OvermodThe decision to cash the Big Engine in was not taken idly, but in a world of PRR losing money and deciding to dieselize fast there was little question which way it would go.
OvermodThe story about the approach curve 'restriction' in Pittsburgh station was well-documented by the T1 Trust, as was the research that eventually put enough lateral into T1s to get around it (I believe it was later removed with track realignment, but don't remember the specifics.) It did not as I recall involve access to all tracks in the station (tight point of a double slip switch?).
Quote from T1 Trust: "A specific problem with 130 lb no.8 switches prevented them from operating through Pittsburgh - but an increase in lateral motion in 1946, and track realignments in the modern era (required to handle longer freight cars than the 1940's) mean that this particular issue has been resolved" Sadly, S1 was retired by mid-1946, if PRR keep her longer, she might have a chance to do what she supposed to do, hauling long-distance train from Chicago to Pittsburgh. I wonder if the Wye which was built especially for S1 (in 39?) was still in Pittsburgh that time……
OvermodThe closest thing PRR really achieved to a grand train was the Congressional Limited so beloved of Dave Klepper. And that, of course, didn't really involve steam power. It might have been interesting to see if PRR would have developed an actual high-speed Fleet of Modernism if the 1928 plans to develop a New Main Line with much higher achievable speeds had in fact been achievable (but that would involve not only no Depression, but no significant use of funding for electrification, for steam to be involved more than 'experimentally').
It would have saved so many people time, including the heads of PRR if the original electrification plan became a fact, the performance of GG1 was so extraordinary compared to post-war steam train like T1, Q2 etc, but I probably wouldn't become a PRR fan since they probably won't spend too much time on new steam engine design.
Electrification of the system was probably the most foresighted thing PRR ever planned and ever did. Imagine how awesome it would be an "RR1" hauling a 16 cars consist, running at 141.1mph straight form D.C to Pittsburgh or even Chicago? But I still prefer Steam locomotive to Electric locomotive. A new High-Speed Main Line between Chicago to Pittsburgh with average speed 90mph+ specially built for Class S1 6100-6109 (using poppet valves and roller bearing side rod ) A route as famous and as successful as the Hiawatha is always my dream.
Jones 3D Modeling Club https://www.youtube.com/Jones3DModelingClub
Well at least everybody's thinking here!
Overmod--161 mph? Wholeeeeee Makinaw. That's nuts.
Not buying a $1.25 million dolllar equivalent for the scrap value of the S1. That would make the initial costs of duplex drives 2.32 billion. No way. The $35,000 put directly into the cost of a Diesel amounts to less than 10%. I don't know playing with numbers doesn't tell the tale though. Was it the S1 or the S2 that had it side all smucked up by a flailing broken side rod.
Jones1945-- I like the corruption angle. Powerful men at Pennsy, Baldwin, EMD, NYC, Alco ... lots of interactions, favours, shenanigans and big big $'s on the table. Things were done, of course.
In the past Overmod has alluded to actual documentation that may exist by executives at Pennsy stating how to go about making the T1's a hopeless engine. They couldn't get Diesels fast enough and I do recall reporters, analysists, shareholders and such hounding Pennsy as to why total Dieselization was taking so long. The answers were reasonable, that it was a huge system and it could not be done overnight. However, they couldn't get rid of steam fast enough and the heat was on. So strange things were happening amidst the big push and rush.
I have asked several times regarding the surprising and somewhat suspicious and mysterious loss shown by Pennsy in 1946 and then again in subsequent years in the late 40's. Perhaps they spent too much on Capital purchases. 1946 and the later 40's were still halcyon days. Sure labour costs were increasing but the railroads did and had the moving and the shaking economy wise.
Real criminals like Stuart Saunders were not in full effect yet but something is real fishy about it all.
They got together and complained about being underpaid for postal services over several years and got a fat settlement with Uncle Sam during this time as well.
I simply do not understand the 1946 loss.. how?
Jones1945It would have saved so many people time, including the heads of PRR if the original electrification plan became a fact, the performance of GG1 was so extraordinary compare to post-war steam train like T1,Q2 etc, but I probably wouldn't become a PRR fan since they probably won't spend too much time on new steam engine design.
Part of the difficulty with PRR steam was precisely that they overcapitalized on obsolescent designs -- all those K4s in the late '20s a notable example -- and then indulged in somewhat wacky electric designs analogous to 'standard' wheel arrangements (O1 approximating an E6; P5 a K4; L1 a lollipop, etc.), and then later making some dubious assumptions with the DD2 that was going to be the design model for the various classes for the electrification west of Harrisburg. This was precisely the time that the great convergence between Super-Power and advances in balancing post-Eksergian was coming together, after the Alco diversion into three-cylinder power was over, and PRR experienced this only peripherally through the J1s (and the process of perfecting them all over again that came from using the 'wrong' blueprint sets!)
Electrification of the system was probably the most foresighted thing PRR ever planned and ever did.
That is true, but remember that dieselization was a direct consequence of the 'electric' planning, giving a great deal of the advantage of 11kV wire to Pittsburgh while avoiding the expense -- and I wish it hadn't, but it made sense at the time -- of the full tunnel bypassing Horse Shoe, which at over 9000' would not have been worked with diesels at PRR's traffic density. We have a prospective 'wartime' plan for the engine classes of the first stage of the electrification, which would have followed the general plan of the DD2 with the horsepower classes reflecting use of the better 428A motors, right up to back-to-back eight-powered-axle units (!) for the part of the railroad far more deserving of the advantages of electrification than the politically-favored route between New York and Washington.
Perhaps interesting, I don't think the DD2 classes were intended to make very high speed. There would, however, be the same design "convergence" that led to the T1 and later the 'centipedes' and A-B-A BP-20 locomotives being the equivalent of a GG1; it's possible that some part of the Q2 design was made to match consists assembled in Enola and fired west over the mountains under wire. Problem is that F units are still a better answer all round, don't require massive expensive improvements to the railroad, and have the same advantages to equipment-trust bankers that saw them prescribed for lost-cause NYO&W.
Imagine how awesome it would be a "RR1" hauling a 16 cars consist, running at 141.1mph straight from D.C. to Pittsburgh...
No call for high speed on that run (even if current Amtrak services make it look a bit normal) -- in fact, we were discussing in another thread how definitively B&O was able to destroy PRR's ability to compete in the extension of service between DC and Chicago by utilizing the P&LE for better speed while keeping the excellent dining-car service. I don't think it could be possible to improve the Northern Central for appreciable high-speed gains with more money than PRR could spare from other more significant necessities; the same is probably true of the Port Road route. Meanwhile the Atglen & Susquehanna was no real speedway for that kind of performance, and not optimized for improvement into one, so it would fall to the New Main Line effort to progressively take out all the kinks and kludges that hampered, and in many respects still hamper, the PRR through Philadelphia (think Amtrak 188) and then out to the west via North Philadelphia. And as noted PRR really didn't think so much of passenger revenues to spend All The Money Required on providing great speed through the Allegheny regions.
I still prefer Steam locomotive to Electric locomotive. A new High Speed Main Line between Chicago to Pittsburgh with average speed 90mph+ specially built for Class S1 6100-6109 (using poppet valves and roller bearing side rod ) A route as famous and as sucessful as the Hiawatha is always my dream.
But this is precisely the route that promised those sorts of speeds (and, supposedly, where the T1s produced them on a number of occasions). I am not sure what improvements could be made between Pittsburgh and Crestline, or to allow 100mph speed to within 6 miles or so of the Chicago terminal as was the case for the Hiawathas, but there was track suitable for 112mph with 70" drivers in between...
Now, the S1 was not the right design for the steam service. Paul Kiefer would disagree with you on the necessity for poppet valves; his 120-mph postwar engine shared many of the characteristics of the T1 but had piston valves and Baker gear (and a rightsized firebox, the boiler being nearly common to Niagaras except for the extra length) and of course the PRR itself took out patents on the technology needed for wholesale conversion of type A eight-valve chests to piston valves. Note that PRR optimized their balance by using extremely short stroke (in fact they would have used shorter, but the web in the driver center between mainpin and axle seat fixed the dimension at 26") and this got around the need for 84" drivers to make reasonable high speed. By the time machinery speeds make 84" desirable again you're in the range where reciprocating steam locomotives are no loner preferable.
So the mantle falls on the passenger version of the mechanical turbine, the one Loewy's design patent likely covers. We now know how unlikely this construction would be, but it was certainly enough for Baldwin to filch the idea for its C&O turbines with all the wrong detail design. The killer here was, and is, the same thing that killed the V1 for freight: the water rate went upside-down above about 7000hp at just the time water treatment and deoxygenation became vital necessities. When the largest eight-axle coast-to-coast cistern gives a range less than 130 miles, you lose any real superiority over even early F units.
There are ways to get the water rate down, but these are difficult to package and to run at 8000+hp size. A case could be made for Holcroft-Anderson recompression, but this requires extensive cisterns, pumping power via separate engines, and some system of mechanical draft, with no guarantee that economy can be achieved in many practical PRR operating circumstances -- little real competitive advantage over MU to scale power to need. (And no particular romance to the appearance!)
Jones1945 Another thing amazes me is that the “Gresley double-bolster 8ft 6in bogies” used on their standard coaches(LNER), a 1920s design managed to go as fast as 90mph+ without falling apart, I don’t know how was the ride quality though, but it is not hard to imagine riding a speed boat. :PPRR 2DP5 vs Gresley Bogie
Although it isn't clear from the photograph, the suspension arrangements for the Pennsylvania truck illustrated and the Gresley bogie were the same. Both used coil springs in compression supporting an equalising beam as primary suspension over the axleboxes, and full elliptical leaf springs on a swing bolster as secondary suspension. The Pennsylvania truck had the equalising beam in full view, while it was hidden behind the side frame on the Gresley bogie. The Gresley beam was straight with the coil springs located on steel rods projecting downward held by collars and bearing against internal brackets on the side frame. The bottom ends of these (coil spring) rods can be seen projecting below the frame inboard of the wheels in the photo above.
The Gresley bogie was rated as better than the standard British Railways bogie (based on the LMS design) and was used on dining cars, and on a fleet of electric Commuter trains based on Glasgow in the mid 1960s. The more modern BR B4 and B5 designs provided a better ride still but they only arrived in the mid 1960s.
The LNER steamlined trains, apart from the Gresley Bogie, were purpose designed and had more modern interiors than the "Coronation Scot" which used standard LMS coaches of the period. Of course, the "Coronation Scot" was air conditioned and had only four seats per compartment in first class so West Coast travellers were not "hard done by". But the ride wasn't as good, not just when passing through crossovers at 57mph instead of 20mph...
Peter
This kind of sort of explains things but I can't seem to connect things very well.
The PRR reports record passenger and freight revenues for 1946, revenue exceeds expenditures, they recieved a whopping 17.6% freight rate increase then go on to say there is a loss due to government regulations.
Yet they state they transported more freight and passengers in 1946 than any year and in the same breath say revenues were down 114 million due to the decrease in wartime traffic and strikes.
The T1's are not mentioned by name but they are definitely mentioned in the article.
They recieved 37 high speed 6500 horsepower steam locomotives and tenders to complete an order of 50.
Someone help me out here and tell me what the heck is going on.
Miningman Well at least everybody's thinking here! Overmod--161 mph? Wholeeeeee Makinaw. That's nuts.
Miningman Jones1945-- I like the corruption angle. Powerful men at Pennsy, Baldwin, EMD, NYC, Alco ... lots of interactions, favours, shenanigans and big big $'s on the table. Things were done, of course. In the past Overmod has alluded to actual documentation that may exist by executives at Pennsy stating how to go about making the T1's a hopeless engine.
Miningman I have asked several times regarding the surprising and somewhat suspicious and mysterious loss shown by Pennsy in 1946 and then again in subsequent years in the late '40s. Perhaps they spent too much on Capital purchases. 1946 and the later '40s were still halcyon days. Sure labor costs were increasing but the railroads did and had the moving and the shaking economy wise. I simply do not understand the 1946 loss... how?
("My owner paid $16,640,000 to build us and dumped us all 7 years later", help me!)
Jones1945I heard another rumor about a story of J-3a reached 165mph during a special run to save a kid (rushed to somewhere to buy rare medicine for the kid), I would believe this story if it was 165kmh not mph.
That plot sure sounds familiar...
Great Milwaukee Road action here, and not a bad story, either...
Regards, Ed
Overmod Perhaps interesting, I don't think the DD2 classes were intended to make very high speed. F units are still a better answer all round, don't require massive expensive improvements to the railroad, and have the same advantages to equipment-trust bankers that saw them prescribed for lost-cause NYO&W.
Overmod But this is precisely the route that promised those sorts of speeds (and, supposedly, where the T1s produced them on a number of occasions). I am not sure what improvements could be made between Pittsburgh and Crestline, or to allow 100mph speed to within 6 miles or so of the Chicago terminal as was the case for the Hiawathas, but there was track suitable for 112mph with 70" drivers in between... Now, the S1 was not the right design for the steam service. Paul Kiefer would disagree with you on the necessity for poppet valves; his 120-mph postwar engine shared many of the characteristics of the T1 but had piston valves and Baker gear (and a rightsized firebox, the boiler being nearly common to Niagaras except for the extra length) and of course the PRR itself took out patents on the technology needed for wholesale conversion of type A eight-valve chests to piston valves.
Sorry I think I messed up the format of my post......
M636C The Gresley bogie was rated as better than the standard British Railways bogie (based on the LMS design) and was used on dining cars, and on a fleet of electric Commuter trains based on Glasgow in the mid 1960s. The more modern BR B4 and B5 designs provided a better ride still but they only arrived in the mid 1960s. The LNER steamlined trains, apart from the Gresley Bogie, were purpose designed and had more modern interiors than the "Coronation Scot" which used standard LMS coaches of the period. Of course, the "Coronation Scot" was air conditioned and had only four seats per compartment in first class so West Coast travellers were not "hard done by". But the ride wasn't as good, not just when passing through crossovers at 57mph instead of 20mph... Peter
As to the 'follow-ons' for the electric district, the answer is actually historical (and verifiable from a variety of sources) -- rectifier/Ignitron locomotives using diesel-style bogies with relatively low wheels and independent-axle traction motor drive (with DC, not universal, motors). This was clear on PRR by the time of the 'experimental' classes ordered in the early Fifties, and culminating in the vacuum-cleaner E44s ordered in the early Sixties. All these predominantly for freight, of course; passenger needs were covered by the wartime GG1s (in what might be considered a reprise of too many K4s in the Twenties) so no New Haven 'Jet' analogues, but that's what you would have seen had the passenger electrification been taken up at a reasonable point after the War.
In parallel, the evolution of the V1 into what became Jawn Henry is an interesting and valuable thing to observe. The 4-8-0+4-8-0 became a span-bolstered C-C+C-C, which turned out to roast a set of hexapole motors beyond reasonable repair in just a few years of testing. How much of that was attributable to drop damage in the main generators and how much of that was overloading may never be thoroughly known.
Anyway, as I mentioned before, the Federal government didn’t want to see the development of the nation’s Aerospace industry slowed down by High speed rail, thus we have what we got today.
OvermodIn parallel, the evolution of the V1 into what became Jawn Henry is an interesting and valuable thing to observe. The 4-8-0+4-8-0 became a span-bolstered C-C+C-C, which turned out to roast a set of hexapole motors beyond reasonable repair in just a few years of testing. How much of that was attributable to drop damage in the main generators and how much of that was overloading may never be thoroughly known.
When I was much younger, I want to own a model of C&O Chessie. I admit I am obsessed with big machines.
V1, or Jawn Henry both have at least one thing in common, they are too big! Jawn Henry was even bigger than S1. I can understand that S1 was *probably built for the 39 World Fair to represent America (without PRR's stockholder's approval), so it was unnecessarily massive, heavy and *expensive.
Overmod the problem being that few if any people designing then seemed to understand the profound split in costs and infrastructure involved in operation to 125mph as opposed to 150 or higher. The French figured this out, right down to the required power infrastructure, and so they've gone from success to success and have pervasive true high-speed rail
Overmodlook at the 'mission' difference between the S1 and T1 spec, and tell me realistically what sort of passenger consist needs to weigh 1000t in a single train that fits real-world platforms, especially from the Forties on as demand for multiple sections starts falling away.
Overmod If you want a reasonable starting point for a PRR "next-generation M1" 4-8-4, I would advocate starting with a "late" C&NW zeppelin H, with or without duplexing, and put a double Belpaire boiler on it
The 1943 proposal is likely a version of the infamous 'Triplex' which led to so much controversy between Carleton Steins and Raymond Loewy. This is amusingly associated with the secret crash development program at Baldwin to produce the C&O M1 turbines 'outside' Steins' patents before PRR made turbines of its own ... there is loving, if potentially highly one-sided documentation of this in some of H.T. Cover's correspondence at the Hagley. Some of the specific points of failure in the M1 design are more comprehensible when you know how they came about...
The spec for the T1 was dialed back to 880 tons at 100mph, a far more reasonable number for a locomotive with four-coupled engines especially in light of the lack of boosters for starting (you will remember that one of the prototype T1s was built with a booster, but had it removed in spite of the ghastly unloading problem created by the long equalizing beam between the engines, which was thankfully purged from the production suspension). This is just about platform limit length of high-speed lightweight coaches for something like a Trail Blazer. There is a certain optimism in designing Pullman trains for 100mph or faster operation over much of PRR where a considerable amount of high speed would involve projection out of one's berth, a consideration that factors amusingly into some of the anecdotes about high-speed running with the T1s.
It's not that Jawn was "too big", it was that he lacked meaningful horsepower for his size, and that characteristics of his electrical transmission made some of Baldwin's claims (the 65mph speed in particular) little better than ill-qualified lies. Something burned out all those motors in no more than three years of testing, and trust me, it's hard to kill a hexapole even intentionally.
Note that a steam-turbine electric today requires a practical continuous horsepower of 8800 or greater just to remain competitive with conventional diesel power, even as it combines all the inefficiencies of mobile Rankine-cycle with water as the working fluid with electrical conversion and drive using truck-mounted motors. It's possible there will be niches for such a thing; I am helping develop them. But it's not very effective as a one-for-one replacement for a class A locomotive, or a properly improved Y-class either.
Boeing as you may know was involved heavily in transit car manufacture at one point (out of the Vertol helicopter plant in suburban Philadelphia). I toured the plant as the first LRVs were coming off the line, and had great hopes for how the future would be. Likewise United Aircraft (which was Sikorski) voluntarily perfected Allan Cripe's train as a showcase for PT6 turboshafts and then made a reasonable show of promoting it -- the 1967 proposal to NYC with detailed timing calculations made by computer is a dramatic positive example. Of course Bombardier the snowmobile company became involved in aircraft production as well as diversifying into high-speed rail production, but that's not really the same. The real problem is that, as for TGV with LGV, new routes optimized for very high speed are required to make true HSR practical. Where that's not the case, it's far better to build to 110mph or 125mph specs, where the costs are not yet ridiculous or weight-saving quite so dramatically required, as in Britain where the HSTs were successful but the APTs (for a nominal top-end advantage of no more than about 25mph) were certainly not.
And as done to death on various Trains fora, there are comparatively few services outside identifiable (and fundable) corridor services where 125mph service enhancements will pay their way.
Interesting thread with many branch lines!
Anyone have any thoughts on how record setting freight and passenger transport translates into a loss when the year previous ( which was surpassed) shows a $49 million profit ...aaannnnd not only that but they enjoyed their recieved 17.6% increase in freight rates!
Everything in the article seems to conflict.
If you recieved a whopping 17.6% hourly pay increase on top of a banner year of hours worked that even beat your last extremely profitable banner year and revenues exceeded expense, but you lost all the money and dipped into last years, then I can only conclude you went to the Casino ... a lot!
It has been my understanding that Pennsy had a sort of military structure, no one at each lower level would dream of questioning those at the next level. I think this makes it easier for secrets and info withheld level to level.
Although some here have lamented the PRR for not preserving the S1, they actually did a decent job of preserving examples of their better known, bread and butter steam locomotives.
Interesting! I guess Gresley Bogie and PRR 2D P5 truck both doesn’t have shock absorber, am I right?
As I said earlier, both these designs had full elliptical leaf springs for the secondary suspension. These are the sort of leaf springs seen on the British LMS three axle bogie above the axleboxes, but combined as an inverted set pivoted to an upright set at each end of the leaves.
A feature of these springs is that the leaves move relative to eachother as the spring compresses or expands and this provides a built in damping that avoids oscillation.
At the time these trucks were designed, automotive style shock absorbers were not generally available, and automotive shock absorbers of suitable capacity only arrived in the 1950s.
If you look at USA streamliners, most prewar trains had full elliptical secondary springing, but post war trains had coil secondary springs with some form of damping added.
It is generally agreed that the PRR S1 and UPRR "Big Boy" are generally the same size overall, despite the UP locomotive having twice as many coupled axles.
Looking at the boiler barrel as something to base a comparison upon, the dimensions were:
S1 100" diameter by 21' 11" long
4000 106" diameter by 22' long
So unsurprisingly, the 4000 has a bigger boiler, but not significantly longer.
I'll have to think about the fireboxes since the arrangements are so different...
Something to add about PRR's financial status in 1946...
IIRC, Paul North posted some PRR ad's from the late WW2 time frame about having to defer maintenance on their track to to prioritizing wartime traffic over maintenance. At the same time the federal government forced the PRR to declare the "savings" from not maintaining their track and then taxing that as income, which was then subject to the high wartime tax rates.
Well thank you for that erikem. Wow that's some kind of twisted up thinking on the government's part.
Overmod The spec for the T1 was dialed back to 880 tons at 100mph, a far more reasonable number for a locomotive with four-coupled engines especially in light of the lack of boosters for starting (you will remember that one of the prototype T1s was built with a booster, but had it removed in spite of the ghastly unloading problem created by the long equalizing beam between the engines, which was thankfully purged from the production suspension).
I didn’t know that the booster was removed from 6111, could you specify the detail of the ghastly unloading problem created by the long equalizing beam between the engines? I tried to search “steam engine unloading problem” on the web but it seems I found the wrong thing. I know the equalizing beam between the 2nd set of and the 3rd set of the driver was removed from the production batch, but I don’t know about how a booster plus the equalizing beam affected the performance of 6111. By the way, if one of the unofficial goals to develop T1 was to outperform Diesel like the NYC Niagara 4-8-4 which successfully achieved, using a booster would at least increase the average annual maintained cost and average annual fuel cost as well.
Miningman Interesting thread with many branch lines! If you recieved a whopping 17.6% hourly pay increase on top of a banner year of hours worked that even beat your last extremely profitable banner year and revenues exceeded expense, but you lost all the money and dipped into last years, then I can only conclude you went to the Casino ... a lot! It has been my understanding that Pennsy had a sort of military structure, no one at each lower level would dream of questioning those at the next level. I think this makes it easier for secrets and info withheld level to level.
I bet 70 years ago when the concept of transparency and Media's supervision were not a daily thing, it was a completely different world compared to nowadays. (recommended thread: Jim Crow laws & railroads ). The military structure thing you mentioned in Pennsy makes it more difficult to find the truth today. If the Head of PRR (or other Class I railroads) did cheating or other shady things, I believe it is a mission impossible to reveal the truth without professional investigation, but many people involved had already passed away, not many railway enthusiasts have that amount of resource and time to find the truth. But I think it is a good start to at least raising the question.
Miningman Well thank you for that erikem. Wow that's some kind of twisted up thinking on the government's part.
If that was the best a government can do to a company which contributed so much to win the war, that was really messed up.By the way, I wish people won't forget that she helped to win the war too:
M636C It is generally agreed that the PRR S1 and UPRR "Big Boy" are generally the same sizes overall, despite the UP locomotive having twice as many coupled axles.
It is generally agreed that the PRR S1 and UPRR "Big Boy" are generally the same sizes overall, despite the UP locomotive having twice as many coupled axles.
M636C but post war trains had coil secondary springs with some form of damping added.
but post war trains had coil secondary springs with some form of damping added.
Post war train truck in US and UK, Top: Commonwealth bogie (UK), Bottom: GSC 41-N-11 Passenger Truck (US)
... could you specific the detail of the ghastly unloading problem created by the long equalizing beam between the engines? I tired to search “steam engine unloading problem” on the web but it seems I found the wrong thing. I know the equalizing beam between the 2nd set of and the 3rd set of driver was removed from the production batch, but I don’t know about how a booster plus the equalizing beam affected the performance of 6111.
The two are really separate issues; I only mentioned them together in the context of problems affecting slipping in the evolution of the T1 design.
Remember that the T1 started with a somewhat ridiculously high FA, and was subsequently dialed even higher by the equalization changes; all this while the N&W J stayed ridiculously low. In other words PRR and Baldwin recognized there would be a price for short-wheelbase duplexing, and expected that the increase in nominal wheel load on driver groups would address it -- the physics did not match their expectations, and one of the things the T1 Trust modeling will find out is the extent of that.
The purpose of a booster on a locomotive of this kind can be thought of as providing an 'additional coupled axle' that at low speed can use the boiler-generated steam efficiently where the main engine(s) can't. They convert a Hudson briefly into a Mountain where starting a relatively long, heavy train is concerned, but when disengaged have no real effect on high-speed running (there is additional mass in the trailing truck, and some addition of unsprung mass on the rear trailing axle, but no unbalanced force in any plane from rotation, as there is with 'auxiliary engines' with rods).
Unsurprisingly, the NYC espoused the things, and perhaps also unsurprisingly PRR found reasons not to support anything the 'green team' was connected with. But as Staufer noted, by the time the Niagara design came to fruition there was no booster, and he noted famously that it was needed 'about as much as a Christmas tree sticking out of the stack' as far as 'starting any load it could pull' was concerned.
The issue at hand is different: whether the additional smooth and gear-enhanced traction provided back at a trailing truck would solve or at least ameliorate the low-speed slipping issues with four-coupled duplexes starting a train over typical yard trackage, or accelerating with short stroke to the 35mph or so where the T1's began to produce real acceleration. This would seem an ideal use even for something as simple as a Franklin E-2, but there's also a degree of 'where's my big savings?' both in first cost and maintenance if the booster only provides "equivalent" slip performance to a comparable 4-8-4. (And if there were problems getting PRR to use front-end throttles and poppet gear effectively, imagine the fun with warming up, engaging, and disengaging boosters with no cutoff adjustment...)
Meanwhile, the original Baldwin design provided for the T1 'thought' that all the drivers in both engines should be equalized together, which required some cleverness to get past the cylinder block for the rear engine. Their solution was the long pivoted beam on the prototypes. One effect of this was pronounced unloading of the forward engine under any particular load. Analysis of the suspension revealed that (no particular surprise) it was better to divide the suspension in the middle of the 'driver wheelbase' and tie off the equalization with helical springs and snubbing (which is choosing the spring rates so the various resonance frequencies are highly out of phase and the system as a whole tends to self-damp - this was a design principle on the GG1s but was later removed). By 1947 all this had been repeatedly refined (there are many noted drawing revisions on the equalization by then!) and things had been perfected about as far as they could be without actual damping via shock absorption.
One big advantage that came into postwar truck design was the use of 'silentbloc' rubber bushings at contact points and joints. The French in particular made heavy use of this (and I think it was instrumental in achieving some of the contemporary high speeds reported for the equipment as early as the Fifties). If you look at the two truck designs you provide, note the radius rods and shock absorbers required especially for outside-swing-hanger designs; I believe John White has a section on proper postwar design in The American Passenger Car (vol.2). More modern designs have much more emphasis on low unsprung mass and controlled degrees of freedom, but still require controlled damping of shocks and other running forces.
What's the source for the streamlined-duplex 'cut' you provided? That looks like something a British enthusiast would provide for a C1a using an auxiliary and perhaps corridor tender instead of track pans; we made very little use of that kind of deep angle cab even with vestibule, and the NYC cabs that had vestibules (the Niagara and A2a Berk important examples) had them up near deck height. Is there a story associated with the picture, or more explanation of its origins? By the way, if one of the unofficial goal to develop T1 was to outperform Diesel like the NYC Niagara 4-8-4 which successfully achieved, using a booster would at least increase the average annual maintained cost and average annual fuel cost as well.[/quote]
To revert to the original request, here are a couple of references:
Loco Profile 24 "Pennsylvania Duplexii" by Brian Reed Profile Publications Windsor UK, 1972. Brian Reed was a locomotive design engineer with the North British Llocomotive Company.
"Rekord Lokomotiven" by Wilhelm Reuter, Motorbuch Verlag Stuttgart 1978 pp 303 to 315, chapter title "The Big Engine".
I have more information regarding the 1937 test run of the Coronation Scot and its description mentioned by Overmod.
There are three separate descriptions of the entry to Crewe in Cecil J Allen's "British Pacific Locomotives" from Ian Allen in 1962. My first edition has the price "65 shillings" pencilled in the back. The 1937 run is covered on pages 137 to 139.
R.A.Riddles, later credited with the design of the BR Standard locomotives, was riding the locomotive.
Part of his description reads:
"Spectators from Crewe coming into view along the lineside; and the train still hurtling at 114 miles an hour. On went the brakes, off the regulator but on we sailed, flames streaming from the tortured brake blocks.... We were still doing 60 to 70 miles an hour when we spotted the platform signal. The crockery in the dining car crashed. Down we came to 52 mph through the curve, with the engine riding like the great lady she is. There wasn't a thing we could do but hold on and let her take it. And take it she did; past a sea of pallid faces on the platform we ground to a dead stand, safe and sound and still on the rails."
Allen's own description is similar but less colourful. He did mention that two cast iron rail chairs in the curves had fractured...
LMS Vice President Sir Ernest Lemon said, at the press lunch:
"Of course, gentlemen, you will realise that we shan't need to do this kind of thing on every trip of the "Coronation Scot"; we were coming in a little faster than we shall have to do in the ordinary course..."
OvermodMeanwhile, the original Baldwin design provided for the T1 'thought' that all the drivers in both engines should be equalized together, which required some cleverness to get past the cylinder block for the rear engine. Their solution was the long pivoted beam on the prototypes.
OvermodOne big advantage that came into postwar truck design was the use of 'silentbloc' rubber bushings at contact points and joints. The French in particular made heavy use of this (and I think it was instrumental in achieving some of the contemporary high speeds reported for the equipment as early as the Fifties).
OvermodWhat's the source for the streamlined-duplex 'cut' you provided? That looks like something a British enthusiast would provide for a C1a using an auxiliary and perhaps corridor tender instead of track pans; we made very little use of that kind of deep angle cab even with vestibule, and the NYC cabs that had vestibules (the Niagara and A2a Berk important examples) had them up near deck height. Is there a story associated with the picture, or more explanation of its origins?
M636C To revert to the original request, here are a couple of references: Loco Profile 24 "Pennsylvania Duplexii" by Brian Reed Profile Publications Windsor UK, 1972. Brian Reed was a locomotive design engineer with the North British Llocomotive Company. "Rekord Lokomotiven" by Wilhelm Reuter, Motorbuch Verlag Stuttgart 1978 pp 303 to 315, chapter title "The Big Engine". Peter
Thank you very much, Peter. Those are some publishment form 70s, I wonder if it is still possible for me to find them. I really want to read them, If our forum members own these publishment and willing to share with me, please kindly pm me! Thank you very much!!
(Edit: I found a copy on the web of Loco Profile 24, but I am not sure if full name of "Rekord Lokomotiven" by Wilhelm Reuter = "Rekord Lokomotiven - Die schnellesten der Schiene 1848-1950", I can found plenty of them on amazon but I can't read German......
M636C ......Allen's own description is similar but less colourful. He did mention that two cast iron rail chairs in the curves had fractured... LMS Vice President Sir Ernest Lemon said, at the press lunch: "Of course, gentlemen, you will realise that we shan't need to do this kind of thing on every trip of the "Coronation Scot"; we were coming in a little faster than we shall have to do in the ordinary course..."
......Allen's own description is similar but less colourful. He did mention that two cast iron rail chairs in the curves had fractured...
It always amazes me that the weight of PRR S1 without the tender was 304 short tons, PRR T1 was 251 short tons while LMS The Coronation Class was only 121 short tons!
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