C2 PROJECT
C2 Project News
Late May 2023
Beer Garden Weather!
A beautifully sunny long weekend saw several of us busy on aspects of the C2, as well as enjoying a few cool beers outside Spooner's! The main focus was the completion of the tender brake gear, but we progressed a few other tasks too.
View of Snowdon and Cnicht on a sunny May morning, from the Cob near Boston Lodge.
Erle has been developing ideas for refurbishing or replacing the screw reverser, and machined up a few trial parts to help us make a decision as to the best way forward with this.
Erle has also been working on a special boring bar. It is required to bore out a chamber inside the Bronze Regulator Sleeve for the Steam Generator. Access is though a 16 mm diameter hole.He tapped the M5 thread in the end for the grub screw, milled the flats and cross drilled a 5 mm hole for the HSS tool bit, then used needle files to square up the 5mm hole. A few hours of filing later Erle managed to get the HSS fitted. The next step is to grind and cut the HSS to size.
Erle has also been working on a special boring bar. It is required to bore out a chamber inside the Bronze Regulator Sleeve for the Steam Generator. Access is though a 16 mm diameter hole.He tapped the M5 thread in the end for the grub screw, milled the flats and cross drilled a 5 mm hole for the HSS tool bit, then used needle files to square up the 5mm hole. A few hours of filing later Erle managed to get the HSS fitted. The next step is to grind and cut the HSS to size.
Special boring bar being manufactured by Erle for one of the last machining tasks on the Turbogenerator.
With work on the cylinders, pistons and crosshead/slidebar gradually progressing, Helen and James worked on some of the piston gland parts. Helen extracted the old studs and re-tapped the holes, and pressed out a badly damaged bronze sleeve that we will need to replace. She then ground off some old burrs, stamped in the part identification, and cleaned the components ready for painting. The following day, James measured up the lubrication arrangements and researched options for replacing the damaged non-return valves. He also applied another coat of paint.
The completed tender brake weighshaft.
Andrew had done most of the welding and machining work on the tender brake weighshaft at the previous working party, but still needed to weld on the two end cranks. He carefully positioned and attached these, then cleaned up the assembly before giving it a coat of primer.
Paul completed the brake weighshaft split bearings which Andrew had started last month. He drilled and reamed out the vertical holes, and made some tubular steel sleeves that were a good fit in these holes to ensure that the two halves of the bearings would remain aligned. Bolts pass through these tubes to clamp the bearing halves together.
Paul then turned the assemblies on their side and centre-drilled the correct location for the main bore of the bearing. This was drilled and bored on the large DSG lathe with the bearing assembly secured in a 4-jaw chuck. The two sets of split bearings are subtly different, mainly to correct for a slight misalignment of their mounting faces on the tender.
Paul then turned the assemblies on their side and centre-drilled the correct location for the main bore of the bearing. This was drilled and bored on the large DSG lathe with the bearing assembly secured in a 4-jaw chuck. The two sets of split bearings are subtly different, mainly to correct for a slight misalignment of their mounting faces on the tender.
Setup for drilling and reaming the sleeve holes in the Vesconite split bearings for the tender brake weighshaft.
Centering the split bearing in the 4-jaw chuck, ready for boring the main bearing.
Paul drilled the assembly in stages to a 2" diameter.
Then a large boring bar was used to enlarge the hole to the required size of 59.1mm.
Split bearing with machining complete. We made two of these.
It was now time for a trial fit of the weighshaft and its brackets, so Andrew shunted the C2 over an inspection pit to give us easier access. Tim came to give us a hand lifting and fitting the brake weighshaft.
The C2 positioned over the carriage inspection pit for trial assembly of the tender brake gear.
Paul prepares to lift the weighshaft and its brackets into position. Dave 2 was positioned above at the top of the rope, to take the weight while Paul inserted the bolts.
Tender brake weighshaft trial-mounted to check that everything aligned correctly. It did!
Tender brake weighshaft trial-mounted to check that everything aligned correctly. From left to right, the cranks will attach to: steam brake cylinder, return spring, hand brake, and the pull rod to the brake gear.
Dave 2 and Paul position the outer reaction bracket.
Last month we had decided to make some reaction brackets to carry the longitudinal brake forces from the split bearings into the tender frame. Paul had cut some plates for the outer bracket, which Andrew welded up and Paul and Dave 2 trial-fitted. Paul lightly skimmed the vertical face on the milling machine to provide a good fit. Dave 2 then drilled the bracket and the tender frame and bolted it into place.
Meanwhile, Paul cut some plates for the inner bracket, and Alan welded them together. The final machining and fitting of this inner bracket will be done at the next working party.
Meanwhile, Paul cut some plates for the inner bracket, and Alan welded them together. The final machining and fitting of this inner bracket will be done at the next working party.
Tender brake weighshaft split bearing mounted on the tender frame, with the reaction bracket being trial-fitted. The red part is the end of the steam brake cylinder which acts on a crank at the outer end of the weighshaft.
Alan welds up the inner brake reaction bracket.
Now that we know everything fits, the last task on Sunday was a coat of primer on the steel parts. Dave 2 hopes to drop in briefly later in the week to apply some top-coats of black paint.
And finally, Wildlife Corner!
Because our C2 shed is usually only occupied once or twice a month, we sometimes find that the local wildlife takes up residence while we're away. In the past we've had Robins and Rock Pipits, Pied Wagtails, Funnel-web Spiders and even a Lizard in the shed. This month's new species was a group of White-tailed Bumblebees nesting in the end of an old sleeper just outside our shed. We only discovered them by accident when Dave 2 trod on the sleeper and some bees emerged to chase him off!
Because our C2 shed is usually only occupied once or twice a month, we sometimes find that the local wildlife takes up residence while we're away. In the past we've had Robins and Rock Pipits, Pied Wagtails, Funnel-web Spiders and even a Lizard in the shed. This month's new species was a group of White-tailed Bumblebees nesting in the end of an old sleeper just outside our shed. We only discovered them by accident when Dave 2 trod on the sleeper and some bees emerged to chase him off!
White-tailed Bumblebees nesting in an old sleeper outside our shed.
As usual, we also helped keep the railway running, covering various driving, firing, standby and supervisor duties, plus some minor repairs on the operating fleet while the works staff enjoyed their long weekend off. There were a few out-of-course moves too!
One of the Welsh Highland trains had ended up stranded at Beddgelert overnight, and Andrew assisted in transporting the crew and loco preparation supplies to Beddgelert early in the morning. Steam was raised while the train was dragged back to Porthmadog with the Funkey diesel. All was ready for the booked departure.
Our next working party is in late June and we hope to get the tender brakes completed.