Valve gear type?

[John_S]

I've started looking into what's next for me and going through lots of Rock Island photos and there's a couple 2-8-0s that interest me; however, I'm stumped as to what type of valve gear these have. Take a look at the cylinders and valves:

[Fender]

Most likely Stephenson valve gear. Piston valves are inside the frames.

[makinsmoke]

Man, I bet it's really busy under there......

[SoCalLiveSteamer#613]

Many engines were built like this in the early years with the inside facing valves. Kinda throws the eyes off. Like everything else though they eventually pushed them back on top because it was a nightmare to work on! Some of the old Stevenson gear engines had compound cylinders as well. Occasionally you can see the extra piston housing in the cylinders of older engines but most of them were later converted back to conventional high pressure steam only. The SP mogul here in Lomita at the museum is like that.

[Bill Shields]

The compounds are called Vauclain Compounds..

Stephensons with piston valves were quite common for a few years until some guy from Belgium came up with a better idea

Some locos actually were rebuilt from slide valves to piston valves by replacing the cylinders on existing chassis and reusing as much as possible (like the valve gear). Jim Stuart told me of several B&M locos that had that 'conversion'.

The British did locos with valves inside the frames clear up to the bitter end.

After that, their loco designers went to work for the motocycle industry, which also came to a bitter end...

[FLtenwheeler]

The Chicago & North Western 1385 at the Mid-Continent Railway Museum has this arraignment.

Tim

[John_S]

Had a moment to dig through http://www.steamlocomotive.com and found these two consolidations.

They both had Stephenson valve gear and were built by Brooks 1917.

Working on the Stephenson on my Allen mogul was enough for me... don't really want to tackle that again, especially with the inboard valves!

[Bill Shields]

Chicken....

If you build it correctly, you don't have to do anything to it (giggle).....

[Doug_Edwards]

Stephensons with piston valves were quite common for a few years until some guy from Belgium came up with a better idea

C'mon Bill, surely you know that Walchearts valve gear predated piston valve use on railroads by decades, not piston valves predating Walchearts! The SP/CP used a modified Walchearts gear in the early 1880's. and the Mason Bogies were built with it also before the turn of the century.

Some locos actually were rebuilt from slide valves to piston valves by replacing the cylinders on existing chassis and reusing as much as possible (like the valve gear). Jim Stuart told me of several B&M locos that had that 'conversion'.

The PRR D16sb 4-4-0 at the museum at Strasburg is one that the cylinders were replaced with piston valved cylinder castings. Apparently, the PRR was too cheap to spend to much money, as the new piston valved cylinders use outside admission valves. Looks like they didn't even change the valve gear!

Regards,

Doug

[Bill Shields]

predated - yes.

common usage in the USA....well, that is another story.

[drgsw464]

john_s
I'm work on Stevenson valve for the Alan models 2-8-0 you move the rocker arms forward one diver set and use a transmission rod

[nickco201]

Many southern locomotives, a good example being many of their K series of 2-8-0s, were built with slide valves/Stephenson then converted to piston valves with new cylinders or universal steam chests. At the same time they received either Southern or walscheart valve gear.
Southern 630 and 722 followed this trend, they looked quite different new. Here is a builders photo of 642 http://southern.railfan.net/images/arch ... ou642.html

Here is a photo of it years later showing the universal steam chest application, valve gear change, and other modifications that the southern carried out on it. http://southern.railfan.net/images/arch ... ky746.html

- Andrew