers operated the Baldwins the other way. Instead of leaving the throttle wide open and making all adjustments with the Johnson bar, they made minimal Johnson bar adjustments and worked the throttle extensively. Different engineers have different views on this topic.
What I found really hard to comprehend was that some of the firemen in 2005 would set the firing valve and rely on the pressure relief valves to keep the boiler pressure at the maximum at all times. So unless the engine was working all out, the relief valves would be blowing off continuously, wasting fuel and water, and - in my view - compromising the safety features of the relief valves.
As for running 35 mph with 31.5 inch drivers, that would be equivalent to running at 49 mph with 44 inch drivers. The times I paced 470s, 480s, and 490s on the 3-rail speed way between Antonito and Alamosa, the engines never exceeded 35 mph. Even at that speed those counter weights and the reciprocating machinery were nearly moving in a blur. If you relate that reciprocating motion to 80 inch drivers, that speed would be 89 mph. WOW - when we timed 844 at 93 mph betwen Rawlins and Laramie, the machinery was reciprocating even faster than those little Baldwins at 35 mph! I would have loved to see that, but we were timing mileposts from the open (gated) door of the baggage car, so the machinery was not visible.
For the 91 inch drivered 05 class 4-6-4s (that I used to make special trips to see in Germany back in the mid 1950s) the 35 mph on 31.5 inch drivers would have translated to 101 mph!
Edited 1 time(s). Last edit at 10/31/2020 11:13PM by Olaf Rasmussen.
