sand domes

[macmodels]

need some information on how the sand dome is constructed. Does the sand go directly on the boiler shell, or doed the sand dome have a floor to keep the sand dome off the boiler shell? Also what kind of valves are used to regulate the sand flow? This is for a freelance 440 american. Any information would be appreciated

[Dan Rowe]

The Lima sand domes have a base casting that has the mechanical valve in it. This valve is operated by a rod extending into the cab where the engineer can reach it.

When the engineer pulls the rod the valve slides and opens a hole to let the sand fall into the sand pipe.

There were also air operated valves that were mounted on the sand pipe. In this case the mechanical valve and rigging would be removed and the air solenoid controls the flow of dry sand.
Dan

[GoldenSpike53]

Are you actually planning to have a working sand dome on your locomotive? What is the scale you are building?

In all the models I have seen at our club track and elsewhere, I have never seen anyone with an operable sand dome. Full scale equipment, yes, but not on models. Hence the question, what scale are you working with?

Dale

[Harlock]

I've seen a few working sanders in 2 1/2" scale...heh. And sometimes they actually get used!

--Mike

[BruceMowbray]

Of all of the prototype sand domes I have seen, they all have a floor so that the sand is contained in the dome itself. The radiant heat from the boiler does a pretty good job at keeping the sand dry. The valves are either a gate type that lets sand flow by gravity to the sand pipes and eventually to the rail head. There are also air operated valves which are operated from a valve in the cab and the air also assists the sand to flow through the sand pipes. The amount of sand that is blown onto the tracks is quite small. When the sanders are on and they are adjusted properly, it is difficult to see the sand coming out of the sand pipes unless the engine is sitting still You can then see the sand grains falling off of the rail head.

I'm not sure how well non scale sand will work in a scale sander. The sander pipes on full size engines are 1 1/2" diameter. In 1 1/2" scale, that's only 3/16". It wouldn't take much to get those tiny pipes clogged.

Bruce Mowbray
Springville, PA
www.geocities.com/trainhead391/