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Gresley A3 pacifics in the LNER

Posted: Mon Jun 10, 2019 7:51 pm
by neildimmer
I have added a collection of photos of Gresleys A3 Pacifics either as built or converted from A1 in the LNER era

46 Diamond Jubilee Potters Bar 26th March 1948
https://railway-photography.smugmug.com ... /i-kcmsNCQ
39 Sandwich Grantham Shed 2nd May 1947 Gresley A3
https://railway-photography.smugmug.com ... /i-WXPw8fb
2504 Sandwich unknown location
https://railway-photography.smugmug.com ... /i-rgGDj25
2578 Bayardo Doncaster September 1932
https://railway-photography.smugmug.com ... /i-St5Tw4k
2598 Blenheim unknown location
https://railway-photography.smugmug.com ... /i-DLCntQv
2746 Fairway unknown location
https://railway-photography.smugmug.com ... /i-7p644j2
2746 Fairway with corridor tender unknown location
https://railway-photography.smugmug.com ... /i-JCRRz2f
2797 Gainsborough unknown location
https://railway-photography.smugmug.com ... /i-XrpQNHx
4480 Enterprise works photo
https://railway-photography.smugmug.com ... /i-TS44FXB
39 Sandwich Grantham Shed 2nd May 1947 Gresley A3
https://railway-photography.smugmug.com ... /i-WXPw8fb

Neil

Re: Gresley A3 pacifics in the LNER

Posted: Tue Jun 11, 2019 1:55 am
by kimballthurlow
Thanks for the photos, they are very evocative.

Sorry, I am not sure if this is the right place to ask this question.
I am unable to figure a technical point about the long tube on the boiler from cab to smokebox, under the handrail.
Both these examples are post fitting of the enlarged superheater headers.
Example 2746 Fairway has the tube on the LHS of the boiler.
Example 2578 Bayardo has the tube on the RHS of the boiler.
Is this something to do with LHS v RHS drive differences?
And what does the tube actually do?

I am unable to find an explanation either on the forum, or in my books.

Kimball

Re: Gresley A3 pacifics in the LNER

Posted: Tue Jun 11, 2019 11:23 am
by Hatfield Shed
Vacuum brake ejector pipe. It's on the side the driver is positioned, as it connects to the 'plumbing' of the brake valve which is very necessarily under the driver's hand.

Re: Gresley A3 pacifics in the LNER

Posted: Tue Jun 11, 2019 8:09 pm
by JASd17
I can understand kimballthurlow's trouble with this query.

The major sources simply do not say the ejector pipe was on the left or the right, depending on the driver's position. A case of steam engineers not thinking it worthy of comment, because it is obvious?

I have known for years that the pipe denoted which side the driver was on, a great help in sorting Eric Treacy negative dates taken in the 1950s, but not really understood what the pipe was for.

I am no longer ignorant on this point, at least.

John

Re: Gresley A3 pacifics in the LNER

Posted: Wed Jun 12, 2019 2:34 am
by kimballthurlow
Hi Hatfield Shed and John,
Thank you so much for you explanations, that is just what I wanted.
I note many of the Gresley-era engines were equipped with the same appurtenance (including the A4, B17 ...).
In fact while reading up on how a locomotive works, it got me thinking of how the vacuum created in the smokebox could be put to use.
I did not think of the vacuum braking system used in the UK.
So now I know.

Again, your answers are very much appreciated.

Kimball Thurlow