Does anyone know what a three cylinder engine is?
The center cylinder is cranked to a driving axle, with the connection located between the frame members. It is angled in order to provide clearance. There were simple, as well as compound versions of this arrangement, but the compounds generally proved impractical in North American use. All survivors in this country are simple engines, as far as I know.
Surviving examples include Alton & Southern 0-8-0 no. 12 in Kirkwood, MO; Baldwin 4-10-2 no. 60,000 in Philadelphia; Southern Pacific 4-10-2 5021 in Pomona, CA; and Union Pacific 4-12-2 9000, also in Pomona.
The three cylinders are high on my list of unique designs that never took off over here in the US.
3-cylinder locos had a speacial exaust chuff as well, from the four chuffs per driver revolution on normal engines, 3 cylinders had six chuffs, making for some very interesting "stack talk"
While here in the US they never really took off, they became fairly common across Europe. Among some notable European 3 cylinders is the A4, thats right, the "Mallard" was 3 cylindered, along with her sisters who still operate today!
As a matter of fact, my favorite locomotive is a 3-cylinder: Alton and Southern #12
This is the 3rd cylinder, located under the smokebox, between the other two cylinders. (Alton and Southern #12)
In the foreground is the crank on Axle #3, the rod running between the frame goes to the center cylinder. You can also make out the "crooked" axle unerneath the rod. It was made this way to make room for the motion of the rod.
You can easily see where the center cylinder is here.
The center cylinder yielded more power in a smaller locomotive, the #12 (pictures above) is an 0-8-0, but still produced more than 60,000 lbs tractive effort! Thats more than some 4-8-2's and 4-6-4's of the time period!
Unfortuantely, the 3rd cylinder was difficult to service, and the costs related to maintenance outweight those saved by fuel economy. These engines became known as "Roundhouse Queens" as they sometimes spent longer under repair than in operation.
This is probably more than you wanted to know, but if you have more questions, ask away, somebody around here will know!
-S.Connor
ACYAll survivors in this country are simple engines, as far as I know.
All four of the locomotives you mentioned still have three cylinders.
In fairness, it should also be mentioned that geared locomotives could and did have three cylinders, crank set to give the same balanced 120-degree angle.
While we are on the subject of interesting 'chuffs', Baldwin 60000 was notable because one of the cylinders exhausted internally, making little if any greater noise than the cylinder exhausts on the 25 class condensing 4-8-4s in South Africa. So you had a highly interesting 'off-beat' audible sound, for all the world like the worst case of mistimed valves ever heard, even though the locomotive was apparently notable for smooth torque.
I'm surprised nobody commented on how a three-cylinder engine with the center cylinder elevated a few degrees is timed to give even power impulses...
ACY[The center cylinder] is angled in order to provide clearance.
Come to think of it-- a few US 4-cyl engines had the inside cyl horizontal even tho they drove the second driver axle. No idea if any 3-cyl engine anywhere was built like that.
Wizlish:
Yes, all four of the locos I mentioned still have 3 cylinders. Was that in question?
Tom
ACYYes, all four of the locos I mentioned still have 3 cylinders. Was that in question?
No. I misunderstood what you were saying; I thought (for some reason) you were commenting on the fact that so many of the US three-cylinder locomotives were rebuilt to simple two-cylinder locomotives.
I thought the only practical three-cylinder compound built in all of modern United States practice was the Baldwin 60000. Almost everything compound that wasn't a cross-compound was four-cylinder, wasn't it? Vauclain, Vauclain balanced, Cole, de Glehn-du Bousquet, what am I missing? The D&H compounds were experimentals, and the Schmidt high-pressure engines apparently weren't successful in road service. I thought B&O kept their watertube boiler pressure limited to what was expandable in a simple engine - under about 350 psi.
Sorry about noting the wrong thing!
The cylinder does not appear to be inclined. This would cause even more clearance problems. The cylinder and crosshead are horizontal and the angle is taken by the connecting rod. The longer the piston rod the shorter and more angled the connecting rod will be. The center cylinder will have to have a shorter stroke and thus less power making it much less attractive.
tdmidgetThe cylinder does not appear to be inclined. This would cause even more clearance problems. The cylinder and crosshead are horizontal and the angle is taken by the connecting rod. The longer the piston rod the shorter and more angled the connecting rod will be. The center cylinder will have to have a shorter stroke and thus less power making it much less attractive.
I think the center cylinder on the Alton engine is angled, but it isn't by much. All three cylinders have the same dimensions (22x28) in all the references I have. Yes, rod angularity is a problem, and one (partial) solution is in the 'cranking' of axles (as mentioned) to clear the longer rod. If I recall correctly, in at least one overseas design the rod is curved to go around an axle, and a separate (also curved) piece is bolted on to keep the rod stiff.
Three cylinders makes reasonable sense in plaes like Britain, where the loading gauge and platform clearances greatly restrict outside cylinder dimensions (to say nothing of insulation thickness!). In the United States that was less of an issue. In my opinion the developments in lightweight rods and balancing during the 1930s made engines with inside cylinders and rods even more undesirable (and rebuilding existing three-cylinder locomotives to 2-cylinder locomotives more preferable).
Am I justified in thinking you are an MG fan?
tdmidget The cylinder does not appear to be inclined. This would cause even more clearance problems. The cylinder and crosshead are horizontal and the angle is taken by the connecting rod. The longer the piston rod the shorter and more angled the connecting rod will be. The center cylinder will have to have a shorter stroke and thus less power making it much less attractive.
If you are talking about the photos I included above, I can tell you from being around that engine (The Alton and Southern #12) so much that it is inclined (Shocked me when I noticed, but it's true!). The whole cylinder is tilted about 15 degrees or so backwards, so that the rear end is lowered.
The center cylinder on the AS #12 is the same size as those around it, and tilting it would produce a longer stroke for the shorter rod, which can be short because the cylinder has already taken the angle.
tdmidgetThe longer the piston rod the shorter and more angled the connecting rod will be. The center cylinder will have to have a shorter stroke and thus less power making it much less attractive.
I am sure the Alco. designers ran into the same issues, and came up with the solution: Tilt it!
I hope my above explanation makes sense, it is hard to describe complex systems over text.
Also, how many of the surviving N.American 3 cylinders have the tilted center cylinder? I know that at least one other, the UP 9000 has it's center cylinder tilted.
Loves the 3-cylinder "oddballs",
-S. Connor
S. ConnorThe whole cylinder is tilted about 15 degrees or so backwards, so that the rear end is lowered.
You will want to explain this differently to avoid confusion. The cylinder is almost surely not tilted 'down' at the back, it is tilted up at the front; there is a very important difference. Think of the whole shebang - cylinder, piston-rod, crosshead, and guide, and rod alignment - being rotated upward around the axis of the cranked axle. The resulting rod angularity either side of dead center is equal, although the geometry as the axle moves up and down on the suspension is a bit different.
... tilting [the center cylinder] would produce a longer stroke for the shorter rod, which can be short because the cylinder has already taken the angle.
I am not sure I understand what this means.
The issue with rod angularity that midget is discussing isn't an offset angle of the rod relative to the cylinder axis, it's rod angularity in the IC engine context -- a shorter rod has its big end swing laterally further for a given stroke (which determines the crank throw) and there are thrust and inertia consequences from that. The relative 'shortness' of the rod is not changed by inclining the cylinder EXCEPT that it becomes possible, with the cylinder elevated and the intermediate axle(s) offset at center to clear, to run a longer rod to a crank on an axle further back.
S. Connorhow many of the surviving N.American 3 cylinders have the tilted center cylinder?
timz All of them-- and just about all the unsurviving ones too. Mr Meislahn decided the A&S engine's center cyl was tilted 6 degrees; the SP 4-10-2s were 9.5 deg, and as I recall the 4-12-2s were too.
All of them-- and just about all the unsurviving ones too. Mr Meislahn decided the A&S engine's center cyl was tilted 6 degrees; the SP 4-10-2s were 9.5 deg, and as I recall the 4-12-2s were too.
I believe that the UP 9000 and SP 4-10-2 needed that higher tilt angle because the center cylinder was connected to an axle much closer to the front of the engine (The second anxle, if I recall correctly).
Also, if I may ask, where did you find the tilt angle for the A&S #12? I have copies of all archived paperwork for her from MOT and in all of that (and the internet) have not seen a measurement on the tilt of the center cylinder.
It's also worth mentioning that most survivors of the N.American 3-cylinders use the Gresley valve gear for the inside cylinder (Baldwin 60000 does not). And according to this information from rgusrail.com, its no wonder that all equiped with gresely are tilted.
Another feature of the Gresley design was the general need to angle the third cylinder so that the inner main rod would clear the first driver axle. On #9000, the incline was 9½°.
All for now,
PS- Not all 3 cylinders used gresely valve gear. Gresely gear wore quickly and was not very suitable for high speeds. Many 3 cylinders (If not simplified to 2 cylinder operation) were rebuilt with Walshearts valve gear on the center cylinder, or had the gresely rebuilt with roller bearings. Some of the UP 9000's had this done to them, but none survived save the 9000, which was not altered.
Now I believe the only 3 cylinder with "speacial" (Not gresely) valve gear for the 3rd cylinder is Baldwin 60000. Not sure what valve gear is used on that, though.
S. Connor,
The Baldwin 60000 is a pretty special locomotive. She was a "one off" construction by Baldwin built as a "demonstrator model" for new locomotive sales. Incorporated in her design were many new and unique features - 60000 had a high pressure boiler with water tube firebox similar to that used in marine construction, Baldwin 60000 was a compound three cylinder design which used the high pressure steam in the center cylinder and exhausted this into the two outer cylinders effectively using the steam twice and incuring economies in this performance.
After touring the nation as a demonstrator - she was converted from coal to oil by western railroads and then back to coal before returning east. Baldwin 60000 was un-saleable in that no American railroad would take on ownership of this one off designed roundhouse queen. Because it was sure to be a maintaince headache.
So It remains today - A BRAND NEW 1926 original Baldwin 4-10-2 steam locomotive - never used up, never rebuild always kept indoors - never repainted and in completely original condition BRAND NEW! Not only that it has spent its entire life moving slowly as an active museum exhibit on one piece of track in the Franklin Institute in Philadelphia PA! Boiler cold fire extinuished for its entire service career! Go Figure that one!
If you get a chance go see the last original new unused American steam locomotive from 1926! I think its really a BACK TO THE FUTURE three cylinder time machine!
Doc
I've seen it Doctor D. and it's stunning. Too bad it's entombed in the Franklin Institute never to run on the mainline again.
Oh well, beats a scrap yard.
By the way, for a really good look at multicylinder steam, up close and personal, there's a video out filmed in Europe called "The Steam Locomotive- Technology and Practice." It'll take you right under the locomotive for an up-close look that can't be beat.
A two-disc set for $39.95, and I can't recommend it enough.
Order from Country Trains, PO Box 250, Ellerslie MD 21529-0250
e-mail ct@hereintown.net
Bought mine at a train show in January and have lost track of how many times I've watched it.
Unfortuantely that "active" part has destroyed her bearings. Decades of rolling untold miles 15 feet back and forth, without lubrication or servicing, have worn many of her bearings "egg-shapped" from what I've heard.
But that still doesn't take away from the fact that she still wears her original paint! What other engine can say that?
S. Connorwhere did you find the tilt angle for the A&S #12?
S. Connor[quoting someone else] Another feature of the Gresley design was the general need to angle the third cylinder so that the inner main rod would clear the first driver axle.
S. Connor PS- Not all 3 cylinders used Gresley valve gear. Gresley gear wore quickly and was not very suitable for high speeds. Many 3 cylinders (If not simplified to 2 cylinder operation) were rebuilt with Walschaerts valve gear on the center cylinder, or had the Gresley rebuilt with roller bearings. Some of the UP 9000's had this done to them, but none survived save the 9000, which was not altered. Now I believe the only 3 cylinder with "special" (Not Gresley) valve gear for the 3rd cylinder is Baldwin 60000. Not sure what valve gear is used on that, though.
PS- Not all 3 cylinders used Gresley valve gear. Gresley gear wore quickly and was not very suitable for high speeds. Many 3 cylinders (If not simplified to 2 cylinder operation) were rebuilt with Walschaerts valve gear on the center cylinder, or had the Gresley rebuilt with roller bearings. Some of the UP 9000's had this done to them, but none survived save the 9000, which was not altered.
Now I believe the only 3 cylinder with "special" (Not Gresley) valve gear for the 3rd cylinder is Baldwin 60000. Not sure what valve gear is used on that, though.
M636CInterestingly, in his first use of the gear on GNR 2-6-0 1000, Gresley used needle roller bearings on the main bearing of the 2:1 lever, although plain bearings were used later.
Something to remember here is that the 'typical' kinds of rolling-element bearings are not good for oscillating motion that does not give at least one full revolution of the rolling elements start to finish. They wear funny. For very small motion, the result can be very like the damage older roller bearings could suffer via fretting when exposed to vibration or shock when not rolling and not oiled.
Now, a needle bearing isn't really a proper roller bearing, as there is no cage and often no full rolling contact on all the pressure surfaces. Think of a Multirol as a hydrodynamic bearing which has hardened steel for all its bearing surfaces, but which cannot gall or seize under load because there is always an open reservoir of lubricant between the hardened line contacts of the rolls and the inner and outer races. This should have been a good technology for the pivots in a conjugated valve gear like Holcroft or Gresley; I can't speak to the quality of the lube or the steel or the fabrication quality of the bearings that were used ... but it's possible that cost and perhaps NIH played some part. My understanding was that it turned out not to be play in the bearing joints that was the principal high-speed issue, but physical deflection of the lever under inertial loading (I have always wondered if there was a resonant component at a critical speed). Of course, once the bearings (particularly plain bearings) started to open up a little, the forces rapidly beat the bearings to where the clearances were excessive -- a little slop anywhere would rapidly force a little slop everywhere, and the slops add up in that gear.
One of the Australian classes got around the issue of shaft whip and bearing play by using a system of gears that turned cross-shafts in bearings. Unfortunately the shafts 'wound up' a bit, as torsion bars in Chrysler suspensions do, and this allegedly produced much the same timing problem as the version with the levers
I think there is an actual difference between Holcroft's and Gresley's gear, although they use the same basic idea. Holcroft's arrangement was for a four-cylinder locomotive; Gresley's for three using the 2:1 lever we all know and loathe. For some reason I remember learning that Holcroft himself accepted this difference, but I may just have heard it during a lecture on valve gear minutiae.
Something my father suggested for using Timken bearings on conjugating levers was to put a pawl and a friction of some sort on the cage of each bearing, so it kept preferentially turning slightly in the same direction (with the rollers bearing properly but scuffing a bit against the edges od the cage slots). I do not know if this would work any better than grease lube in a Multirol for the limited time before the inside valve needed maintenance or attention.
The Reading, early in the 20th century, built several 3 cylinder locomotives. They used Joy valve gear for the central piston valve, Walschearts on the outside cylinders. I believe there were 2 Atlantics and 2 ten wheelers, all Camelbacks, constructed for high-speed heavy passenger service. All were later converted to 2 cylinder power and enjoyed long careers.
The main effect of the raised and angled center cylinder was a syncopated exhaust (Chuff ---- chuff --- chuff -- Chuff ---- chuff...) instead of the evenly-timed exhaust blasts of a two cylinder loco.
Another interesting effect, seen on Alco-built JNR C52 class Pacifics, was 'out of position' counterweights on the main drivers. They had to balance the inside crank and rod end as well as the usual outside rod, so the counterweight was not opposite the visible crankpin.
Union Pacific had some Gresley conjugating mechanisms with plain bearings, and some later ones with needle bearings. When wear problems showed up (plain bearings much more so) some of the plain bearing mechanisms were fitted with needle bearings. Most had the conjugating mechanism replaced with a third Walschaerts valve gear.
Chuck
tomikawaTTThe main effect of the raised and angled center cylinder was a syncopated exhaust (Chuff ---- chuff --- chuff -- Chuff ---- chuff...) instead of the evenly-timed exhaust blasts of a two cylinder loco.
That syncopation is only the result of age, or incorrect valve setting. As built by anyone competent, the crank angles and valve actuation were arranged to give equal inlet and exhaust, and while the exhaust was triple it was regular.
(On Smith compounds and the like, as I mentioned, there was audible syncopation due to one out of every three exhaust events being internal, but that's not what you're talking about.) EDIT - I 'mentioned' this wrong. The exhausts on Baldwin 60000 were timed 90 degrees apart, so the audible 'beat' of the exhaust was as normal for a 2-cylinder DA engine...
Some of the audio recordings of three-cylinder engines, particularly a couple of the Nines near the end of their time, are almost terrifyingly mistimed. Here is a famous example.
Wizlish One of the Australian classes got around the issue of shaft whip and bearing play by using a system of gears that turned cross-shafts in bearings. Unfortunately the shafts 'wound up' a bit, as torsion bars in Chrysler suspensions do, and this allegedly produced much the same timing problem as the version with the levers I think there is an actual difference between Holcroft's and Gresley's gear, although they use the same basic idea. Holcroft's arrangement was for a four-cylinder locomotive; Gresley's for three using the 2:1 lever we all know and loathe. For some reason I remember learning that Holcroft himself accepted this difference, but I may just have heard it during a lecture on valve gear minutiae.
The Australian locomotive with rack and pinion valve gear was the D58. This class started off as an order for 25 further D57 class for wartime traffic in 1942. The cast steel beds arrived from GSI but it was decided that the new locomotive should meet tighter clearances requiring smaller cylinders. The whole design went downhill from there. The rack and pinion gear was intended to allow longer valve travel, since Gresley gear had caused problems with overtravel in the centre valve, and the new gear was intended to eliminate this. When the first locomotive was steamed for the first time expansion locked the gear solid, and the gear was removed from the frame and cantilevered off the cylinder casting. Only 13 of the 25 D58 class were ever assembled starting in 1949 and their place was taken by Beyer Garratts.
Gresley called Holcroft to his office in London to describe the conjugated gear. The meeting is described in Holcroft's autobiography. The layout used was favoured by Gresley, although Holcroft outlined the theoretical disadvantages at that initial meeting but Gresley felt that ease of access for maintenance outweighed the problems. Gresley wanted Holcroft to work for him on the GNR but R.E.L. Maunsell, CME of the SE&CR refused to release him.
Partly to appease Holcroft, Maunsell built two three cylinder locomotives with Holcroft's conjugating gear, a 2-6-0 class N1 and a 2-6-4T class K1, the latter later rebuilt as a 2-6-0 class U1. These had an arrangement similar to that used by Gresley but the conjugating gear was driven directly from the valve gears with outside links rather from the valve spindles as Gresley did.
I believe this was a significant point. The outside valves were located by the valve gears behind the cylinder and valve castings but the centre valve was located by the conjugating gear forward of the castings. As they heated the outside valves expanded forward while the inside valve expanded rearward. Since the valves had to be set when cold, only estimates could be made of the correct position at operating temperature.
When this is combined with wear and flexibility, it becomes clear why Gresley gear is inherently imprecise.
I examined the indicator diagrams of road trials on loco 5711 made during 1929 when the loco was new but run in. The indicator on the centre cylinder was inoperative for most tests but one card was made at 45 mph and the diagrams were very strange suggesting that that that speed the valve was mistimed and the power from that cylinder was about 30% greater than the outside cylinders.
Edward Thonpson lined up the centre cylinders of the A4 class to 17" from 18" to reduce this effect.
M636C
M636CGresley called Holcroft to his office in London to describe the conjugated gear.
I thought this was much later than Holcroft's invention of conjugated gear for four-cylinder engines, and concerned something particularly germane to the present thread: how to make the 2:1 lever three-cylinder gear work correctly with an inclined center cylinder.
Holcroft's gear worked entirely behind the cylinder block so all the valves and valve rods expanded in the expected direction. However if I recall correctly when there was not sufficient space behind the cylinder block, it would all be installed in front of the cylinder block, leading to some interesting rod arrangements to drive it.
I have always thought that part of the differential-expansion issue on Gresley-gear-equipped engines is that actual superheat under some running conditions, particularly WOT at high road speed, was much higher than expected, a likely effect being greater expansion of the valve relative to the port areas in the cylinder block.
Peripherally, but on topic: Can someone post (or re-post) drawings and details of the original 'defective' big-end arrangement on the A4s, and how the design was practically improved after Mallard's 'experiences'? I have read about this (I think in the 'three designers' book) but there were no illustrations of the specific design details.
M636C Gresley called Holcroft to his office in London to describe the conjugated gear.
There has never been any conjugated gear for four cylinder locomotives: all that is required is a 1:1 rocking lever to drive the adjacent valve. This was widely used by the GWR, for whom Holcroft worked during the early years of the 20th Century. Holcroft was at least partly responsible for the detail design of Churchward's standard locomotives, which drew heavily on contemporary designs from the ALCO Brooks works. The GWR four cylinder locomotives followed Du Bosquet De Glehn compounds but remained simple expansion (and used inside valve gear rather than outside). While with the GWR, Holcroft designed his original conjugated gear which used two 2:1 rocking arms and a central oscillating beam with the drive to the centre valve in the centre of the oscillating beam. This was intended for a 4-4-0 much like Churchward's County which was known for rough riding and heavy hammer blow, and Holcroft expected that a 3 cylinder would run more smoothly and be easier on the track. The problem with that gear was that all the cylinders had to be parallel and in line fore and aft and the cente valve had to be above the cylinder.
Gresley produced his first O2 2-8-0 in May 1918 using a mechanism that might have infringed the existing Henschel patent (possibly not a big problem in early 1918) but which didn't work very well. Holcroft had continued to work on alternative conjugating gears and came up with the "Gresley" arrangement about this time. Gresley had been advised of Holcroft's earlier patent which had expired in 1913 and asked him for advice sometime in mid 1918. The new design was prepared in time for the K3 class 2-8-0 in 1920. I think Holcroft was the one who realised that a horizontal valve could feed an angled cylinder but that that valve could not be central, and that realisation led to the design with the single large 2:1 lever. Two designs on the LNER used Holcroft's later design behind the cylinders, the D49 4-4-0 and a rebuild of an NER 4-6-0, the B16/3 and these gave pretty much trouble free service, which I attribute to the elimination of the valve rod expansion problem and the resulting uncertainty in valve events.
The two Maunsell locomotives used the Gresley arrangement with outside links replacing the valve rod drive, presumably to Holcroft's own design, other wise identical to the "Gresley" design. These two were soon rebuilt to use three sets of Walschaerts gear, and a dozen or so similar locomotives were built that way. Holcroft presumably lost interest in the gear, as did nearly everybody else.
The initial response to the A4 middle big end was to insert a glass capsule of a liquid which released a pungent odour on overheating so that the crew were aware of the problem and could ease off before serious damage occurred. I believe different designs were used into post BR days when more accurate optical measuring techniques were introduced and it was found that by mor accurately aligning the whole chassis in conjunction with a heavier inside big end effectively removed the overheating.
THREE CYLINDER locomotives in America were occasionally built before 1910 which heralded modern construction of 4 locomotives for the Philadelphia and Reading Railroad. These engines were 4-4-2 "Atlantic Type" locomotives and included one 4-6-0 "Ten Wheeler Type." These Reading Railroad engines were superheated and used Walschaerts outside valve gear while the inside cylinder used inside Joy valve gear.
THREE CYLINDER steam locomotive development in the United States was not such a unique event in railroad history as one might assume. THREE CYLINDER POWER design as we know it really deals with the product development of ALCO Locomotive Works and its competiton with LIMA and BALDWIN Locomotive Works in the years from 1922 to 1930.
In the 1920's when LIMA Locomotive Works was under the influence of William Woodward with his much heralded SUPER POWER concept. ALCO developed and was going strong with its own heralded THREE CYLINDER POWER concept as the way of the future.
At ALCO this began in 1922 with the development of the MOHAWK 4-8-2 rebuilds of New York Central NYC 2568 and NYC 2569. Going from a 2 cylinder to a three cylinder design in the rebuilding increased the hauled tonage and tractive effort capacity on these locomotives by 25%.
Following this in 1924 Lehigh Valley Railroad contracted an order for 6 engines, the first "New Built" of the ALCO THREE CYLINDER POWER with their 5000 series 4-8-2 "Mountain Type" designs.
ALCO Locomotive Works continued the new concept in developing the THREE CYLINDER 4-6-2 "Pacific Type" and 2-8-2 "Mikado Types." Increase of tractive effort without total increase of axle loading was featured as well as the use of "Gresley" valve gear for the inside cylinder motion. Purchasers were Missouri Pacific RR, Louisville and Nashville RR, Delaware, Lackawanna and Western RR, Wabash RR, and the New Haven RR. Mexico with light rail loadings and Brazil's Sorocabana RR narrow gauge were also customers for THREE CYLINDER POWER.
Delaware Lackawana and Western used its first 4-8-2 three cylinder locomotives for heavy passenger work. This was followed by a second series of 25 three cylinder engines numbered DL&W 2201-2225 which were used for heavy freight, and which order was followed by an even larger class of three cylinder designed engine series of the DL&W 2226-2235 class.
Denver and Rio Grande Western in the market for Rocky Mountain pulling passenger power settled upon the 4-8-2 "Mountain Type" three cylinder design. BALDWIN Locomotive Works produced this successful three cylinder D&RGW class 1600 series of 4-8-2's.
Switch engines also came in for "three cylinder" design. New Haven Railroad tried the 0-8-0. Also of note was a large 0-8-0 transfer engine designed for Belt Railway of Chicago.
------------------------
THREE CYLINDER POWER then took off in the form of "really, really big power" design projects. Because there was a point beyond which regular two cylinder locomotives could not be built. This was the "really, really big power" possible with the 4-10-2 "Overland Type" wheel arrangement developed in 1925 for the Union Pacific but made more famous in 1926 with a demonstrator model constructed by Baldwin Locomotive Works.
This 4-10-2 demonstrator locomotive as it was envisioned by Baldwin was an extremely high technology engine that was never duplicated. The Baldwin 60000 demonstrator engine remains today brand new yet never sold at the Franklin Institute in Philadelphia, PA where Baldwin got rid of it through donation in what appears as a tax write-off.
The 4-10-2 "Overland Type" continued to be built only as THREE CYLINDER power, albeit without water tube firebox, high pressure boiler and compound cylinders of the Baldwin 60000 demonstrator.
Strangely the THREE CYLINDER POWER 4-10-2 "Overland Type" also came to be called the 4-10-2 "Southern Pacific Type" owing to the 1925 building of 49 engines of the 5000 class for Southern Pacific Railroad. Union Pacific RR who first ordered 10 of the 4-10-2 three cylinder locomotives were glad to keep the classification of them as originally given as the 4-10-2 "Overland Type."
Further, not to be so outdone by Southern Pacific RR and its 49 copies of "Southern Pacific Type" so renamed, the Union Pacific RR then undertook the development of its own named THREE CYLINDER POWER design using the "one more step format" of the 4-12-2 "Union Pacific Type" 9000 series engines of "really, really, really big power" locomotive. Eighty eight of these massive three cylinder locomotives were constructed which had an operational speed of 60 miles per hour and a very long service life. Some passenger usage of this astounding 4-12-2 three cylinder locomotive was reported.
It would appear that ALCO and its THREE CYLINDER POWER concept needs to take its place historically along side of LIMA and its SUPER POWER concept!
"Gallop apace, you fiery-footed steeds"
The Bard of the High Iron does it again!
Thanks again for a most enjoyable post, Doctor D!
I think the wrong idea is created regarding three cylinder locomotives if consideration is limited to those within the United States, since they followed a trend started overseas, and the great majority were based on the patented conjugated valve gear developed by Holcroft. As I indicated earlier, all the locomotives built in the UK and the USA using the Holcroft gear were outnumbered significantly by German built locomotives using a Henschel patent conjugating gear. In addition, there were a large number of three cylinder locomotives built in Germany and in the UK that used three separate valve gears, a number with the Baldwin arrangement (or a variation thereof) but many with the third gear inside (like the early Reading locomotives).
The German three cylinder locomotives were built during or just after the First World War, and were thus contemporaries of the USRA types, and like the USRA locos were a standard design supplied to most of the main line railways in Germany before the nationalisation of the early 1920s.
Apart from the Union Pacific, the three cylinder locomotives tended to be discarded and rebuilt as two cylinder locomotives, and the UP superseded the three cylinder locomotives with their well known simple articulated locomotives.
The Baldwin locomotives, while not discarded, lasted longer in general but were not repeated.
A few Baldwin 3 cylinder pacifics made their way to Thailand, where they probably met British built pacifics of the Malayan Railway, which included a large class fitted with rotary cam poppet valves which needed no conjugating gear (Although Gresley manage to build a class of 4-4-0 locomotives with oscillating cam valves driven by the Holcroft gear - fortunately behind the cylinders where is sat for the piston valve versions).
The D&RG Mountains had the same valve gear as 60000, which while unsold is hardly new. It seems to have its original paint under layers of lacquer, and the feet of generations of schoolchildren have worn away the footplate decking. Whether or not Baldwin benefited from the donation to the Franklin Institute we must be grateful that it is there.
Shop men from Baldwin actually changed out the bearings on the 60,000 at the museum years ago. As you stated, the limited movement made the original bearings egg-shaped. I don't know if they have been changed again, but I do know that they have been changed out at least once due to the wear and tear of "museum service".
Who would change them after Baldwin left the steam locomotive business?
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