Why Pennsylvania Railroad did not buy a 4-8-4 Northern Type loco. What is the reason for this.
NDBPRR covered about all of it. He is spot on about the PRR using a 4-4-4-4 design to reduce the pounding on the rails at high speeds. I'm sure that in time the PRR would have perfected the duplex design in time, but diesels quickly killed it. The T1s just couldn't compete with diesel multiple units.
S&S
Modeling the Pennsy and loving it!
The Pennsy did test a 4-8-4, and that was the Norfolk & Western's J Class, one of only two fully-Timkened steamers at the time, the other being the Niagara S1b. Both engines were very finely balanced at all speeds tested by their developers, and I believe the Pennsy test crew ran their J up to about 110 mph, but caused the seizing of one of the valves in doing so. They liked the engine, but were worried that the 70" drivers were too small in the long run, and elected to develop their own 'double' or duplex version of the same engine. Four cylinders, but the same eight drivers.
But the T-1 and its Franklin poppets performed well ----when they were maintained and when the engineer did not just yank out the throttle for maximum steam when starting a train. Recall the obviouly honest story in our magazine about one running 120 mph, and even then near the end of its active service. Troubles were they required a lot more careful and frequent maintenance than K4's and M1's and required a gentle hand on the throttle when starting a heavy train. If it had not been for diesels, they would have been as good as anyone's Northerns. The Central's Niagras were probably overall more successful, but had just as short a life as the T-1's, because of dieselization.
daveklepper But the T-1 and its Franklin poppets performed well ----when they were maintained and when the engineer did not just yank out the throttle for maximum steam when starting a train. Recall the obviouly honest story in our magazine about one running 120 mph, and even then near the end of its active service. Troubles were they required a lot more careful and frequent maintenance than K4's and M1's and required a gentle hand on the throttle when starting a heavy train. If it had not been for diesels, they would have been as good as anyone's Northerns. The Central's Niagras were probably overall more successful, but had just as short a life as the T-1's, because of dieselization.
No doubt the T1 would have been modified and maybe even weight added to help with the front engine slipping. I was a witness to the T1's running and got to see them starting trains on level track. I don't remember any T1 starting a train without one or more major spins. The Illinois Central diamond was just after the westbound train would start up at Effingham, and the front engine of the T1 would slip every time on the diamond.
I read articles about the fact they could high speed slip also, but never saw that on the flat almost level main line to St. Louis. We would drive east and watch them at track speed and they were magnificient at 80 plus.
By the way, that is a J1 on the eastbound track under the coaling tower.
CZ
The PRR had one 4-8-4. It was an electric.
Dave H. Painted side goes up. My website : wnbranch.com
That electric 4-8-4 is how we know that if the Pennsy had HAD a steam 4-8-4 it would have been a class R. Model Railroader magazine once published a neat little drawing by Gil Read showing a hypothetical Pennsy Northern.
A reason the Pennsy did not embrace the N&W Class J (and remember that PRR owned the N&W at one time, which is why some early N&W 4-6-2s have Belpaire fireboxes just like the PRR K classes) in particular is that you had to go through a very difficult process to get a "new" wheel diameter introduced into the system. It was a very hidebound and bureaucratic organization in some ways.
This reached absurd heights sometimes, and a Pennsy designer wanting to bring about a new wheel diamter would comb through old drawings in the hopes that a given diameter might have been used in 4-4-0 days. I seem to recall the Class M 4-8-2 went through that process. Once they could find a precedent, even if a wheel no longer in stock, a big part of the approval process had been addressed.
Dave Nelson
In which issue of Model Railroader magazine was this drawing by Gil Read of the hypothetical Pennsy Northern. Gary
Lima wanted to rebuild a 4-8-2 M-1 into a 4-8-4 poppet valve like the K-4 they did but Pennsy said no. Some middle officers wanted the railroad to buy N&W J locomotives with 80" drivers. Other middle officers wanted the railroad to buy C&NW 4-6-4 Hudsons and Milwaukee S-2 Norherns to get rid of K-2 and K-3 locomotives and most of the K-4 locomotives and push the of the class into local and commuter service to save a lot of money but to the railroad it was the T-1. Gary