Live steam model on 7¼" gauge of the Württembergische T3 no 924

Welcome to this blog. It will inform you about the progress of designing and building miniature live steam, coal fired locomotives for passenger hauling. Currently I'm working on a 7¼" gauge, scale 1:8, German T3 steam locomotive.

In 2006 I started this new project. This is a small 0-6-0 branch line locomotive of German (Königlich Württembergischen Staatseisenbahnen) origin with outside cylinders and Walschaerts valve gear. The loco is about 1.10 metre long and will weigh approx. 100 kg.

On the left you'll find the index where you can browse through the different articles and on the right you'll find all the extra's. On the top tabs you'll find a brief description of my other locos.

Enjoy this site. Erik-Jan Stroetinga. The Netherlands. Europe.

Friday, 31 October 2014

Starting with the pipework

Most of the pipework on the locomotive will be out of sight, but should be easy to fit and maintain. There are pipes needed to supply water from the tanks to the pumps, injector and from there into the boiler.
The connections between the side tanks were a bit of a puzzle. I had to decide in which way I wanted to assemble the locomotive. Tanks first and boiler fitted afterwards, or first the boiler on the frame and then the side tanks put in position on the running boards?

The connections between the tanks and the mechanical driven axle pump, the pipe work between the left and right tank and pipe work between bypass valves, and the injector and future steam pump were drawn (or sketched)  in Solidworks and studied on the model. 
It was decided that most of the pipe work shoud be fitted, before the boiler was on the frame. I read in the Haynes Manual that this methode was also used on the Tornado (by the way a very nice book to read).

This way I was able to fit (and access) most of the pipework, within the limited space between the frames and under the boiler, without too much trouble. The boiler is lifted in its position from the top and can than be connected to the supply pipes from the pumps and injector.

Home made connectors for the tanks were turned of brass with a M16 x 1 thread. The nut (hex. 19mm) was also made from solid brass. This design is big enough  for a 10 mm hole. The flat end pieces are screwed together and will provide the seal. This will be sufficient to prevent leakage, because there is no water pressure to take in account.

The space between the water tanks, here seen from rear to the front of the locomotive. The four connectors in place on the tanks. Only 1 mm of water will be left on the bottom of the tanks when  empty, this is due to the side ways mounting of the connectors to the tanks.

This is the double connection between the left and right tank (lying up side down in the picture).  Due to the opening in the side tanks (to make space for the weighshaft and mechanical lubricater) there is also a connection between the front and back of the tank.

A test set-up of the connecting pipes. The final soldering was done in position on the locomotive. 

This 22 mm pipe with a brass tee fitting (standard pipe fitting) contains a water filter. This can be easily removed for maintenance from the underside of the locomotive without disturbing the boiler.

Top view between the tanks. The pipes do not obstruct the weighshaft.

The pipe work is made from standard brass fittings and 12 mm copper pipe from the DIY store.

The water filters were made from fine brass gauze, soldered in between a brass ring and end cap. One filter will be for the axle pump, the other will be situated in the bottom of the left hand tank for the injector.

The filter assembly. Only three stainless steel M2 screws hold the filter in place.

The first stage completed: connections between the front and rear of the tank and between the left and right tanks. Filling water in either on the left or right tank shouldn't present any problems with water flow between the tanks. Two 12 mm pipes with a 10mm bore connect them together.  Both tanks combined hold a total of 7 litres of water.
On the real locomotive there were also tanks between the frames, even though the loco had only an action radius of 24 Kilometre.  On the model these tanks are omitted.