This one is based on a South Australian Railways design used on their ng lines and similar ones were used on other state ng systems. The water tanks used on the VR ng lines were a temporary arrangement using a tank from a bg wagon fitted into a ng open wagon with the doors removed.
I had been thinking for some time about building a tank wagon, but an oil tank seemed unlikely in the area served by the TVT in the modelled timeframe. I didn't want a bogie water tank, but the SAR design caught my eye recently in a book I was reading and it looked like a good project to keep me occupied during the recent hot spell.
The TVT is located in an area of Victoria that isn't particularly drought prone, so the TVT wouldn't have had a need for many water tanks. I decided I would only make one, instead of my usual batch build.
Like the SAR version, this one is fitted to a wooden under frame and is only 1200 gallon capacity, so within the 5 ton load limit of the under frame. VR water tanks were 2000 gallons and needed a bogie under frame when used on the ng.
The model is built on my standard 4 wheel under frame and the tank was built from polystyrene sheet to simulate the riveted mild steel tank. The rivets were punched into 20 thou. sheet, which was then laminated onto 60 thous. sheet to form a strong braced box shape that wouldn't warp over time, or collapse when picked up by the ham-handed.
The timber baulks under the tank were probably used on the prototype to raise the bottom of the tank above the bottom of a loco tender, so that when the wagon was being used as an auxiliary tender, all the water would be available. The increased tank height also brings the water filler up to the same height as the water filler on a tender.
This photo shows the model before painting, showing the mixture of materials used. I didn't take any progress photos, as there were no techniques used that haven't been shown before. As always, it is difficult to take a good photo of white polystyrene.
This pic shows the finished model, taken this afternoon in a sunny period between rain showers. The signage suggests this wagon would normally be used for transporting potable water to work sites and to manned stations during dry spells, rather than as an auxiliary tender.
TVT Story
Although the TVT route follows river valleys and the rivers are permanent, there is still a need to transport clean water to temporary work camps and for supplying water during extended dry spells to locations that rely on rainwater tanks for their water.
These water gins spend most of their time sitting around in sidings at the workshops until needed. The design was based on the small ng tanks used by the SAR so that some redundant ballast truck chassis could be used. Using the VR design would have tied up bogie chassis that could be better used for paying traffic.
Regards,
Graeme
