Morgan Whyalla pipeline

The Morgan – Whyalla pipeline was an engineering project undertaken by the South Australian Government in 1940 to bring water from Morgan on the River Murray to the industrial city of Whyalla. A second pipeline, by a divergent route, was laid in the 1960s.

History

In 1937 Premier Butler of South Australia negotiated with Broken Hill Proprietary Company to erect a blast furnace at Whyalla to process iron ore from Iron Knob using brown coal from Leigh Creek. Lack of sufficient fresh water was an obstacle, To this end Butler pushed through enabling legislation and sent engineers to Western Australia to inspect their achievements in above-ground pipelines, notably the Goldfields pipeline engineered by C. Y. O'Connor. In 1938 Premier Playford increased the demands on BHP, and came to an agreement with Essington Lewis that if the company were to install a tinplate manufacturing plant, the State would supply the water infrastructure. Playford reckoned on the proposed pipeline also supplying the needs of Commonwealth Railways at Port Augusta for their Indian Pacific and Ghan railways. Prime Minister Lyons agreed to help South Australia with a development loan.

In 1939 Lyons died and was replaced by Menzies; shortly after, World War II broke out and Menzies joined with Britain in declaring war on Germany. Under the changed circumstances, Playford renegotiated the deal in terms of shipbuilding rather than tinplate manufacture. In 1940 the Commonwealth Water Agreement Ratification Act was passed, complementary legislation passed through South Australia's parliament^[1] and South Australia's Engineering and Water Supply Department was given the task of getting the job done, under considerable pressure from the War Department, and with reduced manpower and materials due to exigencies of wartime. The first stage, from Whyalla to the Baroota Reservoir, was rushed through to help supply water for shipping. The whole route, using continuously welded steel pipe (supplied by Hume Pipe Company), four pumping stations^[2] and 127 concrete storage tanks, was completed in 1944,^[3] just in time to alleviate a serious drought that had hit the mid-North of South Australia. The pipeline was officially opened by the Governor of South Australia, Sir Charles Malcolm Barclay-Harvey in 1945.

Description

Morgan is a small town built on high ground overlooking the Murray River at a point the River Murray changes its westerly course to almost due south. The first pumping station is situated on the river bank, 2 miles (3.2 km) upstream from Morgan. Here a large concrete chamber was constructed, the floor of which is below the river's low water level, and the walls of which rise to above the flood level. The chamber is somewhat elliptical in shape and is divided by a wall across the smaller diameter; one half housing the pumps and the other containing the screening machinery. The concrete walls of the chamber are over a metre thick to give it sufficient weight to prevent it floating during a flood. A control room above the chamber houses the switch board, instruments and a diesel stand-by generator. Water is drawn from the river and passes through rotary screens having a fine wire mesh of 200 openings to the inch (80 per cm). This removes all solid matter except colloidal clay, which when present gives rise to a milky appearance. The water receives no other treatment, and its salinity and hardness are less than that of Mundaring water which is used in the comparable Goldfields pipeline. The centrifugal pumps are driven by 400 h.p. (300 kW) electric motors, the power for which was originally supplied from the Osborne Power Station, and later from Port Augusta. The four intermediate pumping stations, which are all similar, fill a receiving tank elevated to 400 feet (120 m), and are each at a lower elevation than the previous storage tank, so the centrifugal pumps run with a flooded inlet and do not require priming. The last pumping station operates into the Hanson storage tanks, which are 1,558 feet (475 m) above sea level and 57 miles (92 km) from Morgan. From Morgan to No. 4 pumping station the pipe travels through arid country; after that it passes through good agricultural land and thence through the Flinders Ranges at Hughes Gap. The pipe then follows the eastern side of Spencer Gulf to Port Augusta and after rounding the head of the gulf continues southward to Whyalla, again passing through arid country. The route was chosen to pass close to all the main reservoirs in the mid-north of South Australia, so that they could be supplied with River Murray water. From the Hanson tanks the water gravitates all the way to Whyalla, a distance of 166 miles (267 km). The total length of the pipeline is 223 miles (359 km) and the pipes, which are of steel, concrete lined and protected against external corrosion by "galvanite", a proprietary zinc coating, vary in size from 30 inches (760 mm) to 21 inches (530 mm).

The South Australian engineers followed the later practice of the Goldfields Water Supply in adopting continuous welding of the pipes. This was soon vindicated when floods hit Port Augusta and Whyalla, causing damage to roads, bridges and the pipeline. At one place, where the water had swept across the road and piled timber up against the pipeline a length of pipe 80 m. between concrete blocks had been bowed outward by over a metre, but had not broken. In another place an 80 m. length of pipe had been completely undermined, and the pipe had sagged about a metre, being dragged down by a large concrete block, weighing about three tonnes, which was left suspended. Close to the block the pipe had buckled, and twisted through 180 degrees without fracture. Two breaks had occurred in the pipeline during the flood, both at places where it was carried over creeks on concrete road bridges. These bridges had been undermined and swept away, carrying the pipe with them. Repairs were made as soon as the flood subsided, and the supply to Whyalla was restored within ten days.^[4]

Related pipelines

A second Morgan–Whyalla pipeline was commenced in 1963 and completed in 1967. It was made considerably shorter by passing the last section under Spencer Gulf rather than around it.

A similar pipeline, from Mannum to Adelaide, began in 1949 and was completed in 1955, just in time to avert a serious water shortage.

See also

• Whyalla Steelworks
• SA Water

References

Sources

Hammerton, Marianne Water South Australia Wakefield Press, Adelaide 1986 ISBN 0 949268 75 5