Please identify mystery linkage on this 0-6-0

[mmagliaro]

Here's another request to identify a part on my project 0-6-0.

Note the long linkage that runs from under the cab all the way to the front, and then connects to a downward
lever.  It is indicated by the red lines in the first photo.



The second photo is a close-up of the front showing that that lever connects to.  But I cannot quite make out what it really connects to.  At first, I thought it might be some sort of connection to the uncoupling lever so the engineer could uncouple the front without getting out of the cab or having another crew member run down there to pull the lever.  But it doesn't look like it hooks to anything near the coupler.  It looks like it might somehow connect to rods that connect to something under the cylinder.  But what would that be for?

Anybody know what this linkage is?

Thanks.

[Chris333]

I forget the name of it, but they help getting the locomotive moving from a full stop. Especially if they are at a dead spot in the action.

The linkage goes to those 2 valves under the cylinders with a link over to the brakeman side and the 2 valves over there as well.

[mmagliaro]

I forget the name of it, but they help getting the locomotive moving from a full stop. Especially if they are at a dead spot in the action.

Wow... that was quick!
Does it connect to a lever under the cylinder?  It looks like that.
Does it somehow move the piston a little bit, or open a relief valve under there?  There are two bolt-head looking things under there that could be valves of some sort.

[Chris333]

Yes. If you look at a shay engine there is a rod that connects all 3 cylinders to linkages to all 6 valves.  More when I  get home.

[Chris333]

Errrr you know what. I think they are cylinder drain cocks.

[mmagliaro]

So the lever opens them to let residual water and steam out?  Maybe that's the secret.
If the cylinder is stuck under pressure, perhaps it can't move, so opening those drain cocks relieves the pressure.
Once it slides and gets through the first few cycles, the drains could be closed again.

[peteski]

Errrr you know what. I think they are cylinder drain cocks.

I also believe that those are the drain cocks.   Heh-heh-heh, I said "cocks"! 

When the loco starts you often see a cloud of steam coming from the cylinder area - that is caused by the drain cocks being opened.

https://www.trainorders.com/discussion/read.php?10,3577238

[delamaize]

Looks like Linkage to the Cylinder Drain cocks to me...

[altohorn25]

They're the linkage to open/shut the cylinder cocks.

[mmagliaro]

Okay, so we've established what the linkage is connected to.
It looks like there is a lever attached to each drain cock, and the ends of those levers are tied to a single
lever, which is connected to that control linkage.  So by moving the linkage, both drain cocks rotate and open.

Is that right?

How come there is no similar linkage on the other side of the engine?

[chessie system fan]

You can see the shadow of what seems to be an identical linkage underneath the cylinder on the other side.

                                                                                                                                                                                                                         |^
And maybe the shadow of a rod right --------------------------------------------------------------------------------------------------------here--|

in the corresponding other location means in goes behind the other cylinder?

Just a wild guess here.

[Chris333]

In your photo right about at the pilot beam there is a pivot. That pivot is a bar that goes over to the other side. On the other side the lever goes from the pivot bar down just like this side, but with no long lever sticking up. Moving the bar from the cab operates all 4 valves at the same time.

A Grandt Line On3 and On30 Porter kits contain all of these parts. I'll dig up the instructions when I get home.

Rod from the cab could be round or flat. Levers up front would be flat bar. Lever from the front to rear valve is flat bar.

I could draw a pic of all this if I was at home 

Like I said look at a Shay because all of this is right in your face on them.

[Doug G.]

Aren't the drain cocks there to get rid of condensate from the cylinders which could be damaged by liquid being in them with the pistons being in the compression stroke since liquid is pretty much incompressible? The engineer operates them before moving the locomotive after it has sat for awhile.

Doug

[Chris333]

Don't know the why, but I know what they look like

[alhoop]

Aren't the drain cocks there to get rid of condensate from the cylinders which could be damaged by liquid being in them with the pistons being in the compression stroke since liquid is pretty much incompressible? The engineer operates them before moving the locomotive after it has sat for awhile.

Doug

Correct!

From "Tales from the Krug":
'Another important steam engine control is the valve that controls the opening and closing of the cylinder cocks. It is located near the boiler backhead just to the left and in front of the engineer. Steam may condense in the cylinders while you are stopped. If you don't blow it out before moving the locomotive the water will cause a hydraulic lock in the cylinders and possibly force off a cylinder head or cause other major damage. So before moving a steam loco the engineer always opens the cylinder cocks to give the condensate an escape route other than a pried off cylinder head. This is much the same thing as opening cylinder cocks on a diesel engine and barring it over to expel water before starting the engine. But on a steam engine you need to do it every time you move the locomotive so there is a "remote control" for the cylinder cocks.
Al'