Bridge Water Mill History

bridgewater mill old photoThis historic flour mill was built in 1860 by a mill engineer from Devonshire, John Dunn (1802 ~1894).

The giant ‘pitchback’ waterwheel known as the ‘Old Rumbler’ was manufactured in Scotland and brought out in pieces and assembled here. It weighs 26.4 tonne and is an imposing 11.27 meters in diameter and required 30,000 litres of water each minute to drive it..

The water came from Cox’s Creek which rises near Uraidla and was diverted to form a dam located just over the railway line towards Aldgate.

The Bridgewater Mill had its opening celebrations on 1st January, 1861 when John Dunn entertained over 100 employees, families and friends. It was one of the states’ finest flour mills and was the only one driven by water. In addition, a steam generation plant was built to take over in summer, when Cox’s Creek ran dry.

Bridgewater Mill Flour won first prize in the International Exhibition in London in 1862 and for many years was transported all over Australia.

In the latter half of the 19th Century the manufacture of flour was one of South Australia’s earliest successful industries and Mount Barker was the main wheat growing district in the state.

As people returned from the Victorian gold fields with money and ambition, flour milling became an attractive investment and by 1870 there were fourteen mills within the district, all competing for trade which could have effectively been handled by 4 or 5 mills.

The Bridgewater Mill was only one of two mills which were constantly in production and continued to work at full pressure until the northern wheat areas opened up in the 1870s and 1880s. Mills were then established at more northerly and convenient locations such as John Dunn’s mill at Port Pirie, Wilmington and Port Augusta.

After this northern shift, Bridgewater reduced production to suit local market requirements and after the closure of Dunn & Co. in 1899 went through a myriad of ownership and activity until the wheel ground to a halt in 1942 when a pinion broke.

The building was further used until 1961 when Hamilton Ewell Vineyards Ltd. Used it as a bond store for the maturation of locally made brandy and whisky.

In 1984 Petaluma Wines purchased the mill and its surrounds and undertook renovation to restore the grand old building and its waterwheel.

In February 2015 Warren & Nicolla Randall purchased the mill and its surrounds and have plans for further improvements including new decking, a wine and coffee lounge and opening for dinners.

Today the mill as an important Adelaide Hills attraction. The restaurant is considered one of the country’s finest, and sitting proud along the Heysen Trail the water wheel is the most photographed land mark in the hills.
The Heysen Trail is a long distance walking trail in South Australia. It runs from Parachilna Gorge, in the Flinders Ranges via the Adelaide Hills to Cape Jervis on the Fleurieu Peninsula and is approximately 1,200 kilometres (750 mi) in length.

Pitchback Water Wheel Design

The Pitchback Water Wheel Design is a variation on the overshot waterwheel as it also uses the gravitational weight of the water to help rotate the wheel, but it also uses the flow of the waste water below it to give an extra push. This type of waterwheel design uses a low head infeed system which provides the water near to the top of the wheel from a pentrough above.

Unlike the overshot waterwheel which channelled the water directly over the wheel causing it to rotate in the direction of the flow of the water, the pitchback waterwheel feeds the water vertically downwards through a funnel and into the wheel just below the top causing the wheel to rotate in the opposite direction to the flow of the water above.
Just like the overshot wheel, the gravitational weight of the water in the buckets causes the wheel to rotate but in the opposite direction. As the angle of rotation nears the bottom of the wheel, the water inside the bucket empties out below and the empty bucket continues around the rotating wheel as before until it gets back up to the top again ready to be filled with more water and the cycle repeats. The difference this time is that this waste water flows away in the direction of the rotating wheel (as it has nowhere else to go), similar to the undershot waterwheel principal. Then the pitchback waterwheel uses the energy of the water twice, once from above and once from below to rotate the wheel around
its central axis.

The advantage of this is that the efficiency of the waterwheel design is greatly increased to over 80% of the waters energy as it is driven by both the weight of the incoming water and by the force or pressure of water directed into the buckets from above, as well as the flow of the waste water below. The disadvantage though of an pitchback waterwheel is that it needs a slightly more complex water supply arrangement directly above the wheel called the “pentrough”.