Pumps or Injectors?

What seems to be commonly used on narrow gauge steam locomotives, feedwater pumps or injectors?

 

I think every Narrow Gauge loco I have worked on has injectors, can't think of a single one which has a water pump? (Probably a dozen or so locos)

Many have an air pump for the braking system, but not a feed water pump. GELERT for instance has a converted weir water feed pump in use as a air compressor.

 

Pumps were sometimes used in very hot countries. Injectors can only inject cold water into the boiler; in some parts of the world, the sun would be fierce enough to heat the water while it was still in the side-tanks, thus rendering an injector useless.

For example, the Welshpool & Llanfair's Joan used two feed pumps during her working life in Antigua, and retained one of them during her early years in preservation. It is visible on the front of the engine in these photographs

https://www.flickr.com/photos/celestialtoymaker/2892372960
https://www.flickr.com/photos/73789322@N04/11102595333/in/photostream/


Presumably, the two locos recently imported from Antigua by FMB Engineering will also retain this feature.

 

Bredgar's loco Siam has a water pump if I recall correctly. Perhaps backing up the reasons given above, as she was from a hot country too originally.

Certainly that is the only one I have enjoyed the company of over the years.

I don't believe it was popular with UK narrow gauge on the whole and I have not found any with pumps that I can think of in South Africa on my visits there either.

 

A lot of the US built locos that operated in Cuba and elsewhere were fitted with crosshead driven feedwater pumps, and many of the locos continued to use these right up to withdrawal. They were also fitted with injectors of course as a crosshead driven pump isn't going to be much use when you are stationary!
I've seen steam driven water pumps in use on a few overseas locos (SG and NG) and the common factor semed to be a marked reluctance to function without much fiddling by the crew or the application of a few carefully aimed blows with a blunt instrument.

It is of course a well known fact that the level of co-operation displayed by an injector is inversly proportional to the level of urgency that water needs to be injected into the boiler and feed pumps seemed to demonstrate similar traits.

Chris

 

All the metre gauge 2-10-2t's on the Harz system have smokebox mounted feed pumps in association with feedwater heaters which are located across the top of the smokebox. A lot of early American N.G. locos. such as 'Glenbrook' at the Nevada State RR museum had cross-head driven feed pumps. Closer to home didn't some KS 'Wrens' also have them? Injectors need clean, cold water and regular maintenance whereas a mechanical feed pump is nigh on indestructible and a boon in,shall we say, primitive conditions! Ray.

 

I know that the Kerr Stuart Wren locomotives were built with one feedwater pump and one feedwater injector. I can see how a pump would be useful for hot climates, and possibly as a backup (at least under "normal" conditions). Don't narrow gauge steam locomotives normally have one or two feedwater injectors? I don't think I've heard of a steam locomotive with three, or four feedwater injectors (at least not narrow gauge).

 

Our Bagnall 0-4-0ST 'Peter' at Amberley has a pump and an injector. I believe the pump was added when Bagnalls were rebuilding it for the Cliffe Hill quarry as it appears to have been a preference of theirs. Not sure whether Isobel at Amerton (built new for Cliffe Hill) has the same arrangement. Peter's pump is operated by a ram connected to the motion.

 

Yes - Isabel has both pump ( on the left hand side) and injector.

Chris Dobbs
Amerton Railway

 

And see the cover photo of August's "Narrow Gauge World" for a splendid shot of Isabel with the cross head driven pump clearly on view.