Gresley A1/3 cut-off indicator gauge plate mounting

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greenglade
GCR O4 2-8-0 'ROD'
Posts: 525
Joined: Thu Feb 23, 2012 1:59 pm

Gresley A1/3 cut-off indicator gauge plate mounting

Post by greenglade »

Good evening all

Can anyone please help me understand how the brass reverser indicator plate was mounted to the backhead? I recollect reading that it was fixed to a wooden board, but I can't recall where I read this. Logic would suggest that the info is in RCTS 2A, but so far, I have failed to find it.
Any info on this subject would be most welcome...TIA

Pete
Hatfield Shed
LNER A4 4-6-2 'Streak'
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Joined: Fri Dec 23, 2011 3:34 pm

Re: Gresley A1/3 cut-off indicator gauge plate mounting

Post by Hatfield Shed »

Not the complete answer: not the right class, indirect evidence, long post original construction date; but I knew I had a somewhat pertinent photo 'somewhere'.

So, the NRM 'Gresley and Stanier' publication, has a picture of Mallard's backhead in preservation. The cut off indicator plate is clearly attached to its support by slotted screw heads. That suggests to me woodscrews, and thus a wooden block will lie behind it. (Annoyingly, in the same book there is a materials specification for the V2, but not a word on how the cut off indicator is to be fitted on the backhead. Quite likely this was well known 'custom and practise' technique and thus went undocumented, as with so much else in long established manufacturing industry. Wouldn't you like it to read 'block of best Honduras mahogany, two coats of clear lacquer?')
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greenglade
GCR O4 2-8-0 'ROD'
Posts: 525
Joined: Thu Feb 23, 2012 1:59 pm

Re: Gresley A1/3 cut-off indicator gauge plate mounting

Post by greenglade »

I hear your logic regarding the screws but do remember there was no Pozi back then, also for example, the running board screws are all slotted machine screws, so it could be steel or wood. Yes, wouldn't it be nice to have such a description for all parts and in mahogany too, I would be in dreamland, but then again, I'd never get my model finished..:) I have found that the A4 mount is different to the A3 Flying Scotsman of today and that, that is different again from an original A1. I did take a lot of photos of 60103 when in York in 2016, I wish I had taken measurements of parts too..

This image gives an idea of the shape of the mount as of today, an unusual shape for sure, period pictures of A1's of the day do not show shape. The A4 is much more straightforward to see and thus fabricate as in photos of Mallard it's pretty easy to see what's what.
indicator mount closeup 2.jpg
Thanks for the reply, I'm still searching and haven't given up yet but may have to settle for the A4 type as that's the more likely, FS today has far too many modern add-ons in place.

Kind regards

Pete
Hatfield Shed
LNER A4 4-6-2 'Streak'
Posts: 1728
Joined: Fri Dec 23, 2011 3:34 pm

Re: Gresley A1/3 cut-off indicator gauge plate mounting

Post by Hatfield Shed »

Most interesting, thanks for expanding on the topic.
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