Steam Loco Cab Fittings

[John Bateson]

Curiousity has got the better of me yet again. My current work centers around the inside of a GCR cab.
Trying to decipher the morass of pipes and stuff, I am stuck on deciding what each of the gauges are used for.
This is a view from the rear (fairly sure about this but it always confuses me) and from left to right I think they are

Carriage Heating
Vacuum
Steam Pressure
Steam Brake

007 Class 9P 10411 Part 2 Cab Gauges.png

Can any member with better knowledge of the gubbins please advise.

I am pretty sure that somewhere in modelling land there has been a cast version of the Intensifore Lubricator - seen each side just under the gauges. Mr. Google has not been able to help.

John

[John Palmer]

Can't help much with this as Great Central engines are a subject about which I know very little. I had hoped that the profile of the various 'Director' variants that appeared in 'Model Railways' for May 1974 might shed some light but unfortunately it does not.

What did strike me was the absence of any obvious pipe connection to the righthand-most fitting. Presumably it's not a 'porthole' window, but is it in fact a gauge?

The most common gauge arrangement used to be a boiler pressure gauge plus vacuum brake gauge and carriage steam heat pressure gauge on such locomotives as were fitted with such accessories. On locomotives equipped for dual working you would also expect to find a brake pressure gauge for the air brake, so leading to a 4-gauge presentation; were any GCR locomotives so equipped?

I don't recall having previously encountered a steam brake pressure gauge, and can't see a good reason to have one if the steam brake is powered by steam drawn off the manifold at boiler pressure, for which a gauge will already be available. Apart from a steam brake gauge your suggested order of the gauges visible looks feasible enough, though you might expect the vacuum gauge to be positioned closer to the driver on the right hand side.

Only other suggestion occuring to me as regards a fourth gauge is that it displayed steam chest pressure as distinct from boiler pressure, an arrangement subsequently to be found on BR 'Standards' - was the GC a precursor for such an arrangement?

[Dave Holt]

John.
Sadly, I have no particular knowledge about the gauges on GCR locos (despite starting a C13 model). It would help to try and work out what the various gauges do if we could see the rest of the back head to see where the small gauge pipes connect to large piping.
Dave.

[Sapper]

John
I noticed your query regarding the cab fittings in a GC loco and your problems identifying gauges etc. I do not know if this would help but I attach a picture of an 'Improved Director' scanned from W A Tuplin's Great Central Steam which may be useful.

Good luck with your build anyway.

Regards

Sapper

Director cab.jpg

[Dave Holt]

John.
Looking at the GCR drawing for the C13 (9k?) tank loco, it shows three cab gauges. From the pipe runs, I believe them to be, from the right hand end:- vacuum gauge, boiler pressure gauge and (the small one at the LH) steam pressure in the lubricator system.
Your original Director photo shows an additional gauge, second from left, which might be the steam heating pressure.
Hope that helps.
Dave.

[John Bateson]

Thanks for the responses. As always, I more more questions than answers (we know a song about that?).
The D11 picture and notes show some interesting bits that are close to the 9P/B3 on which I am struggling, so I will make use of those comparisons, particularly the inside of the sliding windows.
The Intensifore lubricators also seem to be on the left side only (wish I could source a casting of the ones I need). Also the water feeds are side by side, in some engines (8f/B4 etc)they seem to be one in front of the other (see the NRM model) and the GAs.
I have attached the full drawing of the 9P/B3 cab as requested.

007 Class 9P 10411 Part 2 Cab.png

Again, as far as I can make out the fourth (RHS) gauge is attached to a pipe which fit into the smoke box on the RHS. The pipe from this leads to the vacuum brake situated just under the RH window. Both steam and vacuum brakes were fitted to these engines. The steam brake was under the cab and was connected to the smoke box by a large pipe which ran between the handrail and at the front where the boiler joins the smokebox, just below the ash ejector (short or long depending on the date).

I suspect the practical approach must be to solder the correct sizes to the inside of the can and just paint them white - otherwise it just gets more complicated and all but impractical to model.

Useful, if anybody is interested, and far too complicated for our usual needs are the the presentations from Dominic Wells at https://www.advanced-steam.org/wp-content/uploads/2017/06/Dominic-Wells-Brakes-presentation-Part-1-Vacuum-Brakes.pdf and http://www.railway-technical.com/trains/rolling-stock-index-l/train-equipment/brakes/vacuum-brakes.html

And quietly moving on ...
John

[davebradwell]

It isn't a pyrometer is it? They were all the rage in the early days of superheating to check the elephants weren't overheating but I've no idea what they would look like in the cab. They were removed pretty quickly.

I'm wondering why the steam brake would connect to the smokebox but my knowledge is based on 5" g and I can't find my Enginemen's handbook for better information. Certainly there would be an exhaust but would it be worth piping away?

DaveB

[Paul Willis]

It isn't a pyrometer is it? They were all the rage in the early days of superheating to check the elephants weren't overheating but I've no idea what they would look like in the cab. They were removed pretty quickly.

DaveB

I love the idea of having a control for the Prevention of Pyrotechnic Pachyderms

Best,
Paul

[Dave Holt]

John.
Having enlarged the cab drawing, I am certain the arrangement of the gauges is per as my previous response. The small pipe from the RH vacuum gauge connects to the brake ejector/drivers brake valve situated below the RH cab window. The large pipe along the boiler will be the exhaust steam/air discharge from the ejector. The steam brake valve is to the right and below the RH water feed valve. It is connected to the train vacuum pipe, just below the vacuum brake valve, and is actuated by the vacuum. There is also a manually operated handle (vertical) to enable independent use of the steam brake or when moving the loco without creating a vacuum. This valve has a steam supply and a steam feed to and exhaust from the brake cylinder under the cab. This exact operating arrangement is fitted to our rebuilt MN although, in our case, the vacuum ejector/brake valve and the steam brake valve are combined into a single unit.
The LH gauge must be something to do with the lubrication system.
As you say, in our models it hardly matters as the gauge markings can't be read inside the cab.
Dave.

[davebradwell]

Yes, sorry Dave, by zooming, the invisible pipe becomes obvious. The Ejector fitting is certainly something I recognise.

DaveB

[Neil Smith]

I love the idea of having a control for the Prevention of Pyrotechnic Pachyderms

If ever there was a post that showed there would be a use for buttons to give various reactions...

[grovenor-2685]

Or suggests it would be a good idea for contributors to turn off the automatic spelling correction.

[Will L]

Or suggests it would be a good idea for contributors to turn off the automatic spelling correction.

And deny us all those little moments of serendipity Kieth?

[Simon_S]

They turn up in some unexpected places

[Horsetan]

They turn up in some unexpected places...

These are not the ovoids you are looking for....