Towards the end of 2016, S&DSMEE was offered a 3 1/2" gauge LBSC Bantam Cock for use by the club for whatever purposes we saw fit. It was donated by Dave Spooner, a friend of our clubs librarian, Tony Ward, as he had been taken ill and wished for the loco to go to a home where it will be looked after and used. The club committee agreed to take it on, with Tony and myself taking responsibility for its renovation and operation, and soon afterwards this appeared in the raised track shed:  Beautiful as she was, she was not without her little foibles. The major issues we could identify after a bit of a poke around were as follows: - No boiler certification - Regulator would not move - Front left driving wheel was loose on its axle - Injector was not functional - Leaking left hand steam chest - Worn bushes on the motion - Water gauge drain would not seal - Shabby paintwork - Stuck grate After discussions, it was agreed that I would take it back to my workshop and start work on it, hoping to get it in steam for the next running season! The biggest obstacle was going to be the boiler. To run on a public track, the boiler needed both a hydraulic test certificate and a steam test certificate. As there was no previous certificate, it effectively had to be treated as a new boiler and have a full inspection from the boiler tester. This meant removing the boiler from the frames, which is no small task on such a small engine! Eventually though, after a lot of swearing, a few shorn bolts and some gentle persuasion, I extracted it:  When I had removed it, the first big problem I noticed was that a handrail stanchion on the left hand side had been screwed directly into the boiler...meaning that if that was knocked while the engine was in steam, that would result in a rather unfortunate hole directly into the boiler! This is not the sort of thing boiler inspectors like to see (I did make sure to consult with ours about all this), so with the able assistance of Steve Addy we made a bronze screw to fill the hole, and silver soldered it in place using an oxyacetylene torch and some Heat-Stop putty (to prevent the other joints from being disturbed):   Newly-sealed boiler in hand, I then tackled the regulator valve. It was the screw-in type, with the valve itself located halfway along the boiler below the steam dome. When I managed to extract it, it turned out it had managed to seize its thread up, and was no longer turning. A bit of judicious heat from a blowtorch managed to free it up, and I was able to screw it closed. However, it refused to seal, due to the pointed face of the spindle being pitted with age. To tackle this, I decided to machine away the point and replace it with a pad of PTFE. This would ensure a nice seal every time, with the additional benefit of not binding up when the hot engine cooled down after use:  With the regulator repaired and reinserted, I made a set of blanking plugs to seal the boiler up, and filled it to the brim with water. I then used a testing rig borrowed from Ron Cook at the club to do a preliminary hydraulic test up to twice working pressure, which the boiler handled with ease. That was certainly a relief, as from my point of view the boiler is the scariest part to get wrong... At the next opportunity, our boiler inspector Rob Stephens brought his official, calibrated test rig to the track, and between us we performed the test again, and she passed! Armed with a hydraulic certificate for this most essential bit of the engine, I felt happy to move on to the motion work and assorted other jobs. First amongst these was the loose wheel, as a loose wheel would do nothing for the engines performance. I dropped the offending wheels out of the frames, and removed the loose wheel. After a bit of a clean, I could see that the round key that was meant to stop the wheel rotating had been compressed and distorted, presumably due to excessive force and slippage at some point. A bit of persuasion removed the old key and I turned up a fresh, tightly-fitting one on the lathe. I refitted the the wheel using Loctite 638 and the new key (ensuring the wheels were correctly quartered still!), and popped the whole thing back into the frames. I then reattached the coupling rods, to make sure everything still turned freely and to my great relief, all was well.  The next few workshop sessions were spent on all the odd little jobs that were easily accessible with the boiler removed. This included stripping and cleaning the injector in distilled vinegar (a nice mild acid that dissolves limescale and muck without damaging the delicate cones), replacing the piston ring on the steam brake cylinder, cleaning and reseating countless clack valves, rebushing motion work, remaking knackered pipework, cleaning years of muck out of the frames and motion etc. Much of this work would be nigh impossible to do with the boiler in place, so this seemed the perfect opportunity! When I was satisfied that all the structural bits had been done, I set about the slightly awful task of stripping and repainting. As the paint on the frames was in good condition, I opted to leave that as is (albeit much cleaner). The smokebox, running boards, boiler cladding and cab, however, were in a sorry state and would need some love. Tony, our librarian and my colleague on this enterprise, used his powers of research to turn up a small tin of the correct shade of enamel paint for this engine (LNER Doncaster Green, in case you were wondering) and I stripped all the parts and, after a coat of etch primer, started to repaint with a 50% mix of paint and thinners. This way, you can use a brush and with a bit of care still get a clean, fairly smooth finish:   It isn't too bad, as long as you don't look too closely! After reassembly, she looked like this:  Not bad! The next step was to take her down to the track for a test. This will be the first time she has moved under power for a good number of years, possibly even as many as twenty from what I hear! So, let's see what happened:  She lives! There is still a leak in the left hand steam chest (which I forgot to address, but that can be reached easily) but other than that she went like the clappers with no problems for a good couple of hours. A very pleasing result!  The more eagle-eyed may have noticed that the loco bears a different nameplate on each side of the smokebox...Polly O'Flynn on the left, and Bantam Cock on the right! We are still not entirely sure why this is the case so if anyone knows, please do let me know!   I shall update this page when the tender is repainted, and the remaining fettling jobs have been done. |
On The Workbench >