Photo showing the reservoirs atop the tender of this Battle of Britain 4-6-2. I believe the compressor is behind doors at the rear of the tender. Does the engine itself still use vacuum brakes or it it all air braked?
The UK list shows this locomotive presently out of service again.

http://abpr.railfan.net/abprphoto.cgi?a ... -12-23.jpg

I would point out--having built two models of Battle of Britain locos--that the air reservoirs are as-built vacuum-brake reservoirs. Now, that tender has been modified into something not matching any of the Merchant Navy and BB photos I have handy, and it also appears that Merchant Navy tenders had three tanks, whereas BB tenders had four tanks, just as this one has. Swanage, I believe, ran with traditional vacuum braked equipment, so without looking at the hoses or finding a specific roster listing indicating conversion to air braking, don't assume air brake conversion just because of those tanks...........

*#%&)+#@ it, Bob, stop it--you're turning me into one of those damned rivet-counting modelers!

The tender looks like the original BB/WC tender but the sides were later removed (I think this was complete by 1960) so most photographs show the later profile. There were, from memory, several variations of the Bullied tenders but I'm not enough of a rivet counter to be able to begin to explain how to tell the difference. When I saw them in service they were usually doing 60-80 mph and needed cleaning - though 34051 "Winston Churchill" on the funeral train was very clean (memories of a grey day at Virginia Water surrounded by seemingly hundreds of silent people).

I don't think "257 Squadron" ever got air brakes though "Manston" does have them. It looks like a Bullied coach behind the loco and I'm certain there are no air braked examples in preservation.

As Benny Hill used to say "when you assume....". Apparently it was the Manston that got the air brakes, not this one. I don't think I'd ever seen a Bullied Pacific from this vantage point before.

I was lucky enough to fire 34105 "Swanage" years ago (c1987)...

The SR "Lord Nelson" also has these reservior tanks mounted on top of the tender and it seems to be a more or less standard installation on SR road locomotives. My question is what was the operational quirk on the SR that the mechanical department saw a need for the extra vacuum reserves? I don't remember seeing any comparable installations on LMS,GWR or LNER engines?

I was thinking along the lines of maybe it was a similar idea the same as the CNJ ten wheelers with the tender mounted auxilary oversize turbo-generator to charge the coach batteries because of the stop and go pattern of the commuter trains, but for braking purposes (?).

As far as I recall most SR tender locomotives had these reservoirs - I don't know about the tank engines. Some (maybe all) GWR locos had them but they were hidden away, I think LNER "Green Arrow" has them on the rear tender deck (wish I'd taken more interest when I fired/drove it) - large LNER locos are vacuum braked. Don't know about the LMS....