Advice please - N7 brakes

[chaz harrison]

I am aware that N7 tank locos had both Westinghouse and vacuum brakes. When the locos were pulling a vacuum -braked or loose coupled train would the air pump still operate? I have a 7mm model of an N7 with a DCC sound decoder in it. The sound project has the sound of a brake pump but as the loco will only be used on goods trains it might be necessary to disable the pump sounds if they are not appropriate.

If anyone knows I would be grateful for a reply.

[earlswood nob]

Evenin' all
I think the loco brakes were Westinghouse, so the pump would have to run all the time.
Earlswood nob

[1H was 2E]

Just to add a little to Earlswood Nob; my only clear recollection of a Westinghouse loco was an L1 on the Woodford-Banbury one coach shuttle. I recall that the pump would be running even when the loco was standing in the platform, but after running for a few minutes with the loco stationary there was a noise - a load 'fizz' or 'pop' (perhaps a valve closing) and silence. Possibly their was an air tank or reservoir, and when this was fully charged the pump would not be needed. Once again, the more you think about it, the more questions there are; was there any air braked stock about then? - the coach was a Thompson BS or BC.
Don't forget the pump noise was 2 'beats' then a silence equal in length.

[65447]

First question is which locomotive during which period? Although the original GE design was Westinghouse brake only, the Beardmore-built locomotives were originally steam braked with vacuum ejector for the train brakes, while the remaining LNER construction was Westinghouse for the locomotive brake and vacuum ejector for the train brakes. And then there were subsequent modifications, and finally in their later years, following complaints from those living near stations, silencers were fitted to some of the class.

So I'll try and help some more if you could provide the running number/period of your model.

As to operation, there was an air reservoir for the Westinghouse brakes and the pump operated whenever it was necessary to replenish or maintain the air at the operating pressure. This is no different to the modern air-braked stock where you will hear the compressor operating, usually after a station stop when waiting at the platform or following a signal check.

The sound of the pump is well-recalled, even after 50+ years, from spending time on the public road that ran past Enfield Town shed and traveling frequently to Liverpool Street by Quint-Art and lurking around the west side and main line platforms.

It is 'tshhhhh-ta', accompanied by the usual wheezing and hissing of steam in pipes and escaping from joints - - - pass me a hankie...

[Tom 480F]

When working on N7's in the 50's...when pulling a vacuum braked train we would turn off the donkey pump,
When pulling a loose coupled or air braked train we need the donkey pump on.

[kudu]

I just wanted to add that the sound of all those Westinghouse pumps going was what made the Liverpool Street concourse unmistakeable even if you were blindfolded. An indelible memory from the late 50s/early 60s.

Kudu

[RayS]

Liverpool Street - steam wreathing up to the roof, Westinghouse pumps, hot oil, coal smoke.... Oh bliss long gone!

Ray S

[bricam5]

The frequency of the pump operating when standing would depend, to a large extent, on the age of the engine. I recall when we got two L1's at Botanic Gardens 7719 & 7721 both in new condition and Westinghouse braked, the pump was not used for lomg periods as everything was tight(ish). The old class R ( D20 ) on the other hand, the pump never seemed to stop.

[chaz harrison]

Thanks for those replies - helpful stuff. I note the need to have the air pump working when working loose coupled freights. That's what I needed to know.

[chaz harrison]

First question is which locomotive during which period? Although the original GE design was Westinghouse brake only, the Beardmore-built locomotives were originally steam braked with vacuum ejector for the train brakes, while the remaining LNER construction was Westinghouse for the locomotive brake and vacuum ejector for the train brakes. And then there were subsequent modifications, and finally in their later years, following complaints from those living near stations, silencers were fitted to some of the class.

So I'll try and help some more if you could provide the running number/period of your model.

As to operation, there was an air reservoir for the Westinghouse brakes and the pump operated whenever it was necessary to replenish or maintain the air at the operating pressure. This is no different to the modern air-braked stock where you will hear the compressor operating, usually after a station stop when waiting at the platform or following a signal check.

The sound of the pump is well-recalled, even after 50+ years, from spending time on the public road that ran past Enfield Town shed and traveling frequently to Liverpool Street by Quint-Art and lurking around the west side and main line platforms.

It is 'tshhhhh-ta', accompanied by the usual wheezing and hissing of steam in pipes and escaping from joints - - - pass me a hankie...

My model is of 69727 (2625) - an N7/3 built at Doncaster - as running in the late fifties. "Westinghouse for the locomotive brake" suggests to me that the pump would be heard if the loco were on an unfitted freight, yes?

[65447]

Yes, or whilst attached to any of the coaching stock still fitted with Westinghouse brakes, viz. the Hertford Quads and the Quin-Arts. The latter lasted until 1960 in regular service, and until the Enfield and Chingford electrification problems were sorted.

[chaz harrison]

Yes, or whilst attached to any of the coaching stock still fitted with Westinghouse brakes, viz. the Hertford Quads and the Quin-Arts. The latter lasted until 1960 in regular service, and until the Enfield and Chingford electrification problems were sorted.

Thanks for that. My exhibition layout "Dock Green" is goods only (it's a small yard) and the story is that my N7 is on a running in turn and turns up on an unfitted freight. Dock Green will be at Warley at the end of the month, so you could get to see (and hear it) there.