“Pluto” was still standing at the end of the far road, and the stores van is now parked again outside so extracting it will require some effort, but it will not be long. Andrew got the “big MIG” set up and proceeded to start welding various parts, notably the operating lever for the driver’s vac brake valve and the beginnings of the bracket that will support the exhauster. But before he went too far, he was anxious to test an alternative vac/air valve so went back to the LMSCA to borrow their vacuum test pump.
"Plug and Suck"
This kit has been mentioned before – a small electric motor and a vacuum pump connected to a hose that in due course grows into a fully-fledged 2″ vac line. In operation it bubbles away like a Hookah and smells like a 1950s Hoover. We were assured that a good, tight Mk1 carriage can be sucked to 21 inches of Mercury, but our tests a fortnight ago had shown that “Pluto” was anything but tight. The new air/vac valve though was more hopeful and got higher, though revealed another leak or two that had to be dealt with with assorted spanners and paint. By the time the steam loco crept into the shed entrance for coaling, we were tired and ready to call it a day.
A support strut appears...
Sunday: I said in the blog “Of time and screws” (aaagh! way back on February 20th) that hopefully in a few weeks time you would see the big space to the front right of “Pluto’s ” engine get gradually filled with exhauster. It has taken far longer than I expected, but then these things usually do when they are in your ’spare’ time. The bracket for this was not exactly “drawn”, as I had insufficient time/data/inclination to create a fully detailed drawing of all the paraphernalia that forms the front end of “Pluto” and its Foden FD6. Rather, in the tradition exemplified by “Scrapheap Challenge” (which we took part in 7 years ago) the bracket was trialled, ‘designed on the job in conference’ tacked up, tested, taken off and fully welded, trimmed, refitted and the next bit decided on. And when all is about right, taken off and painted! Even now, we are undecided whether to use proper vee belts, or, for speed, simplicity but possibly longer term issues, “NuTlink” again. I think the last may well win.
..and 'kerching' - behold the exhauster.
We were struggling to trial the exhauster in when my nice new mobile chirruped with a number that looked vaguely familiar. It was the Manager from Gwili. 14 901 had been put back into service unexpectedly (it wasn’t rostered) and having “cut-out” a couple of times (after which it had condescended to re-start) it had cut out again and wasn’t even prepared to crank. Andrew contemplated my doing a trip to Carmarthen, but then we remembered a similar incident a few weeks ago, recorded in this blog, where a battery terminal had come adrift. Such is the speed-up I had applied to the alternator that with a little revs on the loco will happily run off the alternator with no battery supply whatsoever, but coming downhill at idle is a different matter, and each cut-out had been on that return leg. A few minutes later a further call confirmed a loose terminal and all was now well. Quite why, after months of operation, the battery terminals should suddenly start becoming slack, is something of a mystery – do the sheep there carry spanners or are the batteries bumptiously bouncing around in their boxes on the Welsh rails?
Andrew decided on another vac test. The standard procedure for ‘fixing’ minor vac leaks at threaded joints is to paint around the join – the paint is drawn into the thread by the vacuum and once dried seals the joint, so yesterday’s visitation of red-oxide needed evaluation. This time the little pump got us to about 16 or so inches, and the function of the brake valve and vacuum release button could be seen and monitored. Given its small size compared to the chunky DMU exhauster we are gradually getting ready to install, we are reasonably certain that it is good enough. Meanwhile another redesign conference came up with an entirely different method of operating the driver’s brake valve from that originally envisaged, though by the time the kettle returned to shed it was only half made. But at least it feels like we’re on the home straight.
Footnote – from York comes the news that Drewry 72229 has performed the day faultlessly in passenger service with its “new” exhauster.