Pikkies of the brake arrangement of a Mk.1 BG at the NRM. First the background... quoted from the Mk.1 Resources topic on this forum:-
Parked out back at the NRM last week (Easter 2013) was a Mk.1 BG, painted in mock LNWR livery and named "Valiant"... no number visible. What was surprising about this carriage was that the underframe was carried on Commonwealth bogies whilst the vacuum cylinder was supported in symmetric V-hangers with the brake pull rod going under rather than over, the bogie headstock / axles. This arrangement of brake gear is not meant to happen... and I cannot work out how the brake pull rod connects to the equalising fulcrums of the Commonwealth bogie.
The number was 81025, or 84025, or even 99782.
The BG was built by Cravens, see here:-
What is unusual about this BG is that the brake arrangement is no longer conformant with what might be expected given the style and placement of the vacuum cylinder / V-hanger. Information from Bob-Reid is that the carriage was built with BR Standard bogies and that those bogies were retained throughout the revenue service... so the change to Commonwealth bogies is likely to have happened after withdrawal.
Commonwealth bogies were built with equalised brake gear and hence the brake pull rod
ought to be above the bogie headstock... and above the brake cross-shaft... with an asymmetric V-hanger and vacuum cylinder outside of the cross-shaft / hanger. Not so here... the V-hanger and vacuum cylinder arrangement is that of a vehicle built with non-equalised BR Standard bogies.
Peering under the CW bogie reveals this:-
whilst looking over the CW bogie headstock shows:-
Other interesting aspects of this vehicle:-
For comparison, here are some photos of the topside of CW bogies with the equalised brakegear... pullrod from brake cross-shaft over the headstock with two fulcrum levers per axle.
regards, Graham