Wednesday, 29 March 2017

HR Passenger Tank

Highland Railway 0-4-4T Drummond Passenger Tank

I decided to build my latest project, a HR Passenger Tank, without the aid of a kit although I was aware when I commenced the project that there were two kits available for the engine... I didn't think that either would be of much help. Laurie Griffin's lost wax castings for this particular engine once again are proving to be indispensable however. I began construction at the end of February and these  pictures chart my progress. The engine is up and running and will have a test run under club conditions on the CDOGG layout at the weekend.

Much of the mechanism is revealed in this rear view.
Chassis and mechanism in close-up.

I've shorted out the wheels on the right hand side of the engine and rigged up wire pick-ups bearing on the top of the left hand side driving wheels, the pick-ups should disappear nicely into the front splashers and side tanks.
The n/s pick-ups are mounted on copper clad insulation board from where a wire leads back indirectly to the motor terminal. The motor gearbox is from ABCGears, it's a Mini 7S with an M1824 motor which will have to run without a flywheel as there is insufficient room for one. It's not the ideal motor-gearbox configuration, though as I had it in stock, it'll have to do.

Rear bogie top view, note guard irons tight behind rear wheels.

I added extensions to the LGM white metal bogie side casting for this engine from 0.4 n/s sheet, the rear guard irons are attached to these...mixed solder and glue construction. The centre hole is for the pivot which at the moment is un-sprung though I'm thinking about this. Wheels run in 1/8" bearings without compensation.

Rear bogie underside
The pick-up arrangement can be seen in this view of the bogie underside. A detachable wire screws to the CCIB and leads to the motor. The right hand side wheels are shorted out, one with a wire and the other experimentally with conductive silver paint, which seems to work well.