Overmod Just as a note, only one of these was built with the Caprotti poppet-valve gear (and was perhaps inevitably nicknamed 'Mussolini'); there were several other test installations of this kind of valve gear in this general time period, with none being markedly successful. (This was around the time that Baldwin acquired the rights to Caprotti gear and tried it on a wide range of product -- equally unsuccessfully.) If I recall correctly it was in connection with K5 testing that Caprotti noted 'your locomotives pull houses, not cars' -- and the detail design of the Italian version of the gear was in some respects not up to North American loads. I have found it interesting that no attempt was made, even for test purposes, to fit any version of the Franklin System to one of the K5s, or for that matter to one of the M1as where the better volumetric efficiency might have meant something important. How much of that was a bad taste left from the Caprotti 'experience', I can't directly say.
Just as a note, only one of these was built with the Caprotti poppet-valve gear (and was perhaps inevitably nicknamed 'Mussolini'); there were several other test installations of this kind of valve gear in this general time period, with none being markedly successful. (This was around the time that Baldwin acquired the rights to Caprotti gear and tried it on a wide range of product -- equally unsuccessfully.) If I recall correctly it was in connection with K5 testing that Caprotti noted 'your locomotives pull houses, not cars' -- and the detail design of the Italian version of the gear was in some respects not up to North American loads.
I have found it interesting that no attempt was made, even for test purposes, to fit any version of the Franklin System to one of the K5s, or for that matter to one of the M1as where the better volumetric efficiency might have meant something important. How much of that was a bad taste left from the Caprotti 'experience', I can't directly say.
Jones 3D Modeling Club https://www.youtube.com/Jones3DModelingClub
Jones1945I wonder why PRR picked Caprotti poppet-valve gear for their first attempt to max out the potential of a Pacific, was there any poppet-valve gear available and proofed successful in America or EU?
Caprotti was THE hot thing in the latter 1920s, one of the follow-ons to the three-cylinder craze. Keep in mind this is very little like the 'British Caprotti' system of the 1950s. As noted, Baldwin thought it would be the 'wave of the future', bought a license, and advocated its use widely ... for a few years, anyway.
From what I saw from a YouTube video, the basic mechanical principle of Caprotti poppet-valve gear was simple and easy to understand.
You wouldn't say that looking at the 'nightmare box' that was actually used on some of those locomotives. Bad enough that it was a complex mechanism with many finely machined components, relatively easy to derange. Now imagine it located between the frames and subject to road dirt and damage!
Franklin’s poppet valves was tested on a K4s but T1 was a completely different design to K4s, PRR was act[ing] on impulse in T1’s case
As far as cylinders and tracting is concerned, 'steam is steam' and there is little difference with the possible exception that the short-stroke relatively small-bore duplex cylinders inherently have more dead-space percentage than a larger block should. In any case, part of the Lima 'second rebuilding' (with the larger superheater and better flow) was to eliminate some of the prospective performance loss inherent in the K4 boiler design, which most critics seem to think it did.
I don't think it is fair (or right) to accuse PRR of impulse-buying the Franklin System valves wholesale. You will note they were never applied to 6100, and while several variants were tested on K4s, never applied to fleet quantities of any other PRR classes in the years between the original K4 and the mass orders of T1s. There was considerable cost, including royalty expense, in buying the proprietary Franklin components, so the perceived value to PRR's motive-power department had to outweigh that cost. Certainly it seems to be factual that Baldwin tried to talk PRR out of using poppet valves on 'their' part of the T1 order, or at least providing competitive piston-valve-equipped T1-size locomotives to test, and was unsuccessful. (They also failed to get a 102-104 sq.ft. grate installed, which is another set of stories...)
Let me repeat here that I think it has been established beyond a doubt (both in original testing and in the reviews made by Joe Burgard in recent years) that the advantages for poppet valves (whether type A or B-2 drive) were present in quality for T1s just as they were observed on the Lima K4 'demonstrator' -- you will see this if you know where to look in the results for the T1 vs. T1a at high cyclic rpm under load.
The mistake that seems to have been made by other roads was to set up and tune performance of a Franklin-System-equipped locomotive for economy at 'equivalent' performance, rather than optimize free running at high speed. This is of course not a "mistake" in terms of how most railroads could or did operate reciprocating steam power... it's that even significant operating economies were eaten up by maintenance issues: witness the NYC poppet-valve Niagara. (You can in fact extract the relevant data from LeMassena's '80s article on the subject in Trains, but you need to do a little work to realize how Kiefer and the Franklin people scaled the installation.)
One of the flaws of K5 that many pointed out was its low FA, the higher TE played a role for her low FA, but why didn't PRR test it on M1, which had 4 pairs of drivers with smaller diameter.
Starting factor of adhesion is kind of a spurious quantity for a locomotive intended for high-speed express service with heavy trains, as most of the higher power is only useful at very high speed ranges. The problem is that some (probably most) operating departments think that the fancy modern technology they paid for ought to be able to start any train it can pull, and make up trailing load accordingly -- then rely on horse-out-the-throttle engineers from the days of dome throttles to get them started.
Where the K5s wound up being operated, the relatively low FA was more than usually problematic: many curves and relatively poor track meant often-compromised adhesion, especially with trailing load sized to suit the theoretically greater capability of the larger Pacific. But I can't help wondering if the conditions there were worse than experienced (proportionally adjusted) by N&W Js in typical service; those had a factor of adhesion lower than a K5.
By the way, despite the low FA, it seems the wheel slipping was not a problem of K5, but I don’t have [much about] them in hand.
The reports I've read all indicate wheelslip was a chronic problem much of the time, but that's just the normal starting wheelslip, not the kinds of high-speed slipping that the T1 would be accused of. It would also be relatively easy to control or arrest slipping with a piston-valve locomotive that has direct throttle and reverser controls. I suspect some of the kvetching would be made by comparison with K4/E6 performance, which would be far less affected by ham-handed impulsiveness in throttle opening.
OvermodCaprotti was THE hot thing in the latter 1920s, one of the follow-ons to the three-cylinder craze. Keep in mind this is very little like the 'British Caprotti' system of the 1950s. As noted, Baldwin thought it would be the 'wave of the future', bought a license, and advocated its use widely ... for a few years, anyway.
Thank you, Overmod. I just found out that I was watching the wrong video , which was an computer animation of “Britich Caprotti” system. I wonder why Baldwin “had a crush” (but not Alco or Lima) on the Caprotti gear which was “more complex and needed expensive maintenance” even though, from my shallow understanding, it was widely used on 400 locomotives in Italy, but wasn't the operation envrionment in Italy was very different from US? three-cylinder steam locomotive wasn't common in the States as well.
OvermodYou wouldn't say that looking at the 'nightmare box' that was actually used on some of those locomotives. Bad enough that it was a complex mechanism with many finely machined components, relatively easy to derange. Now imagine it located between the frames and subject to road dirt and damage!
Overmod I don't think it is fair (or right) to accuse PRR of impulse-buying the Franklin System valves wholesale. You will note they were never applied to #6100, and while several variants were tested on K4s, never applied to fleet quantities of any other PRR classes in the years between the original K4 and the mass orders of T1s…… (They also failed to get a 102-104 sq.ft. grate installed, which is another set of stories...)
Jones1945 ... Caprotti gear which was “more complex and needed expensive maintenance” even though, from my shallow understanding, it was widely used on 400 locomotives in Italy ...
You've heard of 'not invented here'? Fascist Italy was the 'here' for native son l'ing. Caprotti, just as Germany was a fertile place for Diesel engine development...
Here is the nightmare box in action. Just think about keeping this running in American service long-term:
It bears remembering that the New York Central C1a duplex design, presumed as late as April 1945 to be THE high-speed postwar NYC passenger steam power, never had poppet valves even as Kiefer anticipated their use (for economy) on Niagara 5500. That was a decision taken early in the design process, and it is particularly interesting since the 64-ton tender was specifically intended to take advantage of the better thermodynamic performance of the duplex design to permit unrefueled Harmon-to-Chicago service. The fuel consumption in 'typical' NYC service with poppets would likely have been lower, yet Kiefer happily uses long-travel Baker. Tells ya something, doesn't it?
Don't forget the ATSF duplex (oil-burning, cab-forward 6-4-4-4) which as it turns out resembles the B&O and Q1 cylinder arrangement, cylinders at the 'corners' of the driver wheelbase. This would likely NOT have constituted a viable competitor to the evolving diesel-electrics...
Overmod Here is the nightmare box in action. Just think about keeping this running in American service long-term:
Wow I didn't expect I learned so many things today! Thank you for sharing the video, Overmod!
The first thing that came to my mind when I watching the vid was that I guess the box must be filled with a lot of lubricant, oil and stuff in the past or those spinning part will worn out very soon, I don't know what speed of the box was trying to simulate but I played the vid at 10X speed by using a Browser add-on, I think such device were too "exquisite" that it looks like a music box, a clock or something you can find in a kitchen in 64AD more that a device which could control a 200 tons locomotive moving 800 tons of passenger stock at 80mph! Compare to the Walschaerts gear, it is really a bit too much! More parts mean higher chances of malfunction, I bet the frequency and loading of train service were much lower and lighter in Italy, so it worked there but not in the States. It is hard to believe one K5 was equipped with it and served for so long.
Overmod .......and it is particularly interesting since the 64-ton tender was specifically intended to take advantage of the better thermodynamic performance of the duplex design to permit unrefueled Harmon-to-Chicago service. The fuel consumption in 'typical' NYC service with poppets would likely have been lower, yet Kiefer happily uses long-travel Baker. Tells ya something, doesn't it? Don't forget the ATSF duplex (oil-burning, cab-forward 6-4-4-4) which as it turns out resembles the B&O and Q1 cylinder arrangement, cylinders at the 'corners' of the driver wheelbase. This would likely NOT have constituted a viable competitor to the evolving diesel-electrics...
.......and it is particularly interesting since the 64-ton tender was specifically intended to take advantage of the better thermodynamic performance of the duplex design to permit unrefueled Harmon-to-Chicago service. The fuel consumption in 'typical' NYC service with poppets would likely have been lower, yet Kiefer happily uses long-travel Baker. Tells ya something, doesn't it?
By the way, I never heard about the proposed ATSF duplex 6-4-4-4, is it possible to find any drawing or rendering of her? Thanks!
Jones1945The first thing that came to my mind when I watching the vid was that I guess the box must be filled with a lot of lubricant, oil and stuff in the past or those spinning part will worn out very soon
All these camboxes ran with what was essentially bath lubrication; I think that some of the British Caprotti videos show their version of the cambox 'opened up' and you can see the amount of lubricant involved there, too. Interestingly, the T1 camboxes were a very infrequent source of failure; the problem was much more one of inspection (particularly on the one for the rear engine!) than actual breakage. That couldn't be said about the stunted little valve gear that was intended to implement cutoff on type A OC gear. (If you think about poppet action a moment, you will come by first principles to appreciate why conventional SHM valve-gear drive wouldn't really work well on an OC engine with sustainable cam lift profiles, but that's a different discussion...)
I don't know what speed of the box was trying to simulate but I played the vid at 10X speed by using a Browser add-on
You can deduce the necessary speed by looking at the cams and extrapolating that to anticipated road speed based on driver diameter. Diameter speed for the Mussolini K5 would have been 80mph. I suspect the particular advantages of Caprotti's poppet valves would become meaningfully evident at a higher speed than that, probably no less than the 90mph or so that a conventional K4 would top out at.
It is hard to believe one K5 was equipped with it and served for so long
MUCH bigger locomotives were equipped with it -- the list of test locomotives that received a Caprotti experiment is surprisingly long. Part of the premise of cam drive of the poppets is that the force required to operate them is dramatically less than what's involved for piston valves driven via SHM gear like Walschaerts or Baker (I believe for Lima "type C" on the order of 3hp vs. about 35hp). This becomes a meaningful amount of power at very high speed, but is more significant in that relatively lighter components are appropriate for reasonable life. Franklin experience in the '30s made much of their equipment reasonably robust, I think camboxes included (the main issues early on with the T1s being first valve bounce and then spool breakage, neither of which is a real cambox issue as the valve drive is not desmodromic)
ah, yes: Dave Klepper's adored I-5. Not a bad locomotive, and representative of Baldwin's contemporary production (see the similarities to the ATSF 3460 class under the streamlining?)
Pity NYNH&H, after all those wrecks in the Mellon years, was such a slow railroad. These girls never really got to stretch their legs...
Do you mean Harmon, Illinois Overmod? I can't find the service between Harmon, IL to Chicago by New York Central.
I will restrain from snarky remarks.
Harmon, New York was the location where trains to and from Manhattan (New York City) changed between electric and steam power, about 30 miles north (railroad west). So all range calculations for NYC passenger power are made relative to Harmon and not, say, Mott Haven yard, as Harmon is where the steam power would be put on the trains. The required range is 'that much less' than the 999 miles or so that technically separate Chicago and New York on the Water Level Route (either through or around Cleveland -- the unrefueled range being most important for trains like the Century that did not change engines for the short Cleveland electrification but ran through on the lakefront route).
Earlier report shown that PRR S2 Steam turbine and T1 once managed to beat early diesel, but they can't catch up with E7. I refused to accept this as the final result, but it won’t change the fact. ( I wish T1 Trust's 5550 will show the whole world an extraordinary result)
Were you to operate either an S2 or T1 in the same service as the Niagaras used in Kiefer's testing, they would very likely have equaled or bettered the performance vs. E7s. (The C1a design is very powerful evidence if you need it!) The preference for E7s on Pennsylvania is largely driven by other factors, some physical and some political; it was a different railroad with a number of factors decidedly unsuited either to mechanical direct-drive turbine or short-stroke duplex power, especially between Pittsburgh and Harrisburg.
That said, no steam locomotive was competitive against E8s, or E9s, or what could have been provided as second-generation or later high-peak-speed passenger power had the need for that developed. (The closest to that, I think, would have been the C636P; regardless of what the CSR/SRI propaganda may imply, I don't think any reciprocating steam engine would meaningfully sub in for even the original Genesis AMD-103s, let alone Chargers)
There were a couple of threads about bashing up a model of this, but the result didn't resemble the actual proposed design. I'm a little surprised there isn't at least one Web-stored image of the available drawings (of which I have seen two) -- the canonical 'source reference' is in the "Iron Horses that didn't make the trail" section of Worley's Iron Horses of the Santa Fe Trail
Another easy solution for Pennsy: Hudson 4-6-4, but Pennsy wanted something better...
and yes, this design looks like a finger.
Overmod Interestingly, the T1 camboxes were a very infrequent source of failure; the problem was much more one of inspection (particularly on the one for the rear engine!) than actual breakage.
Overmod ...... ah, yes: Dave Klepper's adored I-5. Not a bad locomotive, and representative of Baldwin's contemporary production (see the similarities to the ATSF 3460 class under the streamlining?) Pity NYNH&H, after all those wrecks in the Mellon years, was such a slow railroad. These girls never really got to stretch their legs... …Harmon, New York was the location where trains to and from Manhattan (New York City) changed between electric and steam power, about 30 miles north (railroad west).
Overmod There were a couple of threads about bashing up a model of this, but the result didn't resemble the actual proposed design. I'm a little surprised there isn't at least one Web-stored image of the available drawings (of which I have seen two) -- the canonical 'source reference' is in the "Iron Horses that didn't make the trail" section of Worley's Iron Horses of the Santa Fe Trail
Overmod Have to confess I'm looking for the popcorn to make when Dave Klepper reads this......... ......Ah, well. Artistic license is fun, sometimes. As long as it doesn't reflect engineering 'judgment'!
Jones1945What a way to “…make the duplex a hopeless engine…” ... Both camboxes of T1’s gears were “almost” inaccessible, what in the earth they were thinking when they decided to mass produce T1?
Part of the problem, I think, was that they may have believed what the folks from Balmar were telling them about the integrity of the Franklin System. Not the first time proprietary device performance was somewhat overstated.
The way the rear cambox was located was particularly amusing; it is a principal reason that no gear or shaft conjugation of the type A-equipped T1 could be practically considered. With this removed, there is actually a 12" lightening hole in a diaphragm transom that a shaft could pass through...
During PRR S1’s first general overhaul after she racked up 150,000 miles around 1942, she was extensively de-skirted for better accessibility for daily maintenance and heat dissipation, but on the other hand, from the two prototypes T1 to the 50 production T1, the streamlining casting on the front end of T1 was still fully streamline shrouded ...
This is a little unfair, as the steel of the smokebox was that shape, analogous to the front of the A4 Pacifics in Britain, and there was little point in tinkering with it as, if anything, the front end was too efficient already (the ejection of combustion gas at perfectly suitable rate not rising high enough to escape being pulled down by the aerodynamics along the boiler). For that matter there was little point in modifying the 'prow' on a production T1 to something less "streamlined" like a flat door.
The original 'porthole' front skirting was removed on most engines with almost uncanny speed, replaced with simple (to me, elegant) enclosures for the compressor aftercoolers. There is probably some indication on what this cost, but it certainly indicates PRR was well aware of things impeding maintenance access, and still had the 'will' to modify them actively.
I believe none of the production T1s were actually built with side skirting as on the two original locomotives, and the aesthetics are in my view greatly improved by cutting the skirting back to how the engines appear in general service.
... the streamlining never tested in wind tunnel and unable to “lift the smoke up” ...
This requires a little more discussion, as there are multiple issues.
First, it is almost indisputable that making these engines with small (and non-enlargeable!) grate area, thinking that the combination of greater machine/thermodynamic efficiencies and good passenger gas coal would suffice, was a badly false economy. In an era where even the AAR started advocating washed, sized, good quality coal for locomotive fuel, PRR slid into providing more and more junk, and it is not surprising that you get burning-of-Rome smoke shows when things were even a bit less than perfect.
Second, we need to separate the issue with smoke drifting down the lee side from the issue of smoke coming in through the cabin ventilation in the roof. The latter, really the more serious problem, could have been addressed a number of ways, including a little bit of wind-tunnel analysis to see how airflow was actually being preferentially induced. Meanwhile, to my knowledge no "smoke-lifting" device intended to physically lift airflow or stack plume with air displaced around the upper front of the smokebox ever worked, more than accidentally. And while some brute-force elephant-ear 'smoke deflectors' certainly had effect on other railroads, the actual reason they worked seems not to have been fully understood even by Witte, and perhaps even by Quellmalz half a century and more later, and (as I believe Quellmalz indicated) there are easier and less drag-inducing ways of creating the necessary trailing vortex to move a smoke plume out of the engineer's line of sight.
Harmon of NYC was similar to Harrisburg of PRR wasn’t it? Both of them was a place to switch electric power to steam or diesel power for long distance through trains.
The differences are more significant. NYC used comparatively slow-speed third rail and locomotives for its terminal electrification, something PRR changed out for its major trains (getting rid of those awful L5s in the process) by the early Thirties. PRR to Harrisburg represented a major portion of the trip, and the prospective extension of that electrification to Pittsburgh (likely a priority even with PRR losing money had effective-enough diesel-electrics not been developed when they were) promised some interesting time savings.
It is easy to forget that NYC was actively considering wiring the railroad all the way up to Buffalo after the war; you can see one of the proposed locomotives prominently displayed in that 1947 review of motive power (it has a whole-page plate in the book) and this would be roughly competitive with a PRR Pittsburgh electrification, not incidentally solving the Albany Hill problem on the way...
I read the 6-4-4-4 was supposed to power the Super Chief, it is interesting to know Santa Fe was looking for Alternative power to haul their prime trains after the war.
This was very, very much a 1930s proposal, and inherently dependent on an abject failure of internal-combustion power to perform reliably on an appropriate scale. As the opposed-piston duplex configuration was far from the success anticipated, and the history of EMD on ATSF largely successful from the 'twins' onward in the middle '30s, it ain't surprising that this concept went nowhere fast (especially after the 3765 class with modern balancing proved perfectly happy well up into the duplex top-speed range!)
I believe Dave adored the real I-5 but not her “artist impression drawing" or “conceptual design drawing”. That pic of I-5 just like many other early renderings from different manufacturers, including the streamlined S2 by Westinghouse you posted before, they had nothing to do with engineering 'judgment' and their main function or “existential value” were to impress the potential buyer or used for publicity purpose and usually looked nothing like the real thing.
Yes, but the popcorn was for the comment you made about what you thought the streamlining on the I-5 looked like. (For the record, I agree with you; to me the streamlining looks pudgy although nowhere near as reprehensible as the Mae West treatment on the ATSF 3460 class, but Mr. Klepper I believe likes it)
The I-5 repressents the best 4-6-4 streamlinineg for me, better than Dryfuss, and better than any 4-6-2 as well. Both sides of the Atlantic too. Better than the Greseley A-4. (Not fond of an inverted bathtubs, even one as elelgant as the A-4, the best of the type.)
But, overall, I like the Norfolk and Western Js and the SP Daylights much more. Any streamlined Pacific or Hudson seems "pudgy" compared to a Northern. Or compared to a T-1.
OvermodPart of the problem, I think, was that they may have believed what the folks from Balmar were telling them about the integrity of the Franklin System. Not the first time proprietary device performance was somewhat overstated. The way the rear cambox was located was particularly amusing; it is a principal reason that no gear or shaft conjugation of the type A-equipped T1 could be practically considered. With this removed, there is actually a 12" lightening hole in a diaphragm transom that a shaft could pass through...
Overmod This is a little unfair, as the steel of the smokebox was that shape, analogous to the front of the A4 Pacifics in Britain, and there was little point in tinkering with it as, if anything, the front end was too efficient already (the ejection of combustion gas at perfectly suitable rate not rising high enough to escape being pulled down by the aerodynamics along the boiler). For that matter there was little point in modifying the 'prow' on a production T1 to something less "streamlined" like a flat door.
Overmod The original 'porthole' front skirting was removed on most engines with almost uncanny speed, replaced with simple (to me, elegant) enclosures for the compressor aftercoolers. There is probably some indication on what this cost, but it certainly indicates PRR was well aware of things impeding maintenance access, and still had the 'will' to modify them actively.
Overmod I believe none of the production T1s were actually built with side skirting as on the two original locomotives, and the aesthetics are in my view greatly improved by cutting the skirting back to how the engines appear in general service.
Overmod …In an era where even the AAR started advocating washed, sized, good quality coal for locomotive fuel, PRR slid into providing more and more junk, and it is not surprising that you get burning-of-Rome smoke shows when things were even a bit less than perfect. …And while some brute-force elephant-ear 'smoke deflectors' certainly had effect on other railroads, the actual reason they worked seems not to have been fully understood even by Witte, and perhaps even by Quellmalz half a century and more later, and (as I believe Quellmalz indicated) there are easier and less drag-inducing ways of creating the necessary trailing vortex to move a smoke plume out of the engineer's line of sight…
Overmod …It is easy to forget that NYC was actively considering wiring the railroad all the way up to Buffalo after the war; you can see one of the proposed locomotives prominently displayed in that 1947 review of motive power (it has a whole-page plate in the book) and this would be roughly competitive with a PRR Pittsburgh electrification, not incidentally solving the Albany Hill problem on the way...
Overmod Yes, but the popcorn was for the comment you made about what you thought the streamlining on the I-5 looked like. (For the record, I agree with you; to me the streamlining looks pudgy although nowhere near as reprehensible as the Mae West treatment on the ATSF 3460 class, but Mr. Klepper I believe likes it)
daveklepper The I-5 repressents the best 4-6-4 streamlinineg for me, better than Dryfuss, and better than any 4-6-2 as well. Both sides of the Atlantic too. Better than the Greseley A-4. (Not fond of an inverted bathtubs, even one as elelgant as the A-4, the best of the type.) But, overall, I like the Norfolk and Western Js and the SP Daylights much more. Any streamlined Pacific or Hudson seems "pudgy" compared to a Northern. Or compared to a T-1.
Thank you for sharing your thoughts, Dave. I also like SP Daylights, although I prefer GS-3 to double headlights GS-4.
Jones1945I also like SP Daylights, although I prefer GS-3 to double headlights GS-4.
My introduction to the GS-3 came early, as I suspect it did for some others of you:
But I didn't care much for how fat, almost pig-eyed, the locomotive looked with the single small headlight vs. the conical GS-4 door with the two lights. I spoze de gustibus non disputandum est and all that.
(Later, of course, when the show switched to color, they also switched the train to Diesels; funny that I remember this in amazing bright saturated Daylight paint, not what the current YouTube cuts show... kids' imagination, I guess.)
Overmod My introduction to the GS-3 came early, as I suspect it did for some others of you: But I didn't care much for how fat, almost pig-eyed, the locomotive looked with the single small headlight vs. the conical GS-4 door with the two lights. I spoze de gustibus non disputandum est and all that. (Later, of course, when the show switched to color, they also switched the train to Diesels; funny that I remember this in amazing bright saturated Daylight paint, not what the current YouTube cuts show... kids' imagination, I guess.)
Now I know the shocking reason of why you monopolize that cup of sweet smelling fresh double butter popcorn and refused to share it with me Overmod! You were watching Adventures of Superman and eating popcorn all day long! I am still thinking if I should feel disappointed or not...... But note that George Reeves was not the best Superman I am sure, he can't even stop a SP 28-car consist powered by a 6000hp EMD E8 within 6.5 secs when trying to rescue a street clerk ! Undeniable evidence here:
https://www.youtube.com/watch?v=DeyqyKDLDLY#t=01m58s
Overmod-- Thanks for the Caprotti video. Now is there something on par for the Franklin Type B along with an explanation as to why it would be better, especially for the T1's and the 5550 project.
Keep in mind that when referring to T1s it is always "Franklin type B-2". There is a substantial technical difference in the arrangement and operation.
The original Franklin carried over from Lentz not only oscillating cams (which they thought suitable to be driven from a standard type of continuous-cutoff valve-gear reverse, in part to indicate attractive economies of construction cost to railroad buying agents!) but also the arrangement of valves seen in the corporate emblem (and Kirchoff's "shield") with two smaller admission and two larger exhaust valves per cylinder end (that's eight per cylinder block and sixteen per T1)
'Regular' type B (which is a rotary-cam gear) was developed differently; you will note that in the example fitted to ATSF 3752 there are only three valves per cylinder end. The problem for the T1s was, of course, that the cast engine bed cleverly included all the ports and passages for the type A valve arrangement. So B-2 was 'ginned up to have appropriate bridges and offsets to allow the shifting-cam spherical followers (as illustrated in the '47 Cyc) to work the existing valve arrangement (which in my opinion was better suited to very high speed working anyway), rather than do a T1a-style cutting off of the whole cylinder block across the dead space, making up four brand-new 'catalog' type B compatible castings and jigs to keep them aligned, and firing up the electroslag machines.
I suspect any videos that actually show B-2 in action will have to wait until the T1 Trust has finished more of the virtual models (both for multiphysics and for 'train simulators') that will be used for the initial rounds of testing. I expect one of the things generated then will be an analysis of the Franklin gear, with 'animated illustrations', all the way from the development in the '30s through to type D (the Vulcan 'kits' for the Army).
You and Jones1945 are welcome, of course, to sign up for the engineering task force at the Trust, which will give you access to the repository there.
Well Thank You! Sounds like a capital idea.
Overmod I suspect any videos that actually show B-2 in action will have to wait until the T1 Trust has finished more of the virtual models (both for multiphysics and for 'train simulators') that will be used for the initial rounds of testing. I expect one of the things generated then will be an analysis of the Franklin gear, with 'animated illustrations', all the way from the development in the '30s through to type D (the Vulcan 'kits' for the Army). You and Jones1945 are welcome, of course, to sign up for the engineering task force at the Trust, which will give you access to the repository there.
Yes, when I say 'train simulator' I'm talking about the "Microsoft game" style products, where the virtual model is assembled in 3D graphics and extensive physics can be specified. There were several private efforts documented and coordinated within the Trust technical discussions.
This is different both from the use of Dassault 3DS and software like COMSOL to perform multiphysics analysis on a 3D structural model of the locomotive made from actual drawings and materials characteristics, where the physics emerges from the design rather than being specified or calculated as in the game, and from the use of software like ADAMS or VAMPIRE where the physical response of the device, for example at high speed, can be determined. Note that when the 'smart drivers' are installed, it will be possible to analyze road shock, compliance, and augment in realtime at high speed, which is likely the only way high-speed running at the Pueblo test facility would be permitted.
Extract from "Penny Power I". One of the clay models of 3768 for wind tunnel test. There were more than 20 (I forgot the exact number) different designs of it before finalization.
An advertisement of Franklin Railway Supply Limited in 1947:
Jones1945An advertisement of Franklin Railway Supply Limited in 1947:
It is possible to be a bit cynical about coverage of technical issues in trade publications, but there are a number of accounts of the Franklin System in articles in publications like Railway Mechanical Engineer -- a good one discussing the actual meaning of 'long compression' being found very close to one of the articles on the ICC speed order of 1947 in the first few months of enactment.
There is also a fairly substantial spread by Franklin in the '47 Cyc that covers the system; it clearly shows the continuous-contour cam that finally provided reasonable stepless cutoff control to RC setups, and the spherical follower design needed to make this work ... to the extent it did. There is a technically better, but alas! smaller coverage in '50-'52 ... then all was gone.
It's easy to forget that a whole generation of the Franklin System was designed, tested, proved buggy, and re-engineered without a single customer in these years. That is why I always mention "type C" (shifting-cam RC using long-compression principles) in quotes -- to my knowledge there was never a service engine equipped with this, and the Vulcan conversion kits for Army engines are so different as to be type D. Yes, it's a bit sad that Col. Townsend couldn't even get a demonstrator built ... even at the model scale represented by the double Belpaire 'test article' ... that would show all the late stuff the way 1111 did for roller bearings, and auxiliaries, and Alco, etc.
Overmod…a good one discussing the actual meaning of 'long compression' being found very close to one of the articles on the ICC speed order of 1947 in the first few months of enactment... it clearly shows the continuous-contour cam that finally provided reasonable stepless cutoff control to RC setups, and the spherical follower design needed to make this work ... to the extent it did. There is a technically better, but alas! smaller coverage in '50-'52 ... then all was gone.”
OvermodYes, it's a bit sad that Col. Townsend couldn't even get a demonstrator built ... even at the model scale represented by the double Belpaire 'test article' ... that would show all the late stuff the way 1111 did for roller bearings, and auxiliaries, and Alco, etc.
I found this pic on http://www.rrpicturearchives.net/showPicture.aspx?id=4934659, the date of this photo taken was Aug 15, 1946, but the site also stated that "The date and the location are approximations.".
This photo was taken by an unidentified photographer. Judging by the style and angle of how this photo was taken; the skirting of lounge-baggage car was still attached, I suspect it was taken by Penny's staff for official record, probably during PRR S1's first general overhaul after she racked up 150,000 miles around 1942. During the general overhaul, most of her side skirting were removed. PRR updated their drawings of S1 for this. Note both cylinders were freshly painted and overall the engine and the tender look rather clean in this pic. The front coupler cover was lifted up and hidden inside the frond end shrouding, probably still had the sliver strips attached.
There were different versions about S1's retirement date in the past, some said 1944, some said 1946, but after more files was revealed these years, it is quite sure that she served until the 100th anninsery of PRR and got withdrawn from service in the same year. Her role of hauling the Trail Blazer was replaced by PRR S2 6-8-6 Stean turbine engine and newly arrivered T1s.
I don't have solid evidence, but I believe some pics or important documents were leaked and destroyed during the establishment of Penn Central, there is a article on Classic Trains, titled " Donald Dohner: The man who designed the Rivets" By Hampton C. Wayt, mentioned that during the Penn Central merger, quote: "One day the man was asked to clean out the PRR office in Philadelphia where the model was stored. Everything was to be thrown away, but the man didn’t have the heart to dispose of the model." The model mentioned in this article was a conceptual design of GG1 in wooden model form; painted with color and had a skirting as part of it streamlining. It is not hard to imagine how many important files, pics, videos, models were destroyed during the merger. I wish some people did try to save as many files as they could during the merger.
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As good as an EMD E-8? To replace a T-1 with diesels, even just to fully replace a K-4, at least two E-8 units are required.
As good as an F40P might be better.
Jones1945PRR’s electrification of the Northeast corridor was their biggest contribution to America, the positive affection of Penny’s decision is still there. If things went according to plan, NYC, Philadelphia, Baltimore, Washington D.C, Pittsburgh would have become the largest HSR network at the time.
Only just seeing this by reading on a larger screen.
I don't even think Martin Clement could have arranged HSR to Pittsburgh. That was a different line altogether from what became the NEC. diverging from the high-speed line via a cutoff through North Philadelphia, and even with the proposed tunnel under Horse Shoe would be a difficult proposition for true high speed sustained long enough to make an important difference. (Not that it wouldn't have been fun to watch them try!)
"Balmar" (for Baltimore, Maryland) was the Franklin plant where the poppet-valve equipment was manufactured. I don't remember the full story of the fascinating interlocking ownership of the Coffin empire in locomotive auxiliaries and components, but there are some people like Dave Grover who have teased it out in all its seamy glory, including the Westinghouse role in taking down Baldwin as a locomotive manufacturer, and I encourage you to research this for a side of the 'business' that most railfans never saw.
The only conclusion I was ever able to reach about the T1 smoke was that when the locomotives were designed and tested, the assumption was that they would always be using good PRR passenger 'gas coal' and not the sort of dirty run-of-mine stuff used for lesser power. Trying to run a high-speed 4-8-4 equivalent on unwashed, unsized coal on a 92-foot grate was always going to be an exercise in soot generation, and what was inconvenient aerodynamics with a clear stack became prep for the minstrel show ... can I make fun of it like that in this new post-#metoo world? didn't work out for Schnatter even though he was quoting Harlan, so perhaps we have to watch it. We do know that PRR played with smoke deflectors (I remember them on K4s and of course the 6200) but I have no idea if their versions worked, and I'd surmise not well enough since they were not applied in the widespread fashion they were on, say, NYC.
PRR wouldn't buy Hudsons from Baldwin for the reason I gave earlier: they had just spent to get 475 K4s, including 200 from Baldwin, some as late as 1928 (into the real Hudson era). By the time they were looking at better power, it was into the era of the true high-speed 4-8-4 and there was no point in considering anything but eight-drivered power -- had the divided-drive 84"-drivered locomotive worked out there would have been no need for a trivial little Hudson, and modern balancing made an 80"-drivered locomotive perfectly fast enough for what 'used' to demand an 84" wheel. (You will note the somewhat lamentable history of 84" drivered Hudsons in practice, with C&NW notable for being unable even to reach 100mph in AAR testing, and Santa Fe getting little faster even with much more heroic proportions; no one claims comparable top-speed limitation for the S1 if they are even borderline sane. The question was getting that fast, not sustaining it...)
I might mention, in passing, that studies were done to examine whether the nose of the Trust's 5550 could be built, like the nose of the Chezoom, as one piece of composite that would fold up on hinges to allow access to the components (including, if used, a more standard type of feedwater heater) on the pilot beam. That would have made the porthole type front end much more practical, had it been used, and was considered not a meaningful deviation from historical accuracy for the purposes of the Trust's replication, at the time. It might be interesting to have seen how materials like Cycolac or "Endura" might have been used if streamlined steam had persisted a decade or two later than it did... or, for that matter, if the soybean-fiber-in-phenolic used for the body panels in Ford's hemp-powered Volkswagen analogue had panned out.
daveklepperAs good as an F40P might be better.
Had there been any in the late Forties.
You'd still need at least two F40s, even F40Cs, to approximate the high-speed power of a T1. Even a single Charger doesn't quite get there on paper.
Of course, even a single E8 can be a 'fair comparison' if you don't care how quickly the train accelerates or what its balancing speed turns out to be... especially if the E8 'just runs' much more of the time without needing maintenance or service attention.
daveklepper As good as an EMD E-8? To replacd a T-1 with diesels, even just to fully replace a K-4, at least two E-8 units are required. As good as an F40P might be better.
As good as an EMD E-8? To replacd a T-1 with diesels, even just to fully replace a K-4, at least two E-8 units are required.
Yes, I think an EMD E8, maybe a A/B set, was a good candidate to compare with T1 in late 1940s. As Overmod stated in pervious post that even renowned steam engine like NYC Nigeria was barely as good as an E7 base on the result of Kiefer’s test in 1946. RRR T1 and S2 could outperform early diesel at high speed but the latter didn't have the chance to be mass produced. If 5550 can prove that a T1 using Franklin B rotary cam poppet valves can outperform and as economic as an E8, Pennsy might kept developing coal burning steam engine a few years more. (enough time to give S2 a new firebox and make it works)
Note that In 1937, AAR wanted to see what power was needed to get 1000 tons of passenger stock up to 100mph, thus a test was undertaken in 1938 and the result showed that 3370-3400 dphp were needed to maintain 100mph along the level with 1000 tons, 4000 dbhp was needed to accelerate the train to that speed within acceptable times and distance. I don't know if a 1000 tons passenger consist was still a common thing in PRR system or not after the declining of ridership since 1946, but I think an EMD E8 or A/B set (or even the E7A/B ordered in 1946) were powerful and economic enough to handle PRR's postwar (shorter) passenger consists. T1's high TE and dbhp will always be a fascinating thing on paper, but operation cost was Pennsy’s main concern, not to mention the "79 mph speed limit" thingy, thus they did pick EMD E8 and some “interesting” diesels from Baldwin and Alco instead of building more T1s.
Overmod Only just seeing this by reading on a larger screen. I don't even think Martin Clement could have arranged HSR to Pittsburgh……(Not that it wouldn't have been fun to watch them try!)
Overmod The only conclusion I was ever able to reach about the T1 smoke was that when the locomotives were designed and tested, the assumption was that they would always be using good PRR passenger 'gas coal'…… We do know that PRR played with smoke deflectors (I remember them on K4s and of course the 6200) but I have no idea if their versions worked, and I'd surmise not well enough since they were not applied in the widespread fashion they were on, say, NYC.
Overmod You will note the somewhat lamentable history of 84" drivered Hudsons in practice, with C&NW notable for being unable even to reach 100mph in AAR testing, and Santa Fe getting little faster even with much more heroic proportions; no one claims comparable top-speed limitation for the S1 if they are even borderline sane. The question was getting that fast, not sustaining it...)
Overmod I might mention, in passing, that studies were done to examine whether the nose of the Trust's 5550 could be built, like the nose of the Chezoom, as one piece of composite that would fold up on hinges to allow access to the components (including, if used, a more standard type of feedwater heater) on the pilot beam.
Jones1945Yes, he probably couldn't. But once the electrification was done, the facilities won't disappear after Clement left the office. How to max out the potential of the electrification was depending on PRR’s wisdom.
The issue was not the electrification; it was the railroad itself. Not for nothing was the 1928-on improvement plan contingent on substantial straightening and line relocations, and even then I have strong doubts that sustained fast running between slow points would have been practical for many years, far longer in the event than PRR would have had even had the Depression (and the political priority of the Washington electrification) not intervened.
I don't know if it is possible to extrapolate the rather cryptic data on the 1943 electrification to high speed. My impression of the plan was that it would reduce time by 'snapping' trains that would otherwise be horsepower-limited on grades, and reducing absolute grades (e.g. via the tunnel), rather than being the sort of line revision seen between New Brunswick and Trenton around the time of the Civil War (with station facilities that still look modern today... except for the primitive track!) which translate into high default speed potential. For PRR, that was always more of an electrification priority; examine the actual 'passenger' Main Line west of Philadelphia, and the Atglen and Susquehanna 'low grade' line, and you'll get a sense of what the massive Clement/Rea improvements were often intended to do.
Anyway, what happened in the history told us that Pennsy and Budd can’t even get the Metroliner to work properly, it wasn’t entirely Pennsy’s fault though.
That was a squirrelly time for industrial electronics, let alone complicated control systems for complicated trains (developed in complicated Government programs). It also pays to remember how many times the Northeast Corridor had to be 'rebuilt' before it would actually support very-high-speed operation without an exordinate amount of shock and vibration to the equipment...
Smoke deflector was not something the PRR management wanted to see on their engines, I am still wondering why.
Overmod You will note the somewhat lamentable history of 84" drivered Hudsons in practice, with C&NW notable for being unable even to reach 100mph in AAR testing... C&NW’s Hudson was almost identical to MILW’s F7, if the former’s engine couldn’t reach or hardly reach 100mph with normal passenger stock behind her, this may explain the short life of MILW’s F7.
Overmod You will note the somewhat lamentable history of 84" drivered Hudsons in practice, with C&NW notable for being unable even to reach 100mph in AAR testing...
NYC’s Hudson could reach 95mph max during a publicity test run in 1938 and they seldom and didn’t need to brag about top speed of their trains.
Even in 40s, it wasn’t hard to calculate the average speed of passenger trains, the fastest one was “merely” 71mph.
RRs needed their engine capable to maintain tight schedule; they were not looking for locomotive which could run faster than light. Even Pennsy stayed low-key or simply ignored all these speed claims from railfans.
If there are components inside the “porthole front end” than there should be some way to access to these components. If the production T1 of 1945 had feature like this (foldable front end), Pennsy didn’t need to waste so much time and man power to modify 52 of them.
“Project T1” of 1940s (not 5550) was supposed to be a demonstration of cutting-edge technologies; showing the public the future of coal burning steam locomotive. But unfortunately, it has become an imperfect full stop of steam locomotive.
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