Sunday 26 June 2016

The Bogie Man cometh

Work has continued apace this weekend on the bogies from FR117. You will recall that these are rather brutal three-piece bogies (so-called because they contain four main structural parts - two side frames, a bolster and a spring plank. Yes, I know...). With the benefit of a visit to the hire shop, bogie no.2 came apart with relatively little drama, and everyone was most impressed at the general good condition of all the parts. Meanwhile, the coach itself had the bogies refitted to it to allow it to be moved a few feet. We made a strategic error by parking the vehicle in slightly the wrong place when work started - one lives and learns. Fortunately, a very large pair of trolley jacks (once used for changing nose wheels on Vulcan bombers) makes lifting the coach fairly straightforward. With the coach in its new place, both bogies were removed and the vehicle stood on timbers. Then we found out that the bogies had been colluding; bogie 2 had been sent by its mates to lull us into a false confidence. Bogie 3 proved to be nearly indestructible. None of the fasteners would un-do, even with severe coaxing. Once thermally removed, the spring packs proved to be very fond of their current location, and even the very best the hire shop could provide wasn't going to change their minds. So, it looks like the bogies have decided to enter into an arms race with the tool hire company. This is only going to end one way.....

Sunday 19 June 2016

Wagons and bogies

The Pechot wagon is a rather large steel well-wagon which has been eating welding consumables for a number of weeks now. Quite a number of weeks, actually. Designed by the eponymous French engineer, these wagons were built in quantity for the French military before and during WW1. Quite a few survived, and can be found on many of the 60cm heritage railways in France - frequently converted into coaches. The wagon at Apedale had suffered a tough post-war existence at a concrete works, and had lost a lot of its fittings. These have been remanufactured and re-fitted. It is probably fair to say that the team working on it were getting a little jaded after fitting the nth stanchion pocket - BUT it's finished - the last weld has been made - there is no more (shares in BOC will plummet at start of Monday's trading...). The wagon has now been lifted off its bogies and upturned to allow the underside to be properly painted. Comparisons to a freshly swatted dead fly were voiced at this point. However, with the bogies out, there is chance to admire their engineering elegance. Particularly noticeable is the compensating lever between the two axleboxes with a very unusual centre pivot. This was a characteristic of M. Pechot's design, and means that if one wheelset drops into a dip, the load is transferred (in part) from the other wheelset. This has the effect of making the wagon less prone to derailment on bad track.
Compare this to the brutal simplicity of the ex-South Africa three-piece bogies which are for FR coach 117. Work has now started in earnest on these. None of the engineering elegance of the French bogies. These bogies have two socking great cast steel side frames which carry the wheelsets, and these sit on spring packs which support the bogie bolster, on which the vehicle actually sits. A grand total of eight bolts hold the thing together - but all the side frame mass is unsprung. If you are a railway civil engineer, and have been upset by the site of a three piece bogie exposed in such a blatant way, please feel free to get in touch with someone.




Sunday 12 June 2016

Upstairs, downstairs

After all the activity last week on the internals of the FR coach, attention has shifted downstairs. The vehicle sits on a set of ex-South Africa bogies, which are not original to the vehicle. The vehicle came to us minus bogies, because the FR wanted to re-use the originals under their new coaches. Although we were able to move the coach around on the SA bogies, it was obvious something wasn't right with how the vehicle was sitting. To investigate this, one end of the vehicle was jacked up and the bogie removed; the vehicle was then supported on a timber trestle to allow safe investigation underneath. As suspected, the body is sitting too low on the bogies - so the body is hard in contact with the bogie side frames, which is a bad thing. However, the good news was that the correct vehicle centres are fitted, so it's a fairly simple job to manufacture packing plates to slightly lift the vehicle body and hence create the all-important clearance. The clearance between the body and the side frames is a variable - as the vehicle is loaded, it sinks on the springs, and closes the gap. On the other hand, we don't want the vehicle too high, as it increases the stepping height from the platform. So we'll need to do a bit of careful thinking to get this correct.


Sunday 5 June 2016

Coach un-building

The ex-Ffestiniog coach arrived at Apedale a few months ago now, but with all the WW1 malarkey, we haven't really done much with it yet. A detailed plan for the modifications needed to the vehicle is under development; in support of that plan, we needed to understand the coach a bit better. So, a team of members spent a day starting to strip the interior, checking and tracing the wiring, and understanding the purpose of the various hatches in the floor. If the Ffestiniog want their old menus and playing cards back, do get in touch.....The main parts of the modifications are to alter the underframe to accept the new bogies (sourced from South Africa) and to fit air brakes in place of the vacuum equipment used on the FR. Hopefully, the new couple of months will see us getting into full swing with this project.