20th Nov 2019 in Loco Wednesday Gang
This long-overdue blog is about my recent “journey”. No, not my well-trodden path from Wokingham to Ropley and back, but the thing that fans (and sufferers) of Strictly Come Prancing will understand all too well. In my formative years, I learned a valuable lesson: you don’t have to be the best in the world at what you’re doing, just good enough to succeed and enable you to move on to the next thing.
And that brings me to the subject of this blog. I took on the job of overhauling the brakegear components of CanPacs tender several months ago, and despite my complete lack of engineering skill, it’s coming along nicely; thanks mainly to other other volunteers I work with. It involved finding all the bits, retrieving them from storage, assessing what needed doing, and how much steel we’d need for the task.
The surviving Ashford Works tender drawings leave a lot to the imagination, but eventually we figured out what went where, and identified nearly 100 bushes that needed to be made and fitted, and 45 pins of various sizes. This particular tender had last run behind (I think) 35006 before it was withdrawn in 1964, and it’s fair to say that BR had run it into the ground. Most of the brakegear bushes were worn right through into the surrounding metal, and the pins had been scrapped when the tender was dismantled.
Luckily my team-mates included Alan and Dave who had worked as Engineers, Toolmakers etc, and they got on with making the bushes while I used my limited skill to press the bushes in, and work out what was next. It soon became apparent that there just wasn’t capacity in the machine shop to make the pins, so I started on a journey as the world’s oldest apprentice lathe operator. I last touched a lathe in the same year that 35006 was withdrawn, and that only lasted until I produced a miniature cannon capable of firing a ball-bearing through the workshop window (which was closed at the time). It cost several weeks pocket money to repair the window and I was summarily transferred to the woodwork class.
So, with Alans help, I got started on the Harrison lathe, making a batch of 14 brake hanger pins. These are pretty big pins – 14 ½ inches long and 1 ½ inches diameter – and needed to be made within 5 thou tolerance. At first, the Harrison seemed a bit daunting with knobs and levers everywhere, but after a few Wednesdays of constant supervision I knew enough to allow Alan to get back to bush-making. I was very conscious that I didn’t want to damage the machine, and even more conscious that I didn’t want it to damage me, so I enlisted Mike and Richard to baby-sit me. All four of the people mentioned so far have worked as machinists in their previous lives so the lathe and I were in safe hands.
Along the way, we discovered a couple of ideosyncracies of the lathe. It had a tendency for the cross-slide to jam, and it seemed incapable of machining a parallel cut. A succession of experts regularly appeared, with conflicting advice (cut deeper, cut shallower, feed faster, feed slower, etc) but once they got through all that, a couple of them helped sort out the machine. This included adjusting the gib strip (a kind of tensioning thingy) and getting the tailstock (the right-hand end) centred properly. Once these things were sorted out, the lathe behaved a whole lot better and became a pleasure to use.
Once I’d machined the basic shape of the pins, I was left with a couple of tricky tasks. One was bevelling the ends, and the other was drilling holes for the split-pins. The bevelling really didn’t work out too well – cutting the angle was no problem, but the steel was unsupported a long way from the chuck and this caused a rippled surface. The solution was to use the “steady” which took a bit of setting-up but produced a good finish. The pin-holes were a challenge too, with a lot of time-consuming marking-up using height-gauges, engineers blue, etc, but eventually producing that most elusive thing – a hole in the right place!
I’ve just finished fettling the pins and they are now ready to be sent off for hardening, so I’m ready to move on the the next batch, which are a bit smaller. Perhaps I should have started with the easy ones! I’ve just made a jig that might help with centring those split-pin holes and if it works I’ll cover it in the next blog.
Meanwhile, the bogie-men (Les, Keith, and Welsh-Pete) are still busy with machining Swanage axle horn blocks, and have moved on to shimming the cast steel axle-box liners. Steve has spent weeks machining the white-metalled axle-boxes, and the plan is to get Swanage back on its wheels early next year.
The TLC team (Dave-2Jags, Iain, Kieran, pilot-Pete, Austin-Colin, etc) have made a lot of progress drilling holes in CanPacs tender chassis and it’s new dragbox, but have stopped work on that until the chassis can be turned upside-down. Since then they’ve been occupied with various things, most recently recovering re-usable components from CanPacs life-expired ash-pans. It would be simpler to scrap the whole thing, but the salvaged items could save months of work in the future.
There are many others who turn up and take on the myriad of other tasks that find their way onto the whiteboard “to-do list”. I can’t mention them all, but they vary from emptying the pit, to chiselling out steam pipes.
If you’ve managed to read about my “journey” this far, it’ll give you some insight into why it takes so long to restore locomotives, but also that this is a world that’s accessible to people from all walks of life. If you were thinking of joining us, don’t be put off by the heavy engineering – if I can learn to be a lathe operator, so can you.
Under Assistant Ropley Scribe
The Harrison lathe, weighing-in at 1 ½ tons
A bit of the 2.75” EN36B black bar used for the pins
Pins cut to size but I’m not happy with the bevelled ends
The “steady” helped sort that out
Marked up and ready for drilling the split pin holes – a messy and tedious process
Mike drilling one of the split-pin holes
Holes all in the right place, just a bit of de-burring and finishing required
After a bit of fettling, they are ready for case-hardening
Jig for centring future pins of various sizes
Les and the bogie-men finishing Swanage’s horn guides
Keith – enjoying life down in t’ pit
Dave prepares to cut up one of CanPacs life-expired ash-pans (it has three)
Into pieces like this
So that re-usable fittings can be salvaged