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PRR Duplexes and Experimental Engines ( S1, S2, T1, Q1, V1 etc.)

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Posted by Sara T on Monday, May 3, 2021 8:14 PM

BaldACDC that's very interesting for all the forum's community. Never write a pm about it, we are all tense to get to know the latest news about it.

What make is that phone of Overmod? What is your's? Where did you buy it, what did it cost and where is it where you use it? And why? You know, some people always have important things to tell, even if they have nothing to say. And: it's all so directly connected with the PRR Duplex types, your phone surely is one duplex too. You should go around and set up everybody's phone because there is no-one like you to know how it's done. 

Great stuff, keep on forever and confiscate this thread for the best of everybody.

Ah, we admire you, Oldy Baldy, thank you, oh thank you forever, ..(deleted)

Pirate!

 

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Posted by Overmod on Tuesday, May 4, 2021 12:57 AM

BaltACD
That has to be some sort of interaction between the settings on your phone, the settings on your phone's browser and the Kalmbach forum settings. I don't have the answer.

There really isn't one.  As was explained to me a number of years ago, Kalmbach made a great push into developing site features especially for phones (and then tablets and such) when the iPhone took off after 2007 and 'handheld devices' looked like the Next Big Thing for how target communities were going to be accessing Kalmbach.  

Then this stopped being a priority, and then became actively unsupported.  The money went into lots of ads on devices with more screen real estate to display them, and common features that would run effectively on every kind of device.  It was in the context of the failure of phone access to profile information or PMs that I received the reply that 'there wasn't enough return on investment for Kalmbach to spend tech money fixing free resources' (they didn't say, but I understood the development budget was on more and better dancing ad serving and 'marketing ingenuity')

To my knowledge the 'reset problem' only occurs with mobile connection -- my suspicion is that they don't store the page in the local client on a phone, so when they do something that refreshes the Internet page, it blanks or 'initializes' the text window.

I expect stage 3 of the trains.com site revisions at Kalmbach to fix it, if for no other reason that it will return mobile devices to using some kind of 'supported' code even if the new site isn't "designed for mobile".  I don't think I will object to that even if navigating or reading content on small screens is inconvenient as a result.  

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Posted by Overmod on Tuesday, May 4, 2021 1:06 AM

M636C
I'm surprised that nobody appears to have commented on this post.

I'm surprised that I am evidently one of the nobodies that has not commented.  Where was I when this was posted?  Now I have to get hold of a copy. look it over, and see what we have.

It certainly seems right for the 1944 version.  I copied side and end elevations from material at the Hagley, and I suspect many additional drawings were made before the V1 was formally abandoned at PRR.

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Posted by Jones1945 on Tuesday, May 4, 2021 10:58 AM

Overmod
It certainly seems right for the 1944 version.  I copied side and end elevations from material at the Hagley, and I suspect many additional drawings were made before the V1 was formally abandoned at PRR.

I have absolutely no idea how many versions of the V1 were designed. I thought it was the "finalized" version of V1, even though it doesn't look like something that could have been called "Triplex". I note Hagley uploaded some new old pics to their amazing digital archive recently, I can only hope that they will upload all files related to the PRR V1 there.

For an engine that gigantic, it wasn't easy for any designer to create a standout streamlining for it. The 44 version looks like a huge whale get stranded on the beach. 

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Posted by Overmod on Wednesday, May 5, 2021 9:01 AM

My reconstruction of the 'turbine research' so far is roughly as follows:

'Triplex' was originally a Loewy idea from the mid-'30s, partly related to questions of cab-forward running with coal firing.  He divided the "locomotive" into three parts, a bit like a Garratt's arrangement, with the boiler and engine one unit, the fuel bunker another, the water a third.  As I recall Loewy's discussion (it can be found at the Hagley) these could be coupled in any order, subject to a couple of relatively obvious constraints like keeping a stoker worm between coal fuel and the firing table inside the firebox.

Steins adopted the term for any locomotive with this general arrangement, apparently extending it to having drive wheels under various points, which was not as I recall in Loewy's scheme.  In Steins' original mechanical-turbine patent there are, in fact, large drivers visible as in the S2; this gets changed to the familiar "4-8-4-8" rather quickly in the following patent (look at the filing dates, not the issue dates).

MEANWHILE along comes the Steamotive development, which became 'mature' as a technology around the end of 1936.  Steins does a 'triplex' arrangement for this roughly comparable to the evolving V1, but now optimized to the oil-fired electric-drive system.  The Steamotive idea starts to show its issues around 1940, as Duffy claims; the likely thing being in part the need for oil fuel (with low vanadium, etc) which was by then recognized to be much more efficiently run in diesels on an Eastern road like PRR that is heavily coal-centric.

What gets greenlighted in 1944, notably for the same heavy and high-speed service as the Q2s, is the mechanical turbine with two four-driver-axle underframes separated by the firebox, and a modified Q2 boiler facing backward.  The 8000 nominal hp reflects the Q2 test-plant results extrapolated to the more efficient (at road speed) turbine drive.

This gets cancelled PDQ when the war winds down because PRR has no place for high speed at the water rate needed for 8000hp freight power -- that being the specific issue raised, although explained slightly differently in the decision record.  This is little different from the real reasons the Q2s were no more 'successful' than the revised J1as with lower nominal maintenance cost and fewer expensive quirks.

The V1 gets a renewed lease on life in the late '40s -- largely put together from surviving records.  We have the famous design patent.  It is possible that some of this is intended to 'compete' with -- or establish patent priority over -- the Baldwin turbo electric design from 1945 (developed in somewhat suspicious haste and secrecy, in the PRR view) that culminated in the Chessie turbines.  Note the famous 'design' patent for streamlining from 1947 that can apply only to a V1 chassis; this comes right at the time the Bowes drive proposal claims to address both the water rate and effective 85mph speed restriction of the 1944 design. It almost immediately founders in the whole complex of increasing costs and better opportunity utility of diesel power -- the thing that killed the S2 program and by extension any R development, but that's another story.

Whether or not the "revised V1" was partly intended to help N&W get something comparable to the C&O M-1s for 'the prospective race to Cincinnati' I don't know -- but it might be plausible; like the reason for putting expensive Timken rods on five As.  Certainly by 1950 what N&W is building is all-wheel-electric drive and freight only; the water tube chain-grate boiler comes sometime later, and of course what actually winds up getting built (with all the length and half the power and effective speed) we know.

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Posted by Jones1945 on Thursday, May 6, 2021 8:47 AM

Thank you very much, Overmod.

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Posted by Jones1945 on Tuesday, May 11, 2021 6:43 AM

Rendering of PRR "Triplex", patented by Carleton K. Steins from PRR in 1944, streamlining was probably designed by Raymond Loewy. Note the position of the front cylinder and wheel arrangement in the rendering is different from the patent drawing, let alone other design details including the truck design of the coal tender.

In the patent, it is basically a cab forward PRR Q1 with a reversed boiler, attached to a coal tender and water tender. I don't understand the advantage and selling point of such a design for PRR's system, like how such a design could "attain increased pulling power with minimization of slippage of the drivers incident to starting; to facilitate travel of track curves at high speeds without attendant unbalance".

The rendering is quite attractive though, it gives conventional reciprocating steam locomotive a modern look.

 

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Posted by Overmod on Tuesday, May 11, 2021 8:56 AM

Jones1945
...how such a design could "attain increased pulling power with minimization of slippage of the drivers incident to starting..."

An observed issue is weight transfer at starting, where the drawbar is usually higher than the axle centers.  This unloads the front drivers.  Moving the coal load out of the trailing tonnage reduces that; now that it is in buff it can be used to increase 'downforce' on what is now the firebox end of the frame, and the drawbar at the 'trailing' end can now be made lower if desired

 

...to facilitate travel of track curves at high speeds without attendant unbalance".

This could be a couple of things, perhaps the most significant of which is that the frame of the heavy 'locomotive' is no longer used for primary guiding; the 6 to 8 axles under the coal bunker now do this, with much improved lateral than a typical engine truck can provide and a longer time to effect steering.  

The other key difficulty is steering the rigid wheelbase, which in a normal design puts stress on the leading coupled flanges.  This design steers the flanges much better, and in fact now provides a separate 'engine truck' that can be optimized to further reduce leading-flange impact and wear.

At least such were some of the advantages claimed.

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Posted by Jones1945 on Wednesday, May 12, 2021 6:41 AM

Thank you for the explanation, Overmod. 

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Posted by djlivus on Wednesday, June 2, 2021 12:06 PM
In an article about turbine locomotives M. C. Duffy sustains that the turbo electric V1 was one unit locomotive, without separate tender, "an exceptionally large tank-engine", "an elongated version of M1 class locomotive component". Did the project evolved from a one unit +tender configuration (visible in Stein patent) to a one unit without separate tender? In the photo above it seems to be no separate tender.
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Posted by Overmod on Friday, June 4, 2021 9:10 AM

This sounds almost as if he's conflating some version of the V1 with something like Bulleid's Leader (which was billed as a replacement for an M tank).

It is possible that an early version of a turboelectric locomotive (I.e. pre-Steamotive or Triplex) could have involved an M1 boiler instead of 'something larger' and have been designed as a large single unit.  I have not seen any evidence of this, but I don't claim to know Mr. Duffy's sources -- I should add that I joined the Newcomen Society to get access to some of his articles (e.g. on the Velox locomotive) so I do not and will not disparage what you have read.

Note that any turbo electric locomotive of a size of interest to PRR would involve a significantly bigger, and probably more modern, boiler than an M1's.  At this same general time, the duplex 'successor' to the Ms (which you could think of as 5/4ths an M1a) was being developed -- this of course being the Q1 with all its fascinating detail design.  The point I want you to be thinking about going forward is not so much the horsepower but the associated water rate for a noncondensing locomotive.

By the time a 'buildable' version of the V1 is design-frozen (in 1944) it is mechanical (without the conversion losses of turboelectric drive) and uses a slightly-modified Q2 boiler (remember the HP achieved by the Q2 on the test plant) to achieve the nominal 8000hp -- BUT look at the water rate associated - necessarily associated - with that horsepower out of any turbine drive.  There is no way to package the necessary water anywhere on a single unit using a nose bunker of adequate size followed by that boiler - hence the sensible adoption of a water-only tender as part of the 'triplex' arrangement according to Steins.

Presumably for wartime work (e.g. had Operation Majestic been necessary at full scale) the V1s could be operated with multiple tenders, but I have not seen any design confirmation and indeed the V1 was cancelled very soon postwar explicitly on water-rate concerns -- as far as I remember, before any comparative data on F-units had been obtained.  (There is certainly plenty of discussion later on water saving by EMDs with adequate fuel to run across five divisions)

Now if you remember your PRR motive-power brochures you'll remember that PRR claimed to be working on a "9000hp" turbine.  Even with the claimed economy of the Steamotive cycle this would have been a stretch; most notably there is no possibility of a single locomotive having anywhere near the condenser to accomplish 9000hp (see the drawing provided earlier) let alone something on a common rigid frame like the N&W TE-1 as evolved.

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Posted by Jones1945 on Saturday, June 5, 2021 1:40 PM

Overmod
It is possible that an early version of a turboelectric locomotive (I.e. pre-Steamotive or Triplex) could have involved an M1 boiler instead of 'something larger' and have been designed as a large single unit.

That reminds me of the drawing of the patent:

https://patents.google.com/patent/US2424676A/en?q=Turbine+locomotive&before=priority:19451231&after=priority:19450101

 

 

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Posted by Overmod on Sunday, June 6, 2021 1:01 AM

This is interesting in that it represents just what Duffy describes, but with mechanical drive in Steins' wheel arrangement.

Alben is a Westinghouse guy (this is why so many of his patents show up as assigned to CBS!) and they are turbine and final drive guys -- look carefully as you read and note he's not claiming the "4-8-4-8" arrangement as part of his claims, only as a preferred embodiment.

Note how the patent specifically refers to fuel and water carried on the single unit (presumably as pictured, complete with small turret cab).  With the boiler dimensions pictured this would be a difficult job.

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Posted by Overmod on Monday, June 14, 2021 6:20 PM

MEANWHILE it turns out that GE was apparently in active development of a 6700hp turboelectric using pulverized coal firing, which progressed to the point in 1947 that a test boiler was constructed; cost per mile was calculated at over twice that of 'comparable' diesels and the project was abruptly terminated after Deasy's replacement by you-know-who.

I know nothing about the technical details of this proposal.  Who does?

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Posted by djlivus on Wednesday, June 16, 2021 10:25 AM

That is a very interesting information. There are any drawings about it? It was ordered by PRR?

A little out of topic, the only giant diesel locomotives from cab unit age were Baldwin Centipede at about 270 tonnes and 6000HP Baldwin prototype with 8 diesel engiens at 310 tonnes. I know also John  Yellot 3750 hp gas turbine locomotive project at 288 tonnes, 28 m long, of course not diesel. There were any other GIANT diesel cab locomotives projects?

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Posted by Overmod on Wednesday, June 16, 2021 12:06 PM

djlivus
That is a very interesting information. There are any drawings about it?

Highly likely there are.  This is out of Chris Baer's chronology of the PRR for 1947, and he is with the Hagley Museum in Delaware that has Cover's and the other surviving files of the contemporary PRR motive-power department.

The Essl locomotive really, really ought to have been 'proceeded with' but (reading between the lines) the el-cheapo capitalists controlling the Westinghouse/Baldwin takeover were either not interested in or incompetent at financing the very expensive first cost of fully-'populated' Essl locomotives (in favor of cheaper truss-carbody trucked designs using big slow-turning tugboat-derived engines).  In my opinion the sensible design change... which contemporary Bakdwin build quality probably would NOT have delivered... would be to have the modular gensets feed some common bus architecture to the TMs rather than have all the fun of governing a full 750hp swing per individual axle... but things did not get that far before the experiment turned comical by putting tugboat engines in a 120mph chassis, connecting everything with hoses and driving it with combinations of cheap V-belts, and running the wiring safely under the floor out of sight with no drains.

Let's all go to live in Ground Fault City, shall we?  People trying to run the production PRR Centipedes sure did... not as bad as their turbine-bound C&O counterparts, of course, but for similar reasons from the same nitwits...

Yellott's BCR was a scam.  He was hoping that evolved technology (Hilsch tubes, etc.) would eventually solve the ash problems going into the gas turbine.  Of course the least investigation into the mass flow and gas path involved will tell you of course there isn't a cost-effective way to do that... but Yellott thought he had 'live ones' in the various railroads that wanted to Burn Coal Without Steam, and he pulled the scam off for a surprisingly long time.

The railroad argument, when it came, was surprisingly intelligent: they argued that their support of BCR was only for proof of concept -- the locomotive manufacturers being the people to actually benefit from coal-turbine technology, and therefore BCR's ongoing rather expensive subsidy ought to be taken up by Baldwin, Alco, Westinghouse et al. rather than individual railroad handouts.  Unsurprisingly the whole thing *** down promptly when the free money stopped -- and a good thing too; there was and is no practical way to remove EPA prrmissible levels of ash from the exhaust, let alone the other 'usual-suspects' pollutants...

Of the railroads involved, it was UP that saw the most to gain (remember crappy subbituminous blown over the grates? here's the dream application for it!) and this by a commodius circus or recirculation we found ourselves watching the fascinating science project that was UP 80 (later 8080).  Interestingly perhaps, to this day UP corporate is tighter than a clam refusing to release any material it has about the thing...

The 'answer' to your question about giant engines has two parts.  The first of course is the Erie-built sold to KCS as an '8000hp passenger locomotive' (in the era when it was still uncertain about firemen on diesel 'units') and the CGW numbering of certain F units to give a 'whole locomotive' with a single primary road number which had comparable output.  The other is the pre-'double diesel' UP practice of carrying Dilworth's building-block MU scheme to almost ridiculous extremes... once you owned all the expensive little 1500 to 1750hp 'building blocks', of course... which was to lash up 17 or so and tie 'em to a suitable bunch of cars.

If you have not read Kiefer's 1947 report on motive power (it can be read online at Hathitrust) he has some very good comments about the builder options in late 1946, before 'the market' shook things out a bit.

If you want a fun thing to chase, look up the Ingalls Shipbuilding 2000hp passenger unit... for the pre-1947-ICC-order world where you could operate a 120+mph set of locomotives at 120+mph as long as you saw fit...

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Posted by djlivus on Thursday, June 17, 2021 7:31 AM

Thank you very much for this very complete answer!

In Kiefer 1947 report there is a stuning photo with a stunning 5000 hp electric "2-C-C-2  locomotive project intended for NYC line.

There is also a mention about a 3000 HP AT&Santa Fe gas turbine locomotive intended for passenger trains. Any more info (weight, lenght etc) or drawings about this project?

I also think it is a pitty Essl 6000hp locomotive project hasn't materialized. It would have been maybe one of the greatest diesels. An awesome design if not riveted. For me a giant locomotive is only a single unit locomotive, not a multiple units At least for diesel it was only a convention that 3 units coupled togheter are a single locomotive. Anyway, visually such a lash up lacks the unity, we don t perceive it as a single locomotive.

 

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Posted by Overmod on Thursday, June 17, 2021 9:09 AM

It took quite a bit of work to get to the story behind that electric, and why I think it was a full-size plate, larger than any other picture in the report, but not a line about it was in the text.

I am winging it a bit here, but there was serious consideration to electrifying a substantial part of the Water Level Route... not where you or I would expect it, including the poky third-rail section from GCT to Harmon, but west of Albany.  This both eliminating the issues with West Albany hill and providing much easier sustained high speed without engine changes to the west.  Interestingly I don't recall any proposal to wire the Hudson River part which I think was still 4 tracks with tight clearances and many limiting curves; I suspect ultimately that section would have come to be be wired on the overhead system BUT leaving the third-rail arrangement on the south end, perhaps all the way to Harmon, as it would be prohibitive to try to wire the Park Avenue tunnel and GCT approaches. 

What killed it was the same thing that definitively killed the Harrisburg to Pittsburgh electrification: the advent of practical diesel-electrics.

I am hazy on whether the ATSF 3000hp turbine was actually built as such or whether it developed into the Baldwin-Westinghouse 'Blue Goose' prototype.  I seem to remember two different carbodies using that same four-B-truck arrangement (standardizing on multiples of a B truck was a hot idea in the late '40s -- have you seen the drawing of a PRR sharknose electric with EIGHT B trucks under it?) and the thing that comes to mind regarding it is Allis-Chalmers as the turbine developers.  Perhaps very similar in internal arrangement to the '3000kW' version of this:

http://blog.modernmechanix.com/mobile-power-plant/

or see US patent 2575242.

Here's the original Alco-GE gas turbine (of 1949) which of course would go on to greater acceptance...

http://aliennard.free.fr/Up2_e.htm

The great Thing That Never Was has to be mentioned here; it was supposed to revolutionize practical use of a gas-turbine expander without the temperature issues and compressor losses.  That is the free-piston combustor (which I personally think was a major reason for the Lima-Hamilton merger and then the Baldwin-Lima-Hamilton merger...) -- far superior to anything done with practical compression-ignition motors in the late '40s.

The operating idea as it came to Hamilton Engine was via the German development of bounce-piston air compressors for submarines in the 1930s.  If you arrange two "diesel" pistons back-to-back you can fire them very quickly without any concerns for rod bearings, component acceleration etc. and generate a large volume of pressure exhaust at high (but not alloy-damaging) temperature, which can then be used in a simple-to-maintain turbine expander.  It is easy to arrange nearly any number of gas generators on a common frame, giving better part-load economy than the Baldwin Essl (or any other design of that era using practical Diesel engines with marketable cost-effective construction) at light enough weight that very high power density, easily comparable to the best steam designs 'in a single unit' could be promised.

Baldwin dropped the ball when Westinghouse decided them on exiting the domestic locomotive market, but GM would go so far as to build a carbody for a test version a decade later -- the FG9.

I won't go into why the idea 'failed to thrive' even in shipboard practice... you can easily research it online and you'll find out much more interesting tech and history than I could cram in a post here.

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Posted by Jones1945 on Friday, June 18, 2021 3:08 AM

Overmod
MEANWHILE it turns out that GE was apparently in active development of a 6700hp turboelectric using pulverized coal firing, which progressed to the point in 1947 that a test boiler was constructed; cost per mile was calculated at over twice that of 'comparable' diesels and the project was abruptly terminated after Deasy's replacement by you-know-who.

I have been reading Hirsimaki's book again to find out if this project is mentioned, but I found nothing. What I found is something not related but you guys might also interested, which is the idea of PRR Q3:

"The railroad continued developing duplexes, though. It collaborated with Alco in the fall of 1946 on a 4-4-6-6 "Q3" with a welded boiler. Alco had the only furnace large enough to heat treat (to relieve welding stresses) a boiler of that size. Most likely boilers would have been purchased from Alco with Altoona building the engines. Preliminary plans were drawn up in November 1946, but the project died as the emphasis shifted to Diesels."

PRR wasn't satisfied with the overall performance of the Q2, especially the lack of superiority of the Q2 when compared to the J1, they wanted something even better and bigger! 

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Posted by djlivus on Friday, June 18, 2021 9:46 AM

Q2 locomotive is a giant of 5 meters height (to the top of the structure, without salient smoke stacks), so a larger Q3 could have been even more impressive!

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Posted by Overmod on Friday, June 18, 2021 9:56 AM

Jones1945
PRR wasn't satisfied with the overall performance of the Q2, especially the lack of superiority of the Q2 when compared to the J1, they wanted something even better and bigger! 

This would fit entirely with the promotion of a "9000hp" turbine... up to the point the people in the motive-power department came to their senses and looked at the water rate, same as for the original V1 at 8000shp.  If you take the 'revealed wisdom' about the Q2 as correct, there was insufficient advantage to the complexities of the design to make it 'better' (or even as cost-effective) in service as the improved J1a.  The logical next step -- for the logic of the PRR motive-power folks at the time, who were hidebound in regard for high-horsepower steam as the practical near-term future -- would be to build something that would require the advantages of duplexing, and pay for the added maintenance of the four vs. two cylinders.  That would indicate taking the TE up considerably further (and the ihp probably by at least the 5/4 that the Q1 was supposed to be 'better' than the M1a) while retaining the ten drivers (and probably the 69" wheel and necked cylinders to keep the rigid wheelbase short).  To me it goes without saying they'd need to perfect the proportional version of the antislip control for such a thing; enginemen who didn't 'get' the T1 would not have a clue how to drive a Q3 with the necessary delicate throttle and reverse sense.

It is difficult for me to figure out what the intended purpose of the Q3 would have been outside of wartime.  There was no high value associated with low augment in a world of 50mph freight; this was long before TrailerTrain or similar low-tare intermodal would make high-speed freight useful (and in any case it is difficult to imagine a TOFC consist of a size, in the '40s, to use the Q3's probable horsepower.

What this looks suspiciously like is an attempt to build a 'better Allegheny' just as the Q2 itself was higher-horsepower-at-speed than any contemporary articulated already.  My opinion is that you'd burn a phenomenal amount of coal and blow through scads of water on the test plant, and do the same on the road, making F units even more dramatically advantageous.

It would be interesting to see when this was abandoned.  Likely very quickly after the Symes ascendancy -- in fact, I wonder if this was one of the reasons PRR induced Deasy and Duer to depart.  Interesting that it wasn't peddled to anyone else...

The interesting thing about the "6700hp turboelectric" was that apparently a test boiler was built, tested, and then returned to B&W at the end of 1947.  I suspect there wasn't any actual running-gear detail design (as GE understood what would have been necessary in small steam turbines by that time) which may account for Hirsimaki not covering it, but it is both an interesting 'missing link' in immediate postwar PRR design and yet another indication of how compellingly and quickly the emphasis shifted away from anything involving modern steam at a point between 1946 and 1947.

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Posted by Jones1945 on Sunday, June 20, 2021 5:02 AM

Overmod
My opinion is that you'd burn a phenomenal amount of coal and blow through scads of water on the test plant, and do the same on the road, making F units even more dramatically advantageous.

It would be interesting to see when this was abandoned.  Likely very quickly after the Symes ascendancy -- in fact, I wonder if this was one of the reasons PRR induced Deasy and Duer to depart.  Interesting that it wasn't peddled to anyone else...

Definitely. Your question is answered indirectly in Hirsimaki's book: "One of Symes' first actions after arriving in Philadelphia was to order a study comparing the cost of Diesels and Q2's in freight service between Harrisburg and Chicago. Dated December 11, 1946, it determined that either 80 6000hp. freight Diesels or 202 Q2's were required. The Pennsylvania was finally facing the fact that although Diesels had a higher initial cost ($592,147,29 for an ABBA F3 set vs. $200,000 for a Q2) their maintenance and operating costs were lower. More importantly, Diesels could run far more miles annually than the Q2 due to its higher availability. The conclusion was the Diesels would save the railroad $14,026,000 annually. This was a mortal blow to the advocates of steam power."

There was no way a Q3 would have changed the fact that this thirsty, slippery steam locomotive was inferior to the versatile EMD F3. Dieselization was not something a Steam fan like me want to see but it was the easiest and most straightforward answer to PRR during the transition era. 

Hirsimaki also mentioned a proposal from Baldwin to rebuild the T1s with high-pressure boilers and compound cylinders in 1947, but of course, this proposal was dropped.

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Posted by Overmod on Sunday, June 20, 2021 9:23 AM

djlivus
Q2 locomotive is a giant of 5 meters height (to the top of the structure, without salient smoke stacks), so a larger Q3 could have been even more impressive!

I think it is very likely that the Q3 would have been no taller or wider (these being fixed by the service-area loading gage) and the actual convection section (boiler with tubes) no longer (the 'ideal' aspect ratio being around 1:408 for tubes in the 18 to 20' max range) -- the welded shell perhaps letting a few more tubes be fitted, but not many.

The improvement would be in the firebox and chamber, and (as in the Allegheny) the three-axle trailing truck is a guide to what would be there.  Remember that welded construction gives lighter weight -- Alco in the '47 Cyc advertised several tons -- but most of this would be balanced over the driver wheelbase.  I'd suspect multiple circulators in both firebox and chamber.

The most obvious thing, though, would be the Lima Double Belpaire chamber (as touted by Col. Townsend up to 1949) which is a 'natural' for a locomotive with 69" drivers.  I don't remember the weight difference for this (but it could easily be scaled from the Double Belpaire test boiler preserved at MOT in St. Louis).

The length overall would ideally be kept as short as possible (for siding as well as turntable considerations) so expect the three-axle trailer to have short wheelbase a la T1 and a relatively close (but Bissel-geometry correct) pivot point.  I expect the stoker engine and perhaps other auxiliary components to be on the tender to save weight.

I also expect at least a four-axle A-tank to add water capacity, as noted on the LV's proposed 4-4-6-4 diagram.  As on NYC the tender proper would be optimized for coal, with a water bottom but minimal cistern, with most of the running water supplied via a separate car (with connections on both ends) similar to what was proposed for the V1.  The engine could be hostled and turned in minimum length but given extended range; ash service then becomes a critical-path concern for extended range...

If the engines were built and supported to circa 1950 they would be poster children for Cunningham circulators (which draw from the actual 'downcoming' areas in the convection-section circulation and use jet pumps to transfer this into the high-uptake areas in the water legs; I also think they would assist circulator supply at the throat.

This business with high-pressure compound T1s is interesting... I don't remember any details about it.  Presumably there would have been much more since this was after the alloy-boiler-steel cracking debacle, a higher-pressure firebox design for the restricted grate area (probably a waterwall design?) might be needed, and without conjugation of the engines (necessitating removal of the type A  drive on at least the rear engine) some care and additional devices would be needed.

I think it very clear that Baldwin considered this a 'solution' for the perceived slipping propensity, and that the use of even conventional LP arrangements on the front engine eould give typical 'self-starvation' when that engine was the one slipping.  The case is not so sanguine if higher-pressure slip on the rear engine then pressurizes the receiver... as might be the case for high-speed slipping near the practical adhesion limit, which would be good neither for rod integrity or driver-tire tread characteristics.

As an amusing aside: we might see hybrid valve-gear conversion on these, with some variant of the T1a conversion as part of the LP modifications but B-2 RC on the eight-valve castings retained for the (perhaps sleeved) rear cylinders... that might be interesting to watch at speed...

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Posted by Overmod on Tuesday, June 22, 2021 9:38 AM

Incidentally I think the "6700hp" of the GE proposal is suggestive: that is likely 5000kW, and GE developed a turbo electric plant of that rating for Liberty ships/T2 tankers during the war.   Having Babcock &Wilcox modify or respec a boiler for PC firing (marine would be oil with separately-fired superheat) would be relatively easy...

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Posted by djlivus on Friday, June 25, 2021 4:40 AM

That is really interesting. Any data about the configuration of this locomotive? One unit and tender? Two-units locomotive?
 

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Posted by Overmod on Friday, June 25, 2021 10:30 AM

I do not know.

 I suspect it would have followed GE design and not PRR's Triplex/V1 layout, so roughly following 'two units' for the main locomotive plus water tenders.  Probably not yet the B-B-B-B arrangement rather than the 2-C-C-2 as on the 1938 condensing STEs.  Packaging would be very different if the coal is pulverized and distributed onboard from 'mine run' or even the touted 2" classified and washed coal AAR was advocating in the last couple of years of the '40s, vs. being (explosively) supplied pulverized to bunkers as road fueling.

I think there is much more to the boiler story than we think.  Note that PC firing rules out chain-grate which was a prominent feature of the M2 'automatic' and then the TE1 on N&W, but I think I remember seeing references to pulverized coal with respect to the 'intermediate' STE design (with all axles motored) described in the trade press circa 1950...

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Posted by Jones1945 on Saturday, June 26, 2021 2:01 PM

Overmod
I suspect it would have followed GE design and not PRR's Triplex/V1 layout, so roughly following 'two units' for the main locomotive plus water tenders.

I think I found the information of this proposed locomotive on Page 76, Hirsimaki's book:

"Although the Pennsylvania Railroad was committed to coal burning motive power, this didn't necessarily mean reciprocating steam locomotives. One early effort to study possible alternatives was a 1935 research effort begun in conjunction with General Electric to develop a steam turbine-electric locomotive. It was to burn pulverized coal in a high pressure boiler which would supply steam to a steam turbine. A conventional main generator/traction motor arrangement would then provide traction......

The locomotive's basic dimensions were finalized by late 1939. It would consist of three units with an overall length of 205 feet. The weight on drivers would be 600,000 lbs. and the total weight, 950,000 lbs. At each end would be a cab with a shortened GG-1 style nose. The turbine was to be rated at 6000 shaft hp. or 5000 drawbar hp. at 45 mph. This locomotive was designed to be the equal of the GG1 and the S1 of a few years later. It was to be capable of hauling a 1200 ton passenger train at 100 mph or a 4000 ton freight train at 60mph.

One cab would contain a condenser which would take the waste steam exiting the boiler and turn it back into water for reuse. This would provide what is known as a closed cycle in that the same water would be continually evaporated, condensed and evaporated again. The advantage of this was there would be no boiler scale of other impurities entering the system.

The middle, or "B," unit would house a coal pulverizer, the boiler and the turbine and generator set. The other cab unit would carry the train heating boiler and the coal bunker. There was only a small water tank because of the closed cycle......The locomotive would have had a 2+B-1+B+B-B+B+1-B+2 wheel arrangement......

By mid-1943 the PRR's steam turbine project had evolved from a three-unit locomotive to a single unit housed in an elongated GG1-style carbody mounted on a D-C+C-D chassis. Because of the Steamotives' problems with their condensers, a tender was added to supply water and simplify the design. Unfortunately, the project was cancelled within three years."

 

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Posted by Overmod on Saturday, June 26, 2021 7:14 PM

That three-unit design was pictured in an earlier post here.  I cannot imagine a chassis of the indicated arrangement ("D-C+C-D" implying cast underframe with eight-wheel lead trucks!) being stable at speed, let alone under a single rigid frame, so I'd have to see an arrangement drawing to understand it.  

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Posted by djlivus on Tuesday, June 29, 2021 7:08 AM

https://i.imgur.com/gIMTLeg.png

Here is pictured the D-C+C-D version. I think the design was awesome, a really giant. Of course, I do not know if it was techically viable, but visually it was impressive for sure. Like a turbo giant, super GG1!

 

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Posted by Overmod on Tuesday, June 29, 2021 7:20 AM

Good find!

Now when the Archives open back up I can look to see if I can figure out how the carbody goes on those underframes -- they are drawn as though articulated, but I'd think a C-D+D-C arrangement would guide better and have a bit less shock going into curve transitions.

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