Three Cylinders

[CNJ Camelback]

Where is the third cylinder located on a steam locomotive?  I suspect it is between the two cylinders under the boiler.  I can see only the two outside cylinders on photographs.

[timz]

Probably if you see two cylinders, that's all there are.

If the engine does have three cylinders, the third one is on the engine's centerline. It might drive the lead driving axle, but in the US it probably drives the second one, so it has to be inclined to clear the lead driver axle.

[Jones1945]

This is the LMS Coronation Class in UK, four single-expansion cylinders (16½ inches diameter by 28 inches stroke) all placed under the smokebox or boiler, just like those engine with three cylinders. 

http://wondersofworldengineering.com/streamlined-expresses.html

This one is UP 4-12-2, three cylinders.

https://www.etsy.com/listing/522314595/union-pacific-4-12-2-type-3-cylinder

[BaltACD]

[3rd rail]

Three Cylinder Steam Locomotives....  Not very many of them, kind of a failed experiment. I do, recall an EXCELLENT book from the 1970's Called "Three Barrels Of Steam" by an author named "Boyington".. It was a very detailed piece on the "Southern Pacific" 4-10-2 Three cylinder locomotives. The last time I read that book it was in my local library, but that was a long time ago. Alas, they no longer have that book. That's the problem with the "Drop-Boxes" for returning library books... It's VERY rough on the books! Might as well put them into a dryer at the Coin Laundry.... That's why I always return library books in person to the desk.  

Todd 

[Jones1945]

Class A4 4-6-2 Pacific designed by Sir Nigel Gresley was renowned for its great performance even though LNER #4468 Mallard only achieved a "downward grade" world speed record, it was seen as one of the most successful Three Cylinder Steam Locomotives in UK, The Coronation Class of LMS, LNER's rival, was a Four Cylinder Steam Locomotive, This class was another successful example, both class were seen as a Pride of the UK railroad industry. But you are right, it seems that such design only achieved limited success in the States.

Class A4 (wiki)

 

 

Streamlined Coronation Class (wiki)

 

[rcdrye]

Both the SP 4-10-2 and UP 4-12-2 can be described as "successful" in the sense that they lasted as long as other contemporary types.  An SP Road Foreman of Engines once described the 4-10-2's as "an expensive mistress at every division point".

[Firelock76]

Three-cylinder types never caught on here in the US strictly due to the added maintanance required by that third cylinder.  Over in Europe where labor was cheaper it was another story. 

Here it was "Get 'em in, get 'em fixed, get 'em OUT!  A standing locomotive isn't earning us any money!" 

Off the top of my head I can't think of any European railroad concepts besides superheating and Walschaerts valve gear that caught on here.

[M636C]

Bearing in mind the screen name of the original poster, I am surprised that nobody has yet mentioned the Philadelphia and Reading three cylinder Camelback Atlantics. These were among the first "modern era" three cylinder locomotives.

Class P6 consisted of four locomotives built 1909-1910, numbered 300 to 303, the first and the last being three cylinder compounds (presumably on the Smith system) with outside Walschearts and Joy valve gear on the inside cylinder. This suggests some contact with the English North Eastern Railway, where Smith worked and Joy valve gear was used about that time.

P5c 344 was converted to a three cylinder simple locomotive in 1912.

Both classes were converted back to conventional two cylinder locomotives by 1918 or so and were subsequently superheated.

All of these locomotives remained Camelback Atlantic types during these modifications. This was not always so with the P&R, who trearted locomotives a bit like modelling clay that could be changed to suit any new idea.

The M1 class 2-4-2 Columbia type started as Vauclain compounds more or less equivalent to the Atlantics, became high wheeled (78") 2-6-0s, then 4-6-0s but at least some ended up as 4-4-2 Atlantics after this amazing set of transformations.

Peter

[M636C]

Off the top of my head I can't think of any European railroad concepts besides superheating and Walschaerts valve gear that caught on here.

The Belpaire firebox seemed pretty popular on the PRR and Great Northern and I think Brooks built quite a few locomotives with Belpaire boilers for many other roads.

There was Stephenson valve gear, bar frames (originated by Stephenson), the fire tube boiler, the Giffard injector.....

Peter

[MidlandMike]

I also heard that because of its internal location, the 3rd cylinder was hard to maintain.

[M636C]

MidlandMike

I also heard that because of its internal location, the 3rd cylinder was hard to maintain.

 

At the time the P&R three cylinder locomotives were built, the great majority of locomotives in the USA used inside Stephenson's valve gear, which sat between the frames. Adding a cylinder, connecting rod and  bearing, and slidebars was not that great a change. The difference was that the centre rod and bearing were more heavily loaded than the valve gear and caused more problems if they failed.

 

By the mid 1920s when Alco jumped on the Gresley band wagon, there were few main line locomotives with major components inside the frames and the inconvenience factor was much greater. The P&R locomotives were built for better balance, and the driving gear was less heavily loaded. The Alco locomotives (and a few Baldwins) were built for greater power and the inside cylinder and rod were heavily loaded. Owing to a design flaw, the centre cylinder became more heavily loaded at speed. This affected the LNER A4s on their high speed runs, to the extent that Edward Thompson reduced the cylinder diameter from 18" to 17" to compensate. In the USA with much heavier loads they were close to a failure looking for a place to happen. The UP changed some of the 9000s to the Balwin arrangement of valve gear that at least gave more even loading on the centre cylinder. Several of the smaller roads just converted the locomotives back to two cylinder.

 

Peter

[Jones1945]

Thank you for the informative respond, Peter. Speaking of inside cylinder locomotive, one of my favorites is the GWR Iron Duke Class, there estimated top speed was 80 mph, one of the fastest locomotive at the time. Since they were broad-gauge locomotive, they had a classic, elegance appearance with an interesting proportion.

 

 

 

(Please Mute before playing the video)

 

[Firelock76]

M636C

Off the top of my head I can't think of any European railroad concepts besides superheating and Walschaerts valve gear that caught on here.

The Belpaire firebox seemed pretty popular on the PRR and Great Northern and I think Brooks built quite a few locomotives with Belpaire boilers for many other roads.

There was Stephenson valve gear, bar frames (originated by Stephenson), the fire tube boiler, the Giffard injector.....

Peter

 

Right you are Peter, I forgot about those.  What can I say, it was a loooooong day for me!

[Jones1945]

By the way I found an old post in this forum discuss about the same topic, really worth a look! 

http://cs.trains.com/ctr/f/3/t/220574.aspx

[M636C]

Firelock76

 

 

M636C

Off the top of my head I can't think of any European railroad concepts besides superheating and Walschaerts valve gear that caught on here.

The Belpaire firebox seemed pretty popular on the PRR and Great Northern and I think Brooks built quite a few locomotives with Belpaire boilers for many other roads.

There was Stephenson valve gear, bar frames (originated by Stephenson), the fire tube boiler, the Giffard injector.....

Peter

 

 

 

 

Right you are Peter, I forgot about those.  What can I say, it was a loooooong day for me!

 

I assumed that you were distracted....

But people tend to overlook how much basic work was done by Stephenson and others in the 1820s and 1830s...

And Belgium had some interesting locomotives, aside from the two big name designers.

Peter