This wasnt me, honest guv! We've gone all midland
Entry posted by London cambrian
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That old analogy about buses has come to mind again…
But anyway, whilst I’ve been pottering along with the pannier, the other resident of the workshop has done with building silly coaches and has no moved back to the original past time of wagon building. He blames me for this one but its his own fault really!
His original plan when we went along to the midland railway centre was to go there to get photographs of the Derby lightweight DMU, which we duly got. But I had happened to look on their collection at the centre, and had been asked to take pictures of the Kirtley 2-4-0 for a friend who wants to build some kirtley 0-6-0s! But anyway, parked behind in the vintage coaching stock rake was this Midland railway motor car van.
He’s always a sucker for a challenge, so we grabbed a few photographs and went home. The more he looked the less enthusiasm he had for an all riveted aluminium channel frame for the derby lightweight, the more the motor car van appealed! So, out came the books and a quick search on RMweb sourced some drawings, and after a good deal of studying, and redrawing on CAD, work began.
At the same time I spotted a gas tank wagon built by the Midland railway for the Somerset and Dorset railway. Turns out this was the designs for one of the vehicles that was regularly seen at the buffer stops at Bath Green Park station. So far in our little fleet, we have 1 van, 1 flat wagon, 4 open wagons, 2 bolster wagons and a brake van, but no tank wagons. So it came to pass that S&D tank wagon no2 was built!
https://twitter.com/SDJRailway/status/249437865442938880/photo/1
The motor car van
The van is to a design built in the early 1900s, built we believe t designs for a similar van, which did not have as many louvers. But in general service the vehicles were commonly used to transport car chassis’ to the Rolls Royce body factory! (the plan may be to build one of the 12th scale Bentley blower’s from airfix, and put it in, it’s about the right scale!)
The frames were laid out and made in our traditional manner, using hardwood that is sold as skirting board in B&Q, planed to thickness. All the parts were machined, this vehicle is going to be a true Rolls Royce of wagons we hope (excuse the pun!) The frames were drilled as well, to hold the ironwork, and machined out to accept the buffer springs. Then everything was assembled using PVA glue and cocktail sticks.
The body began to be assembled from a softwood called Obeche. It’s very easily obtainable in dolls house modelling shops and machines beautifully. He started by making each louvered section, as a separate panel. First machining each slat slot on the milling machine, sticking each panel in, and machining it all flat. Then each individual section is glued together and made into one one of four larger panels. Planks are then pitted in, all from the same sheet of wood, to minimise errors and putting the planks out of square.
These can then be fitted to a bottom runner that fits onto the frame. In the gap left, the doors can be made, a wood frame, machined so they overlap in the proper manner, and fit into the frame.
The next job to get some roof arches in, because the van also has opening end doors, these will hold the body square. These I shall be getting laser cut for him, it saves a lot of potentially complex machining. This is as far as the van has got, recently more precedence being put on the other project.
S&D Gas tank wagon
Originally this was only ever a side project, it’s nice to have two or three wagons going on at the same time. This wagon has proved a little more elusive, only two were ever built, but with amazing what a quick appeal in RMWeb turns up! The pic that above was supplied by a fellow RMWebber, showing the tank wagon at Highbridge. It seemed this wagon was used to transfer gas to outlying points on the S&D system. So basically it'll look lovely behind some nice panelled coaches!
But anyway, the chassis was built in the traditional manner, wooden frame, dowel aligned, predrilled etc etc. theres nothing special about it, currently the chassis is at much the same point as the motor car van. The interesting bits lie in the tanks and supports. The supports were made from the same wood as the frame, the radius made by using a fly cutter in the milling machine.
This gave a surprisingly good finish in spite of the slow speed we had to run it at to keep the machine from shaking too much! But the large radius gave a relatively high rotational speed. The 16 angles used to keep them in place were machined to size from a large piece of steel angle, and then chopped to width, once the whole lot had been profiled, saving a whole lot of hand work!
The tanks are a whole different kettle of fish. In this scale to get things to look right, they really do have to be very close to right! So, in the two tanks, there are 16 line of rivets, half offset in pairs of lines, 48 in each. Plus all the rivets in the lap plate, and rivets total around 1100! The main tanks are made 110mm plastic drain pipe, the original scaled up works out at 109.2mm, so close enough! The centre section is of a slightly larger diameter, so a trip was made up to Slater’s Plastikard in Derbyshire (we were going up there to pick up some scale wheels from 17D miniatures anyway!) for some extra-long sheet (A4 was about 5mm too short!) to wrap around. The other problem he faced was bonding the polystyrene to the tube. Flexible cyanoacrylate was the answer, basically super glue with rubber added in! So, with it all stuck in, the process could begin of drilling al the hole in the tank, evenly spaced.
Stretching our milling machine to the limit of its capacity, a rotary table was put on its side, and a relatively cheap tail stock centre obtained, the pipe was fixed between them. The tube fitted just over the chuck on the tables base plate, an a wooden plug in the other end provided a centre to support the tank, and rotate it about its longitudinal axis. Then, using the dials at 7.5 degree between each rivet, and a 1/16th centre drill (an ordinary twist drill would wander too much) 16 rings of 48 holes were drilled in the two tanks. Finally, using a similar process, the last 50 ish holes were drilled in the 4 lap plates, which were again plastikard glued on with flexi cyanoacrylate. Then began the long laborious job of putting all the rivets it!
Not before making an access hatch for the top. Since it’s a gas wagon the filling would have been done by pressurised pipes, but when it was built, a man was need inside to seal the rivets inside. So, an access hatch is on to. This represented a job in itself. The filler was easy, a bit of brass tube we already had in stock for making the pannier tank fillers. A cap made from a bit of steel plate. Now remains one of the few mysteries of this wagon, what was on top of this cap? We suspect a lifting eye, but none of the drawings or pictures confirm this. The hole for the filler was put in the tanks using the fly cutter again, and a ring cut from plastikard. Then, taping the two rings together a ring of holes were drilled in them, for a now familiar two lines of rivets! All the holes are followed up by a pistol drill with a 1.6mm drill, and the rivets popped through with super glue. No we are not prepared to rivet them properly, that would involve rolling a tank properly, I’m not even sure riveting that that close a confinement is possible!
Finally, the tank ends. These were a domed affair, making them doubly difficult to machine! The wagon is always gonna weigh very little with wooden frames, so to add some weight, but not too much, the ends are made from inch thick slices of 120mm aluminium. This we bought at the local model engineering, were we met with some old friends, one of whom owns the brent house track. Anyway conversation to what we had in our bag, oh some big slices of aluminium, but long story short, a mate of his offered to CNC machine the tank ends for us! So, a very complex job, done for us, free of charge! It’s amazing what you can get with friends! We’ll be picking them up this weekend at the brent hosue rally.
This is all the woodwork and plasti covered, I’ll update on the steelwork when theres a bit more to it! For the moment, just buffer stocks have been turned, and the shanks fitted to the knees that rest the buffing leaf springs.
Well, if your still with me, I must say thank you very much! But when its been near 3 months since the last update, and two wagons have emerged in that time, the tank wagon will probably be finished by February time!
I hope some of you find this stuff interesting, to finish I’ll leave you with a quick pick of the pannier tank as it looking at me now, in the lounge out the way, whilst I make some sanding gear rodding for it, and prepare to paint the buffer beams red!
So, cheers all, thanks for following this, maybe net time I can cut the length, but enjoy
Cheers
Mark
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