Interview with a dish engineer, Robin Watson
10 Mar 2011





Chilbolton dish during construction

The following comments are paraphrased from an interview given by Robin Watson in November 2000. Robin was a member of AEI's Apprentice Training School at Trafford Park at the time that the dish was built. He worked on the original scale model for the antenna, and also spent three months in the summer of 1967 participating in the build itself.

"I spent the summer of 1967 working at Chilbolton, a period of about three months. I helped to line up the parabolic profile of the dish structure along with three other people. It was a complex process: we used a theodolite with cross wires to survey the dish. A punch card computer would process the measurements, then send back the necessary adjustments. We would adjust the individual aluminium petals to a perfect fit. It was a lengthy task, as there were 96 petals to get exactly right - I think I fell into the safety net hanging under the dish at least three times!
"I remember that the construction process didn't go completely smoothly. The 400 tonne dish was designed to pivot vertically so that it could point in any direction from straight upwards to directly at the horizon. The weight of the dish had to be counterbalanced so that it would move smoothly, and they mixed up a steel and concrete ballast to do the job. However, they didn't get the calculations for the mix quite right - the dish would move downwards all right, but couldn't be persuaded to go back up again! In the end, they had to weld steel counterweights onto the structure itself to compensate.
"There was one very sad incident that happened during the building of the dish. I was working with another chap installing part of the control system for the antenna. I then left the project on the Friday, and travelled up to Manchester over the weekend. On Monday I saw an article on the front page of the Manchester Evening News that said that this chap had died while working on the dish. He had apparently been trying to do the job of two, and was tragically killed in an accident. It was very sad, especially as the man had been due to leave the following week to get married.
"Although I only worked at Chilbolton for three months, it was certainly a memorable experience. I remember that GEC (the company that took over AEI shortly after the dish was built) was very excited about the potential for these dishes and wanted to build lots of them. I think one or two more were built in fact, including one in Canada, which must have been an exciting project. I recently visited Chilbolton again and the staff were kind enough to show me round the site. I'm pleased to see that our dish is still working smoothly all these years later!"
Contact: Jeffery, Judith (STFC,RAL,RALSP)