Friday, 29 March 2019

Diggin' it

While on the 009 stand at Ally Pally I thought I'd make a start on a project I've been planning for a while. Given the widespread use of ex-RNAD wagons on preserved lines, along with plant such as mini diggers, I thought a digger-carrying wagon conversion would be interesting. Now the RNAD sites had similar converted wagons to carry fork-lifts, except they were loaded from a platform onto a flat wagon, then onto an adjacent wagon which had a ramp down to a lower level deck, allowing the fork-lift to be carried within the loading gauge. These provided useful details but I envisaged an arrangement that allows the digger to be loaded onto the wagon from ground level. A low-loader might be a better solution, but preserved railways make the most of what they have.

So here is the nearly finished unpainted result, thanks to a little effort over the last couple of evenings as well as on the demo stand. The mini digger is from Wiking, to HO scale but looks fine here, while both wagons are adapted from the 009 society kit. The left-hand wagon has one end removed and the other reduced to 2 planks, and is used to store ramps and timbers for unloading, as well as the drill attachment. I'm not sure the best arrangement to stow these and they are currently loose.

The digger carrying wagon itself is significantly adapted. One end is removed and the end frame tucked further under the floor, while the nearer end is sloped down. The end frame is under the sides, which are cut to a taper, and the removed wedge refitted as a sloping brace to the lower end frame. Under the end a beam is fitted just above track level, to be wedged with a timber during unloading to stop the wagon tilting (a detail taken from the RNAD forklift carrier). The wire loops are supports for the removable ramps, while the deck is reinforced with checker plate. The brake handle has had to be shortened too.

To hold the digger in place I fitted a 2mm diameter, 2mm deep magnet in the wagon deck, and another in a hole drilled in the underside of the digger. These tiny magnets are very strong and hold the digger firmly (it can lift the wagon), but allowing it to be removed. There's a couple of strips of lead under the wagon to make it stable. I suspect the real mini-digger would have a very low centre of gravity, despite appearances.

A picture showing how the ramps could be fitted to the wagon, packed with timbers placed over the track, to allow loading of the digger. The ramps and timbers will end up glued to the carrier truck. Note that the digger fits best if reversed on, and the top swivelled 180 degrees.

Stowed and ready to go. This pair of wagons will look right at home in the siding on Hexworthy. I just need to add couplings, and paint the wagons, plus weather them and the digger of course. I'm not sure what colour to paint the wagons - my usual grey, or perhaps a departmental yellow?

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