Kelly Anderson Wrote:
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> BillD Wrote:
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> -----
>
> > Mostly, yes, but this does not explain engine
> > classes Q-1, Q-2, S-1 and T-1.
>
> PRR’s motive power glory days were in the teens
> when they designed the E6s, K4s, L1s, I1s, and
> M1s. At the time of their introduction (and for a
> very short time afterwards), these designs, though
> conservative, were head and shoulders above the
> rest.
Actually these designs remained leaders in their respective classes for quite a while. In fact (according to Kratville in his book on UP's 800 class) the Union Pacific, while acknowledging the inadequacy of the Pacific design to their current passenger needs, looked at the PRR K4s design FIRST when researching what eventually became their 800 class 4-8-4 locomotive. The PRR M1/M1a/M1b's were one of the finest examples of dual-service 4-8-2 locomotives built. Originally built with a nod to replacing K4s Pacifics on long-distance passenger runs, the passenger department nixed them due to excessive "surging" at speed compared to the smoother running K4s class. They excelled in fast freight service and their continued service on the Middle Division until the very end of steam operations (which was originally envisioned to continue until the 1970's, but increased labor costs and a nasty recession in the late 50's killed steam). The "failure" of the M1 to excel in passenger service is probably the most significant event behind the controversial (to non-PRR people) 1928 order of the final 100 K4s locomotives. The L1s class were considered to be excellent locomotives as well (see "SET UP RUNNING" by the late John Orr). Their problem was that many of the class became surplus due to the extensive electrification projects of the 1930's as well as the harsh economic reality of the era.
>
> PRR then proceeded to rest on its laurels while
> the rest of the industry marched ahead until their
> fleet was hopelessly obsolete, and worn out, just
> in time for WWII. They then tried to vault ahead
> again with the Q-1, Q-2, S-1 and T-1, but fumbled
> badly with overly complicated and unreliable
> designs that proved their worth by being scrapped
> within a few years of their construction.
Resting on it's laurels??? I don't think so... during this period the PRR developed the ultimate super-power design... the GG-1. With hundreds of steam locomotives sidelined during the depression and due to electrification, and the economic reality of the era, no competent management would even consider new locomotive purchases given the realities of the era (in fact most railroads did not purchase new power during the depression). And while the more modern designs were ultimately not successful, much of the blame of the "failure" of the T1 duplexii can be attributed to the outstanding success of the 5399 which was equipped with the same poppet steam distribution system as later installed on the T1 class. The poppet valve installed on 5399 so improved the performance of this locomotive it actually outperformed NYC's J-class Hudsons. As for the purported "slipperiness" of the T1's its telling that this only occurred on the west slope of the Alleghenies, and NOT on the western region where the memory of their feats remain legendary to this day. (I once had a friend whose father worked on these locomotives... he claimed the most common repair issue was the straighten out the hand on the speed recorder when it had slammed against the stop. The stop was located at the 125 mph position...) Probably the biggest issue on these locomotives was the location of the rear valve components. The boiler had to be lifted off the frame to service this assembly. Later experimentation with the Franklin Continuous Contour Poppet Valve design were quite successful, but the diesel and the economics due to the effects of the post-war recession, as well as skyrocketing labor costs, spelled the end for steam. The same thing happened to the spectacular Q-2 locomotives... a poor choice of steel (based on war-time shortages) in the boiler resulted in premature replacement of all of the boilers. The Q-2, which in reality was the most powerful non-articulated locomotive ever built, could not compete economically with the C&O-designed J1/J1a class (four cylinders vs. two) and the excess power generation capacity of the boiler could not be fully utilized given the PRR's 50 mph speed limit for freights.
The duplex design came about due to the PRR's emphasis on reducing dynamic augement due to huge piston thrust and heavy reciprocating masses (for example, the thickness of the I1s's main rod at the pin was 11 3/4 inches... that'll shake your kidneys at speed!) Remember, the PRR utilized the world's heaviest rail section on their mainline (152 lb/ft) for good reason... their locomotives pounded the rail that hard. Baldwin had come up with the design, and the B&O had built one, but for several reasons it was unsuccessful (mainly due to the backwards position of the rear engine). Due to the PRR's preoccupation with reducing dynamic augment, they signed up for two locomotives (6110 and 6111) to be built by Baldwin and Altoona (the Juniata shops built both tenders as well). These ran for a couple of years in the Harrisburg-Chicago run, and based on their performance, the railroad ordered 50 more. I really suspect that the problems were not unsurmountable, however the fact that the PRR lost money (for the first time in many years) in their centennial year (1946) and other non-operational issues most likely resulted in their early replacement with diesels the next year.
>
> PRR’s designers in the late ‘thirty’s just didn’t
> have their act together the way that their
> predecessors in the early teens did. Why they
> didn’t just build 4-8-4's like everybody else is a
> mystery. I think it was due to arrogance, “We’re
> the mighty PRR, and we don’t follow, we lead”.
The perceived "Arrogance" of the PRR is mostly myth... I do acknowledge that Kissel (the 1920's head of motive power development, who while a superb mechanical engineer (his development of the KW trailing truck (the predecessor of the highly successful "delta" design) as well as the modern design of the tender for the K4s and M1 locomotives, was in fact a poor "people-person" (not surprising... even today many engineers have poor "people skills".) The PRR did in fact test a 4-8-4, and not just any one, but the best ever... the N&W J class (along with a N&W A and Y class). They choose not to utilize the design, since they already had a good fleet of locomotives on hand (their locomotives were NOT worn-out, at least not until the end of WWII. They had some of the finest locomotive shops of ANY railroad (and in fact were the Number 3 builder of steam locomotives in the US... Lima in comparison was a distant 4th place.) The fact is that when they did need a more modern design they choose the best... the C&O T1 2-10-4 which became the J1/J1a class.
Bill Daniels
Santa Rosa, California
