Duplex Steam Locomotive / Steam discussion

[tnchpsk8]

My Dad retired from the PennCentral just before they became part of Conrail. He had started out on The PRR roughly around 1945 and retired after thirty-five years. He worked as a conductor/brakeman on road freights between Enola/Pitcairen and Enola/Conway. We lived in Altoona and he hired on there before I was born. He worked out of Altoona and also in the yard at Altoona when I was a toddler. Later when I got out of high school he worked out of Enola. They always had a place for him even if it wasn't the cush job all the time.

[andrechapelon]

QUOTE: Originally posted by martin.knoepfel

André Chapelon designed a duplex, too. It was a 2-10-2 for heavy coal and ore trains. However, in Chapelons design, the 2nd and the 3rd axle were coupled by inside-rods, unlike the T1

The June, 1974 (IIRC) issue of "Trains" had an article on how steam could have possibly been saved if the railroads had paid attention to some overseas advances (as well as domestic), most notably those of Andre Chapelon, including the technique mentioned above. There were several design ideas presented. The article was written by Bill Withuhn. If memory serves, Withuhn is or was a curator at the Smithsonian.

Update: Article was "Did We Scrap Steam Too Soon?", William Withuhn, Trains Magazine, June 1974

Source:

Andre

[ndbprr]

The T-1 has been the subject of articles in the PRRT&HS magazine "The Keystone" more than any other in the time I have been a member. The discussion has been very technical at times and The result is (IMHO) a lot of the information about T-1's and slipperyness is wrong. Several engineers have said that other engineers like to leave stations by turning on the sand and yanking the throttle wide open until speed was reached but a t-1 could be controlled by an engineer willing to be more refined in his approach. Everyone agrees that every new class has teething problems and that they could have been solved had diesels not been the real answer. In retrospect the PRR was fooli***o not abandon steam earlier but most of us are glad they didn't!

[Anonymous]

I've looked at all the photo's and I can't tell what valve gear system the T1's used, anyone know?

[Anonymous]

QUOTE: Originally posted by malcand

I've looked at all the photo's and I can't tell what valve gear system the T1's used, anyone know?

They used the Franklin poppet valves, actuated from the crossheads. One T1, the 5547, was altered and equipped with piston valves driven by PRR's standard Walschaerts valve gear.

With regard to the latter day foreign improvements, such as Giesl ejectors, etc.: They might have improved efficiency somewhat, but probably weren't seen as being worth the cost. They were probably all covered by foreign patents, so would have to have been produced under license in the USA which would have added to the cost.

To show you how this kind of thing affected Motive Power departments of various railroads, there were certain outfits that wouldn't use Baker Valve Gear because it had to be purchased from the Pilliod Company, which held the patent. There were railroads (NYC & N&W) that felt that Baker had certain operational and maintenance advantages and was worth the additional cost, whatever it might have been.

But Egide Walschaerts' patent on his valve gear ran out many years ago, and it could be built without any additional cost.

Old Timer

[cefinkjr]

QUOTE: Originally posted by up829

I've seen a few pictures of a T1 poised to race Central E7's out of Englewood but have never read an account of the result. What happened?

Never heard of E7 vs T1 getting out of Englewood but, when I worked on the Central in the late 60s, many old timers told me stories of such races between various trains. They swore that the Central train would invariably beat the Pennsy train. Some even admitted that this might have been caused by a fairly sharp curve east of Englewood on the PRR while the Central's right of way was tangent track for several more miles. [:D]

Chuck

[feltonhill]

T1 5500 was rebuilt with Franklin rotary cam poppet gear after a wreck adn renetered service 7/3/48. It also had teh cylinders reduced one inch to 18-3/4 inches. This arrangement had an outside drive shaft and better accessibility to the camshaft on each cylinder. Got rid of the oscillating cam boxes, one on the pilot beam (under the hood, so to speak), and the other for the rear engine vertically between the frame back of the rear cylinder saddle. Some of the enginemen said 5500 was the best of the lot after the modifications. It would certainly have been much easier to maintain.

[Anonymous]

QUOTE: Originally posted by cefinkjr

QUOTE: Originally posted by up829

I've seen a few pictures of a T1 poised to race Central E7's out of Englewood but have never read an account of the result. What happened?

Never heard of E7 vs T1 getting out of Englewood but, when I worked on the Central in the late 60s, many old timers told me stories of such races between various trains. They swore that the Central train would invariably beat the Pennsy train. Some even admitted that this might have been caused by a fairly sharp curve east of Englewood on the PRR while the Central's right of way was tangent track for several more miles. [:D]

Chuck

The Great Train Stations supplement to a fairly recent Classic Trains has a picture of a T1 on the Broadway racing an A-B set of E7's on the Century out of Englewood dated June 1946.

[Anonymous]

Garth,
Go here for pictures of a perfect T-1 model: http://users.rcn.com/borders/woodings/
Unfortunately the builder Ed Woodings had a stroke and may not finish it. It is about 98% finished and at one point last year I beleive he wanted to sell it. I am not sure what happened to it.
Bill

QUOTE: Originally posted by Garth Hunley


Is there some pictures out there of these "Duplex Locomotives"? It sure would be nice to see the engineering odd balls.

[Murphy Siding]

June 1,1920: America's largest steam roster belonged to PRR-7656 steam locomotives. PRR had 1692 passenger, 4996 freight, and 968 steam switchers. Eleven percent of all American steam locomotives were on the PRR. I imagine that it wasn't unreasonable, even 25 years later, that PRR was so dedicated to keeping, and improving steam power.

[wallyworld]

John Cosby's article was one of the best first person articles about railroading I've read.
I second the request it be posted if possible.This engine has certainly become a legendary beast. One of the great tragedies of railroad preservation is that not one was preserved while many a lowly shifter was.

[feltonhill]

Ed Woodings had a stroke and was unable to fini***he T1. It was about 98% completed, had been run on air but never fired, It needed some reverse gear work and auxillaries. Was sold to a collector.

[Kevin C. Smith]

QUOTE: Originally posted by feltonhill

To support NW611's recall and my earlier statement regarding T1 operation, here's a quote from a PRR internal memo dated 9/29/45 (from Hagley Library):

After we had taken sand at Conemaugh the engineman had the train moving and if he had left the throttle in its position, the locomotive would have hauled the train away, but he jerked it open, the locomotive slipped, the train stalled and we had to put a pusher on to get the train away.

This quote was take from a report by Asst. ME Decker who was riding the locomotive during an extensive over-the-road test period where 6110 and 6111 were being used on regularly scheduled trains.

Previous paragraphs in the same memo describe this engineman's insistence on using a heavy throttle during poor rail condtions east of Pittsburgh, where he allowed the locomotive to slip so badly that Decker stated:

...I was afraid we would do some damage to the locomotive before the engineman noticed the slip and closed the throttle.

If the PRR had gone with a "Challenger" wheel arrangement (4-6-6-4), might that have solved the slipping tendencies or would the lesser weight/driver cancelled out the lower horsepower/driver? Maybe a trailing truck booster might have added enough starting t.f. to prevent driver slips when starting? (And maybe I've got a better chance of winning the lottery than the PRR ever had of breaking down and buying boosters!) This is way too much engineering math for me!

[feltonhill]

I figured someone else would pick up on this but it looks like the booster question went unanswered. I'll try to fill the gap

PRR T1 6111 had a booster as built. However, it added yet another level of mechanical complexity to an overly complicated engine.

PRR wasn't entirely allergic to boosters because all 125 of the J1/J1a 2-10-4's were equiped with them.

Regarding Kevin C. Smith's comment about a PRR 4-6-6-4, IMO what they needed to do was take the Q2's boiler an put a 2-6-6-4 running gear under it. The two-wheel lead truck would have provided adequate front-end stability on a 50-mph freight RR, and there would have been one more powered axle compared to the Q2. Would have helped get all that potential boiler HP to the rail. PRR should have looked just a little bit south and taken note. They did once when they tested N&W Class A 1208, but they still proceeded with the Q2. Didn't work out very well.

[switch7frg]

Old Timer:
A very good post of today .I have read a story about the engines you described in a copy of Popular Mechanics dated Jun /jJul. 1954.The writer is not recalled but very accurate account of these engines .Like Some other writers ,the facts are not distorted or embelished .Some people appear to discredit you ,but you seem to research more than others. .>>> Thank you. Switch8frg.

[wallyworld]

One of the interesting aspects of the T1 and Q2 story is the watershed moment that the PRR shed it's very conservative approach of incremental development of steam development that was backed by extensive testing to move forward so rapidly with the ordering of production of the T1. It's interesting that the NYC feeling the same economic pressures and onslaught of the GM juggernaut came up with the Niagara which was a viable and competitive design based on more traditional design approach. Same for the successful N&W designs which were rejected for development by the PRR. I wi***hat the excellent Black Gold\Black Diamonds book went further into detail on this aspect on a more technical basis. Are there any books anyone can reccomend that analyse this comparison. The Red Devil book did so on a technical basis but I am more intersted in a comparison of corporate design goals based on their reactions to trends in their market.

[Murphy Siding]

wallyworld: I read Black Gold/Black Diamonds. It was an excellent book. The copy I had said "Volume I" on the cover. Is there a volume two? What is the Red Devil book? Thanks.

[Kevin C. Smith]

QUOTE: Originally posted by feltonhill

I figured someone else would pick up on this but it looks like the booster question went unanswered. I'll try to fill the gap

PRR T1 6111 had a booster as built. However, it added yet another level of mechanical complexity to an overly complicated engine.

PRR wasn't entirely allergic to boosters because all 125 of the J1/J1a 2-10-4's were equiped with them.

Regarding Kevin C. Smith's comment about a PRR 4-6-6-4, IMO what they needed to do was take the Q2's boiler an put a 2-6-6-4 running gear under it. The two-wheel lead truck would have provided adequate front-end stability on a 50-mph freight RR, and there would have been one more powered axle compared to the Q2. Would have helped get all that potential boiler HP to the rail. PRR should have looked just a little bit south and taken note. They did once when they tested N&W Class A 1208, but they still proceeded with the Q2. Didn't work out very well.

Ah, ha! I didn't know about the original booster on 6111. Now that you mention it, though, I'm sure I'd heard about the J's being booster equipped, it just slipped my mind. And after I posted the 4-6-6-4 question, I realized that the topic thread started out about rigid frame locos-no way would that ever have worked!

Some nights it doesn't pay to get out of bed...

[feltonhill]

Yes, there is a BGBD Vol. 2. Continues where Vol. 1 left off and it's just a good as Vol. 1.

The book, Red Devil and other Tales from the Age of Steam was written by David Wardale. It covers his exploits in rebuilding one of South Africa's 25NC 4-8-4's in to an improved 26NC called the Red Devil (it was painted bright red). Many other subjects covered in great technical detail including the test of C&O 614 on coal trains. Second edition was printed, may still be available in the US. It was also available from Camden Miniature Steam Services at

www.camdenmin.co.uk

[Overmod]

Always good imho to see feltonhill (et al.) posting on technical matters.

Boosters on T1s would only solve low-speed problems -- and wouldn't have addressed either the slipping at starting or the tendency to break loose at high speed/high power that were the 'big' identified problems with the duplex idea. IIRC even the late-stage multispeed Franklin boosters were supposed to draw steam from the engine exhaust, and were hence dependent on the main throttle being open -- which was the problem in the first place. In my opinion, double throttles for the two engines, allowing 'trim' of steam between the two engines, and some provision to set the reverse so that it could be 'trimmed' likewise, but then worked in gang when desired, would have greatly helped the starting issue; of course, separate throttles (or separate fast-acting independent brake for the front and rear driver sets) and some form of fast-acting slip indicator unambiguously indicating which engine was slipping would have been useful for the high-speed slips.

But boosters -- at least as Franklin made 'em -- aren't the answer to the problem. The J1s used them "correctly" -- to use the steam from that big boiler at low road speed, where the cylinder efficiency or number of power strokes per revolution were still substandard or when cutoff would have to be so late to develop cylinder hp that slipping would be a major problem with those two relatively big cylinders (and relatively primitive valve gear, etc.) But that's a whole different situation from what PRR was assuming the Ts would be used for...

...and IIRC, the Q2s were booster equipped, at least as built, were they not?...

Now, I can see a fair amount of value in having a booster for running, say, a T1 over the Conemaugh division, but you're already relying on having helpers for a train of any substantial length; there just isn't the value on the invested capital for the number of times you'd actually NEED the booster on a high-powered passenger engine. (I think you see the same economics at work on NYC, where a booster would have helped the short 'helper' grade out of Albany station, but NYC chose to leave the Niagaras boosterless and shove with switchers instead...


If I may disagree (in a way that will probably make feltonhill smile) -- if a 2-6-6-4 was the 'right' solution for PRR, it might not have been as good with a "Q2 boiler" as it would with ... well, the boiler on a locomotive like 1208 in the first place, but updated following N&W improvement practice (arch circulators, waffle-grate nozzle, and the like).

IIRC the 'advanced' alloy-steel construction in the Q boilers was one of the notable 'bright ideas' of late-Thirties design practice that failed more or less abysmally: alloys that worked beautifully in stationary-boiler practice, with strict oxygen exclusion in boiler chemistry, not subject to external weather or vibration, and fired continuously rather than heavily and intermittently (with weird and indifferent, in the strike days of the late '40s, coal) did not do well in typical railroad service. Someone may recall the source (and exact wording) of a quote I remember from Trains in the early '70s, that corrosion ate through more than 3/4" of the alloy plate on some of these boilers in just a matter of months after the locomotives were stored. I also remember there was something else about this boiler that gave service problems ... feltonhill, Old, Timer, or one of the PRR mavens should know whether there is truth to this.

Might have been interesting to see whether a "PRR class A" would have been given a Belpaire boiler, or even a double-Belpaire sort of chamber cf. late Lima designs.

Steam was not the only place that conservative PRR went overboard when looking at modern technology -- consider the weird electric designs used up to the GG1 (which of course didn't have roots in the PRR design community!) and the unusual stuff in the Fifties from Baldwin, not to mention the V1 (which I still have trouble trying to figure out) and the original Centipede (a 120-mph electric-locomotive chassis with diesel engines).

If I understand things correctly, the 'duplex' idea was one of the Hot Modern Ideas of the middle Thirties; an attempt to deal with effective use of 'economic high boiler pressure' etc. after the failure of the 'advanced' thinking in something like the Baldwin 60000, and reflecting some of the observations from locomotives like the MILW class As (which were comparatively heavy four-coupled locomotives with high cylinder power). If you are designing something that you expect to run consistently above 90mph with more than six drivers, with a heavy train, it's almost certainly going to require more than two cylinders. The general PRR "answer" to this might have been thought of as a sort of twelve-drivered articulated -- two K4s doubleheaded -- but even if something like this could be arranged to use a single engine crew, it couldn't help but be wasteful of fuel, water, and capital considering the true needs of a contemporary PRR passenger train! Meanwhile, particularly as the ACL R1 debacle came right around the time the duplex idea was reaching 'maturity' at Baldwin, I can understand why a big simple 4-8-4 didn't get the nod for incrementals -- not 'enough' better than an improved M class 4-8-2 (and we might note the arguments over in the NYC tech community that L-class Mountains would have wound up as effective 'better' passenger power compared to the J-3 Hudsons the Government (RFC) funded.) PRR wanted to leapfrog directly to the kind of speed diesels and electrics (and the stillborn V1 steam turbine) would be developing, and that wasn't 100 mph, it was the full Milwaukee-proven 120+ range. Imho it would be extremely difficult to build a simple 4-8-4 that will do this (as opposed to just the general range of 100mph or so) even with modern running gear. I'm not surprised the high-speed designs (the S1 and T1) were not optimized for the mountains, as (IIRC) the clear idea was to continue the 11kV electrification over the entire Conemaugh division through Pittsburgh, with the big steam power only being used to the west. (Diesels being the thing that killed the perceived need for the electrification extension, the swap to DD2s, etc. off by the late '40s) There would simply be little point in running high-speed steam under the wires when the Gs and DDs would do the job better on just about all counts ... and no point in modifying trackage like the curve out of Pittsburgh station to accommodate fast steam locomotives with 'excessively' long rigid wheelbase ;-}

I don't recall whether there's been a discussion of David Stephenson's article concerning the T1s in the C&O Historical Magazine. Here's a link that worked for me:

http://www.findarticles.com/p/articles/mi_qa3943/is_200505/ai_n13642634

The points made in the 'epilogue' about design improvements in 4-8-4s making the duplex concept *as originally sold for locomotives at 'normal' high speeds* (i.e. 85 to 100mph or so) obsolete are, I think, quite valid. Whether PRR would have been satisfied with that range (as, I think, NYC clearly was with the Niagaras) in theory is a question I can't answer with any authority, and I'd worry that the same sort of folks who brought us the "140mph+-on-the-Trail-Blazer-in-1946" style of PRR steam speed reports would only muddy the picture.

[nanaimo73]

QUOTE: Originally posted by Overmod

Always good imho to see feltonhill (et al.) posting on technical matters.

Yes it is.
And it is also good to see you back after 8 months.

[feltonhill]

Overmod,

Always glad to see you on a thread. You've brought up a lot of topics, so I'll have to get something together off line. There's some fairly new info on the Q2 based on the N&W tests in 1948. And yes, they did have boosters.

Just wanted to let you know I'm not ignoring you.

[Anonymous]

QUOTE: Originally posted by wallyworld

One of the interesting aspects of the T1 and Q2 story is the watershed moment that the PRR shed it's very conservative approach of incremental development of steam development that was backed by extensive testing to move forward so rapidly with the ordering of production of the T1. It's interesting that the NYC feeling the same economic pressures and onslaught of the GM juggernaut came up with the Niagara which was a viable and competitive design based on more traditional design approach. Same for the successful N&W designs which were rejected for development by the PRR. I wi***hat the excellent Black Gold\Black Diamonds book went further into detail on this aspect on a more technical basis. Are there any books anyone can reccomend that analyse this comparison. The Red Devil book did so on a technical basis but I am more intersted in a comparison of corporate design goals based on their reactions to trends in their market.

The Staufer NYC Later Power book says the Niagra was intended as a dual-service replacement for the 4-8-2 Mohawks which were also used in both roles. NYC used both classes of power on secondary passenger trains because they were much longer and heavier than the limiteds and more than the Hudsons could handle. The first Niagra was tested with 75" & 79" drivers and 79's were used on the rest mainly for greater economy. The last Niagra built had poppet valves and there were plans for a Duplex version. The book indicates that the Niagras weren't all that advanced in terms of Superpower appliances, just big efficient boilers and well balanced, low maintenance running gear that could rack up 27,000 miles a month, so it seems NYC-Alco was trying to match the reliability of the diesel rather than beating the speed of the Hudsons.

[germanium]

A very informative thread - thanks, gentlemen, for all the obvious thought and effort put in. The posts really are worth reading in detail !!

[feltonhill]

For all readers on this thread - I always give this same speech at some point: support the railroad historical society archives of your choice. It’s the only way technical material will survive so newer generations can read it and learn what happened, and more importantly, why it happened! Their magazines are about the only way highly detailed information will ever see publication for future reference. And websites like this allow anyone who is interested in this stuff to shove things around and learn more.

Overmod,

Thanks for the kind words. Makes the effort that goes into these posts worthwhile. I’m glad you mentioned Al in this thread, assuming you were referring to that well known PRR expert, Al Tooner.......

You covered a lot of ground in your post, but I’ll try to hit those where I can add something.

A lot of the T1's handing problems were the result of ham-handed operation, shoddy maintenance practices, among other things mentioned earlier in this thread. I trust you’ve seen the various articles in PRRT&HS magazine, The Keystone over the past several years (e.g., Vol.34, #3; Vol.34, #4; Vol.37, #1). If not they’re worth a look. Apparently the enginemen who got the hang of them didn’t have much trouble starting. As far as high speed slip is concerned, they also said that it was a matter of adjusting the cutoff. Find the right notch and the problem didn’t occur.

FWIW, the research I’ve done indicates that if the T1 had any adhesion problems during any of the tests on PRR, there were usually due to extenuating circumstances. The specifics of the run and the condition of the locomotive before, during, and after the run are well supported in original source documents that have been dug out of archives over the past 10 years or so (PRR memos at Hagley Library and The Keystone Vol.37, #1, p26-38).

In road tests on C&O and N&W, no adhesion problems were documented in any of the test reports or correspondence written during and after the tests. My point with the T1 has always been this - because of 2-axle engine sets, it would always be more sensitive to rail conditions and track geometry, and that it would be more prone to slip than a 4-8-4 of similar capacity. Joint control of the two engine sets didn’t help, either, but that’s a problem any 4-cylinder power would have. The T1 also required much greater attention to proper handling to get the most out of it. Having said that, in the rough and tumble world of railroading, you can’t and shouldn’t count on great rail conditions, flawless track geometry, scrupulous maintenance procedures, and superbly trained operating crews. They ain’t gonna happen (well, except maybe on N&W)!

Although separate throttles and cutoffs for each engine set may have helped, they would have added yet another level of complexity to an already overly-complex locomotive. The French made the separate throttle and cutoff idea work, but their operating conditions were vastly different from ours and their crews were highly trained, at least in the pre-WW II period.

I certainly agree with your observation that PRR went overboard for the exotic in late steam. IMO they had it right earlier. For PRR’s far-flung operation, the K4/M1/I1/J1 types were likely the better choices. The idea of simplicity seemed to get tossed out the window after the J1/J1a’s.

Alloy boilers did seem to be a questionable idea from what little I know. There are frequent references to seam leaks, caulking, etc. It seems this idea was used on other locos, but I can’t find a specific reference at the moment. Anyone else have info on this??

The idea of a Q2 boiler and a 2-6-6-4 running gear was based on the concept of salvaging the Q2's one good point, since its power transmission left something to be desired. When Q2 6180 was tested on N&W, it did not fare well when used in the same type of service as the N&W’s Class A, at least between Williamson and Portsmouth. The dissimilar engine sets caused a control problem, where the front engine repeatedly slipped, even on sand. In a 1975 interview, N&W’s Robert Pilcher offered the opinion that the Q2 may have had a better boiler than the A, but its running gear needed modification to improve steam usage and cylinder efficiency. Although the N&W test report has yet to be found, a large volume of correspondence written by both PRR and N&W personnel during and after these tests was recently donated to N&W Historical Society archives. Based on this information, the boiler efficiency (not overall locomotive thermal efficiency) for the A was always slightly higher than the Q2, 68% vs about 64% on average. This seems contradictory to what Mr. Pilcher said, but at this point we don’t have all the information available for analysis. In 1948, he did.

Now the question is, whether the A would have been adaptable to PRR’s operating environment, which would mean lower quality fuel rather than N&W’s more carefully graded coal among other things. Most of the N&W photos I’ve seen the tenders seem to filled with golf balls rather than chunks and fines. There are surviving studies indicating N&W’s extreme interest in the increased performance and economy achieved by using selectively screened coal. Whether the A would have done well in a less favorable operating environment, I don’t know. It was a lean, highly focused design; there was no throwing-metal-at-the-problem involved. IIRC, PRR commented about the relatively high back-pressure during the tests of N&W’s 1208 prior to the decision to build 125 J1's in 1941-42. Currently no detailed test reports of the N&W A have been found, so there’s no way to assess what the back pressure was. Steam locos are a great example of systems engineering, and changing one component can sometimes lead to all sorts of unintended consequences.

RE: the C&OHS article. If you can, check out the full article by getting the May 2005 issue of C&O History from C&OHS (COHS.org). They did a super job of presenting graphs and even three newly-found photos of 5511 taken during the tests. I’m a member of C&OHS (and N&W, PRR, NYC, M&P, don’t like to show favorites) and have a copy of the article.

It’s unfortunateT1 history has contained so much overstatement. As a design it deserves more serious scrutiny. When one reads actual source documents and test reports, which are mercifully devoid of BS, a different picture emerges. No, it wasn’t successful like the Niagara and N&W J, but it did better than what we’ve been led to believe. Most of its poor reputation is based on the early performance of the two prototypes, which had problems aplenty (See PRRT&HS Keystone, Vol.37, #1, pgs 20-21). But the production units seemed only to misbehave only when noone was looking. Anthropomorphism, anyone?

When tested over-the-road they performed about as well as a conventional 4-8-4 of similar capacity. On PRR in Sept 1945, there were extensive road tests conducted (Keystone Vol.37, #1, cited above), where both favorable and unfavorable performances were documented and explained. On C&O in 1946 they didn’t slip-slide away like some accounts allege (C&O History, May 2005 cited above). On N&W in 1948 there were no reports of slipping at either low or high speeds, and speeds of up to 90 mph with a 1,500-ton train were recorded (test report N&W HS archives).

Why the caveats and faint praise? Unfortunately the T1 excelled at only one thing: going really, really fast. Once past about 75 mph, very few locomotives could stay with it or operate as economically. But, so what? That’s not where the bread-and-butter operation is. Up to that speed, it used more coal and water per unit of output than the final development of 4-8-4's.

Let’s put the numbers aside for a minute. The T1 is more a creature of the imagination than it is pragmatic. And what’s the cliche, there’s nothing so romantic as a lost cause? What the hey, I even get caught up in it, and I never saw a T1 dead or alive. But I can imagine, somewhere just east of Fort Wayne, sitting at a grade crossing and seeing that gray smudge building above the tracks. Here and gone in a 100-mile-an-hour rush, 5536 is making up some time with 14 cars. Say, wasn’t that John Crosby giving me a wave.......

[Murphy Siding]

Did the other big *coal roads* put as much time and effort into late-steam development as PRR and N&W did? Perhaps, they did, but didn't it get as much attention, because they weren't as successfull?

[feltonhill]

C&O comes to mind with their 2-8-4's (AMC design based on NKP 2-8-4's) and 2-6-6-6's for freight, and 4-6-4's and 4-8-4's for passenger. Last examples built 1948-49.

IC had some interesting, unembellished 4-8-2 and 2-10-2 rebuilds in the post war period.

[Overmod]

feltonhill, I think Murphy's question has more to do with 'innovation' in late steam than with trying it late in the '40s -- and some of the answers you will be able to address much more lucidly than I once that context is defined a bit...

C&O comes to mind, all right, when discussing attempts at "late-steam development" -- not just one, not just two, but THREE steam-turbine-electrics! Don't know if the case has been made for why C&O's anticipated service profile needed a large locomotive with good low-speed TE -- but the Chessie trainsets might be very much the 'equivalent' of the heavy PRR trailing load (yes, due more to grade than to extreme high speed, but in any case more than a contemporary set of passenger diesels might comfortably deliver). I wouldn't have seen this without having my nose rubbed in it quite this way -- but the M1 is a logical follow-on to the stillborn V1, isn't it -- right down to the weird wheel arrangement, which didn't make sense in the Hagley Library reports, but as soon as you look at an M1 undercarriage, it does...

(I should also mention here that it would have been interesting to see what might have been done with a Centipede that had decent build and detail quality, 'standard' implementation rather than being piece-built like steam locomotives, and actually had enough power to hit the 'magic' 6000-hp-per-unit number in the late '40s. We know Baldwin had this specifically in mind with the modular 408-engine "genset" locomotive; I still think it's a pity it didn't pan out. A pair of THOSE might not have had the cachet of 5536 on a 14-car train, but they'd certainly outaccelerate it at any speed up to around 45mph (and perhaps higher!), easily handle that train, or indeed a much longer and heavier one, at New Main Line speeds (at least as fast as a G, if you used the quill-drive undercarriage with snubbers instead of the axle-hung motors), and then with selective shutdown of some of the 408s easily 'tune' fuel consumption to actual trailing load...) Alas! not to be...)

IIRC, the 'long compression' Lima 4-8-6 was being 'pitched' to C&O (and I'm tempted to say that the Lima scam artists who sold the massively overweight high-speed 2-6-6-6s to C&O for use on slow coal trains might have thought it a pretty easy sell!) But by 1949 innovative, high-speed steam power was rapidly on its way out on any of the 'other' coal roads...

One thing about most of the coal roads is that they operate (surprise, surprise!) in mountainous territory with curves and grades that show quick and clear benefit from the use of traction-motored diesel power. N&W had a theology in place that because they did so much business in coal, they'd burn it in their power, too; seems to me that most of the other coal roads realized instead that whatever power was most suited to actually hauling the coal at least overall cost would be preferable... and, accordingly, dieselized with astounding haste (Western Maryland comes to mind, which had some very fine late articulated power that essentially vanished with almost no trace long before it could have been depreciated, and is it a cautionary tale that nobody wanted the locomotives to run, at any price, by that point?

Another point to note about C&O is that they gave up on poppet valves on the S3s, which clearly deserved them, and didn't keep any of the rotary-cam locomotives for any particular length of time. Disabling the feedwater heaters on so much of their power in the '50s doesn't strike me as particularly the kind of 'development' that is being considered, either!

A point that may be worth something is that the 'big steam' coal-road designs that have shown long-term 'staying power' were relatively conventional, but well-proportioned power -- the Reading T1s being a reasonable example, and perhaps the B&O EM-1s -- rather than iconoclastic innovation. It's been my opinion that most railroad managements saw the benefits of diesel-electric power quite early -- in many cases, by the beginning of WWII -- and were only considering steam as 'legacy' or least-expense power once the markets and design of diesel locomotives became well-established toward the end of the '40s. Something clearly happened between 1946 and 1949 that very effectively killed off modern steam experimentation nearly everywhere except N&W -- this despite the high degree of sophisticated approach evident in the '47 Cyc -- and that something was not in all cases related to general use of steam power as such. Imho a large part of this 'something' was experience concerning exactly how much expense in locomotive effective availability, service and maintenance cost, track geometry preservation, etc. could be 'saved' through the use of diesel-electrics -- experience that was meaningful and convincing to 'old-line' through-the-ranks operating people and management alike, not just advertising hype or bean-counter theories -- as much as it reflects problems due to Lewis and the coal strike, or improvements in GM financing options, or the effect of Dilworth's 'unit' design thinking, the effectiveness of postwar diesel engines, etc.

[nanaimo73]

QUOTE: Originally posted by Murphy Siding

Did the other big *coal roads* put as much time and effort into late-steam development as PRR and N&W did? Perhaps, they did, but didn't it get as much attention, because they weren't as successfull?

What was the double Belpaire boiler ? Were any built ?

[Overmod]

Double Belpaire was a method of constructing the combustion chamber in a large-firebox boiler. This took the general profile of a Belpaire crown sheet (as extended forward into the chamber) and 'flipped' it over to constitute the bottom of the chamber as well. This gave a relatively flat plate section for chamber syphons, if you wanted to use them, and of course allowed standardization on what was effectively just one staybolt length for most of the boiler construction.

To my knowledge, no actual Double Belpaire boiler was actually constructed for a locomotive, BUT there is a nifty model in the museum in St. Louis:

http://www.leclairerail.com/Additions-2/7130LboilerLima.jpg