When I first saw this engine, running quietly on steam in the Powerhouse Museum, and read that it powered a gold dredge on the Ovens River in Victoria, I imagined a fairly benign operation, sucking up part of the river bed, extracting gold from it, and replacing the material. The ecology of the river would have suffered local disturbance, but that section of river would have recovered over time. I failed to guess the full impact of gold dredging.
Winning gold in the region around Bright began with panning in the Ovens River in the 1850s. Later, stamper batteries were hauled in to crush gold-bearing quartz from underground mines, both in the valley and in the surrounding hills. The stampers were powered by water wheels or steam engines, and the steam was raised in boilers fuelled by local firewood. Timber was also cut for use in buildings and mines.
But there was a lot more alluvial gold to be won, and it wasn’t just in the river. The first method used to recover gold from the river banks was sluicing with water jets, which washed soil into the river and left parts of the valley unsuitable for farming. Sluicing was replaced by dredging of a much larger area in the early years of the twentieth century. Sixty gold dredges gouged their way through the valley’s 10 metre thick soil, silting the river up, causing it to change its course in places and leaving behind piles of rocks. In 1905 the Victoria government established a Sludge Abatement Board to regulate both sluicing and dredging, except along rivers that were already deemed useless for water supply.
The Marshall engine was made in England in 1909 and installed on the Maori Queen no 2 dredge. (This name reflects the fact that Australia imported dredge technology from New Zealand.) The engine’s output of 86 horsepower made Maori Queen 2 particularly effective, capable of churning through 7000 to 8000 cubic yards of material each week. A good deal of timber was needed to feed the boiler of this one engine, so more local trees were chopped down, contributing further to soil erosion.
Appalled at this destruction, farmers and other local residents formed the Ovens River Anti-Sludge Pollution Association to fight for an end to dredging. In 1911, the protesters won an important victory: the Victorian government ceased granting licences to dredge the river. Despite this, dredging continued until 1954. In 1940 our engine was sold to a timber mill; in its new role it continued to assist the shaping of the Victorian landscape, and it was witness to debates between the timber industry and advocates of tourism and environmentalism.
The engine’s horizontal design makes it an excellent example of the steam engines that powered many factories between 1850 and 1950. Its two cylinders, which allow it to use steam first at high pressure and then at low pressure, make it an example of the ongoing search for improved energy efficiency in engine design. But knowing its story adds greatly to our understanding of the engine’s significance, allowing us to consider the wealth it helped create and the environmental problems and conflict it helped cause.
Written by Debbie Rudder, Curator.