I do not have specific information on the progressive test results of T1 chassis stability. It is possible some of this material survives somewhere at Lewistown.

What I've been proceeding under is the ASSumption that the changes PRR made, progressively, represent the logical responses of knowledgeable people to what the test results woild be showing.

The division of the equalizing into two distinct groups, instead of using the long central equalizing beam between the engines, is one of the major changes to the T1 suspension. There is quite a bit of detail revision in the provision of rubber isolators and snubber spring tuning on the inner anchoring points for the spring rigging. Now, just modifying the suspension to put more load on the axles of the lead engine, or changing the weight distribution between the two axles of that engine, would not require either of those modifications. So these are changes in response to a different problem -- perhaps a combination of problems, and I do not want to sound arrogant by saying perhaps some of the actual problems were poorly recognized at the time, and solutions that were tried may have been directed toward a wrong or improperly-characterized cause, or had unanticipated effects or consequences.


Oh,yes: why use a puny 10. It's class 05 or nothing! (But didn't Gottwaldt et al. note that the class 05 had similar smut-in-the-cab issues at high speed?)

I don't want to be known as that guy but I think that building a brand new PRR T1 is not really a good idea. I say that because the T1's were very slippery on the mountains and always require helpers. The T1's were fast and cool but not that strong. I think that they should build a J1 2-10-4 instead. The J1's were stronger and they were superpower. J1's were able to handle heavy freights without helpers they were powerful and I think they were fast. they were more successful than the T1's and I'm sure the maintenance cost were lower too. I would like to see a new T1 the 5550 to be built but I think a J1 is a better locomotive for today's world. Agree or disagree your choice

steamfan765, I'm not trying to be rude, or a know-it-all, when I say this. I'm saying this because, before I read this article I'm about to reference, I thought the exact same thing as you. That article completely changed my opinion about the T1s.

Classic Trains magazine did an article in their issue of "Steam Glory 3" (issued near the tail end of last year) that talked about the T1s. After investigating the rumors about the T1s being very slippery, it was determined that the T1s weren't as slippery as their reputations would suggest. They had a factor of adhesion well over a 4.00 (which generally makes a locomotive not very slippery). After many T1 crewmen were interviewed, their responses seem to suggest a different scenario.

It wasn't so much that the T1s were very slippery steam locomotives, but it was more that they weren't always handled correctly. After all, the bulk of the Pennsy steam roster was first- and second-generation steam locomotives, and their engineers weren't very familiar with how third-generation steam locomotives behaved. Plus, most engineers were used to how the K4s Pacifics behaved, and treating a T1 the same way as a K4s generally didn't end well. They were two completely different beasts.

Also, regarding the power of the T1s, believe it or not, they are right in the 'middle ground', in regards to the tractive effort of 4-8-4s. They definitely weren't equivalent to the strongest there was, but they were far from the weakest. Also, they developed 6,666 indicated horsepower at 100 mph when they were tested. Clearly, these were not weak locomotives. If you can get a copy of that issue of Classic Trains, I would highly recommend it. It definitely opened my eyes about the T1s.

All this being said, I still stand by what I said earlier in this thread. If a T1 is built, I would be very happy to see that. However, if I had my own choice about which steam locomotive could be built, I would have to go with a NYC J3a 4-6-4. As far as my knowledge goes, it would seem easier to build a 4-6-4 (relatively straight-forward) as opposed to a 4-4-4-4 (a more tricky build). Plus, the NYC's J3a 4-6-4s were very successful during their service lives, whereas as the T1s aren't generally considered a success. Anyway, that's my $.02. You can do with it what you want.

to steamenthusiast4000 I wasn't talking about a J3a class Hudson from the NYC I was talking about a J1 Texas of the PRR one of the fleet of 125. I forgot about the Classic Trains issue you were right they were tricky to handle. Do you think engineers of today know how to handle one of them. I was also talking about maintenance they were more tricky than that of any other steamers on the roster. You were right about them being strong and powerful but engineers today probably wouldn't know how to handle a T1 if many couldn't do it back then what make it different today. Its like I said I do like to see an T1 to be built but I am just saying a J1 is a better choice but that's just my opinion remember that.

When we are successful in getting the T1 Duplex built, you can be sure a J1 Texas will be the next PRR locomotive out of the oven! Actually, the T1 is more practical than the J1 on account of the engine weights, and such. The limiting factor on the T1 will be the active driver wheelbase, although the J1 is fairly long too. It is a fact that the PRR T1 is not generally considered a highly successful locomotive, but 90% of the circumstances that piled up against the T1 had nothing to do with the locomotives themselves. In another day and time, they'd have been quite the machine...although not exactly a cheap date !

steamfan765, I know you were talking about a J1 from the Pennsy. In an earlier comment, one of the first few posted on this subject, I had stated that (to the extent of my knowledge) it would be more sensible to build a NYC J3a 4-6-4 before attempting to build a PRR T1 4-4-4-4. That's what I was referring to in my reply to your post.



I agree about the maintenance requirements for the T1s, and they talk about that in that article from Classic Trains that I referenced earlier. The T1s required far more maintenance and attention than (I think) the Pennsy was used to giving their other locomotives. Also, unlike most of their other locomotives (like the K4s) that could still perform well even with a lack of heavy maintenance, the T1s would suffer from inadequate maintenance, and that could very easily affect their performance.

Is it going to be "Amtrak Compatible" with ATC and ACSES for the NE corridor plus PTC for mainline operation in the rest of the country? It will be interesting to see what new technology they develop to adapt those systems for use on a steam locomotive.

PC

As happens, PTC on the 'modernized' T1 is simpler than PTC on a road freight.

I will presume that everyone knows that ATC, which contains all the implementation issues relevant to a discussion of how to stop steam locomotives electrically, was implemented on steam locomotives as far back as the 1880s, and the great 'flowering' of technology in the '20s and '30s which followed implementation of the Esch Act provisions up to 1928 was almost entirely addressed toward... steam locomotives. An enormous body of knowledge on period equipment has been preserved at the New York Public Library in the files of Frank Sprague's ATC company, (Of course, there are better and cheaper OTS-based systems available today.

Throttles (or throttle and balancing/trim Wagner throttling to the forward engine)were already Franklin Precision air by 1947. This is a proportional-feedback device, similar (unsurprisingly) to a contemporary power reverse. So modulated closing or opening the throttle is not an issue.

Delaying application of the independent brakes and perhaps full application of the train brake can be easily automated with '40s technology (motorized Rotair valve much like the one in my '87 proposal to Conrail). The 'traction control' is air-over-hydraulic caliper acting laterally on cheek plates on the drivers (compare this with the early AEM-7 brakes) and these are relatively easy to modulate as an 'antilock' system as we already have the control modality for part of the antislip/antispin system. Even if lead and trailing truck brakes cannot be made with vented discs, the tender trucks certainly can. So even with the very restricted braking that a train of NEC-compatible cars could exert on the locomotive (I have not forgotten the issues with 110mph GG1s!) braking from maximum permitted Corridor speed via ACSES will not be an issue.

Drifting is a known area where Franklin type B had problems. Some of them are described in the test results for the gear on ATSF 3752. There are a number of ways that bypass or small amounts of admission steam can be used to mitigate any concerns with either drifting or unexpected throttle modulation during a PTC braking 'event' I don't really consider this to be an issue, and it certainly won't be any surprise to address and solve any concerns that may arise during development.


Someone mentioned skills and training. We have several very good accounts of how to run a T1 effectively. On the other hand, the number of ex-PRR engineers whose method of accelerating a train was tied to experience on K4s and M1s, and who would be in the 'pool' of prospective engineers for the rebuilt T1, is probably... shall we say rather small?

Yes, there will be a learning curve on this locomotive. I don't expect it to be very steep, and indeed I expect the automatic systems to make it easy and straightforward. The engine will not be run in average service, with indifferent fuel and maintenance, in an environment where early escape from equipment-trust obligations plays a likely role. Very little about it could not be handled in the maintenance facility about to be built for N&W 611... if that facility is built just a tad longer than strictly necessary, or if work can be done with the doors open at times...

I don't want to create the impression that there are Mr-Know-It-Alls who have answers for every concern regarding a resuscitation of the duplex-drive concept. There may, in fact, be insurmountable problems in making duplexes as cost-effective and robust as their single-engine 'equivalents' -- on the other hand, there may be very significant salient advantages to the duplex in any kind of true high-speed operation of reciprocating locomotives. All that remains to be seen, first in design simulations, and then, God willing, in prototype development. But there isn't much need to invent objections that are not that difficult to redress...

Sure. You just need to look in the grimy faces from the photo of the crew after the steam record not taken downhill on may 11th, 1936...;-)

As to the T1, fascinating as it is, I doubt this approach with an anonymous website will lead to success - at least it is doing no harm so far..

This and other threads have shown some serious points to consider first- lack of car consists, lack of any place to go, lack of any chance to break the speed record in a decent manner (i.e.with a manned train on a real line) and so many other steamers deserving protection meanwhile.

And of course.... so many guys who like to see her running but who seem to prefer "the other guys" to finance it.


Mike

I don't have a Facebook account, but I noticed that Facebook pages display some analytics they call "most engaged insights". I think it summarizes who is doing most of the clicking and visiting on a page. On the T1 Trust page, I see the following:

What I find interesting is that there is a nearly one year gap, less just a few days, between postings on this subject. Just saying...

In that one year between postings the cost of building a locomotive (not just this one) has escalated around 8%, reflected in bidding on recent projects in the railroad industry. The published CPI has little in common with the cost of constructing locomotives.

PC