Duck Reach Power Station, Tasmania

Duck Reach Power Station was the first publicly owned hydro-electric plant in the Southern Hemisphere, and provided the Tasmanian city of Launceston with hydro-electric power from its construction in 1895 to its closure in 1955.

Construction

The site was picked by a surveryor and engineer named C.St John David in 1892.

The plant was a 'run of the river' station, making use of very little storage, and instead using the daily flow of the South Esk River to provide sufficient water for generation. An 850-metre tunnel drilled through mostly solid dolerite rock supplied water from Deadmans Hollow to a penstock which is an iron pipeline. The water discharged at rate of 5,537 litres per second from the tunnel exit. The penstock plunged diagonally down the hill into the center of the rear of the power station where it channeled in to successively smaller pipes and entering the eight Siemens turbines inside the station. From there water was released into the river at the buildings foot.The plant was constructed at a significant height above the South Esk River so as to prevent it from being damaged in the frequent floods that rush down the Cataract Gorge due to heavy rainfall.

Drilling the Tunnel

The tunnel was drilled to a length of 850-metres at a 1 to 110 grade. The tunnel was cut through the hill side instead of being piped around and it took 16 months to complete using pneumatic drills. Dolerite is so hard it took one week of 18 - 8 hour shifts cutting from both ends of the tunnel to cut just 2.5 metres however the average speed of the drilling was about 5 metres a week. Two men were killed in accidents.

Operational History

The following is paraphrased from the display plaques now within the power station:

Originally the installation had a capacity of 75 kW DC, provided by five 15 kW dynamos, and 360 kW AC, provided by three 120 kW alternators. The turbines were manufactured by Gilbert Gilkes and Co., whilst the dynamos and alternators were built by Siemens and Co.. All alternating-current (AC) supply was single-phase. By 1906 demand had risen and it became necessary to upgrade the plant. This was done by removing much of the original equipment and replacing it with four 445hp Francis turbines manufactured by Kolben and Co. of Prague, each coupled to a single 300 kW three-phase alternator again built by Siemens and Co.. This raised the AC capacity of the station to 1.2mW. The original DC equipment remained in use.

Again by 1926 this had become inadequate, and to ease the problem a new 1,180hp turbine coupled to an 800 kW alternator was added alongside the existing machinery. To drive this new turbine a timber flume and a masonry aqueduct was constructed, running from Deadman's Hollow around the bend in the South Esk River to the slope immediately behind the Power Station, where it was led into a new steel penstock running alongside the original one. The addition of this new turbine and alternator raised the capacity of the station to 2mW. In the photograph above, the left-hand penstock is the newer one.

Despite its height above the river, the plant was destroyed in the great floods in Cataract Gorge in December, 1929. However, it was promptly rebuilt and resumed service by 1930.

Still, the plant was still unable to meet Launceston's electrical needs. By 1934 the City of Launceston was also buying electricity from the Tasmanian Hydro-Electric Commission, in addition to operating the overworked Duck Reach plant. In 1944 the Launceston City Council sold Duck Reach to the same organisation.

By then, its days were numbered. Construction of a new South Esk River hydro-electric power plant began in 1951 and the Trevallyn Dam Power Station were completed in 1955. The Duck Reach station was soon closed and its equipment removed. The buildings stood derelict and closed for over 40 years, until 1995 when, on the centenery of its first opening, it was re-opened as a museum. It has become a popular tourist attraction. One of the original Siemens and Co. 15 kW DC dynamos, dating from 1895, is preserved and on display within the station.

ee also

*Renewable energy
*Environmental concerns with electricity generation

References

* Hydro Tasmania; "South Esk Power Development", [http://www.hydro.com.au/home/Tourism+and+Recreation/Great+Lake+and+South+Esk+Catchment/South+Esk+Power+Development.htm] , Accessed June 2006.

External links

* [http://www.parks.tas.gov.au/recreation/shortwalks/duck_reach.html Parks & Wildlife Service, Tasmania - Short Walks #12, Duck Reach]