On some steam locomotives, what are the purpose of the vertical plates which stick out either side from the front of the boiler, a bit like cheeks? Example picture.
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They provide a vertical updraft to lift the smoke higher. Keeps the passengers happy and soot-free. Lots of names for them, but most common non-slang term is ‘smoke deflector’.
ETA: North American rail terminology. Your Mileage Will Vary across the pond.
Good question!
Here’s another photo.
A couple of years ago I became very interested in steam locomotives and studied in depth the Walschaert valve gear and others. This very question ocurred to me and I never found the answer which, now, seems obvious.
huh, I learned something today. I guess I can go home.
Smoke deflectors is correct.
Over here, most steam train enthusiasts will remember them as ‘blinkers’.
Common slang over here is ‘elephant ears’.
People call them smoke lifters, but they’re not intended to lift smoke. Just a plain vertical plate – why would it lift anything?
When the smoke comes out of the engine’s stack, it’s high enough. As long as it stays up there , everything’s fine. But locomotive boilers are roughly cylindrical, with a flat front. That flat front rushing down the track pushes air aside, which likely causes low-pressure areas alongside the front of the boiler. Which the smoke likes to drop into.
The vertical plates extend forward, past the front end of the boiler, to grab that just-hit-the-boilerfront air and redirect it along the side of the boiler, eliminating the low-pressure areas.