Discussion of the T1 and its tests on the Chesapeake & Ohio start at the bottom of Page 2 of the thread below; too bad the C&OHS article mentioned there isn't available online anymore, as C&O's experience with the two that they tested seems to tie in with Mr. Laepple's commentary.

viewtopic.php?f=1&t=35243

Another page on the T1:

http://www.railroad.net/forums/viewtopic.php?t=42536

This thread is starting to get very interesting now that you guys are talking about the science and mechanics of these machines.
In the film clip posted on the previous page by FLO, an interesting wheel slip is shown. Not being too swift, I am moved to ask how such a slip was possible without causing the rear engine to slip also. The links posted by J3a-614 above have some answers.
Is it possible to get more discussion about this? Did articulated locos have similar issues with slip or uneven adhesion?
In the case above, how did the engineer get out of that slip? Was it simply by closing the throttle or by valve setting?
Thank you.

Yes, articulated power could and did slip; a UP Big Boy slips its rear engine at 14:30 in the famous PR film linked below:

http://www.youtube.com/watch?v=Pi7Jac3htts

Too bad the photographer wasn't quite in the right place, but you can hear N&W 1218 slipping starting at 2:20:

http://www.youtube.com/watch?v=so7-Fu2psjc

Controlling the slip would be the same as with a conventional locomotive, cut back the throttle until the slip subsides, then restart with a little less power and gradually increase to accelerate the train--provided you don't have too much for the locomotive to handle, due to tonnage or conditions, including perhaps a throttle that might be sticky and not giving you the control you needed.

There is a well-known audio sequence of a late roller-rod A, recorded by the late O. Winston Link, in a stall near Blue Ridge, Va. The engine and its crew attempted to climb the grade with something like a 20% overload, and almost made it, stalling in sight of the station at the summit. The slipping is so furious, and starts so rapidly, that it comes as an explosion of sound.

614,
Very interesting. The more one learns, the greater the respect one has for the guys who figgured out how to run them!
Thinking back to the T1 video, the front engine went into slip as the train was in motion, essentially creating a 4-0-4-4 !!!! So the builders must have had something figured out with plenty of weight on drivers to have prevented the rear engine from losing adhesion at that moment under load.
Again, trying to get into the heads of the people in the mechanical offices, it seemed like there were enough dyed-in-the-wool steam men left in the latter days to want to try to keep the science alive!
Thank you.

Was I the only one who made a connection between this thread and the "Hogwarts at Universal Studios" thread?

Have the master replicators from Universal make a T-1 replica and all problems solved!! It can go anywhere, not bother the Class One roads, and could be rigged to show routes anywhere- Crestline, Altoona, Pittsburgh..... And probably be half the cost!

Howard P.
Faux, NY

Fixed that for you, Howard....

Thanks, Sandy. I knew you'd "do the right thing".

Howard P.
Call-My-Agent, NY

At least some of the PRR T-1's were fitted with an anti-slip device. There was some sort of butterfly valve that would close when there was an imbalance in the steam passages between the two sets of cylinders, as when one engine would slip. By cutting off steam to the slipping drivers, the engineman had a moment to close the throttle and try again. At least some of the trouble some enginemen had was in not shutting off fast enough. The slippery-ness of the front engine may also have been due to the boiler water surging to the rear as the engine began accelerating, thus unloading the front drivers.

A few points here, The issue with the J1 was due to inadequate materials used in the equalization rigging pins. C&O learned this the hard way early on. The Penn had to dope this out, as they obtained the original Lima prints to build the Big Jay, Heat treated pins were the answer to this, and the Jay caused no more trouble, even at 70MPH. Read about this in the Keystone. Building a T1 today would be asking for a lot of problems unless you go for the 5500 of mid 1948 onward. Why? Outside poppet valve gear..The FRS rotary "B" system. When 5500 was converted at Columbus, the original "A" non-moving parts and framework were left in place, which added a fair amount of extra weight, coupled with the type "B" installation. The valve timing was also modified, in accordance with several years of road experience. The new poppets were infinitely more maintainable as you can imagine. 5500 had a good reputation before the accident that resulted in her conversion to begin with. There is some question as to whether she received the sleeved cylinder conversion of the late '40s. This would add even more weight, reduce TE for a better FoA., and actually increase HP at high speed. We just don't know. A lot has been made of the crew qualities on the Penn, and especially the extra board. The old timers had cut their teeth on early Atlantic types, and were used to starting out with slippy engines...in bad weather or not. PRR maintenance crews were in bad shape after the war to begin with, the the early Diesels paid for this along with the T1. The Diesels were always going to get preferential treatment anyway, and this came down from Martin Clement and the Operating and Marketing Depts. In spite of all this whooptie, the 52 unit fleet did a pretty credible job until FRS / Baldwin quit making spares for the poppet valve system. Today's T1 Duplex can be far more capable than one of the '40s, because of today's better materials, better assembly techniques, and that she can be "blueprinted" piece by piece, as she's built. Go 4 IT !

I disagree with Mr. Jaygee about PRR's management and diesels. It wasn't until Jim Symmes joined the senior management team that diesels were taken seriously by PRR's upper management elite. Symmes had lately been Superintendent in Chicago, where he personally saw the E-units on the Santa Fe and Milwaukee Road run rings around their steam engines. The PRR's Board was very concerned about the railroad's image, of course, but they were more concerned with coal, one of the major commodities it handled.

In addition, by the end of the war, the PRR was hanging on by its fingernails. I've heard it said that if the PRR had not been able to utilize its electric locomotives in freight and passenger service, it's very possible the entire system would have collapsed under the weight of wartime traffic, and that may have led to nationalization of the railways for the duration of the war. Even so, the railroad's steam locomotives and other equipment were all just about used up by August, 1945, so the new and shiny T-1's were welcomed.

But, when those first E-7's came along and went into service between Harrisburg and Chicago and St. Louis, all bets were off. The bottom line, in the end, was that the less complex, tried and true steam engines were known quantities and less maintenance intensive than the T-1's, and that combination doomed the T-1's pretty quickly. Management recognized the advantages of diesels -- my father-in-law was one of the first Harrisburg men to go to EMD school at LaGrange -- and the Blue Ribbon Fleet was dieselized as quickly as new units could be delivered. Even so, it took over 10 years for the Pennsylvania RR to accumulate enough diesel locomotives to retire steam completely. The T-1's didn't have a chance.

Jaygee- I based my statement above on the book "Pennsy Q Class- Classic Power 5" by E. T. Harley. On page 6, regarding the reasons the Q2's were constructed, he says "It should also be noted that the Pennsylvania was very 'dynamic augment conscious' at the time, having experienced a great deal of rail damage from the J1's which had to be extensively modified. Much of this could have been avoided by using the latest C&O prints for their equivalent T-1 class, but the J1 was built to original 1929 standard and over 100 modifications were required to bring it up to date and eliminate what bad habits it had."

This statement doesn't rule out problems with the equalization rigging pins, but it definitely implies there were more problems than that. If you compare builder's photos of the locomotives and later photos of them in service, you can see that the main and at least the intermediate side rods were changed to rods of lighter construction while the locomotives were in service. This seems to back up Mr. Harley's statement that the locomotives experienced problems with dynamic augment, and that extensive modifications were required to correct them.

The book, "Perfecting the American Steam Locomotive", by J. Parker Lamb, has some commentary on the T1. His thesis is that the T1 was a promising design, but a victim of circumstances. It was rushed into service by a railroad that did not have design or operating experience with superpower steam. And its ultimate death was due to bad timing, as diesels came into their own just at that moment.

First, he said the T1 never had the benefit of a thorough shakedown period that new locomotives normally get. He wrote, "the sober reality is that the T1 was a revolutionary new design that was rushed into production while still in the prototype stage."

As for the slipping drivers, Lamb did not call that a design flaw, but just a function of the engine's power. He said it would have been solved in time. As Mr. Laepple said here, a skilled engineer could learn to compensate. Lamb wrote about the slipping:

"As to the problem of high-drivered duplexes being slippery, after some study a mechanical committee of the Association of American Railroads recommended that these designs have larger factors of adhesion, since driver slip usually means that there is too much power for the weight (on drivers)."

While revolutionary, Lamb said the T1 did not measure up to the NYC Niagara. He wrote:

"The downside risk of pushing 'too far and too fast' is illustrated by comparing the T1 design to a contemporary machine, New York Central's S1-class Niagara (4-8-4). The more revolutionary duplex did not come close to the NYC engine's performance or its reliability."

Finally, he said the T1 was a victim of the diesel locomotive's success. Following a huge order for new T1's, the railroad abandoned it and shifted its strategy to diesels:

"Sensing that it had the steam equivalent of the highly successful GG1 electric locomotive, the road ordered 50 more T1's in 1944... Unfortunately this turned out to be a colossal miscalculation by the railroad. For only two years after the last T1 was delivered in August 1946, PRR president Martin Clement announced that 'By May of this year [1948] we expect all of our through passenger trains west of the electrified territory to be dieselized.' This statement was part of a press release announcing a $16 million order for diesel locomotives (both passenger and freight)."

So to sum up, it sounds like the T1 had plenty of promise, but was a victim of timing and circumstances. The story of the T1 is an interesting chapter in railroad history for sure.

I've really enjoyed reading Mr. Laepple's comments about it here too.

I always harbored the opinion that the T1 was part of the reason the PRR started to dwindle. So much money spent on a radical design with too many unproven by time features. Like most folks, I think that fortune could have been more wisely spent on a good 4-8-4, but PRR had this ego thing going for it.
That's my opinion and your mileage may vary.

Is the reason that PRR fell behind in steam because they were so focused on the electrification?

Steve

Some have suggested that was part of it (and I agree), but it was not all of it. Consider that the PRR bought a bunch of steam engines just before the Depression, including the last 100 K4s 4-6-2s in 1927 and filled out the steam roster with 300 M1 and M1a 4-8-2s by 1930-1931, followed by the electrification effort, AND add in the Depression itself, which I believe dropped traffic levels something like 50% across the board, and you have little reason to invest in new steam power.

Put it this way--how many of those K4s, I1s, M1s, and not to mention various H-class 2-8-0s would have been "stored serviceable" for years in the 1930s, along with P-70 coaches and all those box cars, hoppers, flats, and everything else?

The roads that did spring for newer power in the 1930s were roads that didn't have the traffic to justify a lot of new power in the 1920s and were in traffic territory and/or had traffic patterns that didn't favor running a lot of frequent trains (i.e., UP or, more strongly, the NP--I believe the latter ran something like six to eight trains per day across their main line in the prewar era, and half of them were passenger trains), or were roads that were desperate to be competitive (NKP), or were roads that had money anyway, thanks to enormous traffic flows in coal (C&O and N&W). Some only dabbled in newer power (New Haven with some 4-6-4s, Soo with just 4--four--4-8-4s); many carried on through through the Depression with what they had (B&O, IC, L&N, SR). Some roads, like the Southern, never did have "modern" power, until the diesels came--but that's another story.