C2 Project News

July 2019

A weekend of Light Pottering

If Thursday 25th July was the hottest day on record in the United Kingdom, then the Class 158 which Dave 1 travelled to Wales on, without working air conditioning, must have been one of the hottest places on Earth. It certainly felt like it! Paul also battled his way across the country, as he was booked on the roster for Friday. He managed to keep cool by going paddling in the sea at Colwyn Bay whilst waiting for a lift for the final leg of his journey.
Fortunately the rest of the weekend was not so excessively hot, but with temperatures still plenty warm enough, we decided that it was not the sort of weather for a lot of physical exertion. Instead, a weekend of light pottering was deemed appropriate.
After completing the machining of the second motion bracket at the previous working party, Dave 1 called on Dave 2 for assistance in refitting it to the locomotive chassis. Using the spigots made by Dan, the slidebars were also refitted, this time much more precisely than before. Over the successive days, the two Daves reassembled the measuring kit, and carried out a re-measure of the slidebars. We now have an accurate record of how parallel the slidebars are to the cylinder bores, and how parallel they are to each other. This will allow us to finalise the packing we need to insert behind the cylinders and motion brackets to true up the slidebars and cylinders.
With the second motion bracket mounted on the locomotive chassis at a convenient working height, Tom used the big adjustable reamer to ream out the expansion link trunnion holes. Using the alignment jig that Alan had made previously, Tom slowly and carefully reamed out the holes to the same size as those on the other motion bracket. It will make the manufacture of bushes easier if all the holes are the same size.
With parts of the motion now receiving our attention again, Dave 1 asked Scott if he would be interested in sorting through all the parts of the motion, so that we can understand how it all fits together, and when work might be necessary to rebuild it. Scott thought this sounded like an interesting challenge, and it was decided to lay all the components out on the floor of a wagon, to form an 'exploded view'. This proved to be a very useful exercise.
When we took the locomotive apart, quite a few years ago now, we placed all the smaller motion parts in a metal box. At various times since then we have dipped into the box to take a look at individual components, but exactly what was in there was something of a mystery. Over the course of Sunday the box was emptied and each item identified and sorted. There were quite a lot of press tools we'd made to dismantle the motion, so these have been separated an placed in a box near the other 'jigs and tools' box. Similarly, all the old roller and ball bearings have been separated, ready to be replaced with new. Also discovered were tools for fitting the crank pin end caps. We'd completely forgotten we'd made them, so making new tools for this task can be removed from the jobs list!
After a fair bit of head-scratching, all the components were identified and placed in approximately the correct position on the 'exploded view'. Scott then photographed the arrangement in detail, so that we will immediately know where each component fits in the future. We can now start to think about how to restore each component to 'as new' condition.
Drivers side valve gear laid out. - Scott Todd-Howard, July 2019
Using a wire wheel, Tom cleaned some light corrosion from some of the front crashbeam components. Joined by James, and under Andrew's guidance, the components were trimmed to size and weld preps were ground onto the appropriate edges. The components were moved to the welding bay for Andrew to weld up the brackets and the crashbeam itself, in readiness for assembly.
With the crashbeam brackets completed, James (under pain of death if the bufferbeam paint got scratched) and Andrew very carefully offered them up to the front bufferbeam of the locomotive on Sunday evening. A little fettling was needed to fit the brackets around the welds at the ends of the coupler slot in the front bufferbeam. Dave 1 quickly made this adjustment with an angle grinder, and the brackets were bolted on.
Monday dawned bright and sunny, so for final assembly it was considered easier to take the locomotive to the welding set rather than vice versa. Daves 1 and 2 removed all loose items from the locomotive chassis, including the slidebars. Andrew and Mike applied oil to all the bearings and horn faces, while Dave 1 applied wax to the wheel flanges to protect them on curved track. Using the diesel shunter "The Castle Arrrggghhh", Andrew then carefully shunted the locomotive chassis out of the C2 Shed, down 10-Road and up into 4-Road. Of course, with the weather so good, a photo opportunity presented itself, and this had to be taken.
Loco frames on the way to the main erecting shop for fitting of the front crash beam. The new brackets of which can be seen bolted to the front buffer beam. - Andrew Nelms, July 2019
Side view of the locomotive frames with Snowdon in the background. - Andrew Nelms, July 2019
Another view of the locomotive frames at Pen Cob with the new carriage shed under construction on the left - Andrew Nelms, July 2019
As the crash beam was offered up to the brackets, it was realised that a relief was required on the underside of each bracket to fit over the weld bead inside the crashbeam. So, once again very carefully, James and Tom unbolted the brackets from the bufferbeam, and Dave 1 took them back to the C2 Shed to have the offending metal removed with the angle grinder. Final checks were carried out, and the brackets taken back to the locomotive and bolted on again (very carefully!).
Cloth was used to protect the front bufferbeam paintwork while Andrew tack welded the crashbeam to its brackets. The assembly was then removed and taken to the welding bay at the back of 4-Road. While this was going on, and the locomotive was out of the C2 Shed, Dave 2 gave the shed floor a good going over with a vacuum cleaner to remove the dust that seems to accumulate from goodness knows where. Mike and Dave 1 then shunted the locomotive chassis through the yard and safely back into the C2 Shed.
Andrew bolted the tacked together crashbeam assembly to a jig which Dave 2 had made previously, to try and prevent any weld distortion occurring. He then welded the brackets and crashbeam together. To finish off the assembly, the two front crashbeam footsteps were offered up, and after some minor fettling with an angle grinder and wire wheel by Dave 1, welded into place. Andrew will remove any weld spatter and apply primer and paint when he is next back in Wales in a week's time.
Erle has, as normal, been continuing his sterling work on the lubricator overhauls. Saturday morning saw him in the machine shop, turning up a pair of brass ferrules for the third lower strainer. These were soldered in place to complete the task.
The lubricators are designed to work in very low temperatures, and are provided with the facility to pipe steam through them to warm the oil. Erle has investigated the steam heat pipes in our three lubricators, and has found them all to be different! One assembled easily, with the fitting nuts providing a good seal. The next has a different type of nut, which doesn't appear to form a seal against the lubricator casing. It looks like the Chinese just used lots of wadding to try to keep the oil in, or maybe to soak up what leaked out, but we'd like to do the job properly. Erle will do some homework to try and come up with a better sealing arrangement, either a new nut or an insert which will seal against the casing.
Also investigated were the lubricator pump adjuster rods. The rods must not be too short, or full adjustment cannot be made. But they must not be too long either, otherwise the rod will jam when the pump operates. After some careful measurement of the pump geometry and the operating mechanism, Erle has concluded that each rod should be between 75 and 76 mm long. Some of those in our lubricators are in this range, others are not. The rods are quite a simple shape (just a rod with a small groove towards one end to hold the locating spring on), but we suspect they should be case hardened. We'll investigate what facilities are at our disposal for us to make replacement rods where necessary.
Paul completed his driving turn on Friday, but unfortunately had to return home that evening due to pressure of the day job. Andrew took on the role of Boston Lodge Duty Site Supervisor over the weekend. Fortunately all the locomotives in service behaved themselves, so he was able to devote all his time to C2 work. It may not have been the busiest of C2 working parties, but given the weather, we completed a satisfying amount of work.
August 2019 AGM