Prototype information for the modeler

Hello folks

My Great Model Railroads 2010 has just arrived and any one of us can't come away with at least one great idea to improve our own layout doesn't deserve to be called a model railroader (or railroad modeller, as some might say). Well done to all who made this edition and MRR for putting it all together.

 Anyhow, I digress. On the cover we see Dick Rotto's layout and a 2-10-4 climbing Raton Pass.

Can somebody please tell me what those two big, long pipes extending from the top of the cab forward are for. I've looked through my Steam Locomotives Cyclopedia. There I found a photo but no description. Nor can I generalize from my admittedly somewhat limited knowledge of steam locomotives to work it out (this is extremely embarassing, of course, for somebody born in Altoona with family members on both sides who worked for the PRR!).

Any help is greatly appreciated.

Warmest regards
Bill Rice-Johnston

Hi Bill,

Those two pipes take steam from the steam dome back to a manifold in the cab called a turret. The turret has several valves that control the admission of steam to various auxilliaries, both in the cab and elsewhere on the locomotive. These include such items as the air compressors, dynamo, feedwater pump, and injector. On most locomotives there's a pipe connecting to the turret more directly from the boiler steam space above the firebox, but on the large 2-10-4s, 4-6-4s, and 4-8-4s built in 1937 and later, the Santa Fe preferred to take steam for the auxilliaries from the steam dome.

Of course, we Santa Fe fans don't admit that there's anything "funny-looking" about those pipes at all.

And thanks for reading Great Model Railroads. I'm glad you liked it.
 

So long,

Andy
 

As Andy stated, the turret was basically a manifold where the steam appliances would draw "dry" steam. Usually there were several pipes that would rise inside the steam dome to draw this dry steam from the highest point on the boiler. Even the supply pipe to the whistle had a pipe that originated inside the steam dome. This pipe would not be seen from the outside of the boiler.

The turret, being located close to the cab, would be prone to getting waterlogged if the locomotive were running uphill or if it accelerated rapidly and the boiler water level was a bit high. Therefore the turret would draw the steam from the steam dome which was also located toward the center of the boiler.

I am not that familiar with the Santa-Fe practice on their 2-10-4s or why they piped the turret supply on the outside of the boiler.

Regards... Ed

Hello Andy

Thanks for the information.

This brings up a further question: were any locomotives designed to pipe superheated steam to the manifold or would this not have been cost effective?

Thanks in advance.

All the best
Bill

CAZEPHYR:

 

 

 

Texas Zephyr 

The extensions from the turret run back into the cab and the handles in the cab are painted red.   The two globe valves that shut off the manifold probably should be painted red, but I have no color pictures of a real SF locomotive to verify that paint.  I think you are probably correct, as least for the two that do not have extensions.   

Thanks 

CZ

Hi Bill,

It was relatively rare, but some locomotives did use superheated steam in the auxiliaries. One notable example was the original 2-8-4 Berkshire, the Lima A-1 demonstrator locomotive. In left-side photos of this locomotive you can see the large, insulated pipe running along the shoulder of the boiler from the superheater header in the smokebox to the turret just ahead of the cab. While there were advantages to using the hotter, drier steam from the superheater in auxilliaries, there were also disadvantages, such as the need for more expensive lubricating oil to withstand higher operating temperatures. For this and other reasons, the use of superheated steam for locomotive auxilliaries wasn't widely adopted.

So long,

Andy