JuniathaIn view of the topic of this thread actually being the SE three cylinder engine not very special compound engines and lest it will become rather special reading , I’ll stop here , hoping Prof O will also respect that .
I concur. At least I got you to post it!
I think we should have a new thread on this topic, or revive an old one that is apropos, and you should reproduce these comments there. I know of no source on the Web, in English, that describes this so well, and I think it's valuable to have it, but I'm not going to cut and paste someone else's post into another thread myself to do so.
Hi -
>> Interestingly, the 'ideal' ratio between LP and HP swept volume was adjusted by making two of the four LP cylinders different in size (larger; the other two were the same dimensions as the HP cylinders). <<
No , actually that was not the case . First of all it’s not just the displacement volume that matters in relation between HP and LP stage rather than it’s total volume including clearance volume plus of course characteristics of valve gear , namely as concerns degrees of compression used in HP and LP .
While in a typical four cylinder compound the LP unit worked much like a two cylinder simple expansion engine on rather mild steam chest pressure , compression in HP cylinders was always crucial for good working balance in a compound and usually involved an increased % clearance volume .
Secondly , the differing cylinder volumes in LP inside / outside cylinders were not meant to >> adjust << volumetric relation – the same relation could have been realized with all LP cylinders of identical size if only that size was itself chosen to suit intended relation . Having LP in two different sizes simply was a consequence of crank displacements : 90 degrees with HP unit making torque profile similar to that of a two cylinder SE engine ; 120 degrees with the outside LP cylinders and 180 degrees with the inside LP cylinders which in this case provided a total of piston thrust same as one of the outside cylinders making LP unit torque effectively similar to that of a three cylinder SE engine , again if working on but milder steam chest pressure . All in all , the 160.A thus worked rather like a five cylinder engine , a configuration proposed by A. Wolff for a high speed 4-8-4 in an academic investigation on possible high speed rail traffic .
Regards
Juniatha
edit : sorry , somehow HP / LP got swivelidizzied at two points when writing , corrected in blue
Firelock76 SIX cylinders? Ye gods, the mind reels...
SIX cylinders? Ye gods, the mind reels...
It's actually common sense -- if you need big LP cylinder capacity, divide it between multiple cylinders instead of having big dustbins. A clever thing on 160 A1 is that it has one 'pair' of LP cylinders the same dimensions as the HP (for parts and machining commonalty, among other things) and that allows you to tinker with either or both dimensions of the 'other' ones to get your expansion ratio just where you want it. As a fringe benefit you can phase the pairs of LP differently if you want smoother torque peaks...
JuniathaThe one was P.O.Midi 160.A.1 - a 2-12-0 , had a six cylinder compound unit with steam envelopes which - as I have understood vague enough descriptions in literature - on top of it could be set up in various ways for steam to enter before / or after working in cylinder and with superheated or saturated steam , probably a variability allowed for testing , not for a practical service application . The boiler included a re-heater for receiver steam , too . The engine did *not* have triple expansion in two cylinders each for high / medium / low pressure stages but the idea rather was to split up low pressure cylinder volume because the engine’s main purpose was to improve the steam loco’s perpetual weakness : low speed performance and efficiency , which was attacked both by steam jacketing and by increasing tractive effort at short combined cut-off via increase of HP and namely LP cylinder volume and their volumetric relation .
Some recent work by Claude Bersano and Thierry Stora has established that the full flow of steam to the high-pressure cylinders first passed around them, through the 'jackets'. This eliminated much of the need for high superheat to keep HP wall and nucleate condensation losses especially toward the end of the stroke. What this in turn allowed was a very small degree of primary superheat (the HP superheater was less than 72 sq.m!). There are some discussions in which Chapelon indicates the engine could be worked 'saturated' with almost no thermodynamic losses due to the lack of 'conventional' elevated superheat in the HP steam.
The LP 'reheater' actually used a substantial number of Schmidt-type superheater elements, of shorter length than usual elements, in the lower portion of the boiler. This resuperheater had much larger area than the primary superheater, which may have been partially an 'artifact' of the large cross-sectional area needed for LP steam flow. Interestingly, the 'ideal' ratio between LP and HP swept volume was adjusted by making two of the four LP cylinders different in size (larger; the other two were the same dimensions as the HP cylinders).
Here is a longitudinal elevation/section of the locomotive (courtesy of Thierry Stora's site at chapelon.net). I believe there is a better copy available and will provide a link if I can locate it.
Guys ,
The one was P.O.Midi 160.A.1 - a 2-12-0 , had a six cylinder compound unit with steam envelopes which - as I have understood vague enough descriptions in literature - on top of it could be set up in various ways for steam to enter before / or after working in cylinder and with superheated or saturated steam , probably a variability allowed for testing , not for a practical service application . The boiler included a re-heater for receiver steam , too . The engine did *not* have triple expansion in two cylinders each for high / medium / low pressure stages but the idea rather was to split up low pressure cylinder volume because the engine’s main purpose was to improve the steam loco’s perpetual weakness : low speed performance and efficiency , which was attacked both by steam jacketing and by increasing tractive effort at short combined cut-off via increase of HP and namely LP cylinder volume and their volumetric relation .
The 160.A for an engine of 20 t axle load was enormously powerful at already very slow speeds on rising grades without consuming undue amounts of fuel yet would run very smoothly at relatively elevated speeds ( though not tested for maximum speed attainable ) . Wear in drive proved exceptionally low and in fact never needed a classified repair until – premature – shelving and scrapping .
The other was series PLM 151.A - a rather clumsy 2-10-2 ( no , not a 2-4-6-2 because it had those odd inside coupling rods , proposed in retrospective now and then as a cure-all for Pennsy’s T1 - a tongue-in-cheek effort at eating the cake and keeping it . I’m not going to enter topic insane , sorry , inside coupling here , that may remain another story ). The type was ‘successful’ because proud PLM by default never had locomotives built turning out a failure . That’s why they didn’t dump their early ‘attempts’ in 4-8-2 type passenger locos but duplicated them faithfully ( PLM series 241.A , not to be confused with later SNCF 241.A of EST origin ) and only in the following tried to discretely improve them by revamping the drive layout mainly ( series 241.B ) and continued unswerving with further production including then further minor changes (241.D , skipping their one-off prototype 241.C ) and then rebuilding the D type into E type ( still no ways as dynamic as a Jaguar E type ) .
Performance of the 151.A was in the range of DR 44 three cylinder Decapod if the latter was not fully extended , yet at higher fuel consumption with the compound . Still , it worked and thus was successful if you looked at it from a suiting angle . It soon got way out-performed by the 1936 Alsac-Lorraine three cylinder 2-10-2 with a formidably steaming combustion chamber boiler which preceded the DR 45 class which again proved quite economic in fuel consumption yet was ailing off production floor since born with a ‘weak heart’ by Wagner’s dictation , namely a boiler with way too small firebox and radiation heating surface . Some of them were rebuilt with combustion chamber boilers around 1951 – however like all other 20 bar engines rebuilt they were knocked ‘back in line’ with German ever-standard 16 bar boiler pressure , which robbed them 20 % of their up-hill ‘punch’ .
Paul Milenkovic (Channeling Homer Simpson) Mmmmmm! 6 cylinders. And 4 of them inside the frame! Compounding and steam cylinder jackets too!
(Channeling Homer Simpson) Mmmmmm! 6 cylinders. And 4 of them inside the frame! Compounding and steam cylinder jackets too!
Isn't that one the twelve-coupled 160 A1?
If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
CSSHEGEWISCH As long as we're talking four cylinders on a rigid (non-articulated) locomotive, we should not forget any of these: PRR S-1, Q-1, Q-2's, and B&O N-1.
As long as we're talking four cylinders on a rigid (non-articulated) locomotive, we should not forget any of these: PRR S-1, Q-1, Q-2's, and B&O N-1.
Or the PLM 10-coupled locomotive that predates them all. (Not a "duplex", but clearly divided drive for the 'right sorts of reasons' on a rigid frame...)
Juniatha I still prefer the idea they are four - except for in this case they should have four cylinders each .
I still prefer the idea they are four - except for in this case they should have four cylinders each .
Mmmm, maybe we can bring back the D&H 1403???? And the machine shop to keep her running...
First issue of Trains I bought had the article on the D&H high pressure compounds.
- Erik
Wow!
"4 four cylinder locos - and four T1 four cylinder locos fortified by preservation!"
And she has such big strong muscles!
Dr. D
I liked the idea of three individual three cylinder steam locomotives around .
Uhm , oh , arg - or should I have mixed up something here ?
On the other hand - four T1 four cylinder locos fortified by preservation instead of having forfeit life by the reaper's torch wouldn't be too bad , forthrightly said , no ?
=J=
Dr D It's hard to believe that THREE of these unique THREE CYLINDER locomotives survive today considering how uncommon they were, and all three represent big locomotive power. Dr. D
It's hard to believe that THREE of these unique THREE CYLINDER locomotives survive today considering how uncommon they were, and all three represent big locomotive power.
There is one more survivor of the 3 cylinder type, the Alton and Southern #12 in St. Louis. This is an 0-8-0 that was built in 1926 and retired 1948.
That make FOUR(!) surviving three cylinders!
I think that this locomotive is one of the most overlooked in the US, next to the SP 4460, and others that remian unnamed beause I have overlooked them! (Ironically enough)
Dr D
Oh no , please NO !!
It's nothing , it's certainly not meant to be naughty or teaching in any way .
Please mind what we are here for - exclusively !!
I'm just another steam fan as there are thousands around .
Nothing but nothing else .
= J =
Juniatha,
Well dear, after that diatribe - of which I throughly enjoyed every word! I think undoubtdly you are a near relative to that glorious feminine creature a.k.a. MOther Nature! Please feel free to continue to share more of your voluptuous mea culpa, I think we are all heady with the effect!
"Steam train loving, coal burning green enviornmentalist! in love with European steam - ain't another to be found anywhere! - oh yah! - I think I'm in love!"
After all you wrote I wonder how there can be space enough left for the water ...
>> Fresh water preserves the shipwrecks. <<
Actually not . *Fresh water* by definition has a good healthy content of oxygen dissolved - water where steel does not corrode has oxygen content reduced to approach zero - and that's exactly what the problem is in the Great Lakes : lack of oxygen in areas of deep water below some certain depth due to plenty of thoughtless environment pollution going on over decades and decades and decades .
All too long nature has be regarded as 'what's there for free and what has to be chopped down , shovelled aside , channelled away , blown up , levelled and nullified' in order for men to put up their glorious stuff , the same they tear down or abandon just a decade or two later , leaving a devastated area - never taking care because " America is big , rich , healthy , vast and bestowed of endless resources " , just waiting to be retrieved , ripped off , chopped down , blown up , excavated and exploited , taken away without a thanks and without ever giving back no trifle bit to nature .
And in spite of published and known views from orbit showing global level devastations there still are people who believe this could go on forever – I think they also believe 2 x 2 make 6 or 7 or in fact anything except for if that be applied to the price of gas to pay at your local gas station .
Sorry if that's not exactly steam historical , yet sometimes I have to 'blow off' by letting go some other thoughts , mea culpa , no insult intended .
edit : some words retrieved that got lost in the interspace of the Great Gates of Bill's
I'll tell you what Doctor D, if those French guns from Fort Ponchartrain are made of bronze, the preferred metal for field artillery right up to the American Civil War, they're probably just as good as the day they were made and still perfectly safe to fire.
Even they're made of iron, they'd probably be OK to shoot with reduced charges, just to give people the idea and have a little fun. The French made some good artillery back in those days.
Many of you may no know that Detroit and its Michigan Central Station - its a station not a terminal - are on the main line of the former New York Central System. Thats right it was shorter to run from New York to Chicago through Detroit than through Cleveland and Toledo because Lake Erie extends the distance between Chicago and New York. At any rate the New York Cental Hudson locomotives ran under the Detroit River on occasion - NYC did have the tunnel electrified like Grand Central Terminal in New York.
In Canada the New York Central subsidiary was the Toronto, Hamilton and Buffalo RR. which owned among other Hudson locomotives the former NYC 5313 Hudson renumbered TH&B 502 among others. The surviving Hudson tender NYC X5313, fuel water car is from Canada.
I have lived near the Detroit River most of my life, and became a certified scuba diver. I am fairly familiar with the Detroit River which is among few other major American cities - is situated astride an international border.
My friend Kile Sise is diver on the Detroit Police dive team and spends his time in the river for police work. Retrieving weapons, drown people and other first responder stuff. We never tire of talking about stories of what is to be found on that river bottom - which by the way is fairly clear with good visibilty.
The stuff that has gone into the Detroit river in 300 years is astounding. They found and retrieved at the foot of the city center, the French artillery from Fort Ponchitrain - dumped into the river when abandoned by the French 200 years ago - laying on the bottom of the river bed.
Also before its famous sinking - SS Edmund Fitzgerald which went down in a November storm in Lake Superior - lost its bow anchor in the Detroit river. It has been retrieved lying on the surface of the bottom river bed - several ton steel ships anchor.
Cars of every vintage from the 1920's to today are in that river and get pulled out on occasion - along with sunk pleasure boats and scuttled commercial boats. Its a big river with a wide delta - and very fast current - wide with a many channels in the south.
Dredging the Fox Creek they pulled up a 1957 Chevrolet with a human skeleton in it - lost in the 1960's. From the prohabition era in the 1920's a lot of illegal liquor was smuggled across the border - crates of illegal booze are still coming out of the river with drinkable spirits - labels still on the bottles. A "rum runner" speedboat shot up and sunk near Belle Isle yielded booze as well as a Thompson sub machine gun.
Fresh water preserves the shipwrecks. In Lake Michigan near Chicago many WW II Navy fighter planes crashed and went to the lake bottom during the war. Now they are the major source of salvagable WW II military planes - priceless antiques found in every major military museum are coming from the bottom of Lake Michigan. Aircraft of which there are no more to be found - museum pieces are coming out of the lake. Those that went into the ocean are all wortlhless corroded scrap the ones on the the lake are in a time capsule. In lake Superior the crew of the Edmund Fitzgerald is on the lake bottom their bodies not decomposed because of the cold of the water. The wreck site is a declared grave site. On the Lake Ontario bottom are woodern warships of the US Navy - sailing ships - guns - un decomposed sailors - sails - ropes all intact from the War of 1812 - found by Jacque Costeau and his TV crew in the 1980's.
That Hudson Delta truck from NYC 5315 is in that Mohawk river bottom just where it landed in 1940 in no worse condition than those pristine warbirds coming out of Lake Michigan - and except for the force of its impact with the bottom lies just as it went it. I have seen this stuff with my own eyes!
timz Paul Milenkovic why does a speed reached downhill (a 1:200 slope) count as a speed record? A speed record is a speed record. If the train reaches 500 mph down a 4% grade, then that's the speed record. The record for speed on level or uphill track is a different record-- if you think it's a more important record, you may be right. But the record, with no qualifications, is unambiguous.
Paul Milenkovic why does a speed reached downhill (a 1:200 slope) count as a speed record?
A speed record is a speed record. If the train reaches 500 mph down a 4% grade, then that's the speed record. The record for speed on level or uphill track is a different record-- if you think it's a more important record, you may be right. But the record, with no qualifications, is unambiguous.
In order to be a 'legitimate' speed record, the speed should have been recorded in both directions. That's what the FIA requires unless the course is dead level and the wind is dead calm.
Track and field 'records' are disallowed if there is any more than a very light following wind. That's why there are, '*wind assisted,' notes in the record books.
Has any train ever been timed with the elaborate electronic traps required for recording speed records of any other type, mechanical device or otherwise?
As for the vanished trailing truck vs. finding RMS Titanic, the ship was huge and not very dense. The truck was a bunch of solid metal parts with no shell around them. The bottom of the Atlantic doesn't experience river currents, and the bottom of the Mohawk is probably soft silt. If anyone uses modern equipment to locate and raise that artifact they'll probably find it at the bottom of the silt, not sitting on top of it like the Titanic.
Chuck (former cadet marine engineer)
Paul Milenkovicwhy does a speed reached downhill (a 1:200 slope) count as a speed record?
By the way, why does a speed reached downhill (a 1:200 slope) count as a speed record? By that reckoning, would not dropping a locomotive off a cliff and measuring it with a radar gun just before it crumped count as a "speed record"?
By the way, one of David Wardale's arguments for designing a steam locomotive (or any locomotive) for high horsepowere instead of merely starting tractive effort is that if you want to "make up time", it is safer to increase speed on upgrades. If something goes wrong, you can always cut power and slow down. If you speed up on downgrades, you are at greater risk of a runaway accident.
Interestingly, the first flights to exceed the speed of sound may have been in a dive, but the Bell X-1 piloted by Chuck Yeager was the first flight to exceed the speed of sound in a climb, with the pilot returning to the restaurant for his morning coffee. The use of a rocket engine for this plane and this attempt was intentional -- if something goes wrong in a climb, you cut power and slow down. If something goes wrong in a dive, you may never recover from it.
Thanks for kind appreciation , I was just trying to point out some design specifications in three cylinder locos as built . If and when I get to it I want to describe some of the three cylinder engine unit's typical unique characteristics .
British steam : oh , no I don't think British steam loco engineering had much in advance of America's . You should have heard me , uh-so-long-ago when with my late dad as a teen on a special behind a beautifully restored Gresley Pacific when some old Londoners who then looked to me like they might still have worked for the LNER , for it's predecessors , even told me in most impressive words what technical marvels these locomotive were . When they came to take breath , admiring their own ardent worshipping , in my then pretty direct ways I laconically dropped " Well , you know , we always had the biggest and the best .."
Silence .
After the trip my father told me one of those folks had remarked to him " Your young daughter may look like a madonna , but trying to tell her about locomotives will only destroy the picture ."
Gee , I think it was true , I don't even remember which loco it was although I still recall quietly inspecting the finish so sparkling and , yes , admirable ; exhaust was just lightly smoking when at platform before starting and stack talk as the loco spoke up on the trip was perfectly tuned , very short , dry and - as I felt - British .
Boiler explosion :
gee , - oh-yeah , I see ..
Uhm , in case yes ,
to my incalculable guess
- as I freely confess
that Hudson's Delta truck ,
as the name says , is stuck
near below the duck
sitting on a dock
in a bay
- I should say -
not too far away ;
if you care to sway
your head around ,
soon will be found
the rusty rotten remnants
not unlike old Rembrandt's
brownish oil colors
- someone hollers -
within the Hudson water's flow ..
.. oh , sorry , I got to go !
I realize that, and the more I look at Staufer's pictures I wonder if the boiler explosion did't throw it out there. I looks like the firebox blew out the grate, blew back the frame and broke it around the center driver and hurled the rear truck into the river.
When the boilers went up on a moving locomotive under power they usuall went a half mile or more. Still it has to be out in that river in a radius extending from the sight of the wreck. I mean they found the Titanic three miles down in the middle of the Atlantic - this four wheel truck from NYC Hudson 5315 can't be that far! NYC just didn't care, and it was the age when people dumped everything - every sort of junk went into the river to get rid of it.
Dr Djumping the track in Little Falls, NY at 70 mph. The rear four wheel engine truck was never found and assumed to have gone into the Hudson River.... Given the mass of the truck and its speed we are wondering how far it could have gone out into the water?
I know a mechanical engineer when I read one!
We have another thread going about NYC 5315 which was destroyed in a wreck in 1940. The engine hit a rock wall after jumping the track in Little Falls, NY at 70 mph. The rear four wheel engine truck was never found and assumed to have gone into the Mohawk River where it probably remains today. Given the mass of the truck and its speed we are wondering how far it could have gone out into the water? Sounds like you could make an educated guess about that. The thread is the "Union Pacific 4006 tender swap."
Wow! great explanation of the UP 9000 series. The transfer of motion lost to the center cylinder is nicely explained as only science could show! Truely the engine was a behemoth and the fact that Union Pacific stayed with it and included 90 copies is a testament to another age - the age of American "drag freight service."
Truely some American railroads never moved out of the mindset of "drag freight." As long as the train could be started and moved that was all that mattered, it would eventually get over the road! The C&O continued to use its high power 2-6-6-6 Alleghany locomotives into the 1940's in this fashion by operating them at low speeds where their power never became effective.
Science moved on, but C&O opperating managment stayed behind in the past and never did get used to the potential new idea. The last C&O steam locomotive purchased in 1949 was an antiquated 2-6-6-2 design from 1917 of the "drag freight era." Strangely C&O saved it C&O 1309 - Baldwin Locomotive Works last construction - and it is being restored today to use as a tourist engine on the Western Maryland.
I can think of a few similar archaic British locomotive designs of the time that continued to be built well past their age. Industrial engineering as we understand it today did not exist.
You seem quite versed in British Steam Power, wondering if you had anything to do with the recent British reproduction of the 4-6-2 Tornado locomotive?
By the way it always struck me of the overall "simplicity" of the British locomotive construction. No where near the massive weight and design of some US locomotives. For example most British steam was build on a frame of two parallel steel slabs suitably cut out and bolted together. American practice leaned to massive steel castings with all the brackets suitably included and machined in place in what had to be massive machine shop practice.
The science behind British and American locomotive design seems very similar but the method and type of construction varied.
British engineering seems an equal if not better than some of the US design, but the overall locomotive size and power potential was substancially unexplored.
S. Conner,
Thats the way it is with lots of stuff. Sometimes "original condition" is more valuable because "its only original once," but used stuff that is "beat up" is a lot more fun.
I have a WWI Colt automatic pistol. Its in nice shape and I bought it because it was nicely rebuilt and refinished. I can carry it, use it, really enjoy the 1917 piece - and I shoot it lots. If this thing was original I would have to keep it locked up, protected because it would be much too valuable to risk damaging, and every scratch would reduce its value - just a serious investment!
BLW 60,000 shows us just what a steam locomotive was in 1926 - pristine original condition. Its a benchmark! that tells us just how a locomotive should look and be finished. No questions how Baldwin did their work, wiring, piping, assembly, and fasteners, and what was the standard of production.
Sometimes today we repaint this kind of engine to look like a Cadillac instead of a train with the new types of paint finish, we upgrade all the accessories so it can run on modern railroads, with tight lock couplers, and modern brake equipment for crying out loud UP 844 flattened its driver wheels when they were trying to hook it up with a diesel MU so UP844 could control the diesel engine coupled behind the locomotive.
Back in the 1970's the C&O still had a line of steam locomotives in storage behind the shop in Russel, KY. As a young guy of 22 years old I really enjoyed visiting the yard and finding these old steam engines. I those days no one cared if you climbed all over this kind of stuff. There before my eyes was the rusted glory of the age of steam. A C&O 2-6-6-6 Allegheny, a C&O 2-8-2 Heavy Mikado, a C&O 4-8-4 Northern (eventually Ross Rolland 614) it was numbered C&O 611 with roller bearing side rods, also several C&O 2-8-4 berkshires which for some reason the railroad thought were so much more valuable and worth saving than other engines.
All these engines totally devoid of number plates, builders plates, cab gauges, whistles but all original as the railroad left them. As I sat in the cab of the passenger engine C&O 611/614 I thought of what quality was built into that machine - the roller bearing construction the power, the speed. Why would Chessy have saved such an engine to let it go to junk like this - and why only one. It was the best of the best. THE BEST OF THE BEST! Little did I know that someday not to far from that day I would see that engine blast out of Grand Blanc, Michigan under full power with Ross Rolland at the throttle!
PM 1225 crew sponsored a steam special with C&O 614 where I was a car attendant - during lunch I showed Ross Rolland a couple of pictures of the engine in the scrap line at Russel. He wanted the pictures and I traded them for a cab ride that day. Got to blow the whistle and see the locomotive cab restored from that rusty condition by actually riding in it - not the origianl whistle, bell and gauges - but at least it was together all the way back from that condition I had first observed - and well rebuilt. I guess they used much of the cab equipment from the fire damaged American Freedom Train.
Sometimes when an engine gets "let go" its just an opportunity for something better to happen to it. You have to BELIEVE its for the lucky ones!
Come on Ross why don't you cut loose with that Greenbrier so we can see it run with N&W 611. Do anything with it except don't give it to some damn fool museum like the New York Central Museum in Elkhart. All we need is some fool city mayor deciding its part of parks and recreation and needs "bows" and "balloons" so the kiddies can play with it like the fate of NYC3001.
It's great to see these old engines run but sometimes much gets changed! I'm just glad we have Baldwin Locomotive 60000 - its a benchmark!
1.
The Southern Pacific was looking for a dual purpose locomotive for their difficult Donner Pass line , this resulted in ordering the known 4-10-2 three cylinder engines . UP ordered a somewhat lighter version of the same concept , too due to tolerably similar traction demands on their mountain line through the Wasatch Range . While SP was content enough with the engines to order a production batch , UP never found their’s fully satisfying , already went one step further considering a significantly larger 4-12-2 which – in spite of its extra set of drive wheels at the back end – also was to feature an increased wheel diameter . As bigger power arrived , the 4-10-2 on both RRs were much relegated to back end services .
With the 12 coupled wheel arrangement , UP took full advantage of the three cylinder unit in that it enabled six powered axles at no more than an equivalent axle load Mikado’s piston thrust . With a two cylinder unit it would not have been possible to take full advantage of six powered axles in line and in view of UP’s perennial search for increased power *this* was the fulcrum of advantage with the three cylinder unit .
2.
The arrangement of six consecutive drive wheel sets in a rigid frame in spite of presence of some appallingly tight curves on the mountain line and in yards was made possible by applying ALCO lateral motion device as in the leading coupled axle to the sixth in the line also . Although this inevitably increased leverage of hind vehicle end in curves this feature was successful because the fifths coupled axle then providing pivot point for turning the locomotive through curve ran practically parallel to inner rail causing flange wear to remain comparatively moderate in relation to lateral thrust . Since the locomotive was turned around same axle as in the 4-10-2 type , geometric relation remained largely unchanged at front end axles among which guidance of the locomotive was spread , although at increased lateral forces with the longer , heavier Nines . Increased drive wheel diameter was asked for since already UP felt a lack of speed with the 4-10-2 in spite of three cylinder engine unit . As a matter of fact , UP ran the Nines at daily service speeds much in excess of what ALCO had recommended – around 60 mph over the long stretches of Nebraska , with peaks around 70 mph – and paid the price , calculating the increased ton-miles work achieved that way was more than balancing elevated maintenance costs due to increased mass forces causing premature wear , mainly in the Gresley conjugated gear .
All three cylinder were of common 27 in diameter , however for clearance and for containing relation throw to main rod length , as well as piston thrust induced bending forces in the built-up type of crank axle , inside drive was given a stroke shortened by one in from 32 in used in outside drives ; wheel diameter was 67 in .
All three cylinder had piston valves actuated by Walschaerts valve gear with the middle cylinder’s reached via said Gresley conjugation linkage combining the movements of the two outside sets of gear , deplorably taken from the front end of piston valve spindles which introduced inexactitudes from heat expansion of these spindles or workshop tuning of valve gear should have had to take account of it which should indeed have been tricky a job to accomplish with the tools then available .
4.
Gresley’s linkage was no valve gear of its own but just a – non variable – two to one link arrangement . Actually , if you come to think of it , this presented nil savings in total number of bearings involved with valve gear as you will find by simply counting the bearings of one set of Walschaerts , 5 from return crank to valve spindle plus two of minor influence on summation of bearing play at the lower end of the combination lever and its link . In ‘contrast’ , the Gresley linkage featured 6 bearings in angular movement plus three more to compensate between longitudinal movement of valve spindles and angular movement of the link rods . More important , using this derived drive , movement of middle cylinder valve as actuated from return crank and combination lever had to be transmitted over sixteen bearings until at valve spindle ! At the same time , the Gresley linkage increased inertia loads on bearings in each of the outer Walschaerts by 50 % accounting but for each 1/2 of mass of middle cylinder valve to which the linkage’s own masses had yet to be added. Clearly at upper speed range working , this arrangement was inferior to all arrangements using individual Valve gear rod lines for each cylinder’s valve gear . In spite of obvious advantage of easier access , it was therefore not well suited for engines running extensively at high rpm . The fact it worked ‘well’ on LNER where Sir Nigel Gresley was CME and in a largely unimpeachable position was due to locomotive maintenance reaching top level on the LNER as on the remaining of the Big Four railways in Britain in the late 1930s . Although in mint condition , no doubt , being thrashed ( my words , mea culpa ) down 1 : 200 Stoke bank for its record run Mallard pretty quickly suffered failure of inside drive , mainly caused by valve over-travel caused by Gresley derived linkage . It was thus just for little more than a transient glimpse the claimed speed was reached once-only and it proved impossible to maintain even for a short time or middle cylinder drive might have disintegrated . 530+ rpm clearly proved beyond mechanical limits of the Gresley three cylinder type .
In post-war BR service , these engines had exhaust rhythm more or less sharply pronouncing inside cylinder work , again this was due to valve over-travel caused by both elasticity in linkage and summation of bearing play , often combined with now less to-the-point maintenance of valve timing . With Gresley’s retirement his conjugated linkage was dropped from drawing boards , his successors on the LNER did not continue it .
5.
Continental European design of three cylinder engine units in post WW-I years soon came to use three individual sets of motion in both common axle and dual axle drives . In DR design of standard three cylinder types , dual axle drive with individual lines of Walschaerts for each the cylinders , with middle cylinder’s taken from a valve gear crank on center axle next behind crank axle of middle cylinder drive was selected as unified type from the beginning . In both the 44 class three cylinder heavy Decapod as in the 01.10 class three cylinder Pacific access to inner mechanics was acceptable . By my own experience doing gymnastics ‘through’ the inner of a 44 class , exploring the locomotive I can only say I didn’t find it hard to get to any bearing possibly needing attention – with possible objection to design of the leading Krauss-Helmholtz truck where it rests on the leading coupled axle by paw bearings of its own which could have been avoided altogether with just a simple correction in design of the truck’s frame and the axle’s bearings and the way lateral motion was provided – it was what I call a typical example of uninspired design causing avoidable wear and maintenance . All in all , inner rods and bearings of valve gear were not unduly difficult to get to and work on , except for you had to take good care not to bang your head against some sharp edged item unexpectedly standing in your way ; yet I think with a little practice it was no problem to learn where was what and get along through frames and inner mechanics tolerably well – even with my being quite ‘long’ ( and for one having hair down to my hips , which I used to take under my outdoor jacket and sometimes put the hood up , too , in case of such ‘expeditions’ as well as when cab-riding on a locomotive ) . True , what helped was generally much more slender design of relatively lighter European steam in relation to massive US Big Power .
For an example of a fireman climbing inside an 012 three cylinder Pacific during a scheduled stop to do some special case oiling – likely cross head / slide bar which was sensitive in these engines when fully extended – see this scene from a longer video :
https://www.youtube.com/watch?feature=player_detailpage&v=QlW2sV3hWu0#t=3004
--> 012 101 with express stops at Husum ; driver and fireman besides locomotive front with fireman climbing in ; restart of same train on different days at various locations at Husum ; as far as I remember reading statistics 012 101 was one of those engines which no more left Hamburg-Altona shed when steam allocation finally terminated next year with end of summer timetable . By the way , somewhere in this film appears a line "Mit 2470 PS durch die Heide" - 2470 ihp was nominal continuous output of the 01.10 at standard DB boiler steaming rate - the oil-fired engines were capable of substantially higher sustained outputs in the vicinity of 3000 ihp and at Hamburg really were asked all of it on trains consists of up to 15 coaches , averaging some 750 tonnes ( metric ) at scheduled speeds up to 140 km/h .
For general impressions of the Hamburg-Altona based 012 running on the Westerland line towards the North in 1971 , the year before it all ended you might want to check :
https://www.youtube.com/watch?feature=player_detailpage&v=QlW2sV3hWu0#t=1970
--> 1. Scene – express near Burg southbound on the inclined embankment rising to reach the 150 ft above ground level of Hochdonner Bridge crossing the North Sea – Eastern Sea channel ;
2. scene – express passing into curve turning away ;
3. scene – 012 at full cry with 14 coaches express passing small line-side station at full speed ;
4. scene – evening at road crossing , 13 coaches express passing Hamburg bound ;
5. scene – evening , express of 14 coaches northwards towards Heide at 140 km/h ;
6. scene – road crossing , closer perspective on train passing ;
More need for speed ? enjoy this :
https://www.youtube.com/watch?feature=player_detailpage&v=QlW2sV3hWu0#t=2658
--> filmed from car pacing , express on the Emsland line with Rheine based 012 at speed northbound ca in 1973 at line speed limit of 120 km/h – check out that smooth , dead-straight running of the three cylinder Pacific in spite of real badly run down condition two years before the end of regular service for the last few surviving 012s
6.
Few if any of the respectable array of three cylinder locomotives built could be considered fully fledged , most of the known designs described in literature have remained what might be called “two cylinder with an additional permanent booster cylinder in the middle” . Why ? well , since neither their valve gear mechanics nor transmission of power from cylinder to wheels was fully level with outside gears . That certainly applied to the ALCO three cylinder engine through-out its entire era of construction , although some progress had been realized by help of integrated frames cast with cylinders and in hardening against wear , if incomplete , of the Gresley linkage .
In the end , performance in daily ton-miles-intensive traction fell short of heady ALCO promises . This was inevitable since in view of marketing the type ALCO had exaggerated scope of extra tractive effort and power to be gained with the three cylinder engine unit while actual design remained rather raw or imperfect in most of major aspects . To fight excessive stresses in lateral linkage levers and their bearing ALCO reduced middle cylinder valve travel in later batches of Nines , which at that time was considered acceptable as a means against over-travel of valve , yet meant an inevitable reduction in cylinder efficiency and maximum output in relation to outer drive units . Main pivots finally got roller bearings however since equipment was incomplete and the linkage received motion from outer Walschaerts which continued with plain bearings , again success was limited and a full solution of the problem was never realized .
As cool as it is, that also means it will likely not run again. Every speck of paint is as it was when rolled out of the Baldwin works. It is absolutely amazing!
A restoreation would destroy this unique trait. But I would rather see it like this, completely original and intact, than running down the rails with new paint, changes to many things, replaced parts. I just don't think it's worth the trade-off.
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