"The remarks about the WP&YR #69 being a poor steamer have made me wonder if over the years, due to repairs, etc. can/does a steam locomotive go from being a poor steamer to a good one or vice versa?"
What hasn’t been discussed, and what very often changes the steaming habits of any particular engine is the drafting arrangement. Or how much air gets to the fire. Over the years of routine maintenance, each time the front end is removed and replaced for boiler work, if it goes back in a little bit different each time, the drafting can change enough to effect performance.
At the other end, the amount of air that the ashpan allows into the fire has the same effect. A number of years ago, we were hired to overhaul a medium sized 2-8-0 that had been labeled a poor steamer for many years. In the midst of replacing the tube sheet, with all of the grates removed, I stuck my head in the firedoor to talk to the man in there. Glancing down into the ashpan, it struck me that there was not a single air inlet hole in the entire ashpan! The only hole of any sort was the hole for the grate shaker rods! The ashpan had been replaced by the previous operators, whose only priority apparently was to stop embers from falling out onto the track. With proper air openings in the ashpan, and a new “Master Mechanics” front end, that engine became a breeze to fire.
If someone of limited understanding tries to modify the drafting arrangement, they can do a lot of harm without too much effort. On the other hand, much progress has been made recently by Porta and others on upgrading performance through better drafting. In Wardale’s book on the South African “Red Devil” locomotive, he talks about a narrow gage 2-8-4 I believe that he modified the drafting on. He spoke about one long grade that would take 90 minutes for that class of engine to climb with their standard tonnage. The modified engine took standard tonnage up that grade in 50 minutes. It seems very possible to increase the maximum sustained horsepower of just about any locomotive by 50% to 75% by these methods. So just because an engine has a history of poor steaming, it doesn’t have to stay that way.
