Quote from: RAM on June 12, 2017, 03:29:21 PM
The reason no more were built was the fact that the K4 was a better locomotive. One big mistake Penn RR made was not using NW J"s blueprints and made 4-8-4s instead of the T1s. The J's were a much better locomotive then the T1s at a lower cost. Any way that is the way I see it.
The reason only 2 K5 Pacific were built has several answers. They incorporated features that were used to build the M1 class 4-8-2's which were more useful and practical to the Pennsy than more Pacifics of any class. Also the electrification of the Washington-New York line made many K4s engines "free"for the use elsewhere. The K5 was a successful engine in it's own right but just arrived at a poor time for duplication. The K5 was a more efficient engine than the K4s but at the wrong moment in time.
As to the N&W J being a better engine than the T1 that's not even open for debate. Both were very sophisticated and high tech engines at the time The N&W J was designed for mountain railroading and while it COULD do 110 mph, as proven on Pennsy tests and occasional sprints through the Dismal Swamp area west of Norfolk, it was never intended to run at those high speeds continuously whereas the T1 was made for continuous, high speed running. Hence 80" drivers vs 70" drivers. The T1 could be slippery, as could the N&W class A 2-6-6-4, but further examination of the fleet of engines has shown evidence they weren't as bad at slipping as has been rumored all these years. The high speeds caused wheel slip to be much more dramatic than low speeds and that has somewhat created the legend of them being so difficult to handle. The PRRT&HS has had much discussion and many articles on this subject and it's there in back issues of The Keystone magazine for people to read should they desire further light on them.
The tests with the C&O T-1 and N&W J on the Pennsy and the T1 on the N&W proved they designed engines for a particular use and maybe a particular service and they usually didn't work well on another railroad or type of service. Even the type of coal could make a great runner a slug to some degree. The J didn't operate as well on the lower grade coal used by the PRR compared to the high BTU N&W coal typically burned.
There were many variables to steam locomotives that generally didn't apply to the diesels which is another reason they killed steam use and production. It's not just a cut and dried, B&W situation.
We all have our favorites and the N&W J comes out very close to the top of my list and the PRR Duplex drives are near the bottom to me just slightly above the UP Pig Boy.
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