Scrap Tank, complete, painted and ready for action.

7mm scale Scrap Tank HR 23 in Drummond II livery.

No.23 has been built without the aid of a kit and with the help of only a few castings sourced from manufacturers lists. The chimney, which is not available commercially, is the sole 3D printed component, it's made from a robust material and once I'd managed to seat it properly, I thought it looked very well. I inadvertently filed the rivets off the flare while working on it and replaced them before painting with resin transfer rivets, which are about the right size. The model was painted with Phoenix P727 Highland Rly. Dark Green (1885-1912) which is no longer available, it was my last tin. Only the superstructure was airbrushed, the rest of the engine was hand painted with Humbrol matt paints. The frames were painted dark green to which I added a touch of talc and a little matt black to add depth to the detail under the footplate; all the hand painted areas were later brushed with a stiff bristled brush to enliven them. Brightwork was masked before painting began with Tamiya masking tape, helped along by W & N Masking Fluid. Transfers on the buffer beam and rear of the bunker are  Methfix ones by Guilplates, these have no carrying film and are my preference, however they are no longer produced and my supply is running low, so I had to resort to water-slide ones from Fox Transfers for the H . R on the side tanks. 

  

The lamp in front of the chimney is a casting by LGM with a lense made from epoxy glue. Photographic evidence suggests that lamps were rather haphazardly positioned rather than conforming to the rules, which required two lamps on the roof for a shunter or yard engine.

Rear view shows firebox tools on the roof on the fireman's side of the cab and real coal in the 1 3/4 Ton bunker. The rear buffer beam carries neither insignia nor a vacuum pipe, as these yard engines were not equipped with that braking system. The rear windows are protected by vertical bars which were soldered to the brass window surrounds. Coupling hooks are cut from chunky nickel silver sheet and sprung behind the buffer beam, links are formed from n/s wire on a jig.   

Large balance weights were cut from 0.4 n/s sheet and impressed with rivets.

The tools, tool box and the driver and fireman are my own sculpture, cast in white metal in my workshop, they are designed to enliven the confined space of the cab without crowding it.

I constructed the reverser from chunky nickel silver sheet and detailed the basic shape with bits and pieces before painting it. The floor is real wood strip, back-head castings are from LGM and 62C with modifications, the oil cans are my own castings.

HR Scrap Tank, Making a Start in 7mm Scale.

Test running the chassis through the crossings on my track at home. Mini 7E gearbox with M1830 motor and MSC flywheel. The motion plate is in place though the slide-bar, cross-head and connecting rod are yet to be fitted. 

Undoubtedly the Scrap Tank is aesthetically one of the less appealing of Highland Railway engines, it does not have the elegance and visual appeal of so many of their designs. It nevertheless has a certain fascination which has drawn me repeatedly to consider a model of one of these ungainly yet curiously appealing shunting engines. It's a fascination to which I knew I'd eventually have to give in to and  indeed I have... and I've made a start on the model. 

The Scrap Tank, though a fairly simple engine, nevertheless presents some constructional problems of its own, probably the most difficult to solve being the lack of clearance between the coupling rod and the cross-head. The slide-bar and cross-head assembly needs to be as close to the side frame as possible to allow the connecting rod to run parallel to the side frame and not be spaced too far out from the coupling rod on the center driving wheel crank-pin; I'm working on it. 

As you can see above, I've arranged wire pick-ups on the center and rear drivers, which will be hidden inside the side tanks. The front pick-up is not so simple and as yet I have not contrived it. A wide leaf spring will be mounted behind the front driving wheel, which will make arranging a wire pick-up from this wheel difficult. I've not mounted the spring in place yet, nor have I managed to source a casting for it, so it's not an immediate problem. Watch this space... 

Cut-out parts and sub-assemblies for the superstructure await the next phase of construction.. A few castings I need are proving elusive, particularly the leaf springs, so I might try having them 3d printed. 

I wanted to have the chassis running before the turn of the year and indeed it is up and running, which is a good point to leave off the modelling as it's New Years Eve...and go into festive mode!