The bridge deck just after bracing is applied.
The Victorian Railways operated a vast network of rural branch lines. The great majority had a turntable at the terminus to allow a steam locomotive to be turned in order to face locomotive first in the down and up directions.
The VR first installed 50' turntables for this purpose. However, in the early 1900s, these became inadequate for locomotives larger than the DD class locomotives. A program began to replace these tables with 53' tables in most locations which could handle the extra length of the K and later J class steam locomotives. Some places however never received such upgrades under the VR, such as Beechworth and Maldon.
With my intention to eventually build 'Cobram', I will be in need of a table suitable for representation as a VR turntable. However, those models for European and US markets are not only different in any aspects (such as snow platforms!) but they are generally intended for much larger locomotives than those used on the Victorian
Numurkah turntable still in situ.
network and so are too large to represent 53'. Fed up with trying to find a ready made example I set about designing my own based on the table still in situ in Numurkah, Victoria. It's a standard design in a country setting; no dedicated pit, just a well of earth with a leading road.
The finished product.
After measurements were collected and drawings produced, I set about building a pilot from styrene (above). At the centre of the table in the pit is a copper PC board with special tracks. Contacts on the underside of the turntable collect the electricity for the bridge (and turntable road). When the table bridge is aligned with a road, the road is powered for a locomotive to be driven on or off the table bridge. When the bridge no longer faces a road, power to that road is cut, thus providing an 'insulated' turntable similar in fashion to insulfrog points. This can however be overridden by an operator if they wish to control a road not being powered by the bridge.
The turntable is powered by a Walthers turntable motor. The bridge balance wheels are Steam Era Models wheels (10.5mm dia) with their flanges filed off.
The bridge deck is 192mm long, which equates to 54.8 scale feet. The additional 1.8' is necessary for the slightly longer than prototype K and J class models, due to tender spacing associated with curve navigation.
It is painted in the wagon red colour that the VR's tables appear to have been painted in, with a little base weathering, not entirely evident in the photo above.