Last week's bracket, now with added stiffening
The bracket we had finished last week and taken home to get painted – well, didn’t, so was returned and reassembled, but first a number of stiffening pieces were added to ensure that any twist is kept to a minimum. Andrew had, however, had time to strip and reverse the exhauster so that its rotation is now that required by the engine, but in doing so the arrangement of the mounting lugs brought it even closer to the side of the casings and limits our options as regards its mountings and belt tensioning. The oil inlet must be sited above the centre line of the shaft, but mount the exhauster too low and we loose grip (”wrap-around”) on the crankshaft pulley. Similarly the oil level in the seperator must be 12″ lower than the exhauster, so the lower the exhauster sits, the lower the seperator must be – but the DVLR has no pit so the seperator must be mounted somewhere where it can be easily accessed to check or change the oil.
Anyway, while Andrew was welding and cutting and drilling, I got back to the cross-linkage that will drive the vacuum brake valve, finishing off the operating rods and with some minor tweaks, that is now complete and the valve operates from the two handles, but at a later date we will remove the elegant ball-ends and substsitute fixed bits which will support the cross shaft rather than allow it to droop.
That's "lap", now I wonder which way is "apply"?
Having both reached points at which we could go no further, we had decided it was time to do a static air test and sort out any leaks/malfunctions that would be revealed by NOT having a rather loud Foden FD6 drowning out any minor whistling noises. So we hooked up a line from the workshop compressor and proceeded to nip up various crane couplings and unions, new and old. I had forgotten how useful a flare nut spanner is. During this we cured leaks on 1st gear but were slightly disturbed to find that engaging 4th seemed to be pressurising the change-speed box in its entirety, though it seemed to stop as the loco air pressure rose. The change-speed box on a Planet is in reality the ‘guts’ of a Wilson SE4 mounted in a Planet-own casing, so is in principle the same as those in dmus or 03 and 04s (OK some of these are CA4s and CA5s but that’s merely a heavier duty version). The 1st to 3rd gears are simple band brakes and the pistons are reasonably easy to access, and on the genuine Wilson – like Drewry 72229 – the 4th gear diaphragm is mounted on the end. But thanks to the Navy specifying the Foden FD6 running at 1800 rather than Planet’s traditional 1200rpm Dormans, there is a 1.5:1 step down box bolted on in front, and 4th gear air line disappears into the barrel of this box. Now presumably we can disconnect the prop, disassemble the drop box and somehow gain access to the irritating diaphragm/piston rod – but that is a couple of weekends work when our main priority has to be to get the vac brake installation up and running. The transfer date to the DVLR has been set for the 25th and cannot be delayed, so “Pluto” may have to be limited to 3rd for a while until we can arrange to investigate further.