What is this locomotive component for?

[Rik ShawParticipant @rikshaw]

I only ever got as far as completing a 5" rolling SIMPLEX chassis many years ago so my general knowledge of steam loco workings is definitely not comprehensive by any means, so………………

……………. have just been watching this YouTube video in which a loco (I think it must be a foreigner) is puffing its stuff at Bressingham. At approximately 5 minutes and 12 seconds into the movie a closeup shows a device on the side of the engine similar to a finned motorcycle cylinder squirting irregular jets of steam.

What is it?

Rik

**LINK**

[Rik ShawParticipant @rikshaw]

[OuBallieParticipant @ouballie]

Weir type water pump Rick.

Seen it in action close up once.

Geoff – Er, nowt to say! Booger, I'm slipping.

[61962Participant @61962]

It's an air compressor for the brake. A water pump wouldn't need cooling fins. Water pumps were rare on locomotives, Giffard's injector saw to that after 1835.

Eddie

[DMBParticipant @dmb]

Does this mean that injectors used in full size are replaced (in whole or part) by that awful abomination of an axle-driven pump in the miniature sizes? All that friction of an eccentric shoving a fat pump ram along a close fitting pump barrel. At least Stroudley recognised the benefits of a ram of smaller diameter than the barrel. Friction only occurred where the ram rubbed the bore of the stuffing gland. No air locks and would pump water @ any temperature. I believe he also took a friction-less drive off the crosshead.

[OuBallieParticipant @ouballie]

Thanks Eddie for confirming my own suspicion that I may have been in error.

Was going to add '/vacuum' to my post, but for some reason didn't.

The intermittent action of the pump had me thinking vacuum.

Geoff – Ah well just confirms that grey matter not up to scratch right now.

[Author]

Posts