C2 Project News

November 2017

News update from 27th November 2017

The November C2 Working Party started early, as seems normal these days. This time it was Andrew's turn to form the advance party, arriving on Tuesday. In fact, he also managed a few days the week before to work on the C2 as well.
Andrew started by completing the welding up of the coupler components, including the bob-weights. With these components all welded up, he cleaned and polished them, then applied primer followed by paint. Once the final layers of paint are dry the couplers will be ready for final assembly. They positively shine now, so woe betide anyone who scratches them when the locomotive is in service!
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Welding the components for the loco and tender couplings. - Andrew Nelms 15/11/2017
Completed coupling pin assemblies for locomotive and tender - Andrew Nelms 15/11/2017
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Whilst the paint tin was open, Andrew also attended to some of the more recently added components on the locomotive frames. The rear headstock thickening plates (welded on a month or two back) received a top coat, as did the fixings for the rear spring safety loops. For some reason we had managed to miss applying a top coat of paint to the rear spring adjusting buckles before we assembled the suspension at Easter, so these components were also finish painted.
Andrew then turned his attention to fitting the buffer beams to the locomotive frames. The buffer beams are extremely heavy, so it is not an easy task.
The buffer beams themselves are pre-drilled, but the locomotive frame headstocks to which the buffer beams bolt, are not. Firstly, Andrew carefully marked out the hole positions on the rear headstock. After double checking the measurements, he then used a magnetic base drill to pilot the holes with a 10mm drill. Trying to accurately line up a heavy drill hanging from a crane was particularly challenging when working alone on the job.
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Arrangement for drilling the pilot holes in the loco frames for mounting the rear loco buffer beam. - Andrew Nelms 23/11/2017
8 pilot holes drilled in the rear of the loco frames to line up with those pre-drilled in the rear buffer beam - Andrew Nelms 23/11/2017
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Dave 1 arrived on Friday and lent some assistance, which made things rather easier. Using straps and the A-frame crane, the locomotive rear buffer beam was lifted and offered up to the rear headstock. All the holes lined up! To fine-tune the position of the buffer beam, it was supported on hydraulic jacks and clamped to the locomotive headstock. After several checks to make sure the buffer beam was square relative to the rest of the frames, all was ready for drilling.
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Offering up the rear loco buffer beam to the frames. Due to the time and effort carefully measuring out the pilot holes in the frames, they all perfectly lined up with buffer beam. - Andrew Nelms 24/11/2017
The holes in the buffer beams are 24mm in diameter. The plan is therefore to run a 24mm drill through them and through the locomotive headstocks, followed by a 31/32" (24.6mm) reamer. This will provide an accurate sized hole through which we can drive fitted bolts. So, with the rear buffer beam in position, the magnetic base drill was used to drill the holes in the rear headstock out to 24mm diameter. After a cautious start, we started to learn the techniques required for lining the drill up with the holes in the buffer beam; it's definitely a two-man job! As each hole was drilled, an M24 bolt was put through and tightened up, to hold the buffer beam in place on a temporary basis.
Dave 2 took over from Dave 1 to assist Andrew in drilling the final holes in the rear headstock, which allowed Dave 1 to find a piece of bar to turn up a couple of 24mm dowels. The dowels can be used to align the holes in the buffer beams and headstocks, should we wish to take off the buffer beams before finally reaming the holes.
With all six M24 bolts in place, plus an extra two 24mm holes drilled for the safety chain eyes, the jacks and clamps could be removed from the rear buffer beam, and it now hangs in place.
Locomotive rear buffer beam mounted temporarily with M24 bolts. These need changing for fitted bolts which are on order - Andrew Nelms 24/11/2017
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Andrew and Dave 2 then turned their attention to the front of the locomotive. The process was repeated for the front buffer beam, although this time there were only six holes to drill. After about a day's work, Andrew and Dave 2 had fitted the front buffer beam too, using temporary M24 bolts. The front buffer beam gives a C2 (and it's predecessors) much of their characteristic front-end appearance, so Andrew couldn't resist placing the front drawbar and coupler into place to see how it is going to look. We think it looks good!
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Andrew posing while drilling the pilot holes for the loco front buffer beam using the Mag-base drill - Andrew Nelms 25/11/2017
Locomotive complete with front and rear buffer beams attached. It is shown here with the front coupling attached. The bolts will later be replaced with countersunk fitted bolts which will be flush with the buffer beam. - Andrew Nelms 26/11/2017
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With all the holes for the buffer beams drilled, it is now possible to get accurate measurements of the thickness of material that the fitted bolts have to pass through. Dave 1 took a set of measurements to advise us when specifying the fitted bolts.
Colin arrived Friday too, and recommenced work on the stainless steel tender equalising beam pivot spigots. He had turned them to size last working party, but now it was time to cut the M30 threads. Cutting metric threads on an imperial lathe is not straightforward, but the Colchester lathe has the capability, so Colin was determined. He used the lathe to rough out the thread forms, and finished them with an M30 die we had bought specially. It turned out that the greatest difficulty was finding an M30 nut in the works, to check that the thread was exactly correct! Once a suitable nut was located, the threads were declared finished.
With the spigots completed, the pivots could be assembled. Colin degreased the bases which Dave 1 had reamed previously, and tried pushing the spigots into them. He could get them part way with a bench vice, but they were too tight to go all the way home. But the hydraulic press is intended for just such things, and using it, the spigots were pressed into place. A real credit to the accuracy of Colin's turning that he achieved perfectly the interference fit which Dave 1 had intended.
Andrew finished the tender equalising beam pivots by running a bead of weld around the back of each, just as a double assurance against them coming loose.
Having mastered the art, Colin was rather enjoying thread cutting on a lathe, so next in line was a stainless steel spigot for the locomotive brake ratio lever bracket. After turning the spigot to size, Colin roughed out an M24 thread on the end of it. We could not finish this component, as we don't currently have an M24 die (well, we do, but it's a metric fine thread, which is not what we want). But that can be done later, so Andrew was able to weld the newly made spigot into the base which Alasdair made last working party. We'll buy a suitable M24 die and finish the thread next time.
No thread cutting on the next job for Colin, but he tuned three stainless steel spigots for the locomotive brake lateral control brackets. They need a little bit more work before being welded up into brackets (using the plates Chris formed last working party), but it's another job off the list.
Al used a second Colchester lathe to drill out the bases of the locomotive brake hanger brackets. The old worn spigots have been cut off these, and new stainless steel spigots will be made and pressed into the old bases.
At the last working party, Dave 1 had cut a piece of thin steel sheet to form the rear wall of the tender battery box. It will fit under the spine on one side, but has to fit around various structural members. So Dave 2 used an angle grinder to carefully shape the edges of the plate such that it now fits neatly into position around everything else. He also cut a couple of lengths of steel strip which will form a bottom flange to the rear and end walls of the battery box, onto which the floor will sit. These were all trimmed to fit. We now have all the components to welded up the battery box, and this will be done when the tender chassis frames are next inverted.
The tender axlebox roller bearings have now arrived, and thoughts are now turning to getting the axleboxes assembled. On Saturday morning, Dave 1 asked Earl to take some measurements of the bearings and axle end caps, to check how they will fit. It looks like we may need to take a skim off the inside of the original Chinese bearing end caps to get them to clamp the bearings correctly.
Like opening an early Christmas present. New tender roller bearings have arrived. - Andrew Nelms Nov 2017
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Also tested was the fit of the felt seals inside the tender axlebox rear covers. Fortunately they all fit nicely.
To assemble the tender axlebox bearings onto the axle ands and into the axleboxes, special tools will be needed. Dave 1 sketched out an idea for a tool to pull the inner races onto the end of the axles, and Chris went away and made it. Sounds simple, but it's actually quite complex.
Chris turned a disk of steel just smaller than the inside of the bearings, with three holes around it to bolt it to the axle ends. In the centre is a threaded hole to locate a piece of M24 studding. The second part of the tool is a tube which just fits over the axle end. Chris bored out a piece of thick walled tube until it was a sliding fit on the axle ends. He then turned up a plate which blanks off one end of the tube. The plate has a hole through which the M24 studding fits. Dave 1 tack welded the plate to the tube, to make it easier to use. Hopefully this tool will be strong enough to pull the inner bearing races into place.
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Trial assembly of the tender roller bearing puller onto the axle - Chris Veitch Nov 2017
A disk of steel was located in the C2 Shed which looks to be suitable for pressing the bearing outer races into the axleboxes. It's probably a tool which Clare turned when we dismantled the old bearings. But Dave 1 realised that we need a second tool for assembling the axleboxes, to stop the outer race being pushed too far through the box. So he sketched out a disk of precise thickness, which will sit under the bearing outer race to stop it in the correct position when pushed into the axlebox. Chris has started to make this too, hopefully to be completed at the next working party.
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The set of tender roller bearing puller components. - Chris Veitch Nov 2017
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Trial fit of the tender roller bearing puller sleeve onto the axle - Chris Veitch Nov 2017
A few months ago Dave 2 cleaned up and reconditioned those tender spring rocking washers which we can salvage, but, as the weather gets wetter, a patina of rust had started to appear on them. These components need protecting, to prevent earlier work being undone. Earl used a wire wheel to remove the rust before moving them into the paint shop for cleaning with white spirit and the applying of primer. We have agreed with the Boston Lodge staff that, if we leave the components in the paint shop, they will kindly apply a top coat of paint, thereby finishing the job for us.
Two of the original tender spring rocking washers are beyond recovery (one is a very 'special' Chinese field repair, deserved of framing!), and so we will have to make new components. This is a task which we have rather been putting off, as they are a very complex shape which is going to take quite a lot of work. In the pub on Saturday evening, Earl mentioned to Dave 1 that, years ago, he had done an apprenticeship and is keen to refamiliarise himself with machine shop work. In the cold light of Sunday morning, Dave 1 talked through the idea of making the two missing rocking washers with Earl, and he agreed to have a go.
First stage was to find some suitable material. Dave 1 located a bar of steel a little oversize, and with Al's help, Earl and Dave 1 got it to the power saw and cut a length appropriate for making two rocking washers. Next stage was to reduce this bar to the correct outside dimensions. Dave 1 showed Earl how to use the Bridgeport mill, and it didn't take long before Earl was happily squaring the bar up and reducing it in size.
The above are fairly straightforward tasks, but act as a good reintroduction to milling work. To make the rocking washers a lot more milling work, including the use of special cutters and a rotary table, will be required. These skills can all be mastered in due course. We hope Earl will enjoy this 'mini project', and we appreciate him taking it on for us.
The locomotive brakegear components which we left in the paintshop at the end of the last working party have all been painted for us. Thank you for doing this for us Carol. They have been taken back to the C2 Shed to be added to the growing stack of finished brakegear components. Hopefully it won't be too long before we can start assembling the brakegear.
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Carol, in the carriage works, has been painting the loco brake gear components while we were away. Thanks Carol! - Andrew Nelms Nov 2017
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October 2017