Diesels Report

We have been spending some time on the Class 08 D3605 shunter this past few weeks; she was long overdue for an air tank inspection and test. The tanks had to be removed for this. It is a dreaded task as it is filthy under the front of the loco where the tanks and air compressor live. Also, the air tanks are large and heavy. However, young Rory, Andrew, and Magnus got in there and had everything disconnected, and the air tanks were out in no time. I was not there for this but I'm fairly sure they were filthy after that job, the guys and the tanks!

The next task was to prep the tanks, fill them with water, and hydraulically pressurise them for testing. This was done satisfactorily, and the inspector passed them as fit for use. The wall thickness was also checked, and they are still in very good condition with barely any noticeable reduction since manufacture. The relief valve was also tested but found to be passing air and quite worn, so a replacement was tested and set up to the required relief pressure.

Then came the more difficult task of getting the tanks back under the loco. It is nearly always easier to remove things than to refit. The squad for this was me, Rory, and Seonagh. After a bit of shunting and shuffling about to get everything lined up, we had them installed and connected in no time. Once fitted, the engine was started, air pressure built up, and the system tested with no leaks—a job well done.

While all this was happening, the large rear windows in the cab were removed as they had been letting in water for some time. The glass sits in a rubber 'U' section seal, which has perished and rotted with age. This is clamped between inner and outer metal frames. The frames were dismantled, which involved removing a great number of ¼” Whitworth countersunk screws, many of which were corroded and seized in place. After some time with screwdrivers, modified tools, a 'G' clamp and eventually a drill and taper tap, all the holes were cleared and threads chased through, after which the glass was finally removed. The corrosion was removed from the steel inner frame, and the outer frame was cleaned of its old sealant and dried-out rubber. Several coats of paint were applied to the steel frame, and then a nice thick bead of black durable silicone was applied into which to seat the glass. Once that was set and trimmed, the windows were reassembled using new brass screws. A draught strip was added to the inside sealing face of the frame, the windows were refitted to themotors were installed, and new wiper blades were cab, the wiper added to the wiper arms. Quite a satisfying result for all involved.

The Class 27, D5394, had a test run a few weeks ago after fitting one of the new replacement nylon gear wheels we had made to replace the aged and brittle originals. There was another failure of the original brittle gears recently. It seems they cannot stand the starting load from the motor, and the teeth are stripped away (is one theory). We have installed the new gear in such a way as to try out some new ideas for simplifying how it all fits together. After several engine starts from very cold and some test runs, things seem OK. This is an ongoing project, and if successful, it may be very useful to other users of the same set-up. Whilst out testing, we tried to raise the engine coolant temperature, but the day was quite cool, and we never managed to achieve the optimum temperature to trigger the roof fan automatically. Andrew tried his modifications to make the fan initiate by bypassing the thermostat switches but the fan motor did not engage. This is one of those fault-finding jobs that seems to drag on, but we will get there eventually.

The Class 37 (37674) has been out for some infrastructure work, shifting loads and equipment around for the permanent way gang and assisting with the installation of the new Broomhill loop north end point. The North British shunter D2774 has been stationed at Broomhill during all this and is working well.

The Class 31 D5862 has been tucked away indoors, hiding from the weather. She was out for a test run also a few weeks ago after a niggling electrical fault. Thankfully, with the help of Ben Angus, it was resolved very quickly. She ran perfectly after that. It is true to say that all the diesels have benefitted from spending time indoors through the winter or whenever possible; it has made a great difference in reliability and appearance.