C2 Project News

Late November 2019

Update from November working Party 2019

The November working party held much promise for some significant progress. Machining of the motion brackets and cylinders had been completed previously, so it was now time to fit them... permanently.
But before the motion brackets and cylinders could be fitted, we needed packing plates and fitted bolts. Due to some confusion, when Andrew and Julie (works secretary) chased up the packing plates a few days before the working party, it was discovered that they hadn't been made. Our supplier (Empyrium) pulled out all the stops and the packing plates arrived on Friday morning, just as Andrew, Colin, Dave 1 and Dave 2 arrived to commence the working party. Phew! We weren't so lucky with the fitted bolts, and they didn't materialise in time, but that wasn't a show stopper.
Work started with Andrew and Dave 2 moving the motion brackets and cylinders into approximately the right positions to be fitted. This involved moving the locomotive chassis up to the end of our siding, to make room to work on the motion brackets. The plan was to fit the motion brackets first, which could be done with an engine hoist, before fitting the cylinders which require the use of the A-frame crane.
To fit the motion brackets, the leading springs have to be removed. Dave 2 found some wood packing, and fitted it under the frames so that they didn't drop when the springs were removed. While he did that, Colin tapped the remaining holes in the cylinders for the cladding screws. He'd brought a special long tap wrench from home to make the task easier.
The arrangement we had used to fit the springs, using boiler clamps to compress them sufficiently to get the knife edges in, wasn't ideal. We were concerned that there was the possibility of a boiler clamp slipping, which could result in chunks of metal flying around at high velocity; rather undesirable. Dave 1 asked Robco for his thoughts on the matter, and, as usual, Robco was able to provide some excellent advice. A length of channel section was found, long enough to span both springs. Andrew welded on a suitable spacer, and then welded two circles onto the channel. When the boiler clamp screws were placed in the circles, they couldn't slip out. With Colin and Dave 2 on spanners operating the boiler clamps, Dave 1 kept an eye on things as the springs were compressed just enough to remove the knife edges. Unwinding the boiler clamps, again in a carefully controlled fashion, unloaded the springs, and they were free to be removed.
Without the new set of fitted bolts, we knew we couldn't finish fitting the motion brackets. But we wanted to progress the job as far as possible, and that involved reaming out the holes to accept the new fitted bolts. Dave 1 found some of the original fitted bolts which were a good fit in the holes. Using two of the original fitted bolts would locate the motion brackets securely while the other holes were reamed. Once the new fitted bolts are in the reamed holes, we can replace the old fitted bolts, ream those holes and fit the final pair of new fitted bolts each side.
By the end of Friday, the first motion bracket and packing plate had been lifted into place and bolted temporarily, and the second motion bracket was ready for the same.
First Motion bracket Fitted - Andrew Nelms - Nov 2019
Motion brackets fitted for the final time. Andrew Nelms - Nov 2019
It didn't take many minutes for the second motion bracket and packing plate to be lifted into place on Saturday morning. More of a problem was finding a way of driving the 7/8" reamer. There isn't enough space between the frames to get the magnetic base drill in, and the wheels are in the way on the outside of the frames. Dave 1 and Colin had a look around the works, and found a set of ratchet drills, one of which had a 1/2" square socket in the end to take the shank of the reamer. Using the opposite hole as a guide, Colin found it was quite straightforward to align the reamer in each hole and, with a bit of elbow grease, to ream the holes. Dave 2 assisted him in this, and by Sunday morning all the accessible holes (i.e. not the two each side with old fitted bolts) had been reamed. With a good method of aligning and driving the reamer developed, it shouldn't take long to finish fitting the motion brackets at the next working party, once the new fitted bolts have arrived.
Reaming of the bolt holes in the frames. These are usually behind the springs which have been removed for for this task. - Andrew Nelms - Nov 2019
Saturday saw Alan, Chris and Erle join the working party.
Alan was set the task of re-measuring the cylinder and valve bores relative to the mounting faces. Measurements were taken prior to the boring of the cylinders and valves, but now that the bores are straight it made sense to re-measure them more accurately. Using a parallel across the mounting face, and a straight rod held against the nearest edge of each bore, Alan could take a measurement. We know the bore diameters, so this will allow us to determine the centrelines relative to the mounting faces. Alan was a little concerned about the accuracy of his measurement arrangement, but after taking several sets of measurements, he found that he was getting very repeatable results within 1 thou. This gives us confidence that the numbers are correct.
Measuring the bores of the cylinders - Alan James - Nov 2019
Interestingly, after measuring the second cylinder, Alan found that there appeared to be a slight non-parallelism between the mounting face and the bores. It seemed odd that the numbers were exactly the same for both cylinders, which would be highly unlikely if we were seeing measurement errors. After consulting Dave 1 about the way the cylinders had been mounted on the horizontal borer, they concluded that the table of the machine must be a few thou out of true. It's a very small effect, and will be of no consequence to the operation of the locomotive, but it shows what you can find when you measure things accurately.
After completing the measurements, Alan applied paint to the cylinders, ensuring the back faces were properly protected and touching up parts where Paul had previously removed casting flash. It's special paint which should withstand the heat of the steam in the cylinders, even though the can states that it isn't suitable for hot surfaces! It's what the Ffestiniog and Welsh Highland Railways paint all their boiler with, and it seems to work, so we're sure it will be fine.
Finishing the painting of the cylinder blocks - ready to be fitted at the next working party - Alan James - Nov 2019
Chris continued work on the coupling rod knuckle joint covers. While he set up a couple of lathes, one with external jaws and one with internal jaws on the chuck, Dave 2 used a plasma cutter to trim the edges of the plates such that they were approximately round. Using a mandrel which Dave 1 had previously made, Chris then turned the edges, keeping them oversize to facilitate skimming the faces to make the plates the desired thickness. He completed facing off one of the cover plates, and skimmed one side of a couple more, before having to leave on Sunday morning.
Knuckle joint covers at various stages of manufacture. From plasma-cut (left) through to machined (right) - Chris Veitch - Nov 2019
Knuckle joints cheekily posed on James Spooner’s new manifold casting (Just because it was there!) - Chris Veitch Nov 2019
Andrew spent much of Saturday and Sunday making another coupling rod bearing cover plate. We have a total of 18 of these on the locomotive (including very similar big end bearing cover plates), of which we only had 4 Chinese spares to start with. Almost all are subtly different in some way or other, so Andrew and Dave 1 compiled a list of which plates have been made, to keep track of which still need to be made. Andrew is making steady progress in turning out the bearing cover plates, and we're hopeful that all will be completed early next year, ready for fitting the coupling rods.
After finishing the turning operations on the coupling rod bearing cover plate he was working on, and whilst his lathe was set up, Andrew completed the facing off of the coupling rod knuckle joint covers. These cover plates now just need the edges turned to final size and profile, and they'll be finished.
Erle has started work on the third, spare lubricator. This appears to be less complete than the two which were on the locomotive when we bought it. After stripping the lubricator down, he and Dave 2 took the casing outside and steam cleaned it to remove all the oily gunk accumulated inside. A coat of primer, and it's suddenly looking very much more presentable.
Dave steam cleaning the spare lubricator. Nov 2019
The ratchet mechanism of the third lubricator is also in a sorry state. The springs are broken, and will require replacing, to which end Erle has taken measurements of the existing springs. The manual operating handle was broken off, so Erle has turned up a beautifully shaped replacement which matches the handles on the other two lubricators.
Replacement operating handle turned by Erle. Nice job! - Nov 2019
Work on the lubricators includes many small tasks. Erle has fitted handles to the upper oil strainers, as per the Nathan manual. Not only do these make it easy to lift the strainers out, but we believe they also stop the strainer from lifting and bypassing oil. None of the lubricators we bought had these handles, but they did have the slots for them to fit into, so correcting the omission is not too difficult.
On Sunday afternoon, Dave 2 took on the challenge of making brake shoe return springs. These are strips of spring steel, which fit behind the brake shoes to keep them clear of the wheels when the brakes are released. They are bolted to the brake hangers, and we didn't like the idea of having to drill holes in spring steel. Robco suggested that strips of stainless steel might be springy enough, so Dave 2 found some stainless steel offcuts, and had a go at developing a suitable shape of spring. Initial results look promising, so we'll probably have a go at making up a complete set at the next working party. The success or otherwise of the design will only be known once the locomotive is in traffic, but that's still a few years away.
Three of the fitted bolts which pass through each motion bracket are intended to hold the brake hanger brackets for axle 2. The brake hanger brackets were finished and primed at the previous working party, so Dave 1 applied back undercoat to them this time. The brake hanger brackets for axle 2 should be fitted next working party when we finish fitting the motion brackets. The brake hanger brackets for axle 4 may also need to be fitted with the springs removed, so next working party seems like a good time to fit them. At which point, we might as well fit the remainder of the locomotive brakegear! As noted at the top of the page, some significant progress is now being made.
Dave cracking a nut with a sledge hammer taken to new levels at this working party - Andrew Nelms Nov 2019
And just as a taste for the next working party - The new fitted bolts for the motion brackets and cylinders arrived at boston lodge at the beginning of December:
Fitted bolts for motion brackets and cylinders as new from Crabb Engineering - Andrew Nelms - Dec 2019
News Archive 
November 2019