Question for Valve Gear Gurus

Frisco1522 · **Posted:** Mon Feb 10, 2014 12:14 pm

Jim Herron sent me this image from the Barriger collection online and asked what kind of valve gear this is. I've never seen anything like it, but it looks like it would fail fairly easily. I am impressed by Nickel cylinder head covers on a USRA 2-10-2 though.

filmteknik · **Posted:** Mon Feb 10, 2014 12:45 pm

Could this be Joy valve gear?

(photo resized and lightened)

Steve

whodom · **Posted:** Mon Feb 10, 2014 1:36 pm

Wow- that one's got me stumped. Very interesting.

I wonder what railroad it's on? I note the engine has Baldwin disk main drivers, and the only USRA 2-10-2's I know equipped like that were the Atlantic Coast Line's.

Kelly Anderson · **Joined:** Tue Sep 14, 2004 7:52 am **Posts:** 2477

Nigel Anthony Hewer Day · **Posted:** Mon Feb 10, 2014 6:14 pm

Not sure, some of it looks like Hackworth while the link looks like Bakers. Maybe it's a cross between the two. I have never seen anything quite like it before.

Dave · **Posted:** Mon Feb 10, 2014 7:20 pm

I'm looking for my Smith valve gear drawings....but it's not easy to see exactly how this is put together inside the frame. As far as I know, it was just used on one Glover built locomotive, but it would be very interesting to find out there was one more in the world.

dave

SouPac · **Posted:** Mon Feb 10, 2014 7:45 pm

Ha, I just saw this thread but already responded to don's question over on TO. I'm with Kelly on this one, Marshall version one or three. The vertical eccentric rod, engaging a rocker which is tumbled to give valve events, is somewhat complicated in this application by being kluged onto an existing tumbling shaft and also making the events suitable for inside admission.

http://www.trainorders.com/discussion/r ... 10,3319958

Anyway, would be great if they found some documents to flesh out what this really is, a neat question!!

Best,

Stathi

jim templin · **Posted:** Mon Feb 10, 2014 9:58 pm

it is a type of Marshall. I have seen some small Baldwin contractor dinkys with this valve gear. If you'd like to see a variation of this valve gear in person this side of the pond, go find a late model Keck Gonnerman steam engine with their version of this called the Miller reverse.

One thing that amazed me is how many patents for steam engine valve gears there are, and some just seem to be copies of others, the only novelty being mounted upside down

Frisco1522 · **Posted:** Mon Feb 10, 2014 11:05 pm

As Stathi mentioned over on TO, if this was running on rough track, the movement up and down of the main driver would change valve gear settings and make the exhaust sound strange.

Jeff Terry · **Joined:** Mon Aug 23, 2004 12:18 am **Posts:** 281

Not 100%, but I think the locomotive is Seaboard Air Line 2495. I seem to remember seeing a photo of it before.

whodom · **Posted:** Tue Feb 11, 2014 8:24 am

Dave wrote:

I'm looking for my Smith valve gear drawings....but it's not easy to see exactly how this is put together inside the frame. As far as I know, it was just used on one Glover built locomotive, but it would be very interesting to find out there was one more in the world.

dave

Dave,

My first thought was Smith too, but after thinking about it, it's definitely not that. Smith is basically Southern Valve Gear with a linkage replacing the curved slot in the stationary portion of the gear. A friend of mine's dad built a live steamer with Smith VG back in the 1980's.

whodom · **Posted:** Tue Feb 11, 2014 12:07 pm

I did manage to find a photo of a Marshall VG equipped locomotive:

This picture shows how the cutoff is altered:

This one's on an 0-6-4T on the Kirklee's Light Railway in the UK. The photo comes from Martyn Bane's webpage. You can see several other photos of the arrangement here:

http://www.martynbane.co.uk/modernsteam/klr/badger.htm

After comparing the photos again, I'm not so sure the 2-10-2 does have Marshall. The gear on the 0-6-4T drives the valve stem directly off of the linkage connected to the eccentric. The 2-10-2 appears to have some extra mechanism (mostly hidden by the valve gear frame) between this linkage and the linkage moving the valve stem.

Pat Fahey · **Posted:** Tue Feb 11, 2014 1:29 pm

Hi
My guess is Hackworth/Marshall valve gear ?

filmteknik · **Posted:** Tue Feb 11, 2014 1:46 pm

In the interest of completeness, someone posting on the TO thread looked up SAL 2495 in a diagram book which stated that it had Dekle valve gear.

Steve

wurlitzer153 · **Joined:** Mon Feb 10, 2014 11:27 pm **Posts:** 15

This thread finally got me to join and add my tiny little 2 cents.

In my opinion, it looks somewhat like the Marshall drawing posted by Kelly Anderson. It appears to me that the reversing lever rocks on the center pin, with the swinging links mounted to it on the right (pin just above the frame on right). I'm not sure which is the swinging link and which is the output (is it above or below the link). I think the swinging link is the top bar, and its at the extreme top of its travel, and the output is just below it. The link at lower right might either reverse the direction or expand the movement.

While we're on the topic of valve gears, its my understanding that Baker's first gear was based on the Marshall gear. He used this gear on the line of traction engines he produced. Only later did he separate the two components, in the interest of avoiding vertical wheel movement.

filmteknik wrote:

In the interest of completeness, someone posting on the TO thread looked up SAL 2495 in a diagram book which stated that it had Dekle valve gear.

Steve

The Dekle link posted on TO shows a gear very similar to Southern, with the output moved inside of the swinging links. See:
http://www.google.com/patents/US2416982