Slightly OT : Steam trains

Smoke deflectors.

Tom

Smoke deflectors. They channelled air up past the stack/chimney, which lifted the smoke above the locomotive.

Steve R.

On the (OT) subject of steam trains (=locomotives) , can NE1 explain the function of the wooden indicator boards fitted to the front of steam locomotives under test? I assumed that they were all to similar dimensions so eliminating comparative drag factors in the efficiency calculations but this would ignore the large and variable area of smoke box, chimney etc which protrouded above the boards.

In message , IFC writes

Nothing to do with drag. It was a protective housing for an engine indicator and, I think, someone to operate it.

An indicator is a mechanical device which produces graphs of cylinder pressure against piston position. The resulting 'indicator diagrams' can be used to measure performance and evaluate valve gear and breathing.

Thanks for that posting, I appreciate the information.