Flaw wise, I know little of any flaws except the high speed slipping, caused primarily by poor maintenance, not a design flaw. Based on earlier posts here, The 5550 project has several engineers on board, and they have devised a couple of ways modern technology can be used to eliminate the chance of high speed slipping.
Also, the main point of the project is to recreate a locomotive from scratch, even if it doesn't run. Since an M-1 survives, why build another? This is similar to the British Tornado project.
We might yet be able to test the design for longer than the PRR. A group is planning to build a T1 (to be numbered 5550) from scratch.
http://prrt1steamlocomotivetrust.org/
I believe they're going to upgrade the design some, but if built, I'm sure it will last longer than 4 years in service.
Blue Alert! We're at Blue Alert! Aw crap, it's a nondescript GEVO... Cancel Blue Alert!
narig01Many years ago Trains ran a piece on the tale of one passenger crew on the Pennsylvania RR who had a fast run with a T-1. When they got to Ft Wayne there was a note that the chief dispatcher wanted to see then. His remark was to the effect of the train was flying a little too low. The author of tale noted they had clocked many miles in 30 seconds. The dispatcher also used roughly the same language in confirming the speed. Thx IGN
I certainly believe they could run 120 mph given the right size of train and track conditions.
We did not have 100 mph conditions on the main line to St. Louis but the T1's could made good time on any flat land type of track.
CZ
It was the late George Drury in his book on North American steam who said poppet valves arrived just a little too late for American steam builders to master them. He was probably right.
As far as the last 25 T1's being a mistake, that's correct as well. The PRR made the decison to dieselize passenger service in 1946, so in a sense the T1's were out of a job before they were even built. Certainly they were used in passenger service but with the diesel handwriting on the wall they never really got the chance to prove what they could do. C'est la vie.
PNWRMNM While I am not particularly a PRR fan, I have both Volume 1 and 2 of Black Gold - Black Diamonds by Eric Hirsimaki. Most of Volume 1 is about PRR steam power since that was the competition when the diesel came along. The first T1 pair was ordered in July 1940 and delivered in April and May 1942 at a cost of $310,000 each. The rear gear valve for the poppet valves was located under the boiler in a location very difficult to access, and the front valves were located under a streamlined shroud, which soon disappeared. They suffered no end of teething problems including: poor steaming - fixed by replacing the front end nozzles, tender slamming against the rear of the locomotive - finally corrected by changing the spring rigging on the tender trucks, inordinately high failure rate of the poppet valves which often broke at high speed, unreliable sanders, they were slippery, they were very rough riding, superheater units leaked and/or frequently broke. The second batch, of 25, began to arrive in November 1945. Hirsimaki states "Perhaps the most surprising feature on the engines was the older Type A poppet valves which had long since proved unsuitable. The newer Type B poppet valve system was available and it was easier to maintain. However, the railroad opted to retain the Type A valves 'for commercial reasons'. This doomed the T1's from the start." PRR began to place massive orders for freight and passenger diesel locomotives in February 1946. My take is that the first two were a reasonable experiment, and the final 25 were a total mistake. Mac
While I am not particularly a PRR fan, I have both Volume 1 and 2 of Black Gold - Black Diamonds by Eric Hirsimaki. Most of Volume 1 is about PRR steam power since that was the competition when the diesel came along.
The first T1 pair was ordered in July 1940 and delivered in April and May 1942 at a cost of $310,000 each. The rear gear valve for the poppet valves was located under the boiler in a location very difficult to access, and the front valves were located under a streamlined shroud, which soon disappeared. They suffered no end of teething problems including: poor steaming - fixed by replacing the front end nozzles, tender slamming against the rear of the locomotive - finally corrected by changing the spring rigging on the tender trucks, inordinately high failure rate of the poppet valves which often broke at high speed, unreliable sanders, they were slippery, they were very rough riding, superheater units leaked and/or frequently broke.
The second batch, of 25, began to arrive in November 1945. Hirsimaki states "Perhaps the most surprising feature on the engines was the older Type A poppet valves which had long since proved unsuitable. The newer Type B poppet valve system was available and it was easier to maintain. However, the railroad opted to retain the Type A valves 'for commercial reasons'. This doomed the T1's from the start."
PRR began to place massive orders for freight and passenger diesel locomotives in February 1946.
My take is that the first two were a reasonable experiment, and the final 25 were a total mistake.
Mac
I remember one Sunday when we were watching trains at Effingham, Illinois and we could hear what sounded like a train chuffing loudly coming in from the East end of town. Suddenly, a T1 rolled around the curve east of town and glided to a stop. One of the poppet valves was broken and that valve would release the boiler presure into the stack each time instead of pushing the piston. Dad talked to the crew and they said maintaining steam was a problem but they went West out of town with that loud chuff each time the valve opened to the steam chest for that one cylinder. I am not sure but It must have been an exhaust valve that was broken or stuck open. The fireman said the exhaust was lifting the coal off of the grates. No one was happy that day.
inordinately high failure rate of the poppet valves which often broke at high speed,
I was in the cab of several T1's. The crews were friendly in the late forties and a kid could get a look at the cab and they normally opened the firebox door to impress us.
Ever get to ride behind one or visit a cab?
daveklepper I thought we had a T-1 thread on this Forum. Did whoever inaugurated it ask for it to be removed because it strayed too much from the subject? I would like to reopen the discussion with the intent of staying with the subject, althouogh comparitive steam power and even comparing performance with diesels certainly should be allowed. My own impression was that it was a fine locomotive, but needed careful handling when starting a train, and came to late to realize its full potential because of the economics of the diesel.
I thought we had a T-1 thread on this Forum. Did whoever inaugurated it ask for it to be removed because it strayed too much from the subject? I would like to reopen the discussion with the intent of staying with the subject, althouogh comparitive steam power and even comparing performance with diesels certainly should be allowed. My own impression was that it was a fine locomotive, but needed careful handling when starting a train, and came to late to realize its full potential because of the economics of the diesel.
We have discussed the T1 many times and much has been said about it. I am older and got to see them running on the St. Louis mainline and as a railfan, I was impressed. The maintenance issues and the fact that EMD had the E7 available at the same time the production T1's were built doomed all passenger steam. I got to see them above 80 many times and that was a reall treat to watch them glide so to speak with a train.
The start ups were always a problem even if the engineer was easy on the thottle, but they sure could run once moving.
OK, it just got submerged behind newer topics and I didn't find it.
NorthWest Guys, the thread still exists, just on the Classic Trains forum. Here is a link to it.
Guys, the thread still exists, just on the Classic Trains forum. Here is a link to it.
While I had mentioned that the old T1 thread had strayed a bit - I never requested it be closed and removed.
Who among us, when conducting 'friendly' converstations with our friends stays 'on point' and limited to a single topic? I have no problem with straying conversations and unless they become personally abusive they should be allowed to follow their own trail - just like happens in real life.
Never too old to have a happy childhood!
Dave:
Link to photo of 6110 @ http://www.crestlineprr.com/t1pre_deliveryatblw.html
a link to a site with some info on the T-1's and the PRR Roundhouse and Facility at Crestline,Ohio:
@ http://www.crestlineprr.com/duplexexperimentals.html#t1
FTS: ( at the site index for the T-1): "...These locomotives sported 80' drivers, and could easily pull an 18 car train at speeds at 100 mph and more. There is a story told that a road foreman was riding behind a T1, and clocked it at over 120 mph on the flat lands of Indiana! These engines were the first production engines to utilize the Poppet valve. The Motive Power Department wondered why it was that they were failing way more often than they should have. They were designed to run at 100 mph, but could not withstand the punishment of continued running at 100+ mph..."
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