35006 Progress Report, July 2006
by John McMillan, 21st July 2006

With the improved weather we have turned our attention to the outstanding work required to complete the tender. The major task still remaining is the manufacture of the brake gear. We reported last time that we had taken delivery of the castings for the brake hanger arms, and much of our machinist’s time has been spent working on them. There are three pivot points per arm, each of which requires a steel bush to be made and pressed into place. Case hardened steel pins will be inserted through these bushes so that, when in use, the bushes will wear faster than the pins. Eventually, the bushes will require replacement and can be pressed out, and a new set made. This task might be needed after about 200,000 miles, so we’re not anticipating any trouble in this area for a very long time. A set of brake block tensioners is being made; these hold the brake block so that it doesn’t droop and rub against the lower part of the wheel, wearing the block on the lower edge.

We have a complete set of brake shoe holders in store that were acquired years ago from a scrap Southern EMU, and we’re currently in the process of trying them for fit to see if they will be suitable. We won’t know for sure until we have assembled the completed hangers on the tender chassis and checked the alignment of the brake blocks with the wheels. However, an initial investigation suggests we may have to have some different brake shoe holders cast. Our tender has a set of wheels originally fitted to a “Peak” Class diesel, and one of these locos is being restored in Toddington yard . So far we’ve resisted the temptation to make a night time visit with tools to its brake block assembly!

Meanwhile, on the locomotive we are taking the opportunity whilst the boiler is raised, to complete as many as possible of the jobs we thought would have to wait until the boiler lift for the steam test. The main activity over the quarter has been needle-gunning and painting the inside cylinder block, smoke box saddle, and the chamber between the frames immediately in front of the inside cylinder. The front dragbox and frame plates have received the same attention, repeating some restoration work undertaken many years ago, which has since deteriorated. We are using the anticorrosive galvanising paint in all areas that will be inaccessible once the loco is in one piece. This has been covered with conventional undercoat and topcoat of “signal red” between the frames. This area is now so shiny that our painting volunteer thought he’d left a light on between the frames!

Having this area so well restored will make the job of fitting the Snifting valves easier. These valves are fitted to the inside face of the outside cylinders, and prevent vacuum being created in the main steam pipe when the regulator is closed and the engine is still moving. The vacuum would otherwise suck smoke box ash back down the exhaust pipes, which wouldn’t do much for the lubrication. When the regulator is closed, the Snifting valves drop open and allow air to enter the cylinders instead of steam.

Unfortunately we haven’t been able to progress with the boiler cladding this quarter as our contractor has been called away on other commitments, but we’re hoping to see him return soon.

On the boiler back-head we have started work on the faces of the various fittings. The faces need to be perfectly flat to achieve a steam-tight joint, and we are following original Eastleigh practice by not fitting gaskets to boiler fittings for good safety reasons. Gaskets are permitted, but if one blows there is no way to control the leak. Bulleid locomotives never had gaskets originally and we’re doing our best to emulate that practice. The first faces to be tackled were the water gauges. The faces were heavily pitted, so the first task was to clean up what was left and build up the surface to its original thickness with weld. Then followed the tedious job of grinding and hand dressing the faces to achieve the required perfectly flat surfaces. One set has been done, and the second set is well on the way to completion.

On top of the firebox, there is a fifteen-foot length of four-inch diameter pipe, which connects the steam shut-off valve to the steam manifold in the cab. The original pipe is badly corroded and heavily damaged, but it has been useful to us as a pattern for the cladding covers fitted on top of the firebox. We are trying to have a new pipe made in a single length to avoid corrosion problems from pipe joints, and research has been undertaken to identify the correct specification. A couple of promising suppliers have been identified and we have begun assessing these for their willingness and ability to make the pipe.

Finally, to make room in the yard for Toddington MPD during the spectacular Steam Gala in late May, the tender was ‘tripped’ over Stanway Viaduct, the first steam loco tender to pass over in more than 30 years. Let us hope that its next run over the viaduct finds it travelling to Broadway attached to the locomotive!