just a thought :
Hi , all
… Shades of the Pennsy T-1 / NYC Niagara comparisons …
Had the UP Challenger really been a 100 % substitute for the UP 9000 class in daily traffic as concerns actual ( not formula ) starting t.e. and load capacity on ramps ? ( Side remark : the three cylinder arrangement was all but ideal in the 9000 class , further , just the 5th series had been built with cast steel locomotive bed . )
Or in general : could a simple expansion Mallet have started as sure footed in every-day service as a straight rigid frame engine of same number of coupled wheel sets and adhesion mass ?
Provided , it had enough piston thrust to develop the same indicated t.e. , didn't a big Texas type actually live up to practically same level of low speed ramp work as a 4-6-6-4 or 2-6-6-4 in spite of one less coupled wheel set , just because of better actual adhesion by its ten coupled rigid frame single drive set ? ( and I don’t mean by beefing up to the same adhesion mass by using higher engine mass per coupled wheel set )
Actual historical engine classes coming to mind are the PRR J-1 and Santa Fe 5011 class / the N&W A class and UP Jabelmann Challenger …
Regards
Juniatha
Hi, Juniatha. I am unsure of your intent for the question's answer as you frame it, but apart from the match between the J1 and the UP Challengers, the nod generally goes to the other versions of the Challengers in terms of their overall speed with trailing tonnages. Their weight was more lightly distributed on the rails if I have it figured out correctly, so they were easier on the rails, and we all know they could use curvatures with shorter radius than could the all-flanged rigid 10-coupled Texas types. However, when we compare the work that any one pairing could do, there really isn't much difference between them when the mighty Bessemer & Lake Erie and the Santa Fe versions' tractive efforts at start and at speed are taken into account.
Crandell
selector Hi, Juniatha. I am unsure of your intent for the question's answer as you frame it, but apart from the match between the J1 and the UP Challengers, the nod generally goes to the other versions of the Challengers in terms of their overall speed with trailing tonnages. Their weight was more lightly distributed on the rails if I have it figured out correctly, so they were easier on the rails, and we all know they could use curvatures with shorter radius than could the all-flanged rigid 10-coupled Texas types. However, when we compare the work that any one pairing could do, there really isn't much difference between them when the mighty Bessemer & Lake Erie and the Santa Fe versions' tractive efforts at start and at speed are taken into account. Crandell
I certainly agree with your information and would like to add some addtional thoughts.
The higher speed capability is certainly the main factor with the Challengers replacing the UP 4-12-2's, but maintenance was also a factor. The third cylinder with the associated valve gear was always a high maintenance type of design. By the time the first Challengers were built, the 9000 class had run for ten years and were already being rebuilt with disc main drivers and other upgrades to allow higher speeds for the Overland main line. One more factor was the long wheelbase and the problems of using them in certain areas with tight radius cuves. They ended up on the main line and the KP line, which could handle large steam.
Did the Challengers provide a 100% substitute, I would say no since the 4-12-2's were used until they were no longer needed. I am sure others might have different opinions but the Union Pacific continued to use them until very late in steam operations. The 9000 class were used on the Union Pacific for thirty years. By mid 1954, GP9's were coming on line and replacing all steam and the Challengers also. Steam maintenance was always labor extensive and the diesels eliminated the major water problems along with the extensive back shop maintenance.
The 9000 class continued to be used until late 1954 and early 1955 almost to the end of steam, but they were removed from service and the tenders used to build the fuel tanks for both versions of the 4500hp turbines. We have the first 9000 at Pomona Fair grounds for all of us to visit. Nice locomotive.
By the way, the J1 you mentioned is one of my favorite locomotives having watched them run many times in Illinois where I grew up. The pictures of a J1 are mine and they were a great locomotive.
CZ
I think CAZephyr pretty much said it all about the UP's 9000's, except for one thing: That loooong wheelbase was just so cool looking! Twelve drivers! Wow! No half-measures as far as UP was concerned!
But that long fixed wheel base of 6 driving axles limited where they could be operated.
Firelock76 I think CAZephyr pretty much said it all about the UP's 9000's, except for one thing: That loooong wheelbase was just so cool looking! Twelve drivers! Wow! No half-measures as far as UP was concerned!
Never too old to have a happy childhood!
Hi Crandell
My question really focuses on actual tonnage limit ratings for daily service on a given ramp section – you name it .
If we put aside all those extreme opinions offered in various articles in the past about alleged slipping problems with T-1 Duplex it was generally agreed that they were to a certain degree more sensitive at starting because of 2 x 4 coupled wheels drive sets instead of 1 x 8 . Now , my question is if that wasn’t likewise true with 2 x 6 instead of 1 x 12 coupled wheels ?
..
Hi California Zephir
Well , yes , the Challies could rise to some respectable speeds with a formidable revenue load , no doubt , also sneaked round corners more easily than the straight twelve coupled Nines – sure . Further , there were some problems with the middle drive in the 4-10-2 and 4-12-2 engines – actually quite the same problems that were encountered in Europe with three cylinder engines having separated drive axles for inside / outside cylinders . We could go on listing compromises in the Chally and the Nine , then I would likely get into how this and that could have been improved and what it would have enabled the engine to do – but that’s not the point .
What I would really like to know : were the simple expansion Mallets really fully up to pulling capacity of a straight twelve coupled engine of comparable size or were they a match rather for a big Texas type ?
In general : could a divided drive be directly compared ( per number of coupled wheel sets ) to a straight frame drive set or didn’t such an engine need a somewhat larger adhesion mass – either by having one more coupled axle or by higher mass per powered wheel set – to compensate for lesser surefootedness *because* of the divided drive sets ? In such a comparison , considering historic engines inevitably has historical variations in quality of design intervening – however let’s not allow those to blur the picture , let’s boil down to the principal question of what the effect of each configuration was – straight frame / articulated frames . Mind , in modern synchronous electrics as in diesel-electric engines , not just wheel sets of a power bogie but wheel sets of front to rear bogies are being electronically coupled to achieve maximum adhesion and minimize effects of slip spots !
Seeing the J-1 locos at work must have been impressive , thank you for showing the photos !
Hi Firelock
Yes , no half-measures : it’s in the name , this railroad was on the *up* not down *g* and is still around going strong .
Only , why on earth they introduced that longer wheel spacing first to second coupled axle when already they had opted for larger wheels on the twelve coupled as compared to the ten coupled predecessor I will never understand ! Well , sure , obvious reason was that middle drive to second coupled axle : to accommodate a longer drive rod . However , with just a little bit further slanting of center line of middle drive , the leading coupled axle could have been set at the same spacing as the others , saving at least some length in an already long coupled wheel base . (By the way – this 67” , 68” and 69” staggering of drive wheel diameters in the Nine , BB and CSA – all of it smaller than diameter reduction by wear : was it really worth it?)
Further , why did the Union Pacific insist on having the conical boiler section with the slope turned on top in the Nines instead of at the bottom as it was with the predecessor 4-10-2 – an arrangement that was for good reason applied later in 1950s / 60s fully welded combustion chamber boilers designed for high specific steaming rates ? UP didn’t continue that feature in their Challengers and later power .
However , that’s just one point each about the middle drive and the boiler arrangement , so let’s stop it here or else I will end up with a re-design proposal and that wouldn’t be fair in view of long time elapsed since these engines roamed the rails .
Hi BaltACD
Well , sure – however that’s not the question since the long wheel base didn’t interfere with tractive effort on a ramp – except for sharp curves where the flange to rail angle of the leading or first two coupled axles might cause a certain reduction of adhesion available to transmission of tractive effort due flange friction and contact point of wheel wandering away from polished spur on rail head – but that would apply to tight yard radii , on mainline radii of curves these aspects have but limited influence .
However taking into account detailed aspects of adhesion would lead astray from the basic question – see my second answer , second and third paragraph .
( Sorry I saw your posting appear only when I had sent mine , so I edited it to include this answer to you )
edit : trouble getting my formatting to appear as set – hopefully straightened now
Thank-you for your clarification, Juniatha. I believe I understand better what you mean. I guess I would want to know the numbers. What weight would each driver bear in each case, and what horsepower would each driver take prior to slipping at a given speed with a standardized weight comparison. I am out of my depth, naturally, but how do the factors of adhesion compare across drivers between the 9000 and the 3900's? What tractive effort can each locomotive apply to the drawbar at 0.01, 1, 4, 8, 15, 20, 30, and 45 mph on a measured length of track in the districts where they shared work?
If time is a factor, which of the two needed more frequent stops for replenishment after the typical tonnages each was meant to trail at the same speed had been moved 200 miles?
Hi,
you asked:
"Was the UP Challenger a 100 % substitute for the UP 9000 class as concerns t.e.??"
This table may not answer all concerns about TE, however it shows, that basically 4-12-2's and 1936 built CSA 4-6-6-4 Challengers had similar tonnage ratings.
Heavy Challengers built after 1942 had some 100 tons higher ratings, reflecting their higher HP and better downhill capabilities. Example: Buford to Cheyenne is -1,55% grade, they could drift downhill with 1000tons (5100 vs 4100) more than the the 4-12-2.
So, the answer should be yes -edit- err no -equivalent -you name it
Tonnage ratings on the UP were usually only as high as a engine can start its trains on grades safetly from a full stop without stalling again.
Altough tonnage ratings were pretty similar between different classes, they certainly did achieve different road-speeds with their loads.
A wild guess of mine is, T1 and Santa-Fe Texas-Types and Q2-Duplexes would be rated quite similar like "Heavy Challengers".
These questions have been around for a long time and there really isn't a straight forward answer because of the wide range of pulling power and speed a locomotive goes through from start to finish.
A locomotives pulling power generally depends on the size of the wheels it is built with. The smaller the wheels the more tractive effort it can produce when starting a train. But a locomotive with smaller wheels it loses power by leaps and bounds as it moves faster. Locomotives with larger wheels on the other hand have a much harder time getting a train moving but can move a freight train at faster speeds with no problem at all. Doyle once told me starting his 4-8-4 SP 4449 was like "putting your car in 5th gear when you want to get moving".
Another big factor is the weight on the drivers. Both the Challengers and 9000's had a big advantage of having many wheels with a lot of weight on them. Both were excellent designs. Had we put much smaller wheels on the Challengers and the 9000's I am sure we would see record tractive effort being produced (much like the Virginian 2-8-8-8-2) which has very small wheels.
I am sure if we put two trains next to each other,both with equal lengths and tonnage and we put a 9000 on the front of one train and a Challenger on the other they would probably end up pulling about the same speed up until about 15 mph or so. I would say the 9000 would end up leaving the Challenger in the dust from that point on until it started hitting a grade. Then the Challenger would probably pass the 9000 and climb the grade way ahead of the 9000 due to it's much more heavier weight which would cause less wheel slip.
People often ask if todays diesels can out pull those Challengers and Big boys. I still say no way. Yes they have tractive effort way past anything the Big boys and Challengers can ever muster up. But all that horsepower and tractive effort is useless if you don't have the weight to keep the wheels from slipping. Show me a single diesel pulling a mile long train up a 2% grade at 20mph like the steam locomotives did.
Hi Thomas,
But the correct answer is yes.
Depending on how you define a 1 miile long freight-train, show me a steamer that can do that...
I don't want to get too far off the original topic here but we can forget the length and just talk about tonnage. Because tonnage is the same back then as it is now. The 2-6-6-6 Allegheny regularly took 10,000 ton coal trains over the mountains on a daily basis at 20mph using just a single engine. I would have to dig up by book on the Alleghenies but I remember a single locomotive took a 13,000 tons over the hill exceeding 15 mph several times.
The Norfolk and Western class A 2-6-6-4 locomotives were rated at 13,000 tons and could take 10,000 ton coal trains over the mountains with a single locomotive.
The big boys could handle a 10,000 ton up a 1% grade.
I don't know if you ever have worked for any railroad,let alone a class one railroad where you are taking 10,000 ton coal trains over a grade but I certainly have. I was also working for Union pacific when they were using the AC 6000 on our trains rated at 6000 hp and considered to be one of the most powerful locomotives in North america.
I can tell you with 100% certainty you are absolutely dreaming if you believe you can take a 10,000 ton coal train up a grade with a single locomotive. It would probably be coming close to stall speed if you used three locomotives no matter how new they are.
A diesel locomotive can have all the wheel slip technology in the world and all the tractive effort in the world. That still won't change the fact that we are talking a maximum weight of around 230 tons with the majority of them are sitting around 205 tons. They simply can not pull such a heavy load with out slipping the wheels. Even with the most advanced wheel slip technology trying to pull a 10,000 ton train up a grade( I would say pulling a 5,000 ton train up a grade with a single locomotive probably wouldn't work) the locomotive wheels are going to slip or not move at all (because of the constant reduction of the anti slip computer).
Steam locomotives like the Big boys and the Alleghenies weighed around 325 tons with out the tender. A full 125 tons more than your average modern diesel locomotive. It was because of all that weight a steam locomotive could pull 10,000 tons or more up a grade with a single locomotive.
So you can believe what you want to believe. To this day no single diesel locomotive has ever pulled anything close to what the steam locomotive did up a grade with the tonnage they used to pull. You can check all the records you want. Tractive effort no matter how great will always be limited to locomotive weight and the diesels just don't have it.
That may be true but you can plug two or three diesel-electrics together, controlled through MU or DP under ONE throttle, and match the pulling power of that steam locomotive, be it a Challenger, Allegheny or Big Boy.
The big boys could handle a 10,000 ton up a 1% grade
Thomas,
no offense meaning, but this is absolutely, certainly not true. They were rated 4800tons at 1% at unknown speed. At a 1,14% grade, 4000 tons, 15mph were attempted.
GE AC6000 is rated 5000 trailing tons at this grade and speed.
Thomas 9011The big boys could handle a 10,000 ton up a 1% grade.
Thomas 9011So you can believe what you want to believe.
It's a brillian full moon tonight ...
quite right
for a little walk in the still of the night
and a turn of cards in the silver light
Well , alright – that’s pretty much what I’m wondering about . Let’s forget ihp par what-ever for a moment , it’s really just a matter of tractive effort : did 2 x 6 powered wheels transmit an equivalent amount of t e as one set of 12 powered wheels – in actual conditions in actual daily traffic .
It’s quite simple if you boil down to it : would rails have a uniform , constant and invariable adhesion limit (real adhesion , not the formula FOA !!) and the same would apply to the locomotive structures indiscriminatingly – then it would make no difference at all how wheel sets were arranged . However , that’s clearly not so : rail surface conditions vari and with it possible adhesion limit ; how much of that a locomotive can realize also varies according to configuration . Point is , how much did this apply to Mallet compared with straight frame locomotives in actual daily service ? That’s something I hoped people who remember these locomotives in regular traffic could tell something about .
Hi Bigboy4017
Ok , that table tells Union Pacific understood the ’36 Chally as in fact a 100 % replacement of the Nines . My question , to be sure , is : was this realized in daily traffic at the same surefootedness as with the Twelve-Coupled ?
You guess by now : I think not .
It were , if actual rail adhesion factor would invariably be the same over the line and over the year , in sunshine and rain etc . ( everybody , please do not mix this with FOA used in steam loc data tables !! this is the REAL coefficient of friction between wheel and rail expressed as t e / adhesion mass , not the nominal quotient of adhesion mass divided by nominal cylinder t e , mind it ) However adhesion is NOT constant at all , in fact adhesion factor varies depending on conditions of weather , cleanliness of rail head surface , sort of steel used for wheel tires , attaining values between optimum of better than 0.33 and minima that can fall well below 0.1 under adverse conditions , that even with sanding can only be brought up to some 0.2 .. 0.22 – way below optimum condition without sanding !
With any local drop of adhesion due to fouled rail head surface , a longer coupled wheel base with a larger number of contact points – i e wheels – must of necessity be at advantage as with one or two wheels on a ‘slip spot’ the percentage of loss of adhesion is smaller than in a divided drive . However – now we get to influences of actual design – the three cylinder drive of the Nines was not an optimum design and thus it may be the Challies were in fact up to about the same low speed drag performance in actual traffic – in average conditions !
Hi Thomas
I’m not going to engage on that steam against diesel issue , I’ve commented on that in another thread earlier on – it totally leads away from the question at hand , nor is it questionable on a one to one basis a diesel unit even today does not match a Super Power steam loco in power at speed – never was intended to ( ok , except for the specialized few Do-Do units ) . American RRs move very heavy tonnage trains by using multi-unit diesel traction and piling up combined starting t e and also motor hp to suit the task .
Hi Timz Well , maybe the mythical Henderson Quintuplex project would have applied? At least until it's ten full size cylinders have drowned the boiler , which shouldn't have taken too long ..
Hi Timz
Well , maybe the mythical Henderson Quintuplex project would have applied? At least until it's ten full size cylinders have drowned the boiler , which shouldn't have taken too long ..
.
United we stand - God bless America !
Hi all
By the way – since there are hardly any sound recordings of UP and SP three cylinder engines , you might want to listen to this :
On March 25th 1995 four cylinder compound Pacific 18 316 leads a steam special on the ramp near Graefenroda , Germany , with (East-German) DR three cylinder Decapod 44 1093 pusher ; the Pacific then had only shortly returned to special service after being overhauled to running condition at Pila works , Poland - the quality of work had not been to standards , the engine’s cylinders or receiver are leaking badly , leaving most all of the train lifting work to the 44 class pusher – and that’s just what she did ! Listen to the vast difference in tempo of 18 316’s four beats per 83 ins dia drive wheel turn and 44 1093’s six beats per 55 ins wheel turn :
http://www.dampfsound.de/sounds/m18316/cd054s07.mp3
On a Plandampf steam event 44 1093 starts Dg 55610 regular freight at Triptis
http://www.dampfsound.de/sounds/m44dr/bs01s10.mp3
44 class in regular service on (East-German) DR :
oilfired 44 with very heavy freight on the ramp to Unterwellenborn near Saalfeld on April 5th 1980 – outburst of slipping , thereafter slowed but keeping a steady ~ 15 mph
http://www.dampfsound.de/sounds/m44dr/cd002s01.mp3
44 class in regular service on (West-German) DB :
043 469 (oil fired 44 in 1968 re-numbering) nearing the summit at Altenbeken of the long approx 1.2 % grade , 9:05 PM on July second 1971 – the engine is working at about 20 mph constant speed and some occasional roughness in the beats tell of near priming .
http://www.dampfsound.de/sounds/m44db/cd008s07.mp3
On the same ramp at somewhat more speed another oilfired 44 in the early morning on September second 1971
http://www.dampfsound.de/sounds/m44db/cd007s06.mp3
On February 6th 1975 , one year before the end for Ottbergen 44s , 044 591 with freight on the Hortheim – Ellrich-Nordhausen line is long to be heard through the valley on the ramp of Osterhagen – beautiful whistling with echo from forested hillsides , in the beginning of the recording speed is around 20 mph , coming nearer slows below 15 mph , after passing throttle is closed for a short time , then re-opened at almost walking speed ( there must be a cut in the recording , this could have been a slip , recording of train passing is also cut short in this trailer version of the recording ), in the distance the engine bursts into a mighty slip , accelerates powerfully as top of ramp is reached
http://www.dampfsound.de/sounds/m44db/cd089s03.mp3
In the evening of June 28th , in the very last few weeks before end of steam traction on DB : 043 321 plus 043 381 on the ramp leaving Emden freight yard with 4000 t ore train – several times engines start to slip , valve timing is wanting , rough , fuzzy beats tell engines work at the fringe of priming and there is steam bypassing piston valve rings , clanky main rod bearings or cross heads , second engine with piston glands hissing .
http://www.dampfsound.de/sounds/m44db/cd093s06.mp3
( This is a simplified version of my posting - I don't get the pictures to appear ) Hi Crandell Well , alright – that’s pretty much what I’m wondering about . Let’s forget ihp par what-ever for a moment , it’s really just a matter of tractive effort : did 2 x 6 powered wheels transmit an equivalent amount of t e as one set of 12 powered wheels – in actual conditions in actual daily traffic . It’s quite simple if you boil down to it : would rails have a uniform , constant and invariable adhesion limit (real adhesion , not the formula FOA !!) and the same would apply to the locomotive structures indiscriminatingly – then it would make no difference at all how wheel sets were arranged . However , that’s clearly not so : rail surface conditions vari and with it possible adhesion limit ; how much of that a locomotive can realize also varies according to configuration . Point is , how much did this apply to Mallet compared with straight frame locomotives in actual daily service ? That’s something I hoped people who remember these locomotives in regular traffic could tell something about . Hi Bigboy4017 Ok , that table tells Union Pacific understood the ’36 Chally as in fact a 100 % replacement of the Nines . My question , to be sure , is : was this realized in daily traffic at the same surefootedness as with the Twelve-Coupled ? You guess by now : I think not . It were , if actual rail adhesion factor would invariably be the same over the line and over the year , in sunshine and rain etc . ( everybody , please do not mix this with FOA used in steam loc data tables !! this is the REAL coefficient of friction between wheel and rail expressed as t e / adhesion mass , not the nominal quotient of adhesion mass divided by nominal cylinder t e , mind it ) However adhesion is NOT constant at all , in fact adhesion factor varies depending on conditions of weather , cleanliness of rail head surface , sort of steel used for wheel tires , attaining values between optimum of better than 0.33 and minima that can fall well below 0.1 under adverse conditions , that even with sanding can only be brought up to some 0.2 .. 0.22 – way below optimum condition without sanding ! With any local drop of adhesion due to fouled rail head surface , a longer coupled wheel base with a larger number of contact points – i e wheels – must of necessity be at advantage as with one or two wheels on a ‘slip spot’ the percentage of loss of adhesion is smaller than in a divided drive . However – now we get to influences of actual design – the three cylinder drive of the Nines was not an optimum design and thus it may be the Challies were in fact up to about the same low speed drag performance in actual traffic – in average conditions ! I’m not going to engage on that steam against diesel issue , I’ve commented on that in another thread earlier on – it totally leads away from the question at hand , nor is it questionable on a one to one basis a diesel unit even today does not match a Super Power steam loco in power at speed – never was intended to ( ok , except for the specialized few Do-Do units ) . American RRs move very heavy tonnage trains by using multi-unit diesel traction and piling up combined starting t e and also motor hp to suit the task . By the way – since there are hardly any sound recordings of UP and SP three cylinder engines , you might want to listen to this : On March 25th 1995 four cylinder compound Pacific 18 316 leads a steam special on the ramp near Graefenroda , Germany , with (East-German) DR three cylinder Decapod 44 1093 pusher ; the Pacific then had only shortly returned to special service after being overhauled to running condition at Pila works , Poland - the quality of work had not been to standards , the engine’s cylinders or receiver are leaking badly , leaving most all of the train lifting work to the 44 class pusher – and that’s just what she did ! Listen to the vast difference in tempo of 18 316’s four beats per 83 ins dia drive wheel turn and 44 1093’s six beats per 55 ins wheel turn : http://www.dampfsound.de/sounds/m18316/cd054s07.mp3 . On a Plandampf steam event 44 1093 starts Dg 55610 regular freight at Triptis http://www.dampfsound.de/sounds/m44dr/bs01s10.mp3 . 44 class in regular service on (East-German) DR : . oilfired 44 with very heavy freight on the ramp to Unterwellenborn near Saalfeld on April 5th 1980 – outburst of slipping , thereafter slowed but keeping a steady ~ 15 mph http://www.dampfsound.de/sounds/m44dr/cd002s01.mp3 . 44 class in regular service on (West-German) DB : . 043 221 coming from Paderborn with freight climbs the long ramp to Altenbeken viaduct , early morning in July 1972 - steady ~ 20 mph , beautiful whistling in the distance , exhaust resounding through the valley , coming nearer the engine suffers some priming ( hear hard noise in exhaust sound ) and cylinder cooks are opened - there is a cut in the recording of the train passing at 5:43 ( engine sound suddenly gone ) - in the distance engine accelerates powerfully through Altenbeken station ( gaining momentum for second climb coming up ) http://www.dampfsound.de/sounds/m44db/phdirs01.mp3 . On the same ramp at somewhat more speed another oilfired 44 in the early morning on September second 1971 http://www.dampfsound.de/sounds/m44db/cd007s06.mp3 . On February 6th 1975 , one year before the end for Ottbergen 44s , 044 591 with freight on the Hortheim – Ellrich-Nordhausen line is long to be heard through the valley on the ramp of Osterhagen – beautiful whistling with echo from forested hillsides , in the beginning of the recording speed is around 20 mph , coming nearer slows below 15 mph , after passing throttle is closed for a short time , then re-opened at almost walking speed ( there must be a cut in the recording , this could have been a slip , recording of train passing is also cut short in this trailer version of the recording ), in the distance the engine bursts into a mighty slip , accelerates powerfully as top of ramp is reached http://www.dampfsound.de/sounds/m44db/cd089s03.mp3 . In the evening of June 28th , in the very last few weeks before end of steam traction on DB : 043 321 plus 043 381 on the ramp leaving Emden freight yard with 4000 t ore train – several times engines start to slip , valve timing is wanting , rough , fuzzy beats tell engines work at the fringe of priming and there is steam bypassing piston valve rings , clanky main rod bearings or cross heads , second engine with piston glands hissing . http://www.dampfsound.de/sounds/m44db/cd093s06.mp3
( This is a simplified version of my posting - I don't get the pictures to appear )
043 221 coming from Paderborn with freight climbs the long ramp to Altenbeken viaduct , early morning in July 1972 - steady ~ 20 mph , beautiful whistling in the distance , exhaust resounding through the valley , coming nearer the engine suffers some priming ( hear hard noise in exhaust sound ) and cylinder cooks are opened - there is a cut in the recording of the train passing at 5:43 ( engine sound suddenly gone ) - in the distance engine accelerates powerfully through Altenbeken station ( gaining momentum for second climb coming up )
http://www.dampfsound.de/sounds/m44db/phdirs01.mp3
Hello Thomas 9011,
Please let me correct a little bit your dreams of what those steamers were able to output at the drawbar. Max drawbar pull just depends on weight on drivers and their ahesion on the tracks as long as indicated pull at max pressure may be in excess of this. Neither wheel diameter nor excessive hors power or steam preasure will overcome the physics!
For example those 10 000 tons at 1 % ruling grade needed more than 220 000 pounds of tractive effort, which is almost twice of the max of which a Big Boy could deliver on a 1 % grade.
As far as I know, the 4000 had been rated at 3 600 tons on 1.1 % of Sherman Hill.This feature already needed a factor of adhesion of about 0. 20 which is regarded to be the highest to achive in everyday service for steam locomotves. Some Diesels showed up to 0.40 on trials due to their sophisticated AC-drives featuring smoth torque and slip control devices.
No shame on those fine steamers but Diesel and Electrics seem to be the better solution going uphill!
wdh
Hey Juniatha,
Interesting discussion about the actual difference in performance between both 2 and 3 cylinders and rigid frame and articulation! In Germany we once had the by far biggest no. of 3 cylinder engines class 44 decapods, almost 2 000. Thus the difference in daily performance had been evaluated: Factor of adhesion had been rated at conservative 0.185 for all 2 cylinder types while the 3 cylinder types were rated slightly higher at 0.204. There was no difference by no. or diameter of drivers. By sure indeed those 44s could do such a performance while the pacifics suffered by slipping. This may be part of the answer to the question regarding rigid frames versus smaller groups of drivers.These features were used for calculation of max loads on mainline service, as long as resulting speeds didn't drop too much.
Those UP 9000s once had been seriously calculated to produce a max. factor o.a. 0.24 on sanded rails (Dr. Giesl Gieslingen) which haedly could had been achieved by an articulated.
I saw those links to above to sound recordings there are listed ... but please enjoy!
WDH
Thomas 9011 ...So you can believe what you want to believe. To this day no single diesel locomotive has ever pulled anything close to what the steam locomotive did up a grade with the tonnage they used to pull. You can check all the records you want...
...So you can believe what you want to believe. To this day no single diesel locomotive has ever pulled anything close to what the steam locomotive did up a grade with the tonnage they used to pull. You can check all the records you want...
Ok, let's check some real data.
On the B&O's Cranberry Grade, the 2-8-8-4 EM1s were rated at 1500 tons. An ES44AC is rated at 2900 tons on the same grade.
I'd say that blows your fantasy right out of the water.
GP40-2 we are talking about tonnage records pulled by a single locomotive. There is hundreds of steam locomotives that pulled hardly anything including the EM1 you are talking about. My point is that to this day no SINGLE diesel electric locomotive has ever pulled 10,000 or more tons over a grade.
You also don't need to tell me that you can hook up 4 diesels and out pull a single steam locomotive. Yes I know that and I think the entire world knows that. We can also hook up 4 Alleghenies and see who pulls the most tonnage.
If you can find some statistics that shows me any SINGLE diesel electric locomotive pulling 10,000 ton trains over a grade then I will believe you. But so far all I have heard is a unconfirmed post of the AC 6000 rated at 5,000 tons. Even if this is true it is still half of what the Allegheny did and not even close to matching the steam locomotive let alone surpassing it.
Guys you need to start posting some of your links and statistics. I will admit I was wrong on the big boy data but I wasn't wrong concerning the other locomotives.
Concerning the Allegheny pulling 10,000 tons at 15mph... http://www.steamlocomotive.com/allegheny
The Pennsylvania Q-2 4-4-6-4 had a horsepower of nearly 8,000 http://www.steamlocomotive.com/duplex/?page=prr
I'm not going to get into the Yellowstones,or the Norfolk and western locomotives because it is all coming up model railroad stuff.
That is all I am going to say on this subject so we can get back to the original topic.
I have been a sounds of trains collector since the mid eighties collecting vinyl,CD's,and cassette tapes. You are right that there isn't very many sounds of the 3 cylinder locomotives. Howard fogg (the famous railroad painter) recorded some of the 3 cylinder,big boys,and other locomotives and transfered it to a cassette tape. It was given to me by a friend of his and I am sure it was never released to the public. It has some very clear and good sounds of the UP 3 cylinder locomotives pulling freight and passenger trains. It is stored deep in my archives but if I find it maybe I can post it to you tube or something.
J: Hi Bigboy4017
Hi Juniatha,
J: My question , to be sure , is : was this realized in daily traffic at the same surefootedness as with the Twelve-Coupled ?
My comment has been edited from a pretty sure "yes", to a very uncertain "not so sure anymore".
J: ...was this realized in daily traffic... That’s something I hoped people who remember these locomotives in regular traffic could tell something about....
How we can get real data to compare those types? Test-datas are sooo rare....and often hardly to compare. I think 1 Big Boy engineer still lives, but did he had experiences with the 9000s?
J: I’m not going to engage on that steam against diesel issue , I’ve commented on that in another thread earlier on – it totally leads away from the question at hand , nor is it questionable on a one to one basis a diesel unit even today does not match a Super Power steam loco in power at speed – never was intended to
Soooorrry, for putting some comments on that, but some people seem to think one of those 1940ties or later built steamers had an output of 8000hp at a speed of 15mph ;-) It hurts my eye soo much, could not resist to give a comment on that. Promise to be silent now.
J: However – now we get to influences of actual design – the three cylinder drive of the Nines was not an optimum design and thus it may be the Challies were in fact up to about the same low speed drag performance in actual traffic – in average conditions !
And that is big problem: the Challenger had the advantage of being later built, though it seems that the Great Depression mostly stopped all development of steam-technology for a couple of years (9000s: built 1929, CSAs built 1936).
If another class of 9000s had been built, with ingridients of Jabelmann's design-philosophies, that would make a comparison more easier, and more interesting.
However: I see your points concerning FoA. However, basically, "modern" articulates were not so big different than a straight, rigid frame designed locomotive, except, their front drive could swing from left to right and had two independend drive sets like a duplex.
Example: 4000 Class: the front unit drive and rear unit drive, that had the connection rods, were set as a pivot, the others drivers had ALCO lateral motion (TM) devices. All vertical movement was done by springs and proper equalization.
Must correct this from Kratville:
"A tongue and-groove design was adopted for the early 4-6-6-4s for the UP and this basic design was used on the 4-8-8-4s.
... The Big Boys employed the three point suspension system. This lever priciple uses a certain point in the wheelbase (3rd driver of the rear unit on the B.B.) as a pivot or fulcrum point about which the loco. rotates in curves. No lateral play was allowed these drivers, but all other had proportionately greater lateral movement. The front engine's wheels guided the locomotive and controlled front engine movement, the rear engine wheels controlled the boiler, firebox and cab movement. Total effect on the lever principle on B.B's produced a rigidly guided loco. on tangents and a cushioned action as they traversed into curves. With such a long locomotive, the running gear had to be designed to allow vertical movement such as at the top of grades (...). Without special springing, the lenght would tend to overload the drivers springs as the engine crossed convex vertical hump and also overload the trucks and trailer springs at a low spot. The springs themselves, were designed to standard practice with a 60 to 70 % load factor which allowd up to 40 % additional load before the springs would flattern.
...The suspension system was designed J. Blunt, chief engineer of the builder (ALCO), and the springing system by the UP, which also worked out the Challenger springing. On the 3 point springing system, the ftront engine drivers were equalized on both sides and then the sides cross-equalized at the front to the suspension on the rear end of main equalizer beam. Each side of the loco. was equlized as a unit from front to back, including the trailer. The front end rested on the Bissel type center pin of the engine truck. The front truck was a standard ALCO design with Bissel pin. A cross housing, designed by the roller bearings manufacturer (SKF), was used for the journals. The front truck provided for an initial 17 % resistance, then increased gradually as the curve sharpened.
...The drivers were of UP-ALCO design.
..., they were designed with longer stroke the diameter and no wheel failure were ever recorded in this location with the new design. The wheel was designed symetracally, then calculations were made for overbalance wheight to take care of the main crank pin overhang. The driver size on the 4000s was dictaded by the total clearance height of the loco. and 68inches is the biggest diameter that would fit although the road would have desired even larger dia. The drivers were all GSI castings of Boxpok design which at the time, was an ALCO feature. The axle journals were fitted with roller bearings...
...ALCO lateral-motion boxes were used on the first 3 driving axles of both engines (BB4017:errr, well, now, this conflicts of what Kratville reported above that the 3rd driver of the rear unit was set as a fulcrum point) and Franklin compensators and snubbers used throughout both engines."
(.)
Sorry for the long post, BigBoy4017 supposes "Heavy Challengers" were designed with same principles.
It was intended to show how many efforts went into "modern" steamloco-design, that this all simply may overkilled any theoretical disadvantage inherent with articulated design in comparison to a long, rigid wheelbase, dispite of their (theoretical) advantage in FoA.
You can still see 3985 running ~70mph without any effort in 2010 at Youtube. Skipw shoots the most exciting videos...
http://www.youtube.com/watch?v=aH4xZXskLIg
Is this not a better design over all? Or not at all? Can you give a comment on that?
4017
Deviation first then back on topic.
It took TWO Alleghenies to get a 10,000 ton train (140 50-ton capacity cars weight about 9,800 tons), up the 0.55% grade from Hinton to White Sulfur Springs.
Re: the Q2 - referring to steam locomotive horsepower without an adjective (indicated, drawbar, etc.) is meaningless. The quoted figure at steamlocomotive.com is indicated horsepower.
Discussing "grade" doesn't mean anything either unless the percent is given. A 0.5% grade is vastly different than 2%, but they are both still within the family of "grades."
Back to the Challenger vs 9000. - As far as delivering the rated or actual tractive effort to the rail, I agree with the idea that the more coupled wheels, the better at low speed. However, with such an extremely long wheel base on the 9000s, perhaps the articulated 4-6-6-4's could do more than expected because each engine set could find a better footing on less than perfect track. Would this compensate for the greater number of rigidly coupled contact points on a 9000??
With all the equations that are shown , should there be any hogger experiance noted in those facts and figures??. Or is this a given ??
Respectfully, Jim
Y6bs evergreen in my mind
Much of this discussion neglects track maintenance. Also, the only Texas type mentioned was the C&O-PRR. The AT%SF was even better as proven by direct comparison on the PRR Sandusky coal trains. But on "my" thread propositioning the AT&SF Texas as the very best non-articulated steamer (with the C&O-PRR a very very close second), the point was raised by others that Texas types were hard on the track, and the track they used required constant maintenance, so N&W A's, Yellowsstones, Allegainies, and of course all the various Challengers were really better. If Texas types required lots of track maintenance, certainly 4-12-2's would require even more! With the Texas Type one can argue, sure more track maintenance, but much less locomotive maintenance. With the 9000's this argument dissapears and the Challenger is clearly the winner.
If Texas types required lots of track maintenance, certainly 4-12-2's would require even more!
Not nessessarily. And they were moved above 50 mph, in later years more reguarly. It did cost loco-maintance, but not damaged track.
Hello Juniatha
Been away. No doubt about it; on an equivalent trative effort basis, the single set will always outperform divided drive at starting. All the other factors mentioned (e.g. three cylinder drive maintenance, route availability, ...) are separate issues.
It is somewhat unfair to compare the 9000 against the challenger given the rate of development then taking place. I think a modern, roller-bearing, three cylinder 2-10-4 (perhaps based on the ATSF 5011class?), and not a north american simple mallet, would probably have been the next step in steam super-power development.
Per DaveK's comment on locomotives and track maintanance, remember whether an engine pounded the track or not depended on how well the running gear was balanced to begin with. Certainly the loco builders didn't get it right all the time. Sometimes the poorly balanced engines were put under operating speed restrictions, sometimes the poor balance was corrected by simply increasing the driver diameters. Certainly an engine that leaves miles of wrecked track behind it is of little use to anyone.
Alco's solution to balancing was the three-cylander design, which they pushed during the 1920's, the UP's 9000's being the most famous example. The 9000's were certainly a very successful design, but most roads didn't want the maintanance headaches of that third cylander. Improvements in engine design and new steel alloys in the '30's made the third cylander un-nessary anyway.
BigBoy4017 "Was the UP Challenger a 100 % substitute for the UP 9000 class as concerns t.e.??" This table may not answer all concerns about TE, however it shows, that basically 4-12-2's and 1936 built CSA 4-6-6-4 Challengers had similar tonnage ratings. Heavy Challengers built after 1942 had some 100 tons higher ratings, reflecting their higher HP and better downhill capabilities. Example: Buford to Cheyenne is -1,55% grade, they could drift downhill with 1000tons (5100 vs 4100) more than the the 4-12-2.
From Kratville's book on the Challengers...
4-12-2 TE 96,650 lbs
4-6-6-4 TE 97,400 lbs (3800's) 97,350 lbs (3900's)
The 4-12-2's only had 355,000 lbs on the drivers, while the 3800's had 386,000 lbs on the drivers, so the 9000's had a better factor of adhesion than the 3800's and 3900's. On the other hand, the Challengers were intended for use on passenger trains in addition to the fast freight role, having a higher maximum speed rating than the 9000's.
Interestingly enough, the 9000's were intended to replace the older and slower Mallet's.
- Erik
The point about the third cylinder reducing track maintenance is a valid one. But the answer still has to be YES, the Challenger did essentially replace the 9000's. Once Challengers were built and in use, no more 9000's were added. And only a portion of the 9000's were modernized. This would indicate to me that the UP preferred the Challenger design to that of the 9000's.
Our community is FREE to join. To participate you must either login or register for an account.