steam dome question

[bendorsey]

I know what a steam dome is and what it does but why would a loco have two? I've seen a photo and plans for a real engine with what appears to be two steam domes. The rear one has the usual pop-off valves, etc. The front one nothing. Its not an over sized sand dome as there is one of those in between the two steam domes. This on an old 3 foot gauge 2-6-0. Any ideas gents?

Thanks,

Ben

 

[Stationbeem]

Could this link be of any use Ben.

http://indianarailroads.org/board/index.php?topic=8786.0

 

[bendorsey]

interesting. Looking at the diagram on page 6 of the MR (steam) cyclopedia shows the throttle was in the steam dome. That makes sense since you would want it as high as possible so as not to accidently get some (totally incompressible) water in the cylinders. Probably blow the front or rear off if that happened (cylinder cocks anyone, lol). The loco I was looking at was circa 1870's so I guess two steam domes was an idea that didn't really pan out.

Answered my question though - It was prototypical.

Thanks,

Ben