August 2023

Following on from the successful gauging trails in early August and prior to the planned working party over the August Bank Holiday weekend (last weekend in August), Andrew and Dave 2 were able to find a few mid week days to continue some work on the C2.

Although the brake gear on the tender has been completed and tested on the hand brake, we have not yet tested the brakes using the steam brake cylinder. This was previously tested on the locomotive using compressed air and it is thought we should do the same for the tender brakes. Dave 2 scratched around for some valves and fittings and plumbed up a compressed air connection to the tender steam brake cylinder in preparation for testing at a future working party.

A trial fit of the drain cock valves and linkages was also performed. One problem was that the dropper links from the main draincock weighshaft fouls with the brake hanger for the front wheel set. These droppers were made new previously (a couple of years ago) as the old ones were bent and in a poor shape. We now know the reason why they were bent! Dave 2 collected the pipe bender from the main works and very carefully put a neat bend into the droppers so that that there is a sufficient clearance to the brake hangers.

Whilst attempting to line up the bearings for the drain cock weighshaft it was noticed that one of the brackets which mounts the bearing on the fireman’s side was bent. The drawings were checked and then very carefully, the bracket was bent back into the original shape using the fly press.

Despite being down on numbers for this working party (Unfortunately Paul and Dave 1 had prior engagements and so couldn’t attend), Andrew, Dave 2 and Erle were all able to attend. In addition, we had a new recruit for the weekend, Ed (Not Erle’s son Ed, who has helped us in the past), who is studying mechanical engineering at university. We hope the Ed will be able to attend future working parties and put his skills to good use on the C2. We also had some help for a few hours on the Saturday from Olly and Tom while they had a break from their shed duties. So in the end we had what seemed like quite a busy working party.

Andrew’s main task was to machine all the key ways in the reverser weighshaft and the three drain cock weighshafts, so that we can attach the cranks. Andrew was able to spend a bit of time with Marek in the machine shop on Friday afternoon to learn how to use the digital controls on one of the milling machines. Andrew has only previously used the manual controls. It certainly made the job much quicker.

Dave 2 and Ed spent the time over the weekend carefully setting up the drain cock linkages and measuring and forming a new piece for the drain cock reach rod, which has to carefully bend round the front of the firebox and also not interfere with the reverser linkage, which is very close. This involved, assembling some of the reverser linkages too. Some more work needs to be done to decide on the exact length, before the drain cock reach rod can be finished.

On Saturday afternoon, Olly and Tom were able to help for a few hours and they spent the time removing the loco to tender safety chains and cleaning up all the rust and corrosion. Ed was then able to paint the components the Sunday.

Whilst all this was going on Erle, continued with some work on the Tubro-generator governor valve. Work on the turbo generator is now nearly complete and we look forward to testing it under load soon.

Erle previously made a boring bar, made for hollowing out the inside of the Bronze Regulator Sleeve. The chamber formed allows steam to flow round the Regulating Piston and exit through the side port which feeds steam into a jet pointing at the Turbine Blades.

The High Speed Steel fitting through the boring bar was cut to length and then ground flush with the back of the bar and secured with the grub screw. This allowed the bar to enter the 16 mm hole through the sleeve. This then allowed for a 23 mm dia x 20 mm chamber to be turned inside over the exit side port

There are three split gland rings on the back of the turbine. These spring out and hold themselves in the turbine casing with the Turbine rotating inside them. They prevent hot exhaust steam from exiting the casing towards the Electrical side of Generator. To fit the glands, Erle had to very carefully spring them open to get them over the end of the Turbine. To allow two of the glands to pass over empty grooves, a small ring was turned up and then split. This filled the grooves allowing the gland to slide over before dropping into place.

A small but delicate job was to improve the clearances with the head of Graphite Carrier Pivot Bolts to the Turbine Cover. Two washers had been used as the bolt heads did not fully tighten up against the Yoke.

A small undercut was turned under the head of the bolts to remove the unformed part of the thread. This allowed the two washers to be removed.

To lock the pivot bolts in place two 2.5 mm diameter brass split pins will need to be sourced for the cross drilling to finish off..

All in all we had a successful and productive working party. It was well worth the effort.