C2 Project News

July 2018

Putting the Toys Back in the Box

In the first half of 2018, we put in a lot of effort to prepare the C2 chassis for last month’s Hunslet 125 event. So we’ve rewarded ourselves with a slight slowing of the pace over the summer months. There’s still plenty of progress to report though, and we're making plans for the coming autumn and winter.
Our regular end-of-the-month working party was held on July 28-29th, with Alan, Colin, Dave, Erle and Paul in full attendance. Jon was around too, but Paul had distracted him with some train driving duties. Sam also made a brief appearance between his other commitments. Dave in this case is usually Dave 2, but in the temporary absence of Dave 1 he's been promoted!

The main goal was to bring our loco back home from Minffordd, but we had plenty of other tasks in mind too. Over the next year our main targets are to finish off the brake gear, and to refurbish and fit the cylinders, motion brackets and slidebars. This will almost complete the loco and tender up to 'deck level' at the top of the frames. At present, about 80% of the loco’s brake components are complete, while the tender’s are about 30% complete. The cylinders and motion brackets have been cleaned, descaled and painted, but no machining work has been carried out yet.
On Saturday, we took advantage of the loco’s absence from our shed by having a big tidy up and reorganisation. We scrapped some worn-out items that have now been replaced, and stored the spares we’re keeping more neatly. These activities freed up a good deal more space on the floor.

Using the crane and a pallet truck, we have repositioned many of the big items we’ll be needing over the next year or so. The cylinders, motion brackets, slidebars, coupling rods and weighshaft are now neatly positioned on a row of pallets next to the boiler; in this location they are within reach of the crane.

Our fluorescent light fittings had gathered a lot of dust, so Dave and Erle gave them a wash and clean. Erle and Alan re-mounted the photos and display boards that we had taken to Minffordd for Hunslet 125. Throughout this, the broom and hoover were used to clean as much of the floor as possible.
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A clean and tidy shed, with the major components we'll need in the next 12 months laid out alongside the boiler. The three wise monkeys are Alan, Dave and Erle.
Meanwhile, Colin worked in the machine shop, finishing off some more brake components: the brake hanger brackets that bolt to the loco frames.
Recently we have been acquiring the components for our own oxy-acetylene gas set – we’ll need this for work on the boiler, amongst other things. Alan and Dave inspected and assembled all the parts (trolley, bottles, regulators, flashback arrestors, hoses and torch) and leak-tested the assembly ready for use.
Then it was time to get ready for our trip to Minffordd. Last month our policy of taking a load of re-railing gear ‘just in case’ had worked very well in preventing any derailments, so we did the same again. Our favourite wagon wasn’t available so we loaded up a South African ‘DZ’ dropside with all the gear. The Ff&WHR has about six of these; one day in the future they would make a great train for a photo-charter with the C2 as they are similar to the wagons used in China for hauling ore and coal on some of the narrow-gauge lines.
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Paul arrives at Minffordd on our way to collect the C2 and take it back home. We've upgraded from 'Moel-y-Gest' to a top-and-tail formation of Upnor Castle and Criccieth Castle. Colin is manning the Cricc at the back of the train.
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The C2 frames stand alongside the waggon shed in Minffordd Yard, ready to be hauled up the yard curve.
We’d also been asked to move another loco and carriage, so we used two of the medium-sized diesels instead of our usual shunter. The timings of our move were constrained by the passenger train service, and another special train that was running for the Young Volunteers Training Week. We took the two diesels, the wagon and a carriage up to Minffordd at 1620. Detaching one loco, we used the wagon and carriage as ‘reach wagons’ across the awkward 4-way sector plate that leads to the Maenofferen shed where the C2 had been stored. We re-greased the C2’s wheel flanges and lubricated the axleboxes, then hauled it out to the yard loop.
Having detached the carriage and left it where we’d been asked to, it was time for the tricky bit – up the yard curve. This is more than half a circle, and has a nominal radius of 35m. However, the curvature isn’t even and is as tight as 26m in places. There’s also a 1:40 gradient, a level crossing and several sets of points, just to make it a bit more interesting.
Upnor Castle proved an ideal loco for this move – idling in first gear it hauled the C2 smoothly round the curve at about 1mph, allowing us to walk alongside and keep a close eye on it. All went very well, except the sudden heavy shower that turned up half way through the move! Once out of the yard, we coupled up to the Criccieth Castle and detached the Upnor Castle as we had to leave this behind at Minffordd. We then had half an hour to wait before our path back to Boston Lodge, and fortunately the sun came out to dry us off.

The move down the main line was easy and uneventful; we didn’t need an engineers’ possession this time. We had our loco back in its own shed and all the gear put away well before the Young Volunteers’ special train came back down the line.
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The weather was rather changeable; a mixture of sunshine and showers. Here Paul and Colin shunt the Upnor Castle, with a bright rainbow against the threatening sky.
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A broadside view of the C2 frames, ready to return to Boston Lodge. The steep and sharp curve into the yard is visible in the foreground. We've done the hard bit already!
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Waiting for a path. Our train is ready to return to Boston Lodge once the last passenger train of the day has passed.
On Sunday morning we reconvened in the shed. Colin finished off his brake gear components, while Dave gave the loco and tender frames a clean down to remove any dust and rain picked up during the previous evening's move. Alan located the cylinder packing plates and removed the surface rust, while Dave did the same with the slidebars.

Paul and Dave took advantage of a break in the rain to re-marshal the loco and tender. We removed the loco-tender drawbar and then swapped the two vehicles over into the ‘wrong’ order. This will enable us to better position the loco under the crane when we come to trial-fit the cylinders and motion brackets, and it leaves the tender near the door where it is more easily shunted onto a pit for fitting the brake gear.
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The C2 frames back home in the shed. After this picture was taken we uncoupled the tender from the loco and swapped them around, as this will simplify the next stages of work.
Meanwhile, Erle did a series of useful measuring tasks. Firstly, he checked and recorded the actual diameters of the cylinder fixing bolt holes; these take fitted bolts so they aren’t necessarily standard. Then he measured the cylinder and valve bores at a number of locations along the cylinder. This was an initial measure to the nearest millimetre to see roughly what we’re dealing with; we’ll do a more detailed assessment in due course.
Within the measurement accuracy, the cylinder and valve bores do seem to be cylindrical: there is no significant ovality or barrelling of the bores. This is good as it will minimise the amount of material we need to remove when re-boring them.
However, the bore diameters are larger than the original design dimension, and one side is a bit bigger than the other. This probably indicates that the cylinders have been re-bored at least once before.
One option is to bore out the minimum amount of metal needed to true-up the bores. Another option might be to remove a bit more material and to insert liners. This would be more costly and time-consuming, but would allow us to achieve the ‘as-new’ bore diameter.

As part of his historical research, Paul has been acquiring lots of books from China. They include a set of steam loco maintenance manuals published by the Chinese Forestry Railways (the major user of C2s). One of these books includes over a hundred pages of dimensional tolerances; for each of the major dimensions of the loco it gives the design dimension, and the target values after major overhaul and intermediate repair. For some dimensions a worst-case safety limit is also quoted, beyond which the loco should be withdrawn for repair. So, we have something to gauge our cylinder bore measurements against. Elsewhere in Paul’s research he has found information on the typical time and mileage interval between loco overhauls and repairs; these can be compared to our anticipated mileage on the Ff&WHR to estimate the amount of life left in the cylinders. We’re working through the implications at the moment to help us make a decision whether to fit liners or not.

Alan also measured up the slidebars; again these are a bit worn and we can compare their dimensions to the Chinese manual too. It’s proving to be a rather useful little book!
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Extract from the Chinese Forestry Railways maintenance manual for 28-tonne locos (C2 and predecessors). This was first published in 1957 and refers to the class as КП4, КВ4 (the Polish and Hungarian versions that were imported to China in the early 1950s). The first row of numbers represents the cylinder bore dimension. 285mm is the design value for a new loco. After major overhaul (sent back to Harbin works) the bore should not exceed 295mm. At intermediate overhaul (usually at the loco's home railway) 301mm is permitted. Also on this page are the dimensions for the valves, crankpins and slidebars. Does anyone fancy helping us to translate the other 100 pages?
We also had some visits from the youngsters (and the supervising adults) from the Young Volunteers Training Week . It's great to see younger people getting enthusiastic about working on heritage railways. The Ff&WHR has always been good at encouraging this, and together with our apprenticeship programme we have a relatively young skilled workforce compared to many other heritage railways.
That's it for now, but we're all enthusiastic to get back to Wales and continue with the work on the brakes, cylinders and motion. Behind the scenes Paul and Alan are planning the next stages of work, and Sam is looking to re-stock some of the merchandise that sold out over the Hunslet 125 weekend. Meanwhile Andrew has done a great deal of valuable financial work on our accounts. Such activities aren't always obvious or glamorous, but they're essential to keep the group running well, so thanks to everyone!
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