Lake Margaret Power Station - History

History

In 1911 the Mount Lyell Mining and Railway Company decided to make more extensive use of electricity in its smelting operations in the mining town of Queenstown, on Tasmania's west coast. It selected Lake Margaret, a small lake high up on Mount Sedgwick, to the north-west of the town, as its catchment area.

In 1911, construction of a dam was commenced, which raised the original lake by six metres. The water was originally conveyed from the dam via a 2.2 kilometre wood stave pipeline. The Australian Woodpipe Company was consulted and employed to construct the wooden pipeline. The Mount Lyell Mining & Railway Company determined that not only was a wooden pipeline cheaper to construct, but it was also more efficient and durable than iron or steel. The local native Tasmanian timber King Billy Pine was studied but it was decided not to be suitable. In a letter dated 13 June 1913, Albert G. McDonald, an interstate representative for the Australian Woodpipe Company, wrote to Robert Carl Sticht, the General Manager of the Mount Lyell Mining & Railway Co Ltd:

With regard to King William Pine, we are sorry to say that we do not consider this at all suitable for the purpose of pipe construction on account of its lack of uniform density. We did prepare an estimate for constructing the pipe at your Works from Pine to be supplied by you, and our estimate actually worked out at a lower figure than that of your engineers, but we feel that we would not like to be associated with the manufacture of a pipe made from this timber. We regret being compelled to arrive at this decision because we have been searching Australasia for a suitable timber, and thought that the Pine in question might have answered the purpose.

The wood stave pipeline was subsequently constructed from Oregon Pine (Douglas Fir), which was imported from Canada. The timber was shipped to the west coast town of Strahan and was transported to the Lake Margaret precinct via the ABT Railway. This pipeline rapidly deteriorated and in 1938 was replaced by a King Billy Pine wood stave pipeline, with the timber sourced locally. This pipeline was still in service until the 30 June 2006 closure of the Lake Margaret Power Scheme.

The wood stave pipeline originally joined two 29-inch-diameter (740 mm) steel penstock pipes which dropped 330 meters to the power station building in the Yolande Valley below. Due to the efficiency of the scheme another penstock pipe was added in 1919. Due to internal deterioration these pipes were replaced in 1969 with a single 48-inch-diameter (1,200 mm) steel pipe, by contractor John Holland. This replacement coincided with major refurbishment of the power station building, renewal of sections of the Lower Power Scheme wood stave pipeline, replacement of the transmission lines between the power station and the Queenstown substation, and post-stressing of the Lake Margaret dam wall.

The Lake Margaret Lower Power Scheme was opened in 1931. Showcasing the ingenuity and resourcefulness of the men in charge at the time, it was located downstream from the main power station and utilised water that had already powered the turbines in the main station. It housed a single Boving-Francis type turbine which, whilst having to be manually started, could be remotely controlled from the main power station, demonstrating a unique system that is considered significant in the history of power generation in Tasmania and Australia. The Lower Power Scheme was mothballed in the early 1990s.