Were most steam locos in North America 2 or 3 cylinders ? I only remember 2 cylinder C.P.R. locos by the slow chuff-chuff, I also remember seeing 3 cylinder British steam in London in 1965. I assume the 3rd. cylinder was in the middle between the other outside cylinders, right???
Which is why there weren’t very many.
You might pose the question over on the heritage or locomotive forums. I’m sure you’ll get an in-depth analysis (not that you won’t here).
…That 3rd cylinder assy. in the center sure must have been a repair headache. Don’t forget, we certainly had a lot of 4 cyl. engines too.
Most non-articulated North American steam locomotives used 2 cylinders. There are some notable exceptions that used 3 cylinders, the most celebrated example is the Union Pacific 4-12-2, the longest non-articulated locomotive in the western hemisphere.
Shay geared locomotives were often fitted with 3 cylinders as well.
The 3 cylinder design did not fare well in North America, mainly owing to the higher maintenance required by an extra cylinder, and the increased difficulty of reaching the middle cylinder.
I think a lot of the lack of development on this side of the pond can be traced to one simple reason: American steam was free to evolve beyond 3 cylinders to 4. American steam was much larger and favored the development of Mallets, as well as simple expansion articulated (and duplex) locomotives.
I think 3 cylinder steam was most popular in Britain where smaller locomotives were the norm. The added power of the third cylinder on a small frame was worth the trade-off of the maintenance necessities. In the US, it was just easier to add another set of cylinder where they were still accessible for maintenance.
I think the British use of plate frames (at least on somewhat older locs) might have made accessibility less problematic that here.
Engine-only length-- the 4-12-2 might be second place? Engine-and-tender length-- farther down the list?
Something over 99% of all North American steam locomotives were 2-cylinder. I guess there were a lot more 4-cyl engines than 3-cyl, even not counting articulateds? (And maybe we can’t count Shays.)
Edit: turns out that engine-and-tender length of a PRR 4-6-2 with the large tender exceeds that of the 4-12-2. Lots of other engines do too, of course. As for engine-only length, all the PRR duplexes beat the 4-12-2, along with the larger 4-8-4s and 2-10-4s.
Just to point out the obvious – the 3 cylinder Shay and Willamette were succesful because that middle cylinder was easy to access.
Phil
I understand that 3 cylinder engines have great power AND better starting effort then 2 cylinder of the same size and weight.
The Loading Gauge in mainland Britain was constrained by our high level platforms at stations, and 3 and 4 cylinder locomotives offered greater power within that Loading Gauge. The additional cylinders would have been placed between the frames.
The Loading Gauge at Goods stations, however, were commonly even more restricted, and the use of inside (two) cylinder locomotives to shunt such places had to be resorted to.
3 cylinder locomotives were also popular with certain Railways on the grounds of a more even torque, and also at certain yards in built-up areas, as the softer exhaust beats caused less of a noise problem to local residents.
Hwyl,
Martin
I would question whether or not a railway would ever consider the well being of citizens living close to the tracks, " Listen guv’ maybe we should redesign this locomotive so it runs a little quieter eh? hahahahahahahahahahahahahahahahahahahahaha ! ! "
Yes, it does sound a bit rich, but it has been quoted in quite a few books I’ve read.
The railway company involved, the Southern Railway, which existed between 1923 and 1947, did design 3 cylinder humping locomotives for use at its Feltham Yard in London’s well heeled but built up south western suburbs, and elsewhere on its system.
Railway companies were masters of spin to get good news angles, and this may well have been and a major consideration, but it’s also true that 3 cylinder locomotives did have a softer exhaust beat than 2 cylinder examples.
Hwyl,
Martin
Did a three cylinder locomotive have six “chuffs” per wheel revolution? Also, was the third cylinder connected to the first drive axle like an automobile’s piston is connected to its crankshaft?
Yes, they would have 6 exhaust beats per revolution.
3 cylinder locomotives in the UK normally had the inside cylinder drive on the second driving axle, but, given the number of 3 cylinder locomotives built worldwide, I wouldn’t be surprised if someone might come up with an example where the first axle was connected.
Just to add to complications possible, the UK Southern Railway’s “Lord Nelson” 4 cylinder 4-6-0 express locomotives were “quartered” so that there would be 8 exhaust beats per revolution !!
Hwyl,
Martin
A perceptive question ! I believe this was also the case with UP’s 4-12-2’s - but with them, the first axle also had to have a bend in it to clear the driving rod that ran back to the 2nd axle’s ‘crankshaft’. I’m not near my copy of Brian Reed’s Locomotives in Profile book that discussed the 4-12-2’s in depth and maybe some other US 3-cylinder types, so I’m not recalling much else. My vague recollection is that several other US railroads tinkered with 3-cylinder locomotives, mainly as ‘one-of’ experiments - and then usually rebuit them into or back into a conventional 2-cylinder drive. No doubt Robert A. LeMassena had something to say about them sometime in Trains, but I’m not recalling a specific article.
Martin, are you familiar with that series ? It only lasted for 2 volumes, if my understanding is correct - but they are extremely detailed and well-written. They are likely easier to obtain on your side of the Atlantic.
And then there was the Delaware and Hudson, which built a bunch of compound 2-8-0’s, including some with 4-cylinders - but that’s a different topic. Or maybe not - I would think that a simple 3-cylinder would be as
Three-cylinder steamers were tried by more railroads than you might think. Some that I am aware of; Union Pacific (4-10-2, and 4-12-2 types), Southern Pacific (fleet of 4-10-2 types), D&RGW (4-8-2 std gauge). Missouri Pacific (2-8-2), Lehigh Valley (4-8-2), Lackawanna (4-8-2), Indiana Harbor Belt (0-8-0), Union RR (0-10-2), Norfolk & Western (4-8-2). I am probably missing some too. Many of these lasted their service lives in this configuration, but some were rebuilt.
Edit- scratch N&W from this list.
That list is pretty much the kind of population that I had in mind. Do you have any idea how many of each railroad’s type were 3-cylinder ? I’m not recalling that any railroad had a huge fleet, other than UP.
I almost mentioned the IHB 0-8-0, but wasn’t sure about that - maybe I was thinking of its booster engine instead. One of the best locomotive photos and David P. Morgan ‘frontispiece’ essays is -
The grandest 0-8-0 of all
Trains, January 1968 page 18
Indiana Harbor Belt 3-cylinder 0-8-0
( 0-8-0, FRONTISPIECE, IHB, “MORGAN, DAVID P.”, STEAM, SWITCHER, ENGINE, LOCOMOTIVE, TRN )
- Paul North.
HEY ! HEY ! Just found an article in MR June,1984, re: D&RG getting a new 4-8-2 mountain steamer in 1926 in Denver, it’s a 3 cylinder monster, and a great looking locomotive, it’s a Baldwin. The article goes on to a very intersting point: quote: : Sound enthusiasts should note that 3-cylinder engines had an off-beat exhaust caused by the middle cylinder being canted 8 degrees from horizontal. The sound timing was “long,medium,short, long,medium, short” for each driver revolution, rather than 6 equal beats. very interesting.
Gresley liked that, but most? other UK 3-cyl engines used divided drive, with the inside cylinder driving the lead axle.
The SP had 49 4-10-2 type with three cylinders, D&LW had 35 4-8-2 type with three cylinders. And you can add the NY,NH&H to the list as owning 13 4-8-2 with three cylinders.