Duplex Steam Locomotive / Steam discussion

[Overmod]

Two bitty points:

Seems clear to me (from circumstantial evidence) that the NYC poppet-valve test assumptions were geared toward having the same output power with better economy, not higher power with a 'more free' steam rate. I may further speculate that some of the high-speed slipping problem observable with Franklin poppets may have been worrisome enough to contribute to a decision like this. (I find it very difficult to believe that the NYC steam guys would have made a 'mistake' in steam-circuit design, just as I start looking at the lack of a significant combustion chamber on the production Niagaras as intentional rather than misguided maximization of convective vs. radiant heating (cf LeMassena in Trains in the '80s) or excessive conservatism, etc.)

Opinion, likewise: the 'weak point' of the N&W J at high speed was lateral deflection of parts of the valve gear at high rpm, often encountered as a problem with 'conventional' piston-valve drives. Part of the problem that can cause this deflection (high steam-chest back pressures including those attributable to compression; relatively high inertia of the valve components) can be solved with poppets; more importantly, use of a RC with or without continuous variable cams (or, for that matter, a properly-arranged OC drive using roller crank) remove the deflecting components themselves. (The next thing to go would probably be main pins a la MILW F-7, but it would be easy to address THAT question in turn with bigger better bearings in the lightweight rods...)

I'd expect N&W would also choose to go with some form of disc driver (or, at the very least, something like WebSpoke) if going to a higher rotational speed and power with 70" drivers. I'd also expect that some of the exhaust-stand and nozzle developments done in the '50s could have been adapted to make a poppet J run with very little backpressure problems (but proper compression for minimized shock loading on the rods, etc.) given the capabilities of good RC gear. If I may be so bold as to predict, the problem would have been 'grooving' wear of the variable cams at the most obvious 'notches' used in service, with a possible 'fix' being the servomotor varying drive that oscillates the follower slightly about an 'optimal' setting -- another possible solution being either facing or refacing of the cams with metalsprayed hard material. Doubt that it would have improved the situation with N&W steam a bit, because the decision to throw it over was made by lawyers up at the top of the company, not with reference to the effectiveness of steam power in service (not that I'm saying I would have arrived at any different conclusion at the time!)

[feltonhill]

The final improvements proposed for US steam were likely not sufficiently significant to change history.

The double belpaire boiler discussed so far may have been an improvement over a conventional firebox, but how much of an improvement? Overmod mentioned this idea earlier - would it have been enough "better"? For example, would it have been worth the manufacturing problems brought on by a new configuration? Would it have improved combustion enough to be worth the cost? Would there have been enough clearance for driver spring rigging underneath the flat bottomed combustion chamber?

Same with the 6-wheel trailing truck and the 4-8-6. Yes, it would have allowed slower burn rates and more time for heat transfer to take place in the firebox (which is where most of the evaporation took place). These are both good things. But it added weight and length and didn't add more drivers to get the power to the rail. The booster added complexity and maintenance. So, would it have been better when measured on the basis of coal and water usage per unit of output? Maybe, but how much?

The 4-8-6 would have had tough competition between the Niaraga and the N&W J which, on a quick review of available test data, seem to have somewhat similar, and low figures for coal and water usage. This is a very preliminary opinion because I just started to look at all the data that's available. It will be a real minefield to make any equitable comparison between the two. The engineering issues are bad enough, but the fans of both these locos are knowledgeable and vocal. In some respects I look forward to the project, but in others, I don't.

Poppets (RC only) would have been a theoretical improvement but again, how much better were they than a well-designed locomotive with conventional valve gear? There's no really good A vs B comparison. The ATSF 4-8-4 in Vernon Smith's book was an older, low pressure loco which was considerably improved by rebuilding. More than just the valves were changed. PRR's K4 experiments also involved not just poppet valves but also revisions to the steam circuit. So although there was substantial total improvement, which revision caused what increase?

On the other hand, the only valid A-B comparison of poppet valves vs conventional valves would have been the NYC 6023 vs 5500 tests. Problem with that is that 5500's poppet valves were allegedly undersized for the amount of steam the boiler could generate. This is not my opionon, but was covered in the Third Quarter 1993 issue of Central Headlight, published by NYC Historical Society. The results of the test showed only a very modest (almost negligible) increase in power and a 16 % reduction in coal consumption per unit of output. So that opportunity for comparison doesn't work.

Believe it or not, there is a memo indicating that Franklin Railway Supply was considering making a proposal to N&W for poppt valve installation on a J, but nothing came of it. Whether the outcome had been good or bad, it would have interesting so see what happened.

All in all, some of the improvements actually installed or proposed were probably in the right direction on a theoretical basis, but were they good enough to prolong steam use in the US? I doubt it. The final users of steam in the US had one thing in common . NKP and N&W matched locomotive capability to service requirements and operated them at their most efficient power output most of the time. They managed to stave off the early diesels the longest.

Even if final holdout N&W's management hadn't changed in 1958, the die was already cast. N&W knew it had taken steam as far as it could in their type of service. Sure, maybe the Y6's and A's may have continued on another year or so to 1961 or 1962, but IMO that would have been it. In the end, simple straightforward locomotives used at peak efficiency, serviced well and operated on a good physical plant seemed to have proved that the basic steam locomotive concept was pretty good. Any further improvements would be mere refinements that wouldn't hold off the major technological change facing the railroads in the postwar period. After the war, operational economics was the yardstick, and diesels carried a bigger stick.

[Overmod]

Short answer: Yes, but no.

One of the better examples of late steam design is the Duke of Gloucester, BR 71000. Bears noting that several details of this locomotive appear to have been intentionally misconstructed (cf. the firebox and front end) as built -- I stop short of saying 'intentional sabotage' but am reluctant to attribute it to negligence -- which when corrected have given what appears to be a good-running locomotive.

There is no doubt from the surviving evidence that some of the late improvements in valve gear led to better operation (cf. the ATSF testing of Franklin type B on one of their large 4-8-4s) There is equally no doubt that regardless of how 'good' these improvements may have been on the basic machine, they were sufficient for the railroads to consider them 'worthwhile' enough to retain steam. While I think a more wholehearted embracing of those 'improvements' that increased reliability and reliable performance might have kept steam around somewhat longer, it's only in the absence of the development of high-horsepower diesel-electrics that one could imagine mainline Stephensonian steam surviving in general service until now, no matter how effective it might have been made.

Might bear noting that many of the 'sophisticated' improvements that worked well on locomotives with high power that were well-maintained were not at all suitable when things began to degrade. The 'electric' Cossart gear on the Algerian Garratts is a particularly notable example imho. Easy, cheap, and familiar usually wins out in the long run, and in such a framework only the innovations that last long enough to become 'familiar' are the ones that stay adopted.

I'll be very interested to see feltonhill's take on this question!

[germanium]

Feltonhill, Overmod et al. - with all the experimentation going on, were there, in your collective/individual opinions, any really worthwhile improvements on the basic Stephenson machine resulting from this experimentation ?

[feltonhill]

As far as I can gather, the 4-8-6 was a Lima idea. The RC valve gear would likely have involved Franklin Railway Supply because they were the developers of the valve gear. I never read that C&O had any specific interest in either the 4-8-6 or the double Belpaire firebox.

Woodard lived from 1873 to 1942.

[nanaimo73]

Was the 4-8-6 just a Lima idea that they were trying to sell to C&O, or did the C&O have an interest in the double Belpaire before this proposal ?

Would Mr Woodard have been in on planning this boiler, or did the idea come along after he passed ?

Is there a website that covers Mr Woodard ?

Thanks

[feltonhill]

The double Belpaire was to go on a 1938 NYC J3a Hudson. This and other information about the double belpaire and the 4-8-6 are in Eric Hirsimaki's book, Lima The History (pg288 in first edition). I believe this book has been revised and is now out as a second edition.

The first C&O poppet valve installation was on the L1 4-6-4 rebuilds and they had oscillating cam (Type A) gear. The later L2a Hudsons had rotary cam (Type B) gear, which was more accessible for maintenance than the Type A.

For those who have not heard of Vernon Smith, his views were published in his book, One Man's Locomotives. There a section in the book where he discusses the different types of poppet valves and the locomotives on which they were installed. All of us in the locomotive perfomance game owe him a lot!!

[Overmod]

Interesting about the Hudson. Do I presume that the proposal was for one of the J2s, rather than one of the Alco-built classes? (And were they going to fix the cab sag as part of the installation??? ;-})

I have no idea where that "S3" came from... or what I might have been thinking when typing it. 614 is one of that class. The point I was thinking about -- which may have been part of the distraction -- is that classes built previous to the J3as already had poppet valves, and extensive testing (and the valuable experience that came from that testing), as well as promotion and sales activity, for Franklin type B was already well in hand. I concur about it being seen as 'best not to bother so late in the game', BUT it seemed a bit odd for C&O to be building new big steam without poppets when they had been so recently willing to inve$t in the M1s, had poppet-equipped locomotives already, and presumably were aware of developments at Franklin to address the issues of the variable-cam rotary gear. (Is any of this correspondence or technical review still extant? I miss Vernon Smith more and more!)

The reason I brought up the Chessie trains was that, even though the cars were lightweight, I recall the trains themselves were intended to be very long and equipped with amenities like large fi***anks and beaucoodles of domes that were going to take the train weight up substantially compared to a typical 'streamlined' train. From the article in Trains lo these many years ago, I got the distinct impression that the marketing intent was to produce something similar to the California Zephyr experience. That might explain why C&O felt the need to go to something with the very high starting tractive effort of electric drive, but cost-effective high horsepower output at speed that would NOT have been achieved -- for high trailing load -- with either E's or passenger F's at comparable capital cost. (Don't know, but would be interested to know, the extent to which burning coal was a 'political' item of importance for this project, as we know it was over at N&W)

I think that between the V1 and M1 designs, it has pretty clear that there was a minimum size of locomotive that was going to be practical -- and I use the term in a purely technical sense! -- as a unit, and only a train capable of 'sinking' the effective power of such a locomotive would make 'sense'. Almost by definition, that train would be not only fairly heavy and long, but also need fast running -- both in relative peak speed and acceleration. (Now, I could reiterate my point about C&O using the Alleghenies, which were explicitly higher-speed freight power, in what were either by intent or result slow-speed heavy service, but it would be a cheap shot and unjustified slam at C&O to say that that was an 'institutional blind spot' that carried over to other designs of modern motive power.)

On a public computer now, so I apologize if parts of this make even less sense than "S3"... ;-}

[feltonhill]

C&O operated the turbines west out of Charlottesville over the Mountain Subdivision which has a profile that matches its name (see parts of the C&OHS article cited above). However, the lightweight cars coming on line at the time didn't require any more than the already present 4-8-4's and 2-8-4's in use (1948). Seems the three turbines operated for a day or two and disappeared. But their low speed TE could have been put to some use over that segment.

Most recent information seems to lay the blame for the H8's weight problem on the AMC. They apparently wanted to best N&W's Class A and weren't too particular about how they did it. So they kept adding features and iron, making it bigger and badder I suppose, without allowing for anything to be removed to compensate for the weight gain. Lima got stuck building the beast as specified and when it came time to weigh it, reality struck. Operating crew's wages had a component that took weight on drivers into consideration. So that's where the tale of secrecy in the scale house comes from. Most of this is covered in the book, The Allegheny, Lima's Finest and an article in Trains IIRC

Overmod, you mentioned S3 on C&O, I believe it's the last J3a 4-8-4's you were referring to as initial candidates for poppet valves. Would have been interesting, but it was probably best not to bother that late in the game.

As far as the double Belpaire goes, I thought I read that feasibility plans had been done for an installation on an NYC Hudson, but nothing came of it. Again can't lay my hand on the source at the moment. Too many books and files here to find that detail fast enough.

[Kevin C. Smith]

I've always taken "free steaming" to mean that the locomotive(s) in question kept up boiler pressure easily, without too much firing-but that's just me thinking, again.

Also, re you previous post about Baldwin's Centipedes-just off the top of my head, if your big customer was PRR, that HAD to have no small influence...

[Murphy Siding]

What does "free steaming characteristics" mean, in relation to how a boiler is designed? In this context, it was used to describe the design of Beyer-Garratt locomotives. Thanks

[Murphy Siding]

QUOTE: Originally posted by Overmod

(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 never quite understood what Baldwin must have been thinking of when they built the Centipedes, until I ran accross a bit about them in Black Gold,Black Diamonds. It seems that Baldwin was trying to build the diesel locomotive that PRR envisioned would be the answer to their dreams. The idea kind of makes sense-lots of powered wheels on the rail, and somewhat *modular* construction. You might say they were thinking dash-2 thoughts many decades early. That Baldwin seemed to be working on what they perceived their customers needed,makes sense. That they failed,maybe says that their customers' perceived needs may have been incorrect. Did the big locomotive customers of Baldwin really have that much influence on Baldwin?

[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

[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]

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.

[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.

[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]

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.......

[germanium]

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

[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.

[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.

[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.

[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.

[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

[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...

[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.

[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.

[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.

[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.

[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!