< Boiler Installation >
The boiler was mounted on the chassis and most of fitting works were done except tubes from saddle tank.
Blower tube of the Hunslet is running outside of the boiler. The tube is led into the smokebox through an elbow. I made the elbow from two brass parts. The outside part is cut from rectangle bar while the inside part is cut from round bar. They will be silver-soldered. The inside part of the elbow is threaded.
The copper tube is threaded, screwed into the elbow and fixed by a lock nut. Rear end of the tube is connected to the blower valve on the steam dome.
The elbow is fixed on the smokebox side with a nut. A copper tube is connected between the elbow and the blast nozzle. The u-shape is for adjustment of the distance.
I employed 4mm and 5mm copper tubes for fitting works. In order to bend tubes precisely, I made several kinds of pulleys from brass bars. I bend tubes without annealing because annealing makes tubes too soft.
On the left side of the firebox, hand pump and injector are installed. They are OS products. Water in the saddle tank is too hot for the injector, so I will supply cool water from passenger car.
Steam for the injector comes from the injector valve on the steam dome and goes into the injector front. Cool water comes from a nipple on the buffer beam and goes into the injector bottom via a cock valve. Water output comes from the injector rear, goes through a check valve, merges with the hand pump's output and finally goes into the boiler with another check valve. The former check valve is to avoid backward flow from hand pump to injector.
I made a saddle tank's water gauge from an acrylic pipe and brass rods. I adopted large diameter pipe so as to minimize water level vibration. The water gauge will be connected to the saddle tank with a pipe. I made a pair of connecting flanges for now.
The photo shows right side of the fittings. A copper tube from axle driven pump will be connected to the tee. From the tee, the backward tube goes into the boiler with a check valve, while the downward tube is connected to the return valve at the back end of the cab. From the return valve, a return tube is led to top of the tank water gauge.
It is rear view of the fittings. The pressure gauge is connected directly to the steam dome. The whistle valve isn't connected yet.
The boiler is held between the frames with blocks at both sides of the firebox. I add steel angles to secure them. It needs clearance between the blocks and the angles so as to ensure boiler's heat expansion.
Most of full size Hunslet locos have one-piece cylinder jackets which go through running boards. But I adopted separated type because it looks neater. Upper part of the cylinder jacket was made from brass sheet and triangle parts. The triangle parts are cut from rectangle bar with a fine slitting saw. They are soft-soldered and fixed by screws from underneath.
All of the parts so far are assembled together. It's getting close to completion. The next job is the saddle tank.