I loved this story from the first time I read it ... and am still looking forward to some Q2 tales. Gil Reid bought into the story 'big time', and the result is something we should all have on our walls:
But, just as there is no 'real' Santa Claus for Virginia, there is no getting around that 5536 had no unusual mods to the speed-recorder system documented anywhere in the (rather extensive) material so far identified. I am still looking to see if 5500 (which got the rotary-cam setup) might have had a higher encoder and speedometer display put on as part of the conversion ... but for reasons previously and exhaustively described, I do not think there is, or was, any reason for PRR to put more than a "100mph" speedometer on any of its steam locomotives, with the possible exception of the S1 (which I think might have been 110mph, still well short of what was reported on 5536 - I am looking for my backhead shot of the S1 locomotive to confirm this).
Note that Crosby is not a T1 expert - he claims that all the T1s had 'rotary cam poppet valves' which is a strange thing to make it past the Trains Magazine editors. I continue to think that this is akin to the situation where the 161mph Hudson slip tests morphed with the 'serum to Nome' railroaders'-boyhood stories to produce that story about a Hudson rushing medical relief across New York State at 157mph ... a lot of verisimilitude with a few little mistaken points that spoil the tale a bit, like some of John Barnes' early science fiction.
Note that I say this all with extreme regret, as I think the T1 design was easily capable of performing as reported.
Thanks for the Gil Reid artwork. immediately downloaded to my hard-drive. Thanks!
I remember the article and especially the Gil Reid painting. I saw it in a short-lived magazine called "Vintage Rails" which I wished I kept, dammit!
It may have originally appeared in "Trains," but I'm not sure about that.
Thanks David and RME!
I don't have the T1 print but I do have a similar one of an NYC J3a Hudson framed print entitled "79 MPH".
Another really beautiful painting that is on my hard-drive is Rose's Walking through Texas. I really get a lump in my throat every time I look at it. Two Riply Northerns heading into the sunset with SF refers.
Some day I will find the right story to attach to it. Railroading has insipired some terrific painting as well as photography.
One that I am particularly fond of, as telling a story that unfolds as you look at it, is John Winfield's take on Scheeler's Rolling Power called "Three Hours to Amarillo" (I'm not posting a thumbnail, but here is a place where you can see a large preview by clicking the thumbnail (and a great many fine other paintings as well).
John Winfield is a great, great artist. I am fortunate to have prints of his "Extra 3801 West" and "Cab Forwards On Tehachapi". Looking to give myself a Christmas present of "Storming Curtis Hill" showing ATSF 2926 on a reefer block. All his work is excellent.
A great story indeed! Almost made me feel like I was in the cab.
Rio Grande Valley, CFI,CFII
Here's a question for one of you with an engineering degree. This T1 was pulling 14 cars, which I would estimate to be about 1200 tons. Please feel free to amend that estimate if you wish. Add to it another 450 tons for the locomotive and tender. Now tell me how much horsepower would it take to move that load 120 mph on level ground. Also is there a formula one can use to determine HP? In my foggy memory I recall the T1 to be capable of 5000 to 6000 HP. Is that enough to pull off the alleged performance?
tpatrickhow much horsepower would it take to move that load 120 mph on level ground.
No one here knows. We can guess at it, and maybe be right within a factor of 1.5 or so.
tpatrickis there a formula one can use to determine HP?
Horsepower of the locomotive, you mean? There are formulas, but no one would promise they're right. Only way to learn the power of a steam locomotive is to test it.
tpatrick 5000 to 6000 HP
5000 to 6000 HP
The T1 may have been capable of 5000 dbhp, but not at 120 mph.
There is no 'one true' formula for calculating dbhp (which is the only thing that really counts on the road). Chapelon says PRR observed 6760ihp from the instrumentation on one run on the test plant at 100mph indicated, but he does not say what was recorded on the roller brakes for that run (which would be close to wheelrim HP). Machine losses on the T1s were remarkably low, so I would not think dbhp would vary very far from wheelrim output; there should be a correction factor for the high-speed slipping but that's probably impossible to model deterministically, let alone get meaningful numbers from; it should be possible to model the aerodynamic drag under straight and quartering conditions using a second locomotive and a dynamometer car able to record accurately in buff.
Meanwhile, the practical falloff of developed HP at high speed is probably far less on the T1s than most other locomotives, as both admission volume and timing precision will be maintained by the poppet valves up to very high cyclic rpm (as observed on 5399) and the superheat will ramp up to ridiculous levels (as on 614) without producing catastrophic valve issues (as on the high-speed class J testing) if the 1948 valve improvements are used. So the falling 'tail' of the horsepower curve, already relatively broad and flat, may be sustained far longer than anticipated at speeds above those PRR actually tested on the plant. I expect the actual limiting factor to be backpressure in the front end (and characteristics of chassis stability) and both of those to be well above 120mph on level, straight, ideal track.
I think you are vastly overestimating the train weight. If you consult PRR equipment diagrams for the lightweight equipment (for example the POS211a observation) you will find a light weight under 60 tons, and I believe this may cross-relate well with 14 such cars, loaded, representing the design load (880 tons) for the locomotive.
This story and the painting ran in Trains Magazine back in the 60's or 70's - likely I have the issue and can find it.
Doc
RME Machine losses on the T1s were remarkably low
Machine losses on the T1s were remarkably low
Are there any usable sources from machine losses -- friction between the power in the cylinders and power at the wheel rims?
John Knowles had posted a long report on this subject, but it looks to be that his Web site is no longer up. What was interesting about his work is that this machine friction varied with load and speed in a way that made it more complicated than a simple "mechanical efficiency" number. Another point was that the machine friction of a locomotive was much higher than the locomotive's Davis formula rolling resistance, to the point where the machine friction of the locomotive was roughly comparable to the (non-aerodynamic) rolling resistance of the entire train it was pulling.
I am interested if there are other sources going into comparable detail.
If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
Wish to correct my Johe Rose SF ReferBlock painting posting:
Racing into the SunRISE is correct!
Paul MilenkovicAre there any usable sources from machine losses -- friction between the power in the cylinders and power at the wheel rims?
There are some discussions relevant specifically to the T1 in the Engineering Committee sections on the T1 Trust site.
Part of the reason for the machine losses being (relatively) low was the use of roller bearings, and supposedly-more-than-desultory wheel turning to profile. I'm sure the burns from the various kinds of slip did not help the situation, but the magnitude of the difference was probably only a fraction of a percent, the difficulties being much more pronounced in terms of reactions at high speed and increased propensity for very-high-speed slipping.
The difference between Franklin type A and piston valves is substantial, both in relative friction and inertia. Typical piston valves for a locomotive this size would consume something like 35hp around diameter speed, and of course much more at higher speed or if unanticipated high superheat degraded the tribology. Franklin indicated that the hp to run type A was about 3hp (much of which was in compression of the springs and lubricated contact of the little dwarf radial gear in the box). "Standard" type B RC was supposed to be less, but I don't have any material on the specific 4-valve RC conversion ("B-1") that the only RC T1 had, which had more cams and linkage at all 'eight corners'.
ISTR some correspondence at the Hagley that indicated the hp to drive the valves on the T1a was about 22hp, but I don't really know if that was for both or for 'each engine' - the valves are not that much smaller than typical.
As a perhaps-interesting aside, there was some discussion about flexion in the Timken lightweight rods being a source of loss (Chapelon mentions the effect in conjunction with lateral-motion devices and roller-bearing rods). I'm not sure I believe this, but there is strong circumstantial evidence...
I will ask John (via steam_tech) whether his reference is still on the Web, or if not whether I can find a way to put it up or quote from/summarize it here.
daveklepperWish to correct my Johe Rose SF ReferBlock painting posting:
Unless I'm sadly mistaken you need a little more correction - isn't it TED Rose?
While we're on the general subject, here's Ted 'on topic':
and for a couple of you who are enamored of the Milwaukee F7, here's something T1s for all their slipping didn't do:
And, for Mr. Klepper, here's something akin to 'Racing into the Sunrise' that he might appreciate...
RME and for a couple of you who are enamored of the Milwaukee F7, here's something T1s for all their slipping didn't do:
I am guessing that is a representation just a second after broken rod?
Never too old to have a happy childhood!
BaltACDI am guessing that is a representation just a second after broken rod?
It is one of two possible things. The likelier one is the event Scribbins described where (if I recall this correctly) the crosshead seized in the guide due to tribology problems at speed. The train momentum (and thrust from the other side) bent the main, which then windmilled knocking off the shrouding but somehow not digging into the ties and lifting that side of the locomotive.
The other possibility, which I saw documented in a thumbnail picture in Trains years ago without a full narrative, involved a broken main pin. I suspect those were starting to become relatively frequent in the latter-'40s experience with big steam running lots of effective horsepower through just two pins, especially in arrangements like the 'revised' system on N&W Js that put the bending moment on the main far out on the pin (somewhat ironically to relieve a chronic fracture problem on the extended #4 driver pins in the inline tandem-rod original arrangement). I do not know how much actual R&R of roller-bearing rods and magnafluxing of pins actually took place, but have my suspicions that there is a relatively narrow critical range of load in which the failure of the pins would rise dramatically...
Paul Milenkovic RME Machine losses on the T1s were remarkably low Are there any usable sources from machine losses -- friction between the power in the cylinders and power at the wheel rims? John Knowles had posted a long report on this subject, but it looks to be that his Web site is no longer up. What was interesting about his work is that this machine friction varied with load and speed in a way that made it more complicated than a simple "mechanical efficiency" number. Another point was that the machine friction of a locomotive was much higher than the locomotive's Davis formula rolling resistance, to the point where the machine friction of the locomotive was roughly comparable to the (non-aerodynamic) rolling resistance of the entire train it was pulling. I am interested if there are other sources going into comparable detail.
I found this info from a thread from 2012.
http://cs.trains.com/trn/f/741/p/2917510/reply.aspx
NM_Coot Santa Fe test results showed that the 3765 class with limited cutoff could maintain full boiler pressure at all speeds and cutoffs. Test runs with 3766 showed 5450 MIH at 55 to 70 mph and over 5000 IH from 35 to 90 mph. Given the Santa Fe penchant for long runs at high reliability, this high HP over a very wide speed range makes for excellent performance with heavy, fast services where maximum output is required over wide speed ranges. The concept of limited cutoff was recommended for implementation on the 3460, 3776, and 5001 classes. In passing, the test of 3766, as equipped with roller bearings on all axles, gave a mechanical efficiency of about 90% up to 30 MPH and then dropped to about 82% at 60 MPH and 62% at 90 MPH.
Santa Fe test results showed that the 3765 class with limited cutoff could maintain full boiler pressure at all speeds and cutoffs. Test runs with 3766 showed 5450 MIH at 55 to 70 mph and over 5000 IH from 35 to 90 mph. Given the Santa Fe penchant for long runs at high reliability, this high HP over a very wide speed range makes for excellent performance with heavy, fast services where maximum output is required over wide speed ranges. The concept of limited cutoff was recommended for implementation on the 3460, 3776, and 5001 classes. In passing, the test of 3766, as equipped with roller bearings on all axles, gave a mechanical efficiency of about 90% up to 30 MPH and then dropped to about 82% at 60 MPH and 62% at 90 MPH.
emphasis mine
Cruising at high speed...
Not sure how fast this one is moving, but it gives a pretty good idea what the T1 Trust is all about....
Here is a nifty 4-minute video with a lot of T1 footage...
https://m.youtube.com/watch?v=znMu4K71ktY
At Columbus, OH...
Doubleheading with another T1 in the smoke shadow...
Outrunning the camera shutter at high speed...
Burning up the miles with a dinged-up front end...
Coming up the express tracks on four tracks wide...
About to rattle double diamonds...
Station stop at Valparaiso...
Broadside at a bit of an odd angle, but it shows just how big a unit these locomotives are - they are very large...
Fresh out of Altoona Shops...
At Harrisburg PA...
Downgrade on Horseshoe Curve...
Brunswick Green at speed...
Station stop...
Ready to roll...
What was the capacity of the tender?
BaltACD, the numbers for 5500-5549 are 42.6 tons of coal and 19,200 US gallons of water per the info on Steamlocomotive.com.
http://steamlocomotive.com/duplex/?page=prr
The engine and empty tender are reported as weighing 944,700 lbs.
The T1 driver fixed wheelbase was 25 feet 4 inches. This compares to the PRR J1 driver fixed wheelbase of 24 feet 4 inches.
Big units!
tpatrick Here's a question for one of you with an engineering degree. This T1 was pulling 14 cars, which I would estimate to be about 1200 tons. Please feel free to amend that estimate if you wish. Add to it another 450 tons for the locomotive and tender. Now tell me how much horsepower would it take to move that load 120 mph on level ground. Also is there a formula one can use to determine HP? In my foggy memory I recall the T1 to be capable of 5000 to 6000 HP. Is that enough to pull off the alleged performance?
I dont drive trains, I have driven a steamer once and a diesel a few times, but I can explain large loads and speed...
My experience is trucks and I dont mean just one trailer and weighing only 42.5 tonnes(93,600 lbs) but upto 100 tonnes(220,000 lbs).. top speed aloud is 100 kph(60 mph)..
You might think, impossible with 50 tyres under you, 13 axles and and rough roads... But its getting going thats the hard bit, once you get that weight working for you and pushing when you need it, maintaining speed is easy and if our laws aloud, I could easily get upto 130 kph or more, but heat on tyres etc would be a problem... big hills that pulled you down below 80 kph(50mph) meant you had to make the engine work and gearing to pull you over the hill, so you would end up at about 50 kph(30mph)...
A good operator is only limited by the machines limits, there are limits to every machine(my limit was 550hp)..steam engines that are designed for speed, generally are capable of a lot more than they do daily, but then the operator is taking a risk at breaking the gear too...
I have read and heard stories about steamers going a lot faster than they where designed for, but they where designed to do a job and ability to do more, thus giving the engine a chance to last longer in service... Pushing the limits reduces that service time... A good operator should always get the best out of a machine..
I would love to have been able to run an express in an emergency, thats when you could run the fastest without any restrictions...( Like needing fresh cream for the local bailiff)...
I had the pleasure of meeting John Crosby's son a few years ago. He said that it was not an isolated incident and that engineers would frequently exceed the speed limit in order to make up time on a passenger train running late.
His dad ended up as a PRR tower operator in Toledo where he had a lot of time to write.
Leaving Chicago Union Station...
Leaving Chicago...
Passing Van Wert, OH on the advertised...
Waiting for the highball...
Pittsburgh engine terminal...
A little wear and tear but ready to chew up the miles...
Rockville Bridge...
Clean stack through Harrisburg, PA...
Making time through Pittsburgh, PA...
Fresh off the showroom floor...
A musician-author-teacher responded to my Christmas transmission to her as follows:
kgbw49Leaving Chicago Union Station... Leaving Chicago... Passing Van Wert, OH on the advertised... Waiting for the highball... Pittsburgh engine terminal... A little wear and tear but ready to chew up the miles... Rockville Bridge... Clean stack through Harrisburg, PA... Making time through Pittsburgh, PA... Fresh off the showroom floor...
Some engines have the Keystone mounted on the housing just above the coupler. Others have some kind of light mounted there. What is the signifigance of the light?
I would guess that the locomotives with the low-mounted Keystone would be 6110 and 6111, which could be described as pre-production models.
CSSHEGEWISCHI would guess that the locomotives with the low-mounted Keystone would be 6110 and 6111, which could be described as pre-production models.
Out of the 10 pictures that were quoted in my prior post, 6 had keystones and 4 had lights. Can't read engine numbers in the 10 pictures.
BaltACD, my take on the T1 Keystone number plate location is that it changed when the front end was modified.
It looks like even the production units had the low number plate when they had the "fancy" front end with the three small portholes on the sides and an overall more bulbous look, as exemplified by 5528 in the last photo (which appears to be taken right after it was released from the shop). In that configuration, access to the running boards looks to be via grab irons and some recessed steps.
But it looks like the front ends were modified at some point to give access to the running boards by the more traditional slanted ladders, at which point the Keystone was moved up to the prow just under the headlight. It seems like the ladders give better access to the running boards for maintenance crews and it looks like the redesign also removed skirting from the sides in front of the first set of pistons, which I am surmising might also make maintenance easier. The second last photo shows 5500 with the modified front end.
That is just my best guess. Perhaps there are some Pennsy steam experts out there who could shed more light?
There are two distinct front-end styles for the 'production' T1s. The first style is the one with the portholes, and the center low-mounted keystone. These were rebuilt very quickly to the 'later' version with the Timken Stoker-like housing with the 'auxiliary light' in the middle, and keystone up on the prow where it belongs.
By the way: I had thought the light oscillated, a bit like a poor man's Mars light. It does not - it's just an extra 'fog' light. (Found the detail drawings!)
A few more interesting T-1 photos...
PRR T-1 pulling what must be express box cars...
PRR T-1 5537 fresh out of the shop...
PRR T-1 6110 Builder's Photo...
PRR T-1 5501 view of the front end set up...
PRR T-1 6110 being tested at Altoona...
PRR T-1 Prototype testing clearances (Pittsbugh, perhaps?)...
PRR T-1 ready to depart unknown location next to station switcher...
PRR S-1 6-4-4-6 Duplex with 84 inch drivers and total engine and tender length of 140 feet, five feet longer than the Big Boy at 135 feet, racing a NYC J3a Hudson out of Chicago...
PRR T-1 5519 traditional wedge shot from the back end...
PRR T-1 5517 roster shot in Fort Wayne IN...
PRR T-1 6111 publicity shot with rods down on the front drivers...
PRR T-1 55?? getting coaled up...
kgbw49 -
Just love that photo of the S1 Duplex and streamline NYC Hudson 5519 heading east out of Chicago - MAGNIFICENT ANACRONISM! so perfectly illustrated!
The Hudson - Superlative machine near the end of its magnificent career with literally thousands and thousands of successful miles pulling revenue passenger trains at high speed and - THE MARQUE of successful passenger engines replete with roller bearing drive - combustion chamber - and gladiator warrior styling!
The Duplex - the largest high speed passenger engine of its type ever built - experimental - non standard - unusable for most purposes for which it was designed - a vision of the future! And - so very very very fast!
------------------------
The engineer of the Hudson must have felt totally outclassed in his already famous race horse - the engineer of the Duplex must have felt it was time to overthow the reigning speed queen - finally something faster than a Pacific!
The photo shows the real true size - not the height of the Hudson - and the never ending mystery of the duplex!
Both engines are moot - the end of a glorious age of what was and what could have been!
-------------
Thanks for the great photo!
Great shot of the S1 racing the Hudson! I wonder who won the race that day?
One thing's for certain, the loser would have said "We weren't racing!"
A couple of informational items on the PRR S1...
S1 Builders Photo...
S1 at Fort Wayne IN...
S1 in service - the size of the people give scale to the enormous size of this locomotive...
S1 coaled up and ready for service...
I have often wondered how the Lionel people could ever have confused this
with this pudgy thing
when writing a children's story about the Torpedo, the fastest and most modern locomotive in the world. Seems pretty obvious to me that someone got mixed up looking at their historical pictures...
Of course, if the object is to sell Thomas/Skaneateles compatible toys, then you need a short tubby 'streamlined' thing. But honestly now, which one is the better torpedo?
RME,
Had a chance to visit NYC 3001 4-8-2 Mohawk in Elkhart, Indiana this holliday season. Specifically to examine the Valve Pilot Indicator speedometer that survives on this locomotive. This highly accurate speedometer was standard equipment on most of the Central steam locomotives of the World War II vintage. The speedometer of NYC 3001 reads out to 120 mph.
This would seem to challenge your post indicating that Pennsylvania Railroad would not have equipped the T1 Duplex 4-4-4-4 with a speedometer greater than 100 mph and the S1 Turbine 6-8-6 locomotive with a speedometer greater than 110 mph.
---------------------
Examination of PENNSY POWER by Alvin Staufer - page 220 indicates the styling of the T1 Duplex came in three forms - with a fourth modified type designated the T1a.
Type 1 Experimental 1942 T1 - These were locomotives 6110 and 6111 built experimentally by Baldwin Locomotive works in April 1942. 6111 being the only duplex which was equipped with a low speed booster engine. Styling was by Raymond Loewy. These engines were the brain child of famous Baldwin engineer Ralph P. Johnson who also published in 1942 his famous work on steam locomotive engineering THE STEAM LOCOMOTIVE.
Loewy's styling of these two engines was different than the engines that were to follow - they featured a chisel shaped front boiler cowling which came almost to a point - and then tapered far back to the frame location of the first cylinder crossheads. This early design further included a a large front deck appliance cowling with "port hole trim" and no running board ladders. A low mount keystone number board was featured on the lower cowl.
Type 2 Baldwin Production 1946 T1 - This design included a newer boiler front cowl design with a now "blunt prow" that tapered back the chisel shape only to the frame location of the first axle of the front truck. I believe this would have allowed the standard smoke box front course shape to be completly round at the location of the hidden inside boiler front.
This "type 2 production 1946 T1" design retained the same large front deck appliance cowling with its "port hole trim" of the "type 1 experimental 1942" engines.
Type 3 Altoona Production 1946 T1 - This featured the same "blunt prow" boiler front modifcations of the "Type 2 production 1946 T1" design, but now also included changes to a new "narrow lower appliance cowling" which then allowed running board ladders to equip the locomotive front ends - now sans the stylish "port hole trim" design.
The "low mount" keystone engine number board was then moved up to just below the headlight on the blunt boiler front cowling of the locomotive. Further changes included a reduction of the streamline side skirting attached to the locomotive side running boards.
----------------------
Type 4 Altoona T1a - These changes required a re-designation of the type T1 to T1a classification for only one locomotive T1 5547. The "type 4 changes" came about when certain locomotive maintaince problems lead to a rethinking some of the T1's initial features. Opportunity for these needed changes were first considered with the rebuilding of T1 engine 5500 which recieved "continuous contour rotary valve equipment" but remained a T1.
Changes also occured with the rebuilding of T1 engine 5547 which resulted in entirely removing all 4 of the high speed poppet valve gear systems - change significant enough to reclassify engine 5547 as T1a type. This extensive 5547 rebuild included the manufacture of completely new cylinder steamchests for all four cylinders and refitting with retro style - Walschaert valve gear setups - no small task.
The T1/T1a rebuild/re-thinking included other changes to all the following rebuilt engines - a new box style classification lights on each side of the boiler front - and the inclusion of a second alternate headlight systenm - also called a "fog light" - to be mounted on the lower appliance cowl - in place of the former "low mounted" keystone number boards. All engines eventually recieved this treatment.
------------------------------
Staufer notes the following engine power numbers for the T1 Duplex 4-4-4-4 engines which is quite remarkable:
"To fulfill the contract with Baldwin Locomotive Works in the construction of the T1 expermental engines 6110-6111 only 2,980 horsepower was required. 6110 topped this by 38% producing 4100 indicated horsepower at 100 mph.
Compared to Pennsy M1a 4-8-2 design the T1 Duplex produced 46% more drawbar horsepower with but 11% more steam usage per hour.
Test plant data for the T1 Duplex are as follows,
Maximum drawbar horsepower - 6,110 hp
Maximum indicated horsepower - 6,552 hp
Test run at speed of 85.5
Cut off - 25%
Boiler Pressure - 295 psi
Steam chest pressure - 287 psi
Indicated horsepower was 4838 at 38 miles per hour, and was usually above 6000 horsepower at all speeds over 55 miles per hour.
The T1 Duplex out performed 4 unit 5,400 horsepower diesel engines on the property at all speeds above 26 miles per hour.
Engine 6110 made the first run from Harrisburg to Chicago with 14 coaches weighing 1000 tons. From Crestline, Ohio to Fort Wayne, Indiana ran 20 minutes ahead of schedule the run completed to Chicago an additional 13 minutes ahead of schedule - for a total of 33 minutes ahead of schedule. Speed was consistantly in neighborhood of 100 miles per hour.
With a heavier train of 16 cars T1 Duplex 6110 performed even better running the Fort Wayne, Indiana division speedway at an average speed of 102 mph for 69 continuous miles!"
--------------------
I think you might want to reconsider you opinion about the speed capacity of the Pennsy T1 Duplex 4-4-4-4 locomotive.
LIONEL - Also was the worlds best maker of TOY trains - good for running across the rug - under the dining room table - past the "chase lounge" - or alternately round round the X mas tree - a considerable engineering challenge in its own right - when done correctly! You must forgive a few historic in-accuracies to accomplish this!
Indeed the S1 Duplex 6-4-4-6 beauty was truely heroic and considering todays standards of overall size increases in equipment maybe a better choice for reproduction that another less stylish T1 Duplex 4-4-4-4.
Best of the New Year!
Well yes, it HAS been suggested that a replica of the S1 would be a lot more, well let's say "cool," tan a replica of the T1, but remember an S1 replica would have the same problem the original had. Not that it didn't perform well, it performed beautifully. The problem was it was too damn big!
Too big for any of Pennsy's turntables, it had to be turned on wyes, and even then it had to be handled with kid gloves or it would derail. And sometimes it derailed even with kid glove treatment. In a way, it was a locomotive equivalent of a boat built in the backyard that can't get out past the house and to the street.
Too bad, it was a good performer otherwise. Anyway, the size of it was the reason it was the only one built. Too bad it wasn't saved just the same.
I've always greatly preferred the styling of the S1 to the T1 and feel that cleaned up a bit it would have made for a sleek locomotive if applied to a more conventional 4-8-4 (which was probably more what the PRR needed anyway). Just peel back the side skirt to show more of those huge drivers, eliminate the strange fin just under the nose and clean up the pilot and you've got a very pretty locomotive.
Dr DEngine 6110 made the first run from Harrisburg to Chicago with 14 coaches weighing 1000 tons. From Crestline, Ohio to Fort Wayne, Indiana ran 20 minutes ahead of schedule the run completed to Chicago an additional 13 minutes ahead of schedule - for a total of 33 minutes ahead of schedule. Speed was consistantly in neighborhood of 100 miles per hour.
.
BigJim Dr D I am going to question this validity of that statement. Were there any scheduled timetable stops anywhere along the way between Crestline and Chicago? If so, the train could not leave a station, or pass any timetabled point, before the scheduled departure time. Therefore, the train could make up time being late into a station, but the only way that it could run early into Chicago was between Chicago and the last stop where it would have left that station on time.
Dr D
I am going to question this validity of that statement. Were there any scheduled timetable stops anywhere along the way between Crestline and Chicago? If so, the train could not leave a station, or pass any timetabled point, before the scheduled departure time. Therefore, the train could make up time being late into a station, but the only way that it could run early into Chicago was between Chicago and the last stop where it would have left that station on time.
Speculation - 14 coaches might equal the Trailblazer, the PRR's 'through' coach streamliner. Such streamliners discouraged 'local' pick up stops for passengers, relegating them to other local trains that specialized in picking up passengers at every tank town and milk stop. As such, it may have been authorized to operate in advance of it's scheduled times - especially since it was not operating over single track, timetable and train order territory from Harrisburg to Chicago.
Rode the Trailblazer westbound late June 1952. Diesel power after Harrisburg. No pickup stops west of Fort Wayne, only discharge, Arrived in Chicago 15 minutes ahead of schedule. Similarlly only pickup stops east of Harrisburg, no discharge. Comfortable, smooth ride. Only El Cap highlevel coaches better.
The point is, if the train was timetabled, it cannot leave a station before the time stated.
Dr DHad a chance to visit NYC 3001 4-8-2 Mohawk in Elkhart, Indiana this holiday season. Specifically to examine the Valve Pilot Indicator speedometer that survives on this locomotive. This highly accurate speedometer was standard equipment on most of the Central steam locomotives of the World War II vintage. The speedometer of NYC 3001 reads out to 120 mph. This would seem to challenge your post indicating that Pennsylvania Railroad would not have equipped the T1 Duplex 4-4-4-4 with a speedometer greater than 100 mph and the S1 Turbine 6-8-6 locomotive with a speedometer greater than 110 mph.
Except that we have no evidence of a speedometer design for the T1 that reads higher. (And it's highly unlikely that the S1 received a new, faster speedometer than it was given as a high-speed experimental locomotive...) [As a note - the S1 was the 6-4-4-6 duplex; the S2 was the turbine]
It would be interesting to see whether the T1a was fitted with Valve Pilot using a speed reference independent of the Jones-Motrola it was built with (the speed reference for the Valve Pilot's "computer" being taken from a different axle than the 'native' T1 system used), If the device as used on PRR actually had a dial display, it would be interesting to see if it read up to 120mph as 3001's does, or indeed if 120mph is a "standard" for some locomotives that integrate speed recording with Valve Pilot.
Frisco 1351 has a postwar installation of Valve Pilot but I don't recall it having a speedometer, just the 'needle matching' that would have been used at any part of operation. I will have to sneak up and check.
BigJimThe point is, if the train was timetabled, it cannot leave a station before the time stated.
If authorized by special instructions it can. There is more to a timetable than schedule times.
BigJimif the train was timetabled, it cannot leave a station before the time stated.
(That exception is in the 1947 PRR rulebook-- it's not in the 1925.)
In any case, if it doesn't pick up passengers they could run it extra if they wanted to run ahead of its schedule.
Great thread. Not much brings out the photos, superb comments and total fascination as the T1's do.
So mysterious, so imaginative, so fast and powerful and lost to us entirely before we could really understand it, grasp it, know it ..vanished like a dream...and the stories and lore keep coming. A future lost to us, never revealed.
RME, according to Chris Zarhrt's superb article on the Loco Valve Pilot in the Classic Trains special "Steam Glory 3" the Pennsylvania RR wasn't one of the Valve Pilot users.
They were, as follows: Atchison, Topeka & Santa Fe, Atlantic Coast Line, Bessemer & Lake Erie, Boston& Maine, Central Railroad of New Jersey, Central Vermont, Denver & Rio Grande Western, Maine Central, New Haven, New York Central, New York, Ontario & Western, St. Louis-San Francisco, Savanna & Atlanta, Southern Pacific, Union, Western Maryland, Wheeling and Lake Erie.
Just How Big?
The S1 Pennsylvania Duplex 6-4-4-6 and T1 4-4-4-4. How did they compare to the steam power of the age - specifically?
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Firebox dimensions - Grate area - Combustion chamber length: this is where the power comes from.
S1 duplex 6-4-4-6: firebox 198"x96" with combustion chamber of 113" and grate area of 132 sq feet.
T1 duplex 4-4-4-4: firebox 138"x96" with combustion chamber of 84" and grate area of 92 sq feet.
Lets examine a few other famous engines also:
New York Central, Hudson 4-6-4: firebox 130"x90" with combustion chamber of 43" and grate area of 81.5 sq feet.
New York Central, Niagara 4-8-4: firebox 151"x96" with combustion chamber of 81" and grate area of 101 sq feet.
Atchison, Topeka & Santa Fe, Northern 4-8-4: firebox 144"x108" with combustion chamber of 64" and grate area of 108 sq feet.
Milwaukee Road, F7 Hudson 4-6-4: firebox 144"x96" with combustion chamber of 45" and grate area of 96.5 sq feet.
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To put the Pennsylvania Railroad S1 duplex 6-4-4-6 to something of a larger framework compare it to these engines.
Chesapeake & Ohio, Allegheney, 2-6-6-6 articulated freight engine: firebox area 180"x108" with a combustion chamber of 118" and grate area of 135.2 sq feet.
Union Pacific, Big Boy, 4-8-8-4 articulated freight engine: firebox 235"x96" with a combustion chamber of 112" and grate area of 150.3 sq feet.
Pennsylvania Railroad, Duplex Q2, 4-4-6-4 all time highest horsepower freight engine: firebox 162"x108" with combustion chamber of 124" and grate area of 121.7 sq feet.
Pennsylvania Railroad, S2 steam turbine 6-8-6 all time unique design passenger engine: firebox 180"x96" with combustion chamber of 120" and grate area of 120 sq feet.
"Big" in context! -
The S1 Duplex 6-4-4-6 was a high speed passenger engine on the equivilent size of the articulated Union Pacific "Big Boy" and Chesapeake and Ohio "Allegheney" something never duplicated by any railroad.
The T1 duplex although set up with running gear and steam distribution as the ultimate high speed passenger engine produced in mass numbers, its actual firebox grate and size were smaller than the NYC famed "Niagara" and Santa Fe "Northern" and smaller than the Milwaukee F7 high speed "Hudson."
Pennsy T1 Duplex 4-4-4-4 like its famed Q2 partner 4-4-6-4 freight engine were relying on steam distribution technology of the age to achieve their ultimate performance numbers. The Q2 with its outstanding record of freight power and T1 with its outstanding if unrecorded speed record.
Both Pennsy engines and the awsome S2 Turbine 6-8-6 needed development time to achieve their full potential and were never given the chance - because of this they were in some respects partially eclipsed by more conservative and less radical locomotives of equivalent fame.
When it comes to the stuff of dreams though - The Pennsylvania Railroad lives large and took us on a trip un equalled in railroad locomotive history - the mythological journey in steam - of what could have been? - truely written and painted forever large as "American Railroad Glory!" Is it any wonder the T1 trust wants to reproduce a long lost T1 duplex!
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- Doc
Dr D Both Pennsy engines and the awsome S2 Turbine 6-8-6 needed development time to achieve their full potential and were never given the chance - because of this they were in some respects partially eclipsed by more conservative and less radical locomotives of equivalent fame. - Doc
They were eclipsed by what was considered a radical design on PRR, diesel-electric locomotives. The pair of E7A's that were assigned to the "Red Arrow" were getting substantially better monthly mileages than the T1's. High-speed performance looks flashy, but it doesn't mean too much if the locomotive spends an inordinate amount of time between runs being serviced and maintained.
Nice work and summation Dr D. Handy little reference.
At least we had that glimpse and PRR tried. However... the FIX was in.
Dr D The T1 duplex although set up with running gear and steam distribution as the ultimate high speed passenger engine produced in mass numbers, its actual firebox grate and size were smaller than the NYC famed "Niagara" and Santa Fe "Northern" and smaller than the Milwaukee F7 high speed "Hudson."
Smaller grate and firebox? That is the whole idea, of this . . . machine, you know?
https://www.youtube.com/watch?v=2yfXgu37iyI
CSSHEGEWISCH Dr D Both Pennsy engines and the awsome S2 Turbine 6-8-6 needed development time to achieve their full potential and were never given the chance - because of this they were in some respects partially eclipsed by more conservative and less radical locomotives of equivalent fame. - Doc They were eclipsed by what was considered a radical design on PRR, diesel-electric locomotives. The pair of E7A's that were assigned to the "Red Arrow" were getting substantially better monthly mileages than the T1's. High-speed performance looks flashy, but it doesn't mean too much if the locomotive spends an inordinate amount of time between runs being serviced and maintained.
Exactly!! In the NFL, a key concept is "availability" -- if you are oft injured or, in some experimental steamers' cases, laid up in the backshop, fancy stats don't matter so much.
C&NW, CA&E, MILW, CGW and IC fan
schlimm CSSHEGEWISCH Dr D Both Pennsy engines and the awsome S2 Turbine 6-8-6 needed development time to achieve their full potential and were never given the chance - because of this they were in some respects partially eclipsed by more conservative and less radical locomotives of equivalent fame. - Doc They were eclipsed by what was considered a radical design on PRR, diesel-electric locomotives. The pair of E7A's that were assigned to the "Red Arrow" were getting substantially better monthly mileages than the T1's. High-speed performance looks flashy, but it doesn't mean too much if the locomotive spends an inordinate amount of time between runs being serviced and maintained. Exactly!! In the NFL, a key concept is "availability" -- if you are oft injured or, in some experimental steamers' cases, laid up in the backshop, fancy stats don't matter so much.
It appears that the NYC Niagara and the N&W J class weren't simply regarded as fancy locomotives but rather as part of a system, which included the maintenance procedures to keep them out on the road turning miles. It seems that the T1 was put together for high performance, with everything else about them -- training crews as to their performance characteristics, setting up shops to handle them, and so on, were an afterthought.
One of the excuses is that the Pennsy had lost the touch with developing new steam locomotive types and everything that goes with them. That had put a lot of money and effort into partial electrification in the 1930s giving a lot of surplus steam locomotives and little need to update their designs until the mid 1940s.
Another excuse is that the Pennsy way was to introduce a design and "work the bugs out" through extensive testing, a process that was rushed with the T1.
But to the extent that the Niagara was a "success" and the T1 a "failure", all of these locomotives had a short service life and were rapidly replaced by Diesels. Not only was steam on the way out, passenger service was also on the way out, and you could say that the Pennsy was on the long slide to being the Penn Central.
The poppet valves didn't help. The legend goes that the (largely unauthorized) 100 MPH+ running of the crews damaged the poppet valves or their drive cams, and servicing those valves practically required taking the whole locomotive apart. Think of the 4-6-8 valved Cadillacs or some other fancy car offerings of the 1970s and 80s that didn't hold up well in service.
Ok guys - I get it - you believe in the great myth that was the EMD E7 diesel electric locomotive - and this post is about "THE MYTH AND THE MYSTERY BEHIND THE PENNSY DUPLEX T1."
I might remind you that the EMD E7 today is just as dead an issue as the Pennsy Duplex is - in fact preparations are afoot to build a new T1. Here is the mystery and the magic? - that anyone would go to such expense! Truely the Pennsylvania Railroad should have preserved a T1 Duplex.
THE PENNSY DUPLEX AND WEIGHT ISSUES:
If the Pennsy T1 Duplex 4-4-4-4 had been designed with greater weight on the drive wheels - COULD substancial repair costs to the highly successful poppet valve design have been adverted.
The other giant S1 "experimental" Duplex 6-4-4-6 had been fitted with regular retro low speed design Walschaerts piston valve gear.
Considering its operational speed the Q2 Duplex "freight" engine 4-4-6-4 was also given Walschaerts valve gear in its design decision - but also had significantly greater weight on the drive wheels! - this was one factor attributed to successfully eliminating much of the damaging Duplex wheel slipage problem.
WEIGHT OF THE ENGINE AND WEIGHT ON THE DRIVE WHEELS this determines partially the traction given a locomotive and resultant potential to slip the drive wheels under power.
Pennsylvania S1 Duplex 6-4-4-6 - drive wheel diameter 84" - total engine weight 608,200 lbs - weight on drive wheels 281,400 lbs.
Pennsylvania T1 Duplex 4-4-4-4 - drive wheel diameter 80" - total engine weight 497,200 lbs - weight on drive wheels 268,200 lbs.
Pennsylvania Q2 Duplex 4-4-6-4 - drive wheel diameter 69" - total engine weight 621,100 lbs - weight on drive wheels 386,000 lbs.
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New York Central Hudson 4-6-4: drive wheel diameter 79" - weight of locomotive 265,500 lbs - weight on drive wheels 201,800 lbs.
New York Central Niagara 4-8-4: drive wheel diameter 79" - weight of locomotive 471,000 lbs - weight on drive wheels 275,000 lbs.
Atchison Topeka & Santa Fe Northern 4-8-4: drive wheel diameter 80" - weight of locomotive 510,000 lbs - weight on drive wheels 294,000 lbs.
Milwaukee Road F7 Hudson 4-6-4: drive wheel diameter 84" - weight of locomotive 365,500 lbs - weight on drive wheels 216,000 lbs.
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To put the Pennsy Duplex locomotives in something of a larger framework compare them to these engines.
Chesapeake & Ohio Allegheney 2-6-6-6 articulated freight engine: drive wheel diameter 67" - weight of engine 751,800 lbs - weight on drive wheels 504,000 lbs.
Union Pacific Big Boy 4-8-8-4 articulated freight engine: drive wheel diameter 68" - weight of engine 772,000 lbs - weight on driving wheels 545,000 lbs.
Pennsylvania Railroad S2 steam turbine 6-8-6 an all time unique design passenger engine: drive wheel diameter 68" - weight of locomotive 580,000 lbs - weight on drive wheels 260,000 lbs.
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WEIGHT ON WHEELS in context -
700,000 lb engines were the - Chesapeake & Ohio "Allegheney" and Union Pacific "Big Boy" - this is not surprising.
(Consider that the firebox size Pennsy S1 experimental "Duplex" 6-4-4-6 and S2 experimental "Turbine" 6-8-6 were the same as these 700,000 lb locomotives built on a much smaller engine mass of 600,000 lbs.)
600,000 lb engines were the - Pennsy Q2 mass produced freight Duplex 4-4-6-4, Pennsy S1 experimental "Duplex" 6-4-4-6, Pennsy S2 experimental "Turbine" 6-8-6 - this surprises me as I never believed the turbine was that massive.
500,000 lb engines were the - Pennsy T1 mass produced "Duplex" 4-4-4-4, the Atchison Topeka & Santa Fe "Northern" 4-8-4 and on the slightly lighter side at 471,000 lbs the New York Central "Niagara" 4-8-4.
400,000 lb engine was the - Milwaukee Road F7 "Hudson" 4-6-4.
300,000 lb engine was the - New York Central "Hudson" 4-6-4.
PROPORTIONAL ENGINE WEIGHT TO WEIGHT ON DRIVING WHEELS - the critical measurement for traction.
LIGHT WEIGHT ON DRIVE WHEELS - about 1/2 weight of engine resting on the drivers:
Pennsy experimental S1 "Duplex" 6-4-4-6 - 608,200 / 281,400 lbs
Pennsy production poppet valve T1 "Duplex" 4-4-4-4 - 497,200 / 268,200 lbs
Milwaukee F7 "Hudson" 4-6-4 speedster - 365,500 / 216,000 lbs
Pennsy experimental S2 steam turbine 6-8-6 - 580,000 / 260,000 lbs
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HEAVY WEIGHT ON DRIVE WHEELS - about 2/3 weight of engine on drivers:
Pennsy Q2 "Duplex" freight locomotive 4-4-6-4 - 621,100 / 386,000 lbs
New York Central "Hudson" 4-6-4 - 265,500 / 201,800 lbs
New York Central "Niagara" 4-8-4 - 471,000 / 275,000 lbs
Atchison Topeka & Santa Fe "Northern" 4-8-4 - 510,000 / 294,000 lbs
Chesapeake & Ohio "Allegheney 2-6-6-6 - 751,800 / 504,000 lbs
Union Pacific "Big Boy" 4-8-8-4 - 772,000 / 545,000 lbs.
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Pennsy S2 experimental is just a Reference locomotive here - in the above comparison the Pennsy S2 experimental Steam Turbine 6-8-6 falls under different engineering parameters because the smooth torque of the turbine drive is constant - giving steady driving force to the engine. Whereas the piston driven steam locomotive is subject the cyclic transmission of its power increasing and decreasing with every piston stroke eight times per revolution of each axle. A good strong piston thrust can likely break traction resulting in wheel slipage and loss of traction control - thus the requirement of significant portion of engine weight to rest upon the locomotive drive wheels.
DRIVE WHEEL DIAMETER - traditionally divided between "freight locomotives" with small wheels to improve torque transfer to the rail and large diameter drive wheels which revolve a greater distance with each turn favored by "passenger locomotive" design for running at speed.
84" drivered engines were - Pennsy experimental "Duplex" 6-4-4-6, and Milwaukee F7 "Hudson" speedster.
80" drivered engines were - Pennsy mass production T1 "Duplex" 4-4-4-4, and Atchison Topeka & Santa Fe "Northern" 4-8-4 desert racers.
79" drivered engines were - New York Central "Hudson" 4-6-4 and New York Central "Niagara" 4-8-4.
69" drivered engines were - Pennsylvania mass produced Q2 Duplex freight engine - famous for developing over 8000 horsepower. Also, Pennsylvania experimental S2 "turbine" - this is a surprise as the sight of those wheels and drive rods running over 110 mph with smooth turbine drive would have been something special to witness - Could those small 69" wheels would really spin with those massive roller bearing rods at those speeds it was designed to run?
68" drivered engine was - Union Pacific "Big Boy" articulated and largest steam freight locomotive ever built - with 80 mph maximum speed - although never used as passenger power in the past, one is today being restored for just such passenger power use!
67" drivered engine was - Chesapeake & Ohio "Allegheney" articulated and also candidate for highest horsepower locomotive ever built. Some units of this mass produced locomotive were equipped for passenger train use.
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LEARNINGS - yes the Pennsy T1 Duplex was "light of foot" - remarkably so - considering the trauma the railroad experienced with poppet valve gear damaged one wonders why they didn't lighten the spring loading of the front and rear trucks to transfer more of the total engine weight on the drive wheel sets? Possibly the driver axle bearing sets or the wheels themselves were not designed for such greater weight loadings.
Since one of the two sets of drivers slipping was part of the problem one wonders why two throttle setups were not used - one for the front half of the locomotive and one for the rear? Airliner design and ship design often have individual throttles for each engine set up. In this fashion the free spinning set could be throttled back without shutting down the entire locomotive.
Likely the booster engine idea first used on T1 6111 should have been retained on the rest of the fleet of engines for starting purposes as this was a high slipage condition. Station manuvers in slipery conditions often rendered the T1 duplex almost unmanagable. Likely cheepskate Pennsy known for years as poorly equipping its locomotive fleet opted out on the inclusion of expensive booster engines that would have helped this - "extremely high speed" design of the T1 locomotive. Thats my take on it!
Also - what a wonderful locomotive the Pennsy Turbine S2 6-8-6 appears to have been. From an engineering standpoint it looks to be an extremely different steam locomotive than regular conventional piston driven steam engines. In this Pennsy grouping - the famous turbine is really a separate engineering study completely unto itself. In my opinion it was among the most beautiful steam engines Pennsy ever built. I cannot believe they had the courage to build it - then I cannot believe they had the courage to scrap it!
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The huge "American Railroads" Words Fair display engine - the Pennsy S2 experimental Duplex looms LARGER and LARGER in my mind than it ever appeared to me before. It had such massive speed potential - featuring Duplex drive through 84 inch wheels with simple Walscharts valve gear construction. And! the length - all that length! - on a rigid frame! The size of a of Union Pacific articulated Big Boy - which was the largest steam locomotive ever built - I can hardly imagine the courage it took to have the S2 built! Just unbelievable!
- and does the Keystone state still sire such thinkers and builders today! For America's sake I certainly hope so.
2 Years ago, on a cold and dark Friday night, living alone, I suffered a serious heart failure and flash pulmonary edema, after several fading fast attempts at dialing 911, got through, explained calmly, ran outside bouncing off the side of the house all the way and promptly dropped dead as a doorknob at the top of the driveway.
Woke up in a delerium in Saskatoon, 600km away in a hospital bed. One month.
Since then 3 things have kept me alive. 1) My students, they keep me young and hopeful and they need me. 2) The myriad of pills I take every day 3) The thought, desire and hope that one day I could see a T1 yet again steamed up and in full glory.
I'm not kidding.
An E7...meh...thats nice, kinda, but it ain't gonna keep me alive.
Miningman, I am with you all the way. Except that I would take a GG-1 in operation as a TEMPORARY substitute. (And of course Arab - Israeli peace.)
Dr D, I just wanted to say I really enjoyed reading your comparative analysis.
Yes, the mighty diesel ended up conquering reciprocating steam. But that doesn't make the steam locomotive any less grand of a human endeavor.
They were brilliant and amazing men doing incredible things with the technology of the time.
To borrow a few lines from a well-known Broadway play...
Don't let it be forgotThat once there was a spotFor one brief shining moment that was knownAs Camelot.
The power and majesty of the United States railroad steam locomotives of the 1920s, 1930s and 1940s was, and is, most worthy of not only remembrance, but of revival and continuance at every opportunity!
Mining Man, keep watch for smoke on the horizon, because it is coming!
Dr DIf the Pennsy T1 Duplex 4-4-4-4 had been designed with greater weight on the drive wheels - COULD substancial repair costs to the highly successful poppet valve design have been adverted.
And a great long discussion follows - which could be condensed into one brief, but significant, metric: the factor of adhesion (FA). This is normally expressed as the ratio of weight on drivers to TE, and the general 'rule of thumb' in American practice was that this should be around 4.
The T1 was notable for starting out with a remarkably high FA, which in fact was increased still more (!) in development. (Compare this with the very low effective FA for the 70" drivered N&W J class.)
Repair costs to the poppet valves were largely related to design of the valve spools and insufficient return-spring tension. Both had been addressed in principle in the 1948 engineering revisions; as it turned out, with the change to use of diesels on the first-rank trains, only the changed valve springing was implemented. Personally, I have little doubt that the combination of centrifugal casting and alloy revisions to the type A valves would have reduced or eliminated valve breakage or warping as a cause of road problems.
... Whereas the piston driven steam locomotive is subject the cyclic transmission of its power increasing and decreasing with every piston stroke eight times per revolution of each axle. A good strong piston thrust can likely break traction resulting in wheel slipage and loss of traction control - thus the requirement of significant portion of engine weight to rest upon the locomotive drive wheels.
Note that this situation is more related to early cutoff, and to short stroke in T1s, than to necessarily 'peaky' torque. (If you overlay the torque contributions of the four events per rotation in a typical 2-cylinder DA locomotive, as Wardale did at 15-degree increments, you will see that the nominal torque peakiness measured at the driver rim does not need to be excessive.) This is why it is idiocy to start hooking up the reverse within a few "beats" of starting when there's even a suspicion of poor adhesion conditions: it's thermodynamically 'best' to drive on the reverse with the throttle wide open, but the torque becomes peakier even as the peaks become higher (and if, as on the T1s, the torque becomes such as to prolong the angular slip past the 'next' torque peak, things can get out of hand very quickly right up to the engine's ability to make and flow steam...)
Could those small 69" wheels would really spin with those massive roller bearing rods at those speeds it was designed to run?
I am tempted to ask 'why not?' considering that locomotives that run at much higher speed have lower drivers, and the roller-bearing rods on the S2 were in perfect rotational balance (no reciprocating motion or thrust). The DR class 19 motor locomotive also had remarkably small drivers but apparently had little or no trouble spinning up to 110+mph speeds.
... considering the trauma the railroad experienced with poppet valve gear damage one wonders why they didn't lighten the spring loading of the front and rear trucks to transfer more of the total engine weight on the drive wheel sets?
A version of this approach was, in fact, an early part of the response to lead-engine slipping. The original lead-truck lateral accommodation setup had the characteristic (shared with many another high-speed locomotive!) of lifting the frame as part of obtaining non-spring restoring force. This, PRR thought, made the lead engine even with equalized suspension more amenable to slip. Note however that the 'cure' didn't fix the important parts of the disease.
Note also that you can't just go increasing the weight on drivers in a cavalier fashion - the side of the railroad that manages the trackwork and bridges will have something to say to you, and the increased treadwear and other factors that go along with higher driver loading will make your 'numbers' look worse. Much better to take positive action to keep slips from propagating, and ideally train crews how to get 'the most' out of a short-stroke locomotive with modern steam distribution.
Possibly the driver axle bearing sets or the wheels themselves were not designed for such greater weight loadings.
Timken roller bearings in cannon boxes? Boxpok drivers? Not capable of absorbing an extra few thousand lb?
Since one of the two sets of drivers slipping was part of the problem one wonders why two throttle setups were not used - one for the front half of the locomotive and one for the rear?
Same reason Jesus wasn't born in a hotel: there's no room for two throttles, even with air actuation, in the header area.
Now, having said that, it's very clear that separate throttles (and separate valve-gear adjustment) would be useful on a T1, and indeed if we make the assumption that the forward engine is 'slipperier' it becomes relatively easy to incorporate devices called Wagner throttles (see the ACE3000 patent where they are misspelled as "Waggoner" throttles) in the four tracts going to the poppet valves. These are basically fluidic-amplifier servo controlled, so very large openings can be reliably and very quickly modulated; on the T1 they would serve to trim the 'throttle' admitted steam down to where the forward engine would not have a higher propensity to slip, and of course they can close down and then reopen to 'original' position very quickly, which is what is needed to arrest a slip and then go back rapidly to making as high a TE as you can (for starting and for acceleration).
There are also several ways of implementing quick-acting traction control on one engine, which I have described previously; the one that involves the least 'jiggering' uses a split independent foundation to apply driver brakes selectively by engine as well as to the locomotive 'as a whole'.
Likely the booster engine idea first used on T1 6111 should have been retained on the rest of the fleet of engines for starting purposes as this was a high slippage condition. Station maneuvers in slippery conditions often rendered the T1 duplex almost unmanagable. Likely cheapskate Pennsy known for years as poorly equipping its locomotive fleet opted out on the inclusion of expensive booster engines that would have helped this - "extremely high speed" design of the T1 locomotive.
I, too, remain surprised that boosters weren't taken up as an 'answer' to T1 slipping, but it is true that all the way through 1948 they weren't seen as the right answer, even to the point that a fabulously invasive technique for installing piston valves was worked up and actually installed ... on a locomotive that did not get a booster.
Part of the situation likely involves the reason why the T1s had those funky Turbo-Inspirators instead of more reliable FWHs: overall weight, and weight distribution. A typical Franklin booster on that short-wheelbase truck would increase the effective polar moment , put even more weight on the rear of the locomotive chassis, involve more steam and control lines, and still be useful only for slow-speed operations.
The Lewty booster is a better example all around of what the T1 needed: light, high-speed drive at the truck, and good positive-displacement power carried as sprung mass.
what a wonderful locomotive the Pennsy Turbine S2 6-8-6 appears to have been. From an engineering standpoint it looks to be an extremely different steam locomotive than regular conventional piston driven steam engines. In this Pennsy grouping - the famous turbine is really a separate engineering study completely unto itself. In my opinion it was among the most beautiful steam engines Pennsy ever built. I cannot believe they had the courage to build it - then I cannot believe they had the courage to scrap it!
If you could read the correspondence on this locomotive after the middle of 1946 or so, you might change some of your opinion on the thing. Whether or not you agree as I do that the V1 configuration made a better turbine locomotive, there's little doubt that PRR considered the S2 a 'locomotive of the future' ... right up to the point things started going wrong. In my opinion, the day it started stripping staybolts (a thing that it proved repeatedly good at!) was the day the bloom started coming off the rose.
Note that in a 1948 Westinghouse catalog you can plainly see 4-8-4 turbine locomotives depicted, and I am reasonably certain there were roads that could have found them interesting (albeit only with something like a Bowes drive that could get rid of the colossal steam demand at starting and low speed). I think a solution for the need to provide very large exhaust plenum volume for low turbine backpressure, but also the problem that such a large volume makes for enormous draft issues at high exhaust mass flow, could be found -- but it certainly wasn't on 6200 as built, and it's instructive that no attempt was made when the problems started to rear their heads.
Look here, how many times do I have to tell you, the 6100 is the S1. The 6-4-4-6 duplex is the S1. It's the TURBINE we were just discussing that is the S2.
Very nice RME...having read through several different long threads on the forum in various places over the years and several more recent articles ( last 5-10 years) mostly technical in nature on the T1's, a great deal of useful information has come to light. It appears we know more now than we did a decade ago, especially along the lines of how to overcome problems.
So my question(s) to you is: Will the T1 Trust 5550 project incorporate these fixes right from the intial construction in the hopes they work out, or perhaps just some of them initially, the major ones which I am aware of, and see how it goes? How true to the as built T1's or any modifications later adopted by the Pennsy will the 5550 actually be?
Will the welded frame rather than one piece cast affect anything. Especially performance...should be somewhat better, no?
It is certain that externally it should be the same. Will there be some digital devices installed in the cab and throughout in various locations?
There was still at least one still in Altoona in 1956 because there is a picture of it in a line, dead of course. Such a shame it was not hidden away somewhere or simply purchased by a museum or deep pockets. The S1, S2, a T1 and a Q2 should never have been scrapped but I understand the reasons and the pressure, along with the thinking of the day. Cripes, they even junked their crown jewel Penn Station.
...and one more...how is the project coming along? I recently ordered the Baldwin print from them.
kgbw49 Mining Man, keep watch for smoke on the horizon, because it is coming!
You have a lot more faith than I do. As I see it, the trust is trying to raise several million dollars for what comes across as a giant engineering experiment that they might never be able to perform, assuming that this machine can actually be built.
Miningman ... Will the T1 Trust 5550 project incorporate these fixes right from the intial construction in the hopes they work out, or perhaps just some of them initially, the major ones which I am aware of, and see how it goes?
There was a great deal of discussion early on to 'get these points documented' and design potential fixes for them. An important methodological issue is that the locomotive will be extensively modeled in several programs, and given extensive multiphysics testing, before significant amounts of actual construction money have to be allocated. One point is to leave key parts of the design 'open' so that things like Deem conjugation can be installed if they prove necessary or desirable.
At least some of the reason for historical integrity in the design is to establish as far as possible the truth or error of the "railfan" assessment of the T1 as a dog and a failure, and by extension the duplex concept as an impossibly slippery and fundamentally flawed idea. It is of course easy to design a conjugated duplex that does not share the design problems and implementation failures of the early T1 effort - for example, by conducting better training and crew assessments so that crews called to run T1s would know how to run modern locomotives of this design correctly under the sort of running conditions PRR would require ... and, by extension, to provide a training protocol for engineers in the 21st Century to learn best practices and, by extension, how to handle a duplex with minimum difficulty.
How true to the as built T1's or any modifications later adopted by the Pennsy will the 5550 actually be? Will the welded frame rather than one piece cast affect anything. Especially performance...should be somewhat better, no? It is certain that externally it should be the same.
As noted, the externals, and the fundamentals of the running gear, will be kept as close to the 'evolved' versions as possible, with certain exceptions (some of which are intended to give better running conditions for excursion service). The decision was made, early on, to have as much 'historical' T1 as possible, and that ruled out, for instance, things like the use of 'cheek plates' and side-acting independent brakes. However, it is likely that the valve gear will be modeled on Franklin type B or "C" (with external drive to the cams, as on locomotive 5500), probably with the 'drive arm' type of shaft suspension rather than the heavy angle frame used on earlier Franklin RC installations, which will give 5550 a different external appearance. (I think this is justifiable, as had the T1s remained in first-line service more locomotives would have been converted to type B-2 (the version of RC optimized to work with the 8-valve type A cylinder configuration) with the improved shaft arrangements worked out for type D.) This also facilitates the installation of Deem conjugation if that becomes desirable, and eliminates the weight, cost, and complexity of the internal camboxes and derived motion.
The welded frame (likely a combination of lost-foam castings and fabrications) is expected to be both stiffer and lighter than original. For reasons of code compliance alone the boiler will be all-welded and made of modern steel composition, which is already recognized to produce significant weight-saving and some leeway in locating auxiliaries on the locomotive; this will allow use of a different feedwater-heater arrangement (personally, I'd love to demonstrate how to build and maintain a historical Turbo-Inspirator setup, but that arrangement appears to have been originally installed more for weight-saving than operational effectiveness, and it has about the same charm for reliable operation that a rebuilt Winton 201A would for the Flying Yankee. I suspect that a range of the 1948 improvements will be applied (which, again, is in keeping with likely PRR practice if the engines had been kept for first-line service) specifically including better alloys and finishing for the valves and their mountings.
I suspect there are better alloys for the Timken rods, including the current cerium-bearing formulations. The rods, interestingly, will be made to exact historical dimensions, with bushings for the anticipated use of modern Timken equivalents for the rod roller bearings. I expect that both the axle and rod rollers will outlast several sets of driver tires, especially if frequent dressing of the tread profiles is made.
Will there be some digital devices installed in the cab and throughout in various locations?
Yes, but they will be modular and removable, so that the engine can be operated in full "legacy mode" when desired. The one exception is that I don't expect the historical PRR cab signaling to be fully duplicated electronically unless specifically-earmarked fundraising for it is provided, as there's no operating benefit to be gained from it now.
My preference is to use a fixed harness for the various digital and electrical devices, as its visibility would be minimal and its presence would not compromise any of the 'historical fabric', but there are alternatives that are even less intrusive. I happen to think that designing versions of the auxiliaries that can run on 220V AC power under logic-bus control makes sense for actual operation, but that is a decision to be made much closer to "run time".
The locomotive will be fully PTC compatible. It made no sense to design it otherwise, whether or not there are present exceptions or grandfathering for steam locomotives. Safety is safety, first, last, and always.
As an aside, I expect that the actual drivers on the locomotive when it reaches operational completeness will all be instrumented. There has been some foon opinion expressed here and on some other forums that the cost of "instrumented wheelsets" far exceeds any practical budget. I would ask whether people that have experience in building plasma-physics equipment are likely to lack either the engineering or fabrication skills needed to construct instrumented Boxpok driver sets, or the equipment appropriate to calibrate them and then derive meaningful data from the installation. However, there is no question in my mind that all drivers, not just the main, would need to be extensively instrumented before any high-speed operation of the locomotive is made. And the same likely goes for the lead and trailing truck wheels, and the lateral-accommodation mechanisms used in both trucks.
One topic still under discussion is the extent to which the locomotive will provide HEP-compliant power. 3463, for example, is intended to have a full implementation at 440V and perhaps at DC-link traction voltage, and the genset involved is a key part of the 'technology demonstration' behind Project 130. While it would of course be highly valuable to have HEP capability on 5550, it is difficult to see where it should be packaged (as opposed to dedicated HEP generation in a separate car). I suspect that decision will be made at a considerably later stage in specified detail design.
The S1, S2, a T1 and a Q2 should never have been scrapped but I understand the reasons and the pressure, along with the thinking of the day ...
Correspondence at the Hagley indicates just how much effort was made to preserve the S1, with the decision essentially coming down to the perceived importance of the scrap value at a time when PRR was showing a loss and incurring heavy cost for rapid dieselization. The Q2 was essentially a 'win-the-war' locomotive, and once that war was over PRR could get just as good service (for how they ran peacetime freight trains) out of much-more-easily-maintained J1s. I believe the same 'expedience' regarding equipment trusts applied to the Q2s that applied to the T1s; both classes "had to die" perhaps in the most embarrassing manner contrivable to get the bankers to release PRR from the ongoing heavy indebtedness that those locomotives represented.
The S2 as built rapidly demonstrated it was a remarkable flop. It would have been highly interesting to see the 4-8-4 follow-ons that Westinghouse, at least, saw coming ... but you can assume that these would have had different gearing and turbine layouts, much better exhaust, and probably (in my opinion at least) arrangements to permit turbine rotor speed separate from driver rotational speed -- most likely some version of the Bowes drive that was considered for the V1, although other approaches (magnetorheologics for one) were possible in that era. The idea of the S2 riveted boiler with All Those Popping Staybolts rapidly queered any particular enthusiasm for the direct-drive turbine as early as 1946, before the 'perfect storm' that led to new steam-locomotive design's rapid exit; the V1 was of course a much better locomotive for nearly any practical PRR purpose ... and the water-rate issues killed that.
Cripes, they even junked their crown jewel Penn Station ...
By the time Penn Station came down, it was euthanasia. You may not remember what it was like to walk through in the early '60s -- I barely remember myself -- but it was NOT any kind of crown-jewel majesty, and this was before the era of 'easy money' for retro-historical architectural renovations. Unlike the situation at GCT, the proven value of the air rights over Penn Station were immediate, massive, and of significant value to a rapidly-hemorrhaging PRR with very little interest in the passenger business at all.
(Interestingly enough, the original drawings for GCT clearly demonstrate that framing to support an office structure of over 20 floors was included in the design and construction of the concourse; the Breuer disaster that kicked off the organized Save Grand Central effort was to sit over the waiting room at the front. Anyone from New York understands why the 'preserve the view down Park Avenue' argument was a crock by 1977...)
...and one more...how is the project coming along?
Nicely. I encourage anyone to subscribe to their 'Trail Blazer' newsletter and to review the content of their site periodically. Personally, I think the effort is fast approaching the point where a case can be made for 'interested parties' to put up substantial parts of the build cost, with reasonable assurance that both the knowledge and the professional management needed to complete the project successfully in all necessary respects can be provided.
RME NOT any kind of crown-jewel majesty
NOT any kind of crown-jewel majesty
Two questions.
How was Stanier's "Turbomotive" in Britain "successful" in the way that the Pennsy S2 turbine was not? I mean the Turbomotive wasn't successful in the sense that they built a fleet of them, but it wasn't popping staybolts either, was it? And wasn't the multiple-nozzle turbine, creating a kind of "notched throttle" the inspiration for the S2, or did they go a different path?
Second question -- what is the problem with "overcylindering" a steam locomotive, that is, giving it more tractive effort than the adhesion can take? The advantage of more cylinder capacity is that you can run it at lower cutoff and higher efficiency at speed? As to the disadvantage, couldn't there be a throttle notch where at low speed and full gear, you instruct the driver, "Look, don't exceed this notch or you will slip the wheels"?
RME- Wanswheel wins with the 20 foot jump shot!
Grand Central and Washington Union were in a similiar condition and did not end up in the swamps of New Jersey. Grand Central came close though. I believe you have mentioned you are a New Yorker so come on, you know better. I know you know better. It's a deep story with many levels to it. What did Saunders settle for out of court for his shenanigans...$7 million or so personally...big big dollars in the '70's.
Does anyone here have a simple chart showing PRR and NYC yearly bottom line losses (or profits, there were some) 1948-1968.
Thanks for the great answers on the T1's and the 5550 Trust. It really should be a doable project. Hollywood elites blow that much on a single party at times.
Did not know that there was a discussion within the Pennsy regarding saving the S1. Perhaps that decision was the "one decision" that really marked a turning point and signalled the end of the Pennsy's soul because it was pretty much all downhill from there. As far fetched and goofy as that sounds there is something, actually much, to be said for pride, integrity, symbolism, spirituality and philosophy..when you sell out for a few shekels you lose, and big time. The S2 was already built, it was beautiful and represented a failure but a very brave and bold attempt ...it could have been kept, it meant something serious to the Pennsy at the time. It would be a marvel today, to look upon and know its story. As for a T1 and a Q2, facing the bankers and their equipment trusts, well fine, but I'm keeping one of each on the roster, no big deal. Just one from each fleet. New expensive Diesels were on the new handy dandy GM monthly payment plan for eternity. Just like the rest of us And I still have my 1969 Chevy Malibu convertible ragtop with the bench seat and an AM radio...and an ashtray. It's who I am. ( runs fine, looks great, just for summer nowadays). Also a '73 Vette, a monster really that I bought new and a '82 Vette which is my S2 if you will.
The Pennsylvania Railroad represented so many things, including the building of and the fabric of America itself. They diminished themselves and rejected this heritage. The "knowers" know.
Can't seem to find the right words tonight.
Anyway ...while I'm at it saving the past ( as most of you know I firmly believe that too much was lost) I'm also nominating for preservation an 1) A-A set of Baldwin Centipedes 2) an A-B-A set of Baldwin Pennsy class Bp-20 Passenger Sharks 3) an A-B-A set of PA's, thinking NYC this time and 4) 2 nice back to back New Haven Alco DL109's, any paint scheme is fine. Of course it is understood a NYC Hudson and a Niagara.
Got to prep up for classes tomorrow. G'nite.
When you consider that PRR was operated at a loss in 1946 (the N&W dividend payments covered PRR's dividend payment), it should be easy to explain why preservation of the past might be non-existent in the corporation's planning. PRR's soul was pretty much owned by the wealthy families on the Main Line who expected that dividend and a decent stock price as their divine right.
Glad to have what was saved, squirreled away in the Northumberland roundhouse and now at the PA Railway Museum.
daveklepper Glad to have what was saved, squirreled away in the Northumberland roundhouse and now at the PA Railway Museum.
Amen to that David! As the old saying goes, "Don't cry because it's over, smile because it happened."
RME et.al,
THE PENNSY DUPLEX AND FACTOR OF ADHESION ISSUES:
This has given me the pleasure of reading Ralph Johnson's book The Steam Locomotive, specifically chapter X on "Tractive Force"; Johnson you will remember was the chief design engineer at Baldwin Locomotive Works and the primary design engineer leading the Pennsylvania Railroad T1 Duplex experimental locomotive development of the 4-4-4-4 engines 6110 and 6111.
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To quote Ralph Johnson from his book, "The hauling capacity of a locomotive is determined by the relation between the tractive force developed and the resistance of the locomotive and train, and both of these factors are dependent on the speed.
At starting and very low speeds the power capacity of any locomotive will permit large tractive forces to be developed. The limiting factor is the frictional resistance or adhesion of the rails which opposes the forces tending to slip the driving wheels. The ratio or factor of adhesion is the adhesive weight of the locomotive divided by the rated tractive force and is usually about 4 although in many cases it varies slightly above or below this..."
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TRACTIVE EFFORT AND FACTOR OF ADHESION for the T1 and S1, Duplex locomotives compared to other common locomotives of the era.
Pennsylvania S1 Duplex 6-4-4-6 - Drive wheel diameter 84" - weight of engine 608,200 lbs - weight on drive wheels 281,400 lbs - Tractive Effort 71,900 lbs - (FA) Factor of Adhesion 3.92
Pennsylvania T1 Duplex 4-4-4-4 - Drive wheel diameter 80" - weight of engine 497,200 lbs - weight on drive wheels 268,200 lbs - Tractive Effort 65,000 lbs - (FA) Factor of Adhesion 4.13
Pennnsylvania Q2 Duplex 4-4-6-4 - Drive wheel diameter 69" - weight of engine 621,100 lbs - weight on drive wheels 386,000 lbs - Tractive Effort 100,800 lbs - (FA) Factor of Adhesion 3.58
Lets examine the few other famous engines for comparison:
New York Central Hudson4-6-4: drive wheel diameter 79" - weight of locomotive 265,500 lbs - weight on drive wheels 201,800 lbs - Tractive Effort 43,400 lbs - (FA) Factor of Adhesion 4.28
New York Central Niagara 4-8-4: drive wheel diameter 79" - weight of locomotive 471,000 lbs - weight on drive wheels 275,000 lbs - Tractive Effort 61,500 lbs - (FA) Factor of Adhesion 4.47
Athison Topeka & Santa Fe Northern 4-8-4: drive wheel diambeter 80" - weight of locomotive 510,000 lbs - weight on drive wheels 294,000 lbs - Tractive Effort 66,000 lbs - (FA) Factor of Adhesion 4.35
Milwaukee Road F7 Hudson 4-6-4: drive wheel diameter 84" - weight of locomotive 365,500 lbs - weight on drive wheels 216,000 lbs - Tractive Effort 50,300 lbs - (FA) Factor of Adhesion 4.10
Put the Pennsy Duplex locomotives in a larger context compare these:
Chesapeake & Ohio Allegheney 2-6-6-6 articulated freight engine: drive wheel diameter 67" - weight of engine 751,800 lbs - weight on drive wheels 504,000 lbs - Tractive Effort 110,200 lbs - (FA) Factor of Adhesion 4.27
Union Pacific Big Boy 4-8-8-4 articulated freight engine: drive wheel diameter 68" - weight of engine 772,000 lbs - weight on drive wheels 545,000 lbs - Tractive Effort 135,400 lbs - (FA) Factor of Adhesion 4.02
Pennsylvania Railroad S2 steam turbine 6-8-6 an all time unique passenger engine: drive wheel diameter 68" - weight of locomotive 580,000 lbs - weight on drive wheels 260,000 lbs - Tractive Effort 70,500 lbs - (FA) Factor of Adhesion 3.70
Lets rate these engines just by (FA) Factor of Adhesion:
New York Central Niagara 4-8-4: Tractive Effort 61,500 lbs - (FA) Factor of Adhesion 4.47
Atchison Topeka & Santa Fe Northern 4-8-4: Tractive Effort 66,000 lbs - (FA) Factor of Adhesion 4.35
New York Central Hudson 4-6-4: Tractive Effort 43,400 lbs - (FA) Factor of Adhesion 4.28
Chesapeake & Ohio Allegheney 2-6-6-6: Tractive Effort 110,200 lbs - (FA) Factor of Adhesion 4.27
Pennsylvania T1 Duplex 4-4-4-4: Tractive Effort 65,000 lbs - (FA) Factor of Adhesion 4.13
Milwaukee Road F7 Hudson 4-6-4: Tractive Effort 50,300 lbs - (FA) Factor of Adhesion 4.10
Union Pacific Big Boy 4-8-8-4: Tractive Effort 135,400 lbs - (FA) Factor of Adhesion 4.02
Pennsylvania S1 Duplex 6-4-4-6: Tractive Effort 71,900 lbs - (FA) Factor of Adhesion 3.92
Pennsylvania Q2 Duplex 4-4-6-4: Tractive Effort 100,800 lbs - (FA) Factor of Adhesion 3.58
Learnings: In responding to RME
"...a great long discussion follows - which could be condensed into one brief but significant, metric: the factor of adhesion (FA)."
You indicated in your last post that (FA) Factor of Adhesion was much clearer indication of the Duplex driver slip problem. I feel that this comparison of the unreliability of (FA) to specifically disclose any clear conclusions significantly disproves this assumption. Clearly the 1/2 vs 2/3 driver weight comparison gives a much clearer picture of the problem to the average reader.
The locomotive with the highest (FA) Factor of Adhesion 4.47 was the New York Central Niagara 4-8-4 and the lowest (FA) Factor of Adhesion 3.58 was the Pennsylvania Railroad Q2 Duplex 4-4-6-4 supposedly having solved the driver slippage issues. The Union Pacific Big Boy 4-8-8-4 was also one of the lowest (FA) 4.02 Factor of Adhesion locomotives.
The Pennsylvania T1 Duplex 4-4-4-4 had a (FA) Factor of Adhesion 4.13 - between - the Chesapeake & Ohio Allegheney 4.27 and Milwaukee F7 Hudson 4-6-4 (FA) Factor of Adhesion 4.10.
Little or no obvious conclusion can be drawn about driver slippage owing to casual review of published statistical (FA) Factor of Adhesion numbers.
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Aside from all this - what about the Pennsylvania Q2 Steam Turbine 6-8-6: Tractive Effort was 70,500 lbs which puts it above that of the New York Central Niagara 4-8-4 Tractive Effort of 61,500 lbs and Atchison Topeka & Santa Fe Northern 4-8-4 Tractive Effort of 66,000 lbs. The Turbine does outweigh the these two famous engines by 80,000 lbs and 100,000 lbs respectively though.
The (FA) Factor of Adhesion 3.70 for the Pennsy Turbine S2 must be considered similar to that of Diesel Electric locomotives because of the smooth torque transfer of the turbine is similar to that of the electric motor drive for the Diesel Electric which usually had a (FA) of 3.33
Remarkably: the the Pennsylvaina Q2 Duplex 4-4-6-4 which had a (FA) Factor of Adhesion of 3.58 is astoundingly closer to that of the Diesel Electric 3.33 than any steam locomotive. Likely the wheel slipage is an issue pertaining to another aspect of development.
Further learnings: In reading Johnson's text he discusses the Tractive Effort situation further. Specifically with the inability of existing theoretical engineering models to deal with power and tractive effort relating to boiler horsepower utilization and speed.
Johnson writes, "As the speed is increased, the available tractive force falls off until a point is reached at which the boiler can no longer supply the steam required by the cylinders at full stroke. IF greater speed is desired, it is necessary to use the steam more efficiently, and this is accomplished by shortening the cut-off. This procedure shortens the percentage of stroke during which steam is admitted to the cylinders, and during the balance of the stroke the expansion of the steam from boiler pressure towards atmospheric pressure does the work...It is evident that under these circumstances the tractive force that a locomotive can develop is dependent not only on the cylinder and driving wheel dimensions, but also on the steaming capacity of the boiler."
Poppet valve gear design was able to achieve steam cut-off rates that Walschaerts valve gear was never capable of. I assume that is why New York Central and Pennsylvania Railroad were both experimenting with poppet valve design advantages and problems. New York Central Niagara 4-8-4 engine 5500 was equipped with the poppet valve gear and Paul Kiefer the Chief Engineer for the railroad considered the NYC 5500 the most powerful ever built for the railroad. Giving the NYC Niagara 4-8-4 an extremely high (FA) Factor of Adhesion of 4.47,
Likewise the Pennsylvania Railroad T1 Duplex 4-4-4-4 of similar poppet valve design developed the principle of steam distribution beyond what Paul Kiefer did by doubling the effective cylinder capacity! Likely the power developed by this "low cut-off" steam distribution system took the T1's steam locomotive running performance at speed, and Tractive Effort at speed into undiscovered engineering areas - result WHEEL SLIPAGE AT SPEED! a continuing and re-occuring problem because of the power developed by "low cut-off" and high steam distribution cylinder capacity.
Was the T1 (FA) Factor of Adhesion of 4.13 really enough? How many Duplex locomotives of this type or design were ever developed by any railroad anywhere in history? I also wonder if the company test facility dynometer with steel wheel roller drive ever fully did, or ever was fully capable of testing these T1 performance (FA) Factor of Adhesion parameters at high loading and and under high power conditions. In this capacity the T1 remains a remarkable engine - who did anything like it? And so unequaled in railroad history!
Thats my considered opinion -
Paul Milenkovic How was Stanier's "Turbomotive" in Britain "successful" in the way that the Pennsy S2 turbine was not? I mean the Turbomotive wasn't successful in the sense that they built a fleet of them, but it wasn't popping staybolts either, was it? And wasn't the multiple-nozzle turbine, creating a kind of "notched throttle" the inspiration for the S2, or did they go a different path?
My understanding of the S-2 is that the steam flow rate was proportional to tractive effort and almost independent of speed. Starting a train would cause a significant drop in boiler pressure with resulting flexing of the firebox. Above 70 MPH it was more efficient than any reciprocating steam locomotive, but not at low speeds.
- Erik
Dr D You indicated in your last post that (FA) Factor of Adhesion was much clearer indication of the Duplex driver slip problem. I feel that this comparison of the unreliability of (FA) to specifically disclose any clear conclusions significantly disproves this assumption. Clearly the 1/2 vs 2/3 driver weight comparison gives a much clearer picture of the problem to the average reader...
What I intended, by bringing up FA and its use as a 'rule of thumb', was to illustrate that is is not a reasonable predictor of slip propensity for duplexes. (I have already discussed the likeliest reasons ad nauseam in other threads and will not abuse the horpse any further.)
PRR made changes that ran the FA of some T1s to 4.48, which is getting into the 'throwing horsepower away' category, and still had both the low-speed and high-speed slipping. (I think, but can't prove without references I don't have access to, that this included the sleeving of some locomotives' cylinders, a rather extreme measure considering that stalling was an issue at that stroke even with the original cylinder bore...)
As you note, FA isn't necessarily a good predictor of slipperiness, but then again, without knowing other details about locomotive configuration or engineer training, it won't be. It is a ratio that gives a guide to achievable adhesion. We have ample proof that the FA of the N&W J (which is somewhat 'artificially' low due to the large weight and small driver diameter) does not mean that the engine is intolerably slippery, just that more care needs to be exerted when accelerating from a stop or low speed. I believe you will also find that the design of the throttle and cutoff controls are important in achieving both 'fine tuning' of steam flow and rapid reduction and return for slip arresting.
Remarkably: the the Pennsylvaina Q2 Duplex 4-4-6-4 which had a (FA) Factor of Adhesion of 3.58 is astoundingly closer to that of the Diesel Electric 3.33 than any steam locomotive.
Remember that this engine is immensely heavy and has divided drive, but a very significant reason for the low nominal FA is that a very sophisticated (for its time) control system was provided to arrest slippage quickly and automatically. Why that system did not work reliably is important reading for people designing bold new systems to address old railroad problems... Bucky, are you reading along?
Specifically with the inability of existing theoretical engineering models to deal with power and tractive effort relating to boiler horsepower utilization and speed. Johnson writes, "As the speed is increased, the available tractive force falls off until a point is reached at which the boiler can no longer supply the steam required by the cylinders at full stroke. IF greater speed is desired, it is necessary to use the steam more efficiently, and this is accomplished by shortening the cut-off. This procedure shortens the percentage of stroke during which steam is admitted to the cylinders, and during the balance of the stroke the expansion of the steam from boiler pressure towards atmospheric pressure does the work...It is evident that under these circumstances the tractive force that a locomotive can develop is dependent not only on the cylinder and driving wheel dimensions, but also on the steaming capacity of the boiler."
However, were you to read Johnson more carefully, you will see that he's discussing the effect produced by cutoff itself, not the distinctive advantages of poppet valves. It's important to regulate both timing and duration very precisely for high-speed work, but the advantages come in at higher speeds than most railroads regularly worked locomotives - see the discussions of the T1 vs. T1a in sources like the Keystone to see the difference.
New York Central Niagara 4-8-4 engine 5500 was equipped with the poppet valve gear and Paul Kiefer the Chief Engineer for the railroad considered the NYC 5500 the most powerful ever built for the railroad. Giving the NYC Niagara 4-8-4 an extremely high (FA) Factor of Adhesion of 4.47,
The last half of this sentence, and perhaps some others, are missing from the post as I received it. But it is important to remember that Kiefer specified the 5550 to make the same horsepower as the 6000s ... think about it a moment, why would you need or want more hp out of a single 4-8-4 in NYC service ... but with much higher efficiency in both fuel and water at sustained high speed. (LeMassena did a long and reasoned article on this in Trains in the '80s). Even at the time the 1947 report on motive power went to press, Kiefer had no hard data on how well this would perform, but was certainly hopeful enough to cite it there. I would also note that the proposed C1a material that has survived shows nothing but typical Baker gear - in other words, largely a duplex Niagara.
Unfortunately, NYC went with the type A gear to drive those poppets, and appear to have suffered many of the same complaints PRR did with practical maintenance. The 5500 was laid up out of service long before most of the piston-valve Baker Niagaras were out of service, and it does not appear that NYC considered the additional maintenance and aggravation sufficiently 'worth' the saving in fuel and water to make the logical 'fixes' (cf. the valve improvements for the T1 by 1948).
Likewise the Pennsylvania Railroad T1 Duplex 4-4-4-4 of similar poppet valve design developed the principle of steam distribution beyond what Paul Kiefer did by doubling the effective cylinder capacity! Likely the power developed by this "low cut-off" steam distribution system took the T1's steam locomotive running performance at speed, and Tractive Effort at speed into undiscovered engineering areas - result WHEEL SLIPPAGE AT SPEED! a continuing and re-occuring problem because of the power developed by "low cut-off" and high steam distribution cylinder capacity.
All this would come as quite a surprise to the Baldwin and PRR engineers, who knew perfectly well what the steam would do. (The 'surprise' was with some of the momentum effects on the Q2, which did take duplex design into undiscovered country...)
The principal problem was the physical reduction of the proportion of adhesive contact due to road conditions or shock (again, as I have covered too many times to avoid MEGO). The secondary problem was the relative absence of means to recover from the slipping, and the tertiary was not training enough enginemen to handle advanced locomotives. None of these are related directly to high horsepower and steam distribution in distributed drive at speed, except (perhaps) insofar as a slipping engine might 'starve' the other of working steam, causing deceleration that would complicate re-acquisition of adhesion on the slipping one.
I also wonder if the company test facility dynometer with steel wheel roller drive ever fully did, or ever was fully capable of testing these T1 performance (FA) Factor of Adhesion parameters at high loading and and under high power conditions.
The answer to the question as you asked it is "yes" (with the caveat that the physical contact patch between driver and roller is slightly different from that for driver to railhead). The reason the 'caveat' doesn't matter is that functionally it would produce the phenomenon of slipping more readily than dynamometer testing out on the railroad would. So the relative absence of uncontrolled slipping on the test plant came under conditions of nominally poorer adhesion, and this might have lulled the engineers into thinking the situation with slipping was not as dramatic as it proved to be. (As a peripheral issue, there is some question whether the effect of weight transfer due to drawbar pull is less noticeable when the drivers are on independent rollers than on straight track -- personally I don't think it would be.)
The question you should have asked was whether the test plant was fully capable of testing the T1 parameters at high loading and high power in real-world road conditions. And there, the answer is not only a bit obvious, but justified by events.
In theory, it would have been possible to put cam profiles on the rollers to simulate various types of road shock or simulate the effect of low joints or rail gaps, perhaps even making the profile servo-adjustable. (This in fact is part of the 'roller-rig' design for testing the T1 Trust locomotive). It would also be nominally possible to change the contact profile of the roller surfaces. However, one key thing missing was the ability to test under reduced-adhesion conditions -- even if the test-plant engineers agreed to subject their precision machinery to gobs of dirt and ice, there is little practical testing of sanders or their alignment possible with the test-plant geometry. All these things show up glaringly in T1 road experience, and I can't help but think that an organized dynamometer-testing series would have given better data than test-plant running in those respects.
But in the end, until the early displacement by diesels, there were engineers who learned how to get great performance from the T1s and so did.
The point is well-made but I don't think that a formal training program in how to operate a T1 could have been set up. It would have implied that only qualified engine crews would be assigned to T1's and the operating brotherhoods would have opposed such classifications. It would have also hamstrung the operating department because T1's would have to be guaranteed for specific runs.
CSSHEGEWISCHThe point is well-made but I don't think that a formal training program in how to operate a T1 could have been set up. It would have implied that only qualified engine crews would be assigned to T1's and the operating brotherhoods would have opposed such classifications. It would have also hamstrung the operating department because T1's would have to be guaranteed for specific runs.
Believe you me, brother, I don't argue with anything you say. Even the use of preference in calling assignments (giving people the choice of taking the T1 as called if they knew how to get the most out of it) would likely not have passed Brotherhood muster.
What I was thinking of was more along the lines of an accelerated version of air-brake transition training in the very early 20th Century, where various means of delivering the lessons about modern 'locomotive driving' would be conveyed and reinforced. I would argue that if this had been started around the time the S1 was being seriously undertaken -- perhaps as late as the first recognitions that the two T1s as built could be flighty -- it might have had the effect of changing default response in key respects.
Now, whether PRR as a corporation could have done this with the necessary degree of indirectness (remember the history of the Bishop coupling knife!) is another matter. One approach that has worked in other areas is to develop a 'cadre' of people who could get the most out of the duplexes, and then have them be the developers of "training" material for others that would cater to their particular preferences and attitudes.
Note that I dodge all the issues connected with the wisdom of issuing Ferraris to UPS drivers without any particular warning. Or whether (as I think might be documented, if we can believe Arnold Haas, at NYC) there was actual corporate effort made to create techniques that fail, in an atmosphere of failure, to help with getting out of equipment-trust arrangements.
Documented you say?...wow now that would be a good find. It certainly fits considering the rapid demise starting almost right away, say 6 months to a year after being built.
Seems the T1 hit the proverbial perfect storm ....corporate sabotage, poor grade coal, E7's. They must have had a few friends and believers at the PRR and Baldwin but they didn't stand a chance.
T1 on the turntable...
T1 going somewhere in a hurry...
T1 with L1 Mikado helper coming up the Altoona grade after passing Horeshoe Curve...
T1 at speed about to hit the diamonds at Plymouth IN...
T1 at a mainline coaling and watering station - notice train behind the tender...
Pennsylvania Railroad travel poster...
Broadway Limited travel poster...
Advertising poster...
S1 1939 Pennsylvania Railroad Calendar image...
Regarding the first picture posted by kgbw49 titled "T1 on the turntable"....can anyone clarify what is going on here? Is there a diesel switcher ahead of it? The tender appears empty, void of any coal, or is there some out of view deeper in the bowels. Is that steam popping out of the right side? I just don't quite understand...is it coming or going? It appears to be fairly new...not much wear and tear, even the coupler seems little used...or is it just the black and white photo? Where would the photographer be located to take such a shot?
What piqued my interest were those two "torpedoes" on the tender deck.
I always thought the T1 had a more-than-passing resemblance to a U-Boat.
Firelock76What piqued my interest were those two "torpedoes" on the tender deck. I always thought the T1 had a more-than-passing resemblance to a U-Boat.
Suspect they are the engine's Main Air Resevoirs that the designers weren't able to locate on the engine itself without disrupting the asthetics of the locomotive.
It looks like it is being pulled on to the turntable by a shop switcher - it looks like there is a slight exhaust coming from the stack of the shop switcher at the front end of the T1.
Also, there are a lot of single tenders located around the turntable at all points of the compass, and the T1 tender is in pristine condition. So could this picture be at the Altoona Shops and this T1 has just been connected to its tender?
Just one supposition, but then again I am definitely not Hercule Poirot and this is definitely not the Orient Express!
Kgbw49- Thanks for the attempt at an explanation. There is definitely a story there in the picture. Yes there are tenders everywhere with no engine attached and they all look pretty good. The one to the left of the T1 is pristine also and looks recently re-lettered and painted, so its logical to assume its a tender shop, which existed, of course, in Altoona. The "steam" or whatever it is I was referring to is about a quarter of the way down from the tender on the locomotive off to the right and projecting upwards. Also there is some kind of "thing" at the top of the rear ladder on the T1's tender. Where the heck was the photographer located to get a shot like this? The 3 workers to the right are watching this intently.
It's also dated 4-11-1946 so some of the T1's were pretty new.
Maybe its one for the Trains feature "Whats in a picture"!
Firelock76I always thought the T1 had a more-than-passing resemblance to a U-Boat.
MiningmanAlso there is some kind of "thing" at the top of the rear ladder on the T1's tender.
http://www.billspennsyphotos.com/apps/photos/photo?photoid=175558063
http://www.billspennsyphotos.com/apps/photos/photo?photoid=175558064
http://www.billspennsyphotos.com/apps/photos/photo?photoid=72302807
http://www.billspennsyphotos.com/apps/photos/photo?photoid=72302808
https://en.wikipedia.org/wiki/Trainphone
Great stuff wanswheel!
BigJim Miningman Also there is some kind of "thing" at the top of the rear ladder on the T1's tender. That is for the [now someone give the correct name] "induction radio", where the PRR used the wires on the telegraph poles to send the radio waves(?) in order to communicate with the crew.
Miningman Also there is some kind of "thing" at the top of the rear ladder on the T1's tender.
That is for the [now someone give the correct name] "induction radio", where the PRR used the wires on the telegraph poles to send the radio waves(?) in order to communicate with the crew.
Trainphone is the PRR's name. Allows cabin and headend to talk. Also, talk to nearby trains.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
S1 in revenue service in a heavy snow storm...
PRR Crestline Ohio roundhouse - notice T1 or perhaps S1 on the lower left - track to extended stall - and compare size of locomotive to the two J1 2-10-4 units on the middle right of the picture...
PRR T1 5518 on the far western reaches of the Pennsylvania Railroad at St Louis MO...
Proud crew posing 5527 at Englewood IL...
S1 in Fort Wayne IN...
S1 in Pennsylvania Railroad Calendar painting...
T1 5516 broadside in St Louis MO...
T1 5516 at the St Louis Union Depot trainshed...
S1 under a massive signal bridge in Chicago IL...
Temporay detour - happened along on this great K4 vs Hudson "race" out of Chicago photo with the K4 in the lead...
And this K4 vs Hudson "race" photo with the Hudson seeming to have the edge...
Have not been able to locate a T1 vs Niagara race photo yet...
T1 possibly doubleheading on a coal train? (check out the trailing unit and the car behind the tank and see what you think)...
Altoona Works Roundhouse No 2 - Locomotive Finishing Shop - launching pad for the T1...
And of course, what would have happened if the Norfolk & Western J tests had made a bigger impression - this photo is actually in Roanoke VA but notice the Pennsylvania baggage car on the left...
Well as I've stated previously, nothing brings out the photos and comments more than anything if it's regarding the T1's.
Regardiing my comment about "some thing" by the rear ladder on the tender...I was well aware of the induction radio/phone system and the antennna's... we still use something vaguely similiar in underground mining operations called a leaky feeder. A person has to be in a drift or crosscut where there are permanent wires strung along the back ( that's the "roof" for non miner types, ...we cringe at that term). The receiver is usually a small box and microphone pinned on your chest near the shoulder, just like the police use. Does not work everywhere. Not easy to communicate through a mile or two of solid rock, on several levels and up to surface.
I've looked at that picture for a while now and for some odd reason I didn't get the fact that it was just a bunch of intersecting shadows that really threw me. Given the date and the condition I would say this is a new engine getting it's tender just as kbgw49 thought.
So much has been written on their demise and the reasons why..stillborn really. It really adds to the mystique of the loco itself.
Just an Aaron Rogers Hail Mary throw here, and theoretical to boot, but was there anyone who would have been interested in picking them up on the cheap. I understand Pennsy was shopping then around pretty early...yes I know N&W and C&O tried 'em out ..I'm thinking more along the lines of out West...UP Passenger service? They may have been tempting at a low initial price vs Diesels E7's and 8's, which could have then been diverted funds to freight Diesels. Just trying to find them a second chance...that would have been something. Geez, I said it was a Hail Mary OK?
It sounds like a great idea but why would UP or ATSF even look at a T1? Both roads were already committed to dieselization and they both had well-designed 4-8-4's on the roster in dual service. Secondhand T1's would have been oddballs on either roster.
Kgb, I'm pretty sure that's the S1 in the Crestline roundhouse photo. The S1 was famous, or maybe infamous, for being too large for the Pennsy's turntables and that aerial shot's a pretty good illustration of same. Man, that thing's HUGE!
CSSHEGEWISCH- Sante Fe would not even consider this idea..no doubts whatsoever. UP might consider it for the reasons I gave..to better hasten dieselization of freight hauling. They could forgo expensive E's, so more for freight units. The Overland Route would be just fine for fast running of passenger trains and the T1's would be up to the challenge. Imagine T1's along side Big Boys and Challengers. They could have got 10 years out of them easy. If Pennsy sold them off very inexpensively along with all the parts and support it could have been a viable thing. Of course at this point I have to stress the theoretical aspect of all this. It does however raise the intriguing question of what UP's steam guys could do with these racehorses.
Southern Pacific under Russell is also a theoretical possibility. He thought diesels were very expensive and slowed down purchases here and there keeping steam in reserve in large numbers. It's possible say '48. Russell was a maverick and a bold thinker and could be very unconventional. Again, purchasing T1's at a huge discount allowed for more dollars for diesels on freight. Picture fast coast running and segments of the Sunset with T1's sporting orange and red hues.
Well, the PRR did try to sell T1's to the C&O and the N&W as well, but neither 'road was interested.
Maybe they should have tried Espee and UP. Would have been interesting to say the least.
We have to remember this was the era, albeit the tail end of same, when just about every major 'road had it's own ideas of what a locomotive should be and were pretty parochial about it. It took EMD/GM to break them of that outlook.
"Here's the diesel. You know what it can do for you. You know you want it, but forget custom jobs, take them as they are or leave them!"
We all know what happened.
Re Tenders for T1 -
I believe that Altoona made all the regular production T1 tenders and half the locomotives. Which means that at some point they came "tenderless" from Baldwin Locomotive Works and - in the beginning of their lives went into the Altoona shop to be completed - likely the reason a new tender would be without coal.
Seems there was an extended birth process for some original T1's. To say nothing about how long it would take to assemble a reproduction.
I would guess the photo was taken from the roundhouse roof by a company photographer.
T1's 5500 to 5524 were built in Altoona and 5525-5549 were built by Baldwin but all of the tenders were built in Altoona. So it is logical to think that 5525 thru to 5549 were transported without their tenders to the tender shop in Altoona. It is very likely that is what we are seeing in this picture.
I wonder if any photograph exists of the Baldwin builds being hauled en route without their tenders.
You know the more I look long and hard at these posted pictures from Wanswheel and kgbw49 the more the T1's do "look" like they were a UP or SP locomotive and kind of out of place on the Pennsy. It adds even more to the mystery, lore and tragedy of these great machines.
Firelock76Well, the PRR did try to sell T1's to the C&O and the N&W as well, but neither 'road was interested. Maybe they should have tried Espee and UP. Would have been interesting to say the least. We have to remember this was the era, albeit the tail end of same, when just about every major 'road had it's own ideas of what a locomotive should be and were pretty parochial about it. It took EMD/GM to break them of that outlook. "Here's the diesel. You know what it can do for you. You know you want it, but forget custom jobs, take them as they are or leave them!" We all know what happened.
In Don Ball Jr.'s book 'The Pennsylvania Railroad 1940's-1950's' there are statements of the tests both C&O & N&W conducted with the T1's vs. the home roads comparable motive power. In each case the PRR T1 was found inferior to the home road power.
Look up the old T1 thread on this forum for a fascinating and very informative debate on the T1's ...especially covering their trials and tribulations on the N&W and C&O. General consensus was the trials were unfair and badly flawed. Combine that with corporate sabotage and group think and the answers are quite obvious.
Lets hope the 5550 project becomes a reality. We will see for ourselves and get the truth.
MiningmanGeneral consensus was the trials were unfair and badly flawed. Combine that with corporate sabotage and group think and the answers are quite obvious.
The folks commenting and putting forth detailed technical answers plus very valid opinions on that form were hardly uniformed. The C&O tests in particular were not right. N&W tests were better but the N&W guys were not going to let the Pennsy motive power designers show them up. They were doomed in any case right from the start wether they were the best thing ever or not.
You just made my point!
Miningman The folks commenting and putting forth detailed technical answers plus very valid opinions on that forum were hardly uninformed. The C&O tests in particular were not right. N&W tests were better but the N&W guys were not going to let the Pennsy motive power designers show them up. They were doomed in any case right from the start whether they were the best thing ever or not.
The folks commenting and putting forth detailed technical answers plus very valid opinions on that forum were hardly uninformed. The C&O tests in particular were not right. N&W tests were better but the N&W guys were not going to let the Pennsy motive power designers show them up. They were doomed in any case right from the start whether they were the best thing ever or not.
There's no particular need to castigate either C&O or N&W for running 'unfair' tests, except insofar as the load and expected performance fell outside the achievable performance envelope of a relatively light, short-stroke locomotive. And N&W's assessment of the locomotive seemed reasonable for its operating conditions ... just as PRR's assessment of the J locomotive was reasonable. The people actually conducting the tests were not fools.
Big Jim's statement is spot on: the actual C&O testing did not appear to feature slipping (the problem was stalling, quite the opposite issue), but 'revealed railfan wisdom' (regrettably including DPM if I remember correctly) made it common knowledge that T1s slipped dramatically and this was an important reason they 'failed' on C&O. Believe me when I tell you the PRR designers weren't going to show up the N&W design team, particularly Voyce Glaze (see his calculations for a 4-4-4-4 in Calculation Book #1, short as they are) or vice versa - they were professionals with distinct senses of design optimization. N&W knew going into the tests that a locomotive with 80" drivers and 26" stroke wasn't going to do the same work as a J on their railroad, and they had comparatively little need for the benefits of duplex divided drive either in augment or mass reduction at the costs the T1 design imposed. (N&W is also notable for having eschewed Franklin type A entirely, not for want either of technical knowledge or willingness to develop new forms of locomotive power - in my opinion this is no accident.)
The sad thing for the T1 design, in my opinion, was the remarkable bad timing: they were badly needed in 1941, still important in 1945, an afterthought by 1947, an embarrassment by 1950. The history of the V1 shows similar details; I think the S2 is perhaps the most dramatic demonstration.
Ironically there is this photoshopped picture of a "C&O" T1 out on the Web...
With respect to these tests, I read somewhere that the T1 "test article" didn't arrive for the tests in tip-top condition. Kind of like trying to sell a used car and not bothering to wash it, clean out the insides, and have any Check Engine light condition serviced, first?
Kgbw49- That photoshopped picture is downright ugly as can be...it looks like a ridiculous running shoe.
Paul Milenkovic- That is true. There are good accounts in the old T1 thread a couple of years back with Juniatha, M. Sol and Overmod comments and many others...it is a great thread to read through, with a lot of references and accounts to those tests.
The thread was around March 2012...David Klepper and Firelock were commentators ...lot of great stuff.
Juniatha
Miningman - LOL! There is Nike's next shoe - the Nike T1 Flyer!
Kgbw49- Good one! Now I'm starting to seriously rethink that Southern Pacific T1 idea of hues of red and orange. Likely a disaster.
UP could have picked them up cheap, cheap, cheap and forgone new expensive passenger diesels. By the time they were done, say 1959 it was becoming obvious that passenger was in serious decline. They could then pick up second hand relatively new E's in surplus from other roads for what was left. A win-win. Also, for some reason I do not think the UP steam guys would be insulted by these...I think they would have seen them as a challenge and souped them up to their liking. Probably have one extant today. I'm really not crazy, just wishing and dreaming.
MiningmanKgbw49- Good one! Now I'm starting to seriously rethink that Southern Pacific T1 idea of hues of red and orange. Likely a disaster.
I think it is easily possible to adapt the Daylight scheme compellingly to a T1, even one largely stripped of skirting (or given SP-style skirting in their shops). Perhaps if Juniatha comes back to comment on being quoted in this thread, she can 'gin up a picture for us, as she's already done drawings of some improvements on the T1 streamlining.
The problem is that there are parts of the Daylight runs that involve significant grade and curvature, and climatic conditions under which the T1s were demonstratedly slippery-natured. I don't think a short-stroke engine would do well there, no matter how dramatically faster they might prove on other parts of the runs.
UP could have picked them up cheap, cheap, cheap and forgone new expensive passenger diesels.
On a railroad that stopped development of heavy passenger steam in the 1930s, and used diesels on their Streamliners almost exclusively? My own suspicion is that, as with ATSF, most areas where UP ran steam fast enough, with limited enough grade for the train weight required to justify a T1, would be dieselized in preference ... no matter how cheap the locomotives, even with adequate 'spares' and a full documentation of the care and feeding of the parts of the poppet-valve drive gear, could be provided. (And that, again, would be strictly limited for PRR by how they could get out of their equipment trust obligations for such new locomotives...)
By the time they were done, say 1959 it was becoming obvious that passenger was in serious decline. They could then pick up second hand relatively new E's in surplus from other roads for what was left. A win-win.
I think it was obvious that passenger was in decline for the sorts of trains the T1 would run long before 1959, and this would be exaggerated by 'repeats' of the kinds of service interruption that the T1s experienced on PRR (not all of which would be solved by the 1948 improvements, or the likely adoption of oil firing on UP -- there is NO way to adapt a T1 to use typical UP "coal"). In order for UP to overcome the maintenance issues observed for Q2s vs. J1s (twice as many cylinders, valve-gear servicing difficulties, etc.) they'd have to run faster trains than the later classes of FEF, and while the duplex reduction of augment might allow operation closer to 'Streamliner' average speed, there are places (I think Sherman Hill would be one) where a short-stroke unconjugated duplex would be at a very decided operational disadvantage.
Also, for some reason I do not think the UP steam guys would be insulted by these...I think they would have seen them as a challenge and souped them up to their liking.
At what cost, exactly, over the supposed bargain of their acquisition? By the time you did the firing and perhaps tender conversions, installed B-2 gear, and put in independent control of the two engines, you'd be well-up on the out-of-pocket cost for a year's worth of financing on an equivalent set of E units through GM. And still with all the rising costs of manpower and facilities needed to service a steam locomotive...
Probably have one extant today. I'm really not crazy, just wishing and dreaming.
Perhaps the thing to consider would have been what SP developed (perhaps with Lima) if the duplex concept had been made to work as expected, with a proper firebox size and less flickety valve gear ... and the advent of practical diesel-electric power had not included Sloan/Hamilton/Dilworth's version of EMD. We know ATSF had perhaps the most exotic duplex on the boards (oil-fired 6-4-4-4) and while I wouldn't want to see SP take up the proposed T&P duplex styling even through slitted eyes, the locomotive likely under that styling would have done nicely at lower augment, had that been perceived as desirable instead of more orders of 'straight' GS locomotives. But that of course is far more wishing and dreaming than we've already been doing...
[/quote]
RME- Thanks for the great reply. If this could nudge Juniatha back for a bit in the forum then that would be worth it.
Makes one wonder if the designers and builders and also those regular folks in the roundhouse that laboured on them, and those that ran them, that believed in the T1's, ever contemplated that in 2017 they are still being debated, admired, admonished, fixes put forth and so on.
I think more in the last ten years have been written and a keener knowledge and sense of them than ever. That alone is validation.
Miningman RME- Thanks for the great reply. If this could nudge Juniatha back for a bit in the forum then that would be worth it. Makes one wonder if the designers and builders and also those regular folks in the roundhouse that laboured on them, and those that ran them, that believed in the T1's, ever contemplated that in 2017 they are still being debated, admired, admonished, fixes put forth and so on. I think more in the last ten years have been written and a keener knowledge and sense of them than ever. That alone is validation.
MiningmanRME- Thanks for the great reply. If this could nudge Juniatha back for a bit in the forum then that would be worth it.
I doubt it. It was a loss. Sadly, she let me know that one or two posters (none of us) drove her off.
I've got Juniatha's e-mail. (Not at liberty to give it out.) I've tried several times to get her back but no luck, not even a reply. Maybe I'll try again. I don't know.
I miss that young lady.
Here are a couple of brief YouTube videos with a lot of T1 footage...
https://www.youtube.com/watch?v=4hgKcGnEihc
https://www.youtube.com/watch?v=znMu4K71ktY
It is rather mysterious and puzzling as to why folks leave the forum after being so active and a very popular contributor. Comment forums are definitely not for the thin skinned or impatient. Personally I find people who jump in without reading the posts leading up to their comment quite frustrating. Many simply do no due diligence or inform themselves before shooting off their big yap. Of course there are always the trolls which if left unchecked can destroy a website. The Classic and Trains posts are pretty good at finding a balance without too much nonsense. For comparison, try your favourite sports team comments section and blogs..that is seriously ridiculous stuff populated by people with far too much time on their hands...they have become meaningless.
For myself, working full time in teaching, time constraints come into play as well...so much to do in such little time. While some are retired that is not the case for all and even in retirement some are more busy than ever.
( As an aside, grammar, puctuation and spelling are horrid..beyond belief at times...it is a product of an education system that no longer corrects these things, fast paced lives and the Internet world..nontheless many come across as being illiterate)
Also, who knows who is truly who? Some reappear under different names, or at least it certainly appears that way. Many do not fill out the biography or post any basic information on themselves.
I really enjoy the forums when I can. There are many who have left for reasons unknown to us. It is a loss in many cases.
Miningman, please be just a bit more tolerant of spelling and punctuation errors. Sometimes they represent lack of time for checking, typos, and a triumph of impatiance over accuracy.
Dave- Of course, in your case it is very understandable...as it is for others. It is easy to see the difference.
I apologize if this question has been asked previously on this forum (possibly in an older thread) but did PRR ever consider modifying the T1 fleet with the electro-mechanical wheelslip control system used on the Q2's? I read on the T1 trust site that they have considered such a system for their design..
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
daveklepperMiningman, please be just a bit more tolerant of spelling and punctuation errors. Sometimes they represent lack of time for checking, typos, and a triumph of impatiance over accuracy.
As well as not having a working spell check on this particular version of forum software. Prior versions did and many other organization's forums currently have spell check.
carnej1did PRR ever consider modifying the T1 fleet with the electro-mechanical wheelslip control system used on the Q2's?
I have never seen any indication of this, including when reviewing the extant documentation at the Hagley. That's not to say it wasn't discussed, only that no evidence of adapting the equipment or re-engineering the system to passenger standards was made.
In a couple of respects it was apparently well-understood that the system needed major redesigning -- first, the system was virtually useless using its original 'bang-bang' implementation logic, and second, the bearings and pivot arrangement for the butterfly valves were neither reliable nor maintainable in service. (These two issues may be related; the original electromechanical design would have been easy to implement proportionally, but sticking valves would have thrown that operation off badly, leading to full excursion 'by default' as the only operational choice...)
I consider it highly unlikely that any attempt at mechanically valving the steam would be desirable -- the Wagner throttles are not only much less visually obtrusive, they work properly at any degree of superheat and need little if any calibration as they age in service. And in any case a mechanical traction-control system acting on the wheelrims directly is a better form of quick implementation and release for borderline slip conditions, and this as an adjunct of independent brake is much easier to control.
My understanding concerning Juniatha was that she was working too hard to be posting to this forum extensively. Perhaps that will change in future, or she will take a periodic interest in things that happen here.
I've read this entire thread - no one mentions the article in the Keystone in Fall 2014 called "90 MPH and beyond". The author has done significant research to help dispell cliams made by the brits of the world steam locomotive speed record. Much of his findings involve the T-1 on the Ft Wayne Division. Much is documented - some is not. The Franklin Valve story is told in detail especially what the Franklin engineering teams found when they timed T-1 speeds in the loco cabs in daily operation - 140 mph was not uncommon but exceeded the warranty speed of 120. They had to use stopwatches as the speedometers weren't metered high enpough. This and other stories are told in rich detail and is a must read for anyone with interest in the T-1. (My favorite is the alleged elapsed time of the military special during WW2 from Crestline to Chicago.) No wonder the T-1 Trust people want to establish the absolute steam locomotive world speed record once and for all.
Out of curiosity, who is the author of "90 MPH and beyond"? I have a few back issues of the Keystone with T1 related articles but not Autumn 2014.
Edit: Looks like it was Neil Burnell, and I do have it.
--Reed
[quote user="BigJim"]
[/quote above]
Yes it can, if it is an "Advanced Section" of the train. Which the PRR did regularly with many NY - Washington expresses during WWII. Once rode from Washington to NY in 3hr 5min.
The data may have been from an Advanced Trailblazer or Advanced Broadway.
This was common practice on both the Pennsy and the Central.
Carriers can have trains do what they need or want them to do - to wit a possible train order.
FIRST NO. 1 ENG 5501 RUN 1 HOUR ADVANCE FORT WAYNE TO CHICAGO.
This would require trains that had to protect against NO. 1 to protect against this train one hour in advance of NO 1's schedule as printed in the Timetable.
The reality is, on a multiple track railroad, such a order would not be necessary and the PRR from Fort Wayne to Chicago was a double track primarily current of traffic signaled railroad.
In today's world of railroading Amtrak's Auto Train routinely operates from orign in advance of the scheduled 4 PM departing time from the terminals at Lorton and Sanford.
BaltACDCarriers can have trains do what they need or want them to do - to wit a possible train order. FIRST NO. 1 ENG 5501 RUN 1 HOUR ADVANCE FORT WAYNE TO CHICAGO. This would require trains that had to protect against NO. 1 to protect against this train one hour in advance of NO 1's schedule as printed in the Timetable.
Way back when you would be amazed at what carriers did way before Lawyers made this society so afraid of being sued into oblivion for the smallest thing that they force compliance over service. My boss has always run a very safe operation yet way back in the 80's and up to the mid 90's his drivers knew if they had to push the book so to speak to get that load there then the boss and his father had their backs. My late father in law told me countless times of how he threw his logbook in the bunk in the 70's to get loads thru for his boss.
I rode such trains in the NY -Washington corridor. Believe me, both the PRR and New York Central did. And Amtrak can if it wsnts to in the corridor, but they usually simply assign a temporary train number and issue a temporary schedule.
daveklepperI rode such trains in the NY -Washington corridor. Believe me, both the PRR and New York Central did. And Amtrak can if it wsnts to in the corridor, but they usually simply assign a temporary train number and issue a temporary schedule.
Multiple track territory was normally not operated under Timetable & Train Orders method of operation - with that being the case Schedule times were of limited to no importance.
daveklepperI rode such trains in the NY -Washington corridor.
Guess you mean, trains that passed stations ahead of schedule when they were not scheduled to receive traffic at those stations. That was legal in PRR Rule-251 territory-- no train order needed.
I meant advance sections of regularly scheduled trains, most frequently the advanced Congressional, later renamed the advanced Afternoon Congressional.
In other words, both the Central and the Pennsy, instead of running a second section ten minutes behind the schedule train, ran an advanced section ten minutes earlier.
But I also rode trains meeting your description, the northbound Silver Metior, Souterner, East Coast Champion, and Flordia Special frequently arrived at and left Philadelphia, Newark, and New York as much six or seven minutes ahead of schedule. Probably also true of the Broadway Limited, Trailblazer, Jeffersonian, etc, substituting N. Phill. for Phill.
And the northbound Crescent was a special case. At one point the Southern public timetable showed times in the corredor that were probably correct for times when the train ran as an entire train north of Washington. But all times that I rode it, a string of rebuilt P-70's with a PRR diner was attached, it ran as a regular Washington - NY hourly train, with times earlier than those shown in the Southern timetable.
daveklepperBut I also rode trains meeting your description, the northbound Silver Meteor, Southerner, East Coast Champion, and Florida Special frequently arrived at and left Philadelphia, Newark, and New York as much as six or seven minutes ahead of schedule.
I was given to understand that at least part of the reason for 'detraining passengers only' at some of these later stops was to avoid issues with early onward departure -- not just keeping the hoi off the Pullman trains.
davekleppernorthbound Silver Metior, Souterner, East Coast Champion, and Flordia Special frequently arrived at and left Philadelphia, Newark, and New York as much six or seven minutes ahead of schedule.
So presumably the employee timetable showed them as discharge-only at Philadelphia and Newark, and they didn't appear in the Form 12 and Form 79 public timetables at all.
Most of the years I rode them, they did not appear in the Wash - NY and Phila - NY PRR public timetables. I did ride them though, on occasion, Wash - NY, with a conductor that did not mind. Very useful idea when the regular hourly trains were crowded. I suspect he gave my ticket stub to a regular NY - Wash conductor to hand in, rather than have to answer questions.
timzSo presumably the employee timetable showed them as discharge-only at Philadelphia and Newark, and they didn't appear in the Form 12 and Form 79 public timetables at all.
I am informed from a different source that some Amtrak trains were given official permission to leave stations early; they were said to be denoted in timetable with code "L". I do not have material to substantiate this, but I suspect timz does.
"L" meaning they weren't supposed to board passengers at that stop? If the station was between NY and Washington, that was enough to make an early departure legal.
Most other RRs in, say, the 1970s and earlier had rule 92, which flatly forbid leaving any station ahead of time. Nowadays I think many? all? dispatchers are allowed to authorize passenger trains to leave early-- tho there would rarely be any reason to do that.
timz"L" meaning they weren't supposed to board passengers at that stop? If the station was between NY and Washington, that was enough to make an early departure legal. Most other RRs in, say, the 1970s and earlier had rule 92, which flatly forbid leaving any station ahead of time. Nowadays I think many? all? dispatchers are allowed to authorize passenger trains to leave early-- tho there would rarely be any reason to do that.
There is no longer a Timetable and Train Order form of operation which relies on time and other factors for movement authority.
From the Dispatchers view point today, he or she really doesn't care if a passenger train leaves in advance of the scheduled departure time. Authority for movement is given via either Signal Indication or Track Warrant Control - neither of these means of authority are time related.
Yes, the dispatcher doesn't care if a passenger train leaves early-- but if it picks up passengers at that station, Amtrak usually doesn't want it to leave early. If a following train can pick up the passengers in a few minutes, the dispatcher can apparently authorize a train to leave ahead of its public-timetable schedule. (Presumably he'd have to radio the conductor and engineer and give them the OK.)
timzYes, the dispatcher doesn't care if a passenger train leaves early-- but if it picks up passengers at that station, Amtrak usually doesn't want it to leave early. If a following train can pick up the passengers in a few minutes, the dispatcher can apparently authorize a train to leave ahead of its public-timetable schedule. (Presumably he'd have to radio the conductor and engineer and give them the OK.)
All that is in the hands of the passenger operator.
kgbw49 Have not been able to locate a T1 vs Niagara race photo yet...
Very overdue, but such a photo has surfaced!
Can't seem to make out the numbers of the racing participants, but no doubt in my mind who 5535's crew was rooting for.
Considering the original topic, I've no doubt in my mind that an S-1b could make 120 mph as well. The closest way to make this comparison is with the N&W J's making 110, multiple times, on the Ft. Wayne Division, all at original boiler pressure. The S-1b's had much more power in reserve at 100 mph, and would've been the only locos besides the T1's to develop >4,000 DBHP at such speeds. Certainly the only locos with piston valves!
One could only wonder, therefore, how the two designs would fair with the FSSD Type B-2 or even Type D valve gear. Both the NYC's and PRR's "5500's" exhibit benefits and drawbacks of the original Type-A gear. I suspected both types were too large for the motion they were built with and latter research basically confirmed that. Type B gave PRR's 5500 better performance and maintainability without sacrificing its high speed advantage (as with the T1a), so equipping the same gear to NYC's 5500 would've put its power to better use. The latter could already developed more power than an S-1b; it just kept choking on that power trying to get it on the rails
I have tried to answer this five times -- with the 403 Forbidden 'nanny' system each time. Remains to be seen what I may have to do to give it the attention it deserves.
Overmod I have tried to answer this five times -- with the 403 Forbidden 'nanny' system each time. Remains to be seen what I may have to do to give it the attention it deserves.
Something seems iffy on this end too. When on Page 5, the buttons seem to read -1, 0, 1, 2, 3. Haven't the foggiest why, it's been a while since I've been active here, though hoping it's easier to answer for you
RailfanGXY Overmod I have tried to answer this five times -- with the 403 Forbidden 'nanny' system each time. Remains to be seen what I may have to do to give it the attention it deserves. Something seems iffy on this end too. When on Page 5, the buttons seem to read -1, 0, 1, 2, 3. Haven't the foggiest why, it's been a while since I've been active here, though hoping it's easier to answer for you
A prima facia case ot Kalmbach IT's loose association with reality. Can't even count straight and display same.
BaltACDA prima facie case ot Kalmbach IT's loose association with reality. Can't even count straight and display same.
To be fair to the Bangalore contingent, the "problem" here is likely in a mismatch deep in the back-end engine code, between the 'optimized' post-2018 page structure and the system in global settings that is supposed to let you see threads 'last post first' (it blows up when you have it set and try to click on the 'ascending order' control in a particular thread, so there are other improprieties in the codebase). When we actually get the promised 'stage three' renovation, probably about the year 2048... this and the other little foibles will be fixed. At least we can hope they will be.
Now that I have restarted the computer again, let's try a reply as far as we can get. This may take a while, so wait until all the stuff is composed (again) and added inline.
RailfanGXYConsidering the original topic, I've no doubt in my mind that an S-1b could make 120 mph as well.
The only actual 'evidence' for Niagaras reaching or exceeding 120mph is from Arnold Haas. He is the fellow responsible for the idea that the PRR's S1 ran over 142mph with the Trail Blazer in 1947, and he also noted that he'd seen J3a Hudsons run at that speed many times, so I am nowhere near as assured as Bill Withuhn was that the design would actually go that fast.
I'll mention later how a Niagara might be optimized to actually run at high speed with piston valves.
The closest way to make this comparison is with the N&W J's making 110, multiple times, on the Ft. Wayne Division, all at original boiler pressure.
The 610 also benefited greatly from Voyce Glaze's balancing, which put only about 85lb of overbalance in the mains (nominally for the vertical component of piston thrust at designed 'dash' speed) with the 'rest' distributed in the mains. The requisite stiffening of lateral compliance (which led to at least one derailment of 611 on 'diesel suitable trackwork' during her excursion career) allowed less overbalance than strict formulae like the ones that crippled the ACL R-1s initially, and at least some of the surge component could have been addressed by installing a Langer balancer. On the other hand, there was certainly an issue with the J rod arrangement as designed, or more particularly with fractures in the long rod pin on #4 pair, which was fixed with a whole new design... that unfortunately slung the mains far, far outboard.
The S-1b's had much more power in reserve at 100 mph, and would've been the only locos besides the T1's to develop >4,000 DBHP at such speeds. Certainly the only locos with piston valves!
One could only wonder, therefore, how the two designs would fare with the FSSD Type B-2 or even Type D valve gear.
B-2 as described would have in my opinion been highly suitable to NYC 5550 -- it was the rotary-cam drive of type B or C adapted to drive the eight valves per cylinder of type A as built. Had 5550 actually been proportioned and built as a 'super Niagara', that would have been promising indeed -- but the locomotive was designed and intended to show better operating economy at 'the same' horsepower range as the piston-valve engines, and as a result had grossly 'choked' steam mass flow at what would be required to make use of the precise timing and intake/exhaust separation of the Franklin System gear. Note the promise inherent in the design as it is described in the 1947 survey of motive power... and how the locomotive was scrapped in 1950, without even considering its improvement by use of the 1948 PRR 'list'.
What could have been tried instead was a T1a-style conversion to a new chest arrangement, but using two piston valves per cylinder dedicated to separate admission and exhaust (there was at least one contemporary patent with such an arrangement, and a number of modern designers including Wardale have taken it up). That might have given you the effective performance of the C1a, and in turn at least the possibility that a 64T tender could work as well (the boiler was essentially the same between the two locomotive designs).
Both the NYC's and PRR's "5500's" exhibit benefits and drawbacks of the original Type-A gear. I suspected both types were too large for the motion they were built with and latter research basically confirmed that.
Type B-2 gave PRR's 5500 better performance and maintainability without sacrificing its high speed advantage (as with the T1a), so equipping the same gear to NYC's 5500 would've put its power to better use.
The latter could already develop more power than an S-1b...
The other thing that 'ought' to have been tried, which also concerns porting and dead space, was reversible compression control. This would take the form of a fancier set of Okadee-style blowoff valves with modulated trip, venting not to atmosphere but into well-insulated reservoirs, from which developed mass-flow overpressure could be reintroduced early in the return strok so that the cylinder-tract pressure just equaled available chest pressure at the moment the valves started unshrouding. This would conserve and use a greater proportion of nominally-available superheat and also result in much faster effective 'cylinder filling' with a suitable charge for long expansion in the very short time available.
The S1 doing 142 in '47? Not questioning the speed too much, but that would've been a full year after 6100's last logged assignment. Quite the sendoff if true.
As little as I immediately understand (boy I have a lot to read), I should clarify my stance on Franklin A. When saying the locos in question were too big, I was referring to how they seemed to wear the motion out, outrunning or out-steaming the valves specified design limits. Comparing that with how every other engine with poppet valves here seemed to be smaller, or not ran at sustained triple digit speeds on the regular, it seemed to me that the PRR didn't account for how much bigger the T1 was, only having the boosted performance of a "dainty" K4 to compare. I had thought the NYC overestimated how powerful their engine was too, but it seems their choice was more deliberate, rather than an oversight.
Not sure I ever considered the T1's nightmare box to be a cause of any failures, though the foreign nature of its design likely deterred many shop crews. I recall one andectdote of one of the Space Sisters being found in a yard, and it taking some disciplinary threats for crews to start prepping it for service.
Now you mention a "double piston" design, I can sort of understand how that would be an alternative to the poppet valve arrangement. With the animations I've seen of Franklin's OC and RC gear, as well as British-Caprotti, a pair of pistons would seem to fit well
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