C2 Project News

October 2017

Making Brakes

The October C2 Project Working Party turned out to be a busy and productive one, with up to eleven people working on the project at various times over four days. Most of the work was focussed to the locomotive brakegear, and significant progress was made.

Paul and Dave started things off on the Thursday. Paul set up the Bridgeport milling machine to bore holes in the brake block carriers to accept the bushes we intend to fit. With 15 brake block carriers to machine, the operation took a while, but all are now finished. The new ones had been painted by Carol since our last working party. Paul also tidied up the five Chinese brake block carriers with an angle grinder to improve their fit to the composite brake blocks. They have now gone to the paint shop for Carol's attention.
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Milling out the holes in a brake block carrier, to accept Iglidur bushes. The clamping arrangement ensures a consistent position of the hole relative to the brake block.
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There were 15 of these to do: 10 new fabricated ones, 2 Chinese cast iron, and 3 Chinese cast steel. One will be a spare (the loco and tender together have 14 wheels).
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The 10 new brake block carriers complete and ready for bushing. Carol had kindly painted these since our previous working party.
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We forgot to take a photo of the spring safety brackets. This photo was taken just a couple of feet below them, showing the most frequent resident of the C2 shed!
Dave decided to bolt the rear spring safety brackets onto the locomotive frames. With just four bolts to fit, it shouldn't have taken long, but after fitting the first bracket it became apparent that the second was too low. The solution to this was to make a packing piece. An ideal piece of steel was identified, which happened to have been acquired for making the brake ratio link. So Dave first marked out the dimensions of the ratio link, then cut off the excess material with which to make the packing piece. A few hours work on the Wanderer milling machine and the Asquith drill, and the packing piece was fitted under the second rear spring safety bracket. It's amazing how long those little 10 minute jobs can take!
Since he had marked out the brake ratio link, Dave then continued work on it and drilled out the three holes along it's length. The holes were a little undersize at this stage, so that they can be bored out after bosses have been welded to the link.

Paul made the boss for this link on the lathe, and Rob welded it on.

Later in the weekend, Paul and Matt used a bench grinder and linisher to create radii on the ends of the brake ratio link.
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The brake ratio link, with boss welded on and holes milled out in the correct positions, but before the corners were rounded off.
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Milling the holes in a brake equalising triangle.
Once the brake block carriers were complete, Paul turned his attention to the brake equalising triangles. These are relatively small triangles of steel plate with three holes in, which distribute the force from the brake cylinder equally to all eight brake blocks on the locomotive. Since each triangle is at a different position in the system, each has a different geometry, and Paul has carefully calculated this. After cleaning up the outer edges of the profile-cut triangles, the holes were bored out using the Bridgeport milling machine, which has a digital readout making easy to accurately position the holes. The brake ratio link (above) was completed in a similar way.
The locomotive brakegear comprises a large number of small(ish) components, most of which are relatively straightforward to make; cutting to size, drilling a few holes, welding a boss on here and there, etc. Since both Paul and Dave had started to make progress through the list of parts, it seemed quite natural for the working party to continue focussing on this aspect of the locomotive overhaul.
Dave cut up a length of 10mm thick by 125mm (5 inch) wide plate which would ultimately form three brake lateral control brackets. We actually wanted 110mm wide plate (which we were unable to buy), so Dave used the Wanderer milling machine to remove 15mm from the edge of what were now three plates.
On Saturday, the pace really picked up when Ed, Earl (Ed's dad), Alan, Sam, Colin and Alasdair arrived. We had some visitors from the Welshpool and Llanfair Light Railway for a footplate experience, and of them Richard offered to work with us for half a day as well. Richard assisted Paul in forging the plates for the brake lateral control brackets. Each bracket required a right angle bend, which was achieved by heating it to red heat with an oxy-propane torch, and then bending it over a former. It is definitely a two man job! Richard continued to work on components for these brackets, using the band saw to cut some lengths of 30mm round bar, and some triangular gussets.
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Chris marks out a brake lateral control bracket, ready for drilling and shaping.
We were joined by Chris and Matt on Sunday. Chris marked out the hole centres and the outside shape on the brake lateral control bracket plates.

Dave trimmed the length of the plates using the band saw, and Alasdair and Earl used the Asquith to drill all the holes.

Finally Chris and Earl used a cutting disc, grinder and linisher to form the outside shape of each bracket.

Unfortunately we didn't have time to get the bracket components welded up - a job for the next working party. In the mean time, Dave protected the parts with a coating of oil.
Sam and Alasdair used a plasma cutter to cut out a piece of 20mm thick plate to make the base of the brake reaction bracket, while Ed set to with a angle grinder to remove the mill scale from the brake hanger profiles which we had taken delivery of a few weeks back. Paul used the Wanderer milling machine to neaten the edges of the brake reaction bracket base which Sam had cut. He also shaped some similar plate to make two small triangular webs which will support the boss that is welded to this plate.

Dave showed Alasdair how to use the Asquith, and using this Alasdair drilled five fixing holes in the brake reaction bracket base plate, and one larger hole for the main pin. Alasdair also used a countersink to create a weld prep around the pin hole on the rear of the base plate, so that the pin can be welded in. Chris then used an angle grinder to put radii on the corners of the base plate. With all parts of this bracket now finished (with the exception of the pin which will be fitted later), Paul set them up in the welding bay, and Dave welded them together.
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Dave supervises Alasdair, as he drills the holes in the brake reaction bracket.
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Components for the brake reaction bracket assembled for welding.
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Dave welds up the brake reaction bracket.
Ed created weld preps on the brake hanger profiles, and on the bosses that will be welded to them.

Each of the brake hangers required a small hole drilled through it, to fix the brake block retaining pin chain. These chains will prevent the pins getting lost when brake blocks are being changed. Also required were two small tapped holes in the edge of each hanger, which will be used to bolt on a spring steel strip which holds the brake block off the wheel when the brakes are released. Dave marked out and drilled all of these holes, while he and Earl carefully tapped the holes on the edges.

Alan spent most of the weekend welding. With the brake hangers descaled, drilled and tapped, he welded a boss onto each end of each hanger. After welding, he used an angle grinder to neaten up the edges of the welds.

Matt used a wire wheel to remove the last traces of dirt from the brake hangers and used white spirit to degrease them ready for painting. Another job for Carol!
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The brake hanger production line.
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Alan welds the bosses on to a brake hanger.
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Matt does the final cleaning-up of a brake hanger. These are now all ready for painting.
Not all of the work related to the locomotive brakes. Earl spent Saturday with the wire wheel, carrying out a final clean of the motion brackets; two large and complex castings. By the end of the day all rust had been removed, and a wipe over with a white spirit soaked rag made them ready for painting. You can guess what Earl spent most of Sunday doing! The brackets look so much better now that they have an even coat of primer on them.
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Earl has already painted one motion bracket, and is giving the other a final wipe-down before painting.
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The two completed motion brackets, in primer. They will be painted red eventually.
Colin is quite an expert when it comes to lathework, but we like to give him new challenges. This weekend we asked him to make two stainless steel spigots for the tender equalising beam pivots. One end of each spigot is a particularly tightly toleranced diameter, as it needs to be a press fit in a reamed hole in the pivot base. The other end is an M30 thread. Thread cutting on a lathe is not the easiest of jobs at the best of times, but using an imperial machine to cut a metric thread adds a whole new level of fun. Colin has checked that the Colchester lathe is capable of doing this thread turning, and so has ground up special tools to form the thread and the undercut at the end of the threaded portion. By the end of the weekend he had turned the bodies of the spigots, and now they are ready for the thread cutting.
Several of our regular volunteers were on the loco roster during some days of the working party, including Andrew and Colin. A notable low point in Garratt availability over the weekend required some changes to the roster, with larger FR locos double-heading on the WHR, while smaller FR locos double-headed on the FR. Of course this required more people: Paul covered the Duty Site Supervisor role on Sunday, and Sam drove the Taliesin.
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Taliesin and Linda double-headed one of the FR service trains on Sunday. Several of the C2 Project Group were involved in keeping the service running over the weekend.
As the weekend drew to a close, and after we had given all our work areas a good clean up, we were able to take stock of all that had been done. We have made:
  • Eight locomotive brake hangers, ready for painting.
  • Completed 15 brake block carriers for loco and tender, plus a spare
  • One locomotive brake ratio link, ready for painting.
  • Three locomotive brake equalising triangles, ready for painting.
  • One locomotive brake reaction bracket, just requiring cleaning and painting.
  • All the parts for three locomotive brake lateral control brackets.
  • Two tender equalising beam pivots, just requiring thread turning.
  • One adaptor plate for the spring safety brackets, and fitted both brackets
We have also cleaned and primed the motion brackets, and sourced some more materials for the tender battery box. Last and by no means least, several of the younger volunteers have learnt some useful new skills.
Needless to say, we are delighted at the fantastic progress made! Many thanks must go to all of those who gave their time to help us. We couldn't do it without them.
November 2017 
September 2017