There is a group that is recreating the PRR Class T1 4-4=4-4 duplex with the avowed intention of breaking the speed record for steam locomotives. OK, great. BUT…I can’t imagine any Class I where such an attempt might be made letting it happen. No management will permit any private excursions - no matter what the speed - due to the disruptions to their operations, they don’t have track and roadbed capable of supporting 125 MPH plus operation, the exposure to liability suits should something go bad terrifies them (and they won’t accept an excursion operators’ insurance to cover them) and view the idea of the terrible publicity if there is a wreck with horror. What about UP? Their steam program is a carefully controlled corporate effort under the total control of Omaha with equipment of known capability operated within its known limits. As Marcus Tullius Cicero put it, “Qui Bono?” How does UP benefit by hosting such an operation? So what’s the deal? How do the T1 folks intend to get around this?
This was extensively discussed in the original feasibility plan and should still be identifiable on the Trust site.
Any high-speed testing will be done on the TTCI Fast Loop in Pueblo. There is design and planning in place for the instrumented wheelsets necessary for this. Instrumentation to detect emergent resonances and systems capable, if necessary, to break them well enough and long enough for safe deceleration, were also part of the design spec.
Before any high-speed testing is done ‘IRL’ the design will be fully multiphysics-analyzed, and the locomotive will be run at all presumptive speed and power ranges on its roller rig before any actual high-speed operation is made.
The world record still is held by the famous LNER A4 Pacific “Mallard”, which pulled an actual train with that speed on a mainline.
Are there any cars that can run that fast around? If not, the speed record will be subject to challenging.
THIS is the only rig I would even feel marginally safe in performing a speed test on an unproven (copied) design of a reciprocating steam locomotive:
Locomotive_Testing_Plant_(1904_World's_Fair) by Edmund, on Flickr
Unfortunately, this one — and the one at Altoona — are long gone.
Perhaps the British kept theirs?
Regards, Ed
The short answer is spelled PRIIA; the slightly longer one includes Amfleet with some suspension modifications. There are other possibilities including some waiver activity (not unjustified in the highly controlled conditions at TTCI). The plan was to use AEM-7 style trucks, motors and control for the regulated-dynamic-load dynamometer car, which also gives inherent high-speed capability if correctly secondary-suspended. Which it would be. Since the AEM-7 stuff will likely be gone, or restricted from running by Amtrak policy, some other source of 125mph+ motored truck may be needed – Siemens from ACS64 or Chargers would work fine.
Even short recourse to history will reveal that not only was the T1 exhaustively tested on the Altoona plant (making appropriate hay of that ‘unproven design’ crack) but was one of the locomotives that exceeded its measurement capacity. There have also been great technological improvements in high-horsepower static dyno equipment since the age of the St Louis fair or the construction of Rugby, and I recommend these to your attention.
I should probably add that much of the early rhetoric about ‘smashing Mallard’s record’ or whatever was more than a little misguided and I believe has been ‘walked back’. It is obvious in many ways that even a T1 with the 1948 improvements and full dynamic balancing with low overbalance is vastly more capable than an A4 Pacific; 5550 will be considerably more so. It proves nothing significant to go demonstrate that with blood and treasure.
As I’ve pointed out, there are three steam replica projects of far more relevance in the historic-record context, all of which are smaller scope than the T1 Trust’s project. One of these is a replica 86" drive McQueen/Buchanan 4-4-0 (to prove the feasibility of the first true 100mph sustained running); the other two are, respectively, a full contemporary re-creation of PRR 7002 as she ran during the alleged 127+mph time (I personally doubt anyone will arrange that, but there’s nothing shy of building one, learning to run it fast, and trying that could disprove that), and a replica Hiawatha A class, the only thing really likely to have been faster than a T1. (Don’t come to me with fibs about alleged ‘120mph’ 3460 class locomotives or those Milwaukee F7s so suspiciously similar in all respects to the C&NW E-4 that couldn’t even get to 100mph with a train; on the other hand Mr. Bruce, who ran Alco and was in a peculiarly good position to know, said the A was easily good for over 128mph … you’ll appreciate where he got that number … and we owe it to his memory to find out if he was right.
(BTW all these things are 1:1 scale model railroading so it is completely within TOS to keep discussing them here.)
What I was implying by the untested design crack is that although the Built By Baldwin T1 WAS thoroughly tested AND proven on the Pennsy’s West end, a COPY made solely from blueprints alone has NOT been tested and is not a duplicate of the original locomotive but a fabrication of what may be available in today’s marketplace as far as steam locomotive knowledge and parts resources that may be at hand.
Do you think the T1 trust has the same knowledge, skills and capability that the fully-staffed Baldwin Locomotive Works and the Altoona Works had during the development and building of the Pennsylvania Railroad’s order of the T1s?
Will it have a cast steel bed plate? Will the steel have the same characteristics. From what I understand the boiler is being fabricated form one inch plate. Will that have any effect on the center of gravity from the original T1? Will it handle curves in exactly the same way as the Baldwin product?
PRR Photo
Sorry if I caused you any grief in your short recourse in history.
Warm regards, Ed
Trust me, Ed, there are people with comparable intelligence and practical experience working on the detail design of the locomotive. And on recreating the materials science and manufacturing methods. And testing and modeling of the design with tools that BLW could only have dreamed of.
You can carry on with that whole 1940s-knew-best line if you want; this is America and I’m not the forum police. I would point out, a bit archly, that Baldwin certainly didn’t build these engines in a way considered particularly successful, including the initial design and fabrication of their ‘non-one-inch-plate’ boiler wrappers; I think you might want to look into precisely what the engineering committee at the Trust is doing before you half-acidly go to town disparaging it as incompetent.
This with all respect to your considerable historical knowledge and collection of documentation sources.
(Oh, by the way, the term is not ‘cast bed plate’ or ‘frame’ either, it’s just cast engine bed (precisely to discriminate homogeneous one -piece casting from those also-ran ‘cast frames’.
As noted in a different context a few days ago, the Trust does have sources with competence in large steel castings, and has gotten estimates for a comparable cast bed – the problem being that if more than one pour is required, which would not have been too problematic at Granite City where they were set up to crank out hundreds, but is a big thing for one-off production of something this complex and accurate, the cost balloons. Now, it may turn out to be necessary to cast the bed after all, and push the time estimate and funding plan back accordingly. All this is known and discussed, with actual modern foundrymen who don’t BS.
I find the endavour to subject a multi million dollar build of a steam engine to the unknown risks of attempting a speed record, which has no reason, nor any value, rather questionable. I can only assume that there is a substantial amount of false pride attached to that.
Whoa! Hold the horses! You are about to derail!
You got me there. [:$][:$][:'(]
I had just been reading about the antics on the “Foot Plate” of the Mallard and the word plate was stuck in my mind. I won’t make that mistake again.
Dummy me [D)]
A locomotive bed is a one-piece steel casting for a steam locomotive that consists of the
Its well known between Crestline and Ft.Wayne the T1s hit 90-100 mph on a routine bases in regular service.
I’ve seen the arguments about the lack of a solid cast frame before and the mention of how we can never truly replicate it just like Baldwin built the original.
But this is the 21st century, the world of instant communication and self landing rockets. We have materials available that weren’t even in labs 50 years ago. There are definitely things we know now that the guys in Baldwin in the 1940’s would have killed to know. The extensive Solidworks drawings coming out of the T1 trust are a modern drafting wonder.
It’s not like the knowledge of steam locomotives have been lost, physics are still the same laws, math is the same, and countless heritage railway’s and modern FRA codes have kept steam locomotive knowledge alive. If anything the resonance of the locomotive can be tested using a Matlab or Python code, a timesaver compared to the hand calculation the original engineers would have done.
Really the only thing that is still in doubt is that pesky frame. If they can find one lost mold casting company with a sand bed big enough, its certainly possible to still cast the frame. However with modern techniques, welding might just be simpler and faster.
And, all of this has WHAT to do with model railroading? Just curious…
The biggest limitating factor for high speeds are the reciprocating, unbalanced masses, i.e. the valve gear and connecting rods, which rotate at a tremendous high speed, causing the loco to buck like a stubborn bronco, damaging the track and what not. Just imagine one of the side rods breaking …
The British steam locomotive steam records were judged according to pretty strict objective standards for precision and thus the Brits have always tended to cast shade on steam speeds records which were either more loosely judged in their opinion (I think the NYC’s 999 record falls in that category, even though it was intended to be a record breaking run by the railroad itself) or are more purely anecdotal, as some of the Milwaukee Road speed records tend to be. There are also anecdotes about the Pennsy T1 and the speeds that crews hit that the railroad itself would not have advertised or sanctioned or evaluated because the crews were exceeding published speed limits. I recall a story in Trains magazine about a crew that found itself on a work train (!) pulled by a T1 in its final months of service and the engineer basically said “hey watch this” and let her rip.
Just a few years ago the CB&Q E5 streamlined diesel and the Nebraska Zephyr train set had a series of excursions over a weekend on the BNSF line to Quincy IL and back. I watched it go through Mendota IL and it was flying (and as I was putting down my camera I noticed that I was totally surrounded by grass fires set by the hot exhausts – probably a few decades of carbon buildup were involved!). Given the tangents on that line - the real racetrack of the old CB&Q – the crew let her rip, maybe forgetting that the engine now had a GPS transponder on it and the dispatcher had access to speed information. Story is that they briefly got it up to 100 on track where Amtrak would probably be limited to 79. Fortunately that track has few grade crossings so the train was in relatively little danger of making a crossing before the gates were down. The DS got on the radio and asked some pointed questions about speed and so that little experiment was ended. I heard about this from folks who were listening on their scanners.
Dave Nelson
Well, they aren’t restoring an original, because none exist. They are building a replica, from scratch. So it’s a model of the real thing, just in 1:1 scale.
–Randy
Dave - you are on the spot there! Mallard´s speed record is quite debatable, as the line had a slide downhill grade. Sir Nigel Gresley himself questioned the record and saw the speed more in the vicinity of 124mph, than the split second tachometer reading which showed 126mph. This would make Deutsche Reichsbahn class 05 002 the fastest steam engine - until PRR T1 breaks it officially.
Should your layout have a stretch of triple track, you can have all those engines race against each other!
I would rather have seen them put the money and effort in to getting the 1361 running or build a new K4s.
oldline1