Weekend Rails

what we do for our kids

Of pipes, brackets and buffers

7th October 2018

I thought I'd start with a bit of RS8 that will be, forever, Bristol.


And once more, Monday saw me back up at Tunstead. Again, not as many bodies as I would have liked - Alan G popped in a few times but was covering elsewhere, Liam G may not be with us any more and that left me, Andy H, Pete C and Wayne. With the engine having been mounted finally last week it was time to get the springs in place. As Andy H is keen on caving he volunteered to go down into the dark depths of the pit and work from underneath. But first we lifted the loco to remove the plywood packers RS8 has sat on since we wheeled it and that proved a problem. The left hand side came out reasonably reasily, but it was as if the right hand side packer had bonded itself to the top of the axlebox, and the axlebox itself seemed reluctant to slide in the hornguide - as we lifted the front of the loco on the crane, it came up with it rather than the wheel stay on the rails. It slowed things down, but not all that much. In due course the springs were back into place, with the pillar pins and hangers once again. Without the front ballast weights in it is pointless setting the springs too accurately, but in a week or so it will be time to set them up somewhere near so that the converter output points nearer to the gearbox input and the propshaft will therefore span the gap.


While we had the front of the loco in the air, we decided it was a good time to bring the front axle round into position and get the side rods refitted. I had made great efforts to ensure that we had the axles in the right way round and they were in fact only 10 or 15 degrees out of position, and with a bit of barring they were in synch. The side rods had been split apart for painting some weeks ago, so it was a bit of trial and guesswork since those that split them (Jack and Liam) were no longer around. After first putting the left hand side rod at the right hand side and vice versa, we figuered it out and the left hand side went together quite easily.


It must have been beginners luck, for when we got the right hand side on, the new (driving) crankpin had oodles of pin exposed and the front crankpin was overhung by the bearing assembly. Now, I daresay those readers who have assembled Avonside or similar 4 wheeled saddle tanks all this will be obvious, but all the photos we consulted didn't reveal the subtle differences. For the side rods are thinner in their section than at the crankpin bosses. This is normal - if you made them the same section all the way through as is neccessary to provide sufficient meat at the crankpin they would look ridiculous - but on all the diesel shunters I have worked on they are symmetrical. But on RS8, having once been an 0-4-0ST with additional rods at the outside and cylinders, crossheads, etc around and ahead of the leading wheels, these are not. To keep the side rods parallel to the frames, the bearings are different front to rear. And yes, as we had put them together, we had got the rear bearings into the front housings and the fronts into the rear, which doesn't work at all. Andy H spotted it first and after managing to convince the rest of us, it all went together properly.


The special studs I had ordered from Sigma6 (the quarry's independent workshops) were picked up by Pete C and we thought it would be plain sailing to get the rear buffers on, but I had not looked closely enough and some of the fixings needed to be bolts not studs, so we got the two rear buffers on, after a fashion, on the upper pair only, and even then those backplates on the buffers were reluctant to go into the recesses. We shall battle those again when the appropriate bolts are available.

Meanwhile Andy and Wayne had spent some time cleaning up the engine ready for the application of a 'proper' paint, and I spent a while at the front of the engine working out what fixings I still needed to resolve. When we ran the engine at Sigma6 late last year, I had struggled to find the fixings and in the end run it without the viscous damper. But the damper is a bit important, it removes a lot of the out-of-balance vibrations which otherwise tend to undo rather important screwed bits. Not just the front pulley to the crank, but a big nut clamping two cones needs to stay 'king tight else the oil pump drive gear gets lazy. I had been confused about this, and wondered whether we ought to rebuild the front end with a new timing gear backplate and cover, but finally consulting the parts books and other engines showed me that all that was missing was the correct 3/8 UNF bolts. So I tried the damper back on with the only bolts I had to hand and from it determined what they ought to be for ordering during the week. And in between we got the battery isolator mounted properly, a few more components primed and a supporting beam ready to go back in. For a days work at first it didn't seem all that much, but in retrospect, with just four of us, had achieved quite a bit. Andy H went off with a bit of homework as he often does. So much of RS8's copper piping was stolen, and the oil cooler different on the new engine compared to the old, that there is no pipe to carry the coolant to the transmission cooler. He went off with a couple of bits to re-configure, and has sent in this montage of the work progressing, with a piece of slightly smaller bore tube acting as a sleeve across the join.


I look forward to seeing whether it fits tomorrow and finishes that bit of plumbing.

There hasn't been a great deal of progress during the week, unless you include receiving coolant bottle fittings and ordering cutting coolant ready for the ceremonial 'rotabroaching of the buffer beams'. On Friday though, I had to go down to the Portakabin as we had agreed to supply the Ivatt group at Rowsley with some lorry sheets to go over their Class 58 donor. These were some that I bought through an ebay deal a year or two ago and for the most part had lain in the 'kabin ever since. We loaded them into the van and I ran them up to Rowsley, where a couple of their members helped me unload.

But Saturday and Sunday though, Andrew and I were back in action. On Saturday I was down first and doing a bit of hurried tidying as we were lead to believe that there might be some visitors, although in the end nobody came. The chassis of the pseudo-Wickham was lifted and put on its side to take less space and be ready to remove various corroded pieces on the top surface, and I pottered around getting a few bits into the container and away from the floor. When Andrew arrived, it was to make a start on fitting the front-to-back 2" vac pipe on 1382, for which he had previously made a couple of brackets for pipe clamps.


After threading the pipe ends (during which I suggested trialling some oil, which I had for use in chain lubricators on Charlie and Cheedale, as a cutting lubricant, which seemed to have the right effect) he added the neccessary end connections and we hoisted 1382 a couple of foot on the Mattersons to give him a better working height.


Getting the brackets into position and welded was quite colourful and gave him a sweater with a new ventilation hole in the front. I found myself supporting the first and second pipes while their clamps were bolted up - you can see from the picture (below) that he has taken the only route possible, sneaking between air receiver and spring, and, right behind my head, the even bigger obstruction otherwise known as a traction motor.


I was bemused that he started with these parts, rather than the 'rotabroaching of the buffer beams', apart from the fact that the coolant adaptations aren't quite ready. [There is history here. Back about 8 or 9 nine years ago, we started air-braking Claire down at the late-lamented Snibston Discovery Park. Since Claire has thick buffer beams, I had bought a specially manufactured rotabroach bit - and if you don't know what a rotabroach is, it's like an apple-corer for steel - and we set to work with a mag drill borrowed from RMS. All appeared to be going well, if slower than we expected, and were about 80% of the way through when the rotabroach bit snapped off. It's still there in Claire's rear beam, we simply had to take pipework around it rather than through. I went to the manufacturer to ascertain what had gone wrong. 'Was there play in the slides of the mag drill?', asked the expert. 'A little' I admitted. 'And how about the coolant?', he asked. 'Coolant?' I answered, 'we kept pulling it out and adding more Trefolex'. 'Aaah', he said. 'There's your problem, with that depth you need an arbor with provision to inject coolant down to the cutters.'.. This time we'll be ready.]

After marking out and cutting two pieces of plywood to form the seat bases for RS8, I continued tidying up the nuts and bolts, (that job is going to take ages..), cleaned out the former fuel header tank from 14901, now to become the transmission oil reservoir for RS8, and started making its cork top joint to seal the cover plate.

Today, again, I was down before Andrew and this time with the label machine added more markers to various shelves that are loaded with bolts. These are of course the moments that you find two different pigeon holes actually contain the same size, length and head of bolt. I have been getting to the point today where my eye is sufficiently back in tune to look at a bolt and instantly spot whether it's a metric, a Unified or a Whitworth thread form, and when I've been picking up filthy old plastic bags which turn out to be 7/8 UNF, or loose pieces on Pluto's running plate which are 7/16" Whit, or something equally obscure, this can save time. Part of the reason for this enthusiasm is to clear Pluto, which, like every level surface in the Geoffrey Briddon building, becomes a repository for all manner of things if left standing still long enough.

And Pluto hasn't been active for a couple of years or more, since it returned from the DVLR with a reported coolant leak. Not an arduous task to rectify, save that the leak is reported to come from a joint on a part of the block which has the dual role of being hollow for coolant circulation and also part of the front mount. But I was at a customer's recently with a Cummins pidling coolant out around a water pump where the tapped holes had all but worn out. A proper solution would be to helicoil the tapped holes and bolt it back up tight, but of course it's in a position where you have to remove the radiator to get at it. Remembering many years ago at Llanuwchllyn where a friend was faced with similar problem of a severely leaking radiator, but 'cured' it with no less than 3 tins of Radweld, I had agreed with my customer to try a temporary repair with similar chemical solutions such as Barsleaks with surprising success. So I proposed to Andrew that shortly we would refill Pluto with water, drop on some batteries and a few Barsleaks pellets and see if the loco can be got running and cured without so much effort as lifting the front of the engine, stripping and re-jointing the offending part. It's worth a try, and would be good to see Pluto roaring around again.

Andrew allocated his day to 'manufacturing something for Adolf' and set about 'designing' a set of brackets and cross channels to carry the main air receivers under the rear of the loco. Now on a new build, this task is one that is carried out immediately after the frame has been fabricated. The main pipes - train air lines, feeds to brake cylinders, and such, get put in while the frame is upside down - so much easier to lower them into position with a crane, with good lighting and ease of access. In Adolf's original configuration the receivers were above the frame, rear of the fuel tank, but our layout, being based on Thomas Hill parts, doesn't allow for that, so under the rear they will go, two mains and a smaller auxiliary res, all of them stainless steel.


Here he is cutting the cross pieces, and if you think they look like old point rodding you're right, but in between they've been slides for windows on RS8. With 4 substantial right angle brackets welded to the insides of the frames, it should be straightforward to get the receivers in and secure, and build up interconnecting pipework and drains. I had dropped on to the replacement arms for the low loader, and as the machined bits were back from Sigma6, I pressed the bushes in on the press and left them for Andrew to weld, which he did later.


And that's about it for this week. I had the book of words for 03901 but never got around to following through the possible wiring issue. We had meant to get the 12ton box van down and put the ex-VBA racking into one end of it - but then found that the racking was an excellent place to lay the Wickham frame against. Back up to Tunstead tomorrow, and maybe sort a date for re-wheeling the PCV, and get on with RS8 naturally. See you all next week?


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