Building the Parkes telescope

The Parkes telescope during construction. Photo: CSIRO

Australia got off to a good start in radio astronomy just after the Second World War. Staff of the CSIRO Radiophysics Laboratory (later the Division of Radiophysics) made the first Australian efforts. They used radio-receiving antennas and other equipment left over from war-time, turning them from their original purpose of receiving man-made radio signals to studying the natural radio waves produced by objects in the cosmos. The equipment was rough and ready, and often improvised. But by the late 1940s and early 1950s it was clear that the days of improvisation were over, and that the next steps had to be fairly big ones. In turn, this implied that much planning and fair sums of money would be required.

The first proposal was to build a large air-warning antenna that would double as a radio telescope. The Radiophysics Laboratory had close links with the Royal Australian Air Force (RAAF): during the war it had worked for the army, navy and air force and just after the war it was advising the RAAF on radar and navigation equipment, including air-warning equipment. At the time it seemed that the best way to extend that technology would be to build larger radio-receiving antennas. Radiophysics staff began thinking in terms of dimensions of hundreds of feet. At one stage they proposed to build a wooden antenna, 100 feet in diameter, rotating on a track and costing all of £A365. A large antenna like this could be used for both air-warning and for radio astronomy. But the RAAF was even more strapped for cash than CSIRO, and had no money to put towards such a project.

In 1952 it became clear that CSIRO too had no chance of getting a large capital sum to fund such an instrument. Some way had to be found to squeeze it out of the existing Radiophysics budget. So a proposal was drawn up for a cylindrical antenna, lying on its back, 1000 feet long and 200 wide, made up of five adjoining elements. Each element would be 200 feet square, lying on an east-west line and scanned by cable and winches in the north-south direction. The total cost was to be about £A125 000, spread over five years. But once again the answer was ‘no’.

US support

Now a new factor appeared. Unlike Australia, the USA had been slow to take up radio astronomy after the Second World War. The leader of the Division of Radiophysics, Dr E. G. Bowen, had many contacts in science and industry in the USA, and he urged them to help the USA to take up radio astronomy, mainly by building a large radio-receiving antenna. The proposal fell on receptive ears. The Division of Radiophysics wrote a detailed specification for such an instrument, and a program of scientific activities that it could be used for. It was tacitly understood that this telescope would go ahead at the California Institute of Technology, and that the Carnegie Corporation might provide up to $5 million for it.

About the time that these plans for a telescope were being drawn up, the large American foundations such as Ford, Rockefeller and Carnegie were changing their emphasis in supporting science, giving less to the US and more to other parts of the world. Vannevar Bush (President of the Carnegie Corporation) and Alfred Loomis (a Trustee of both the Carnegie Corporation and the Rockefeller Foundation) suggested that the proposed large telescope be built in Australia, with financial assistance from the USA. The Carnegie Corporation had accumulated $US250 000 that it was obliged, for certain reasons, to dispose of in the British Commonwealth, and the Corporation’s trustees granted this money towards the construction of a telescope in Australia. This grant was followed by another $250 000 from the Rockefeller Foundation.

Government Support

The last hurdle was that the overseas bodies required that their own grants be met, dollar for dollar, by the Australian Government. The Government rose to the occasion and contributed to not only the capital costs but the running costs as well. A year later the Rockefeller Foundation gave a further $US130,000. The telescope now had an assured future.

At that time there was no-one in Australia capable of building the Parkes telescope or even doing the engineering design. So CSIRO went to Britain for advice (it was thought to be cheaper than the USA). The first person consulted was Barnes Wallis (of ‘dambusters’ fame), who was then the Chief Engineer of Vickers. He advised on the problems of deflection of the telescope’s structure, first by thinking of incompressible columns (he held the patent to this device) and then by recommending automatic compensation for changes to the dish's parabolic shape (which was in fact used in the telescope). In a significant departure from the design of previous telescopes, Wallis recommended that the telescope’s mounting system (the way in which it is turned and pointed to different parts of the sky) be 'alt-azimuth', rather than, for instance, the equatorial mount used on the earlier radio telescope at Jodrell Bank in the UK. And just for good measure, Barnes Wallis came up with the idea of the telescope’s guidance system, the 'master equatorial'. Wallis’ contributions far exceeded his very small retaining fee – which, in any case, it seems that he was never paid.

The detailed engineering design for the Parkes telescope was done by Freeman Fox, the company that had designed the Sydney Harbour bridge. The design contract was placed in 1956 and completed in 1959. After this came the search for a construction contractor: CSIRO settled on the MAN Company (Maschinenfabrik Augsburg-Nurnberg A.G.) in Germany. The contract was placed in 1959 and the telescope completed in 1961.