Mud, steel and an unshakeable vision: The construction of the Lovell Telescope

Sir Bernard Lovell’s ‘giant paraboloid’ was originally proposed in 1951 and complete by 1957. Why did it take so long to build? The short answer is that no-one had ever built anything like this before. The new radio telescope was to be 250ft diameter, 290ft high and fully steerable to focus on any area of the sky with pin-point accuracy. There were plenty of small steerable dishes around at this time, but Lovell understood that something significantly larger was needed to advance the new science of radio astronomy.

Although the scientific community supported him, Lovell initially struggled to find an engineer to take on the challenge. Many simply did not think it was possible to build such an instrument.  But in 1949 he met Charles Husband, a Sheffield-based engineer who considered the proposition and concluded it was achievable; ‘about the same problem as throwing a swing bridge across the Thames at Westminster…’.  But as they were to discover together, the requirements of enormous size and absolute precision, to be executed in a muddy Cheshire field, would be an engineering challenge like no other.

Above: Charles Husband and Bernard Lovell in front of the almost-complete telescope in 1957 (Copyright University of Manchester)

In this clip from Lovell’s oral history interview on Web of Stories, he explains just one such problem. In 1954 when the construction work began there weren’t any cranes large enough to handle the mass of steel that was involved, so Husband built a series of cranes and gantries until they had something that could work at the enormous height of the telescope. This is typical of Husband’s innovation; at every stage of this often fraught construction project he was prepared to find new approaches and original solutions, refusing to be limited by existing technologies. He understood that Lovell was breaking new grounds in science, and the telescope could break new grounds in engineering. In many ways, and despite difficult moments in their relationship, Lovell and Husband represented the perfect partnership of science and engineering.

Lovell’s construction diary, held at The Royal Society, gives an almost day by day account of the telescope’s construction. Reading the entries, you experience the saga through Lovell’s eyes. You feel his frustration at steel price rises and worker strikes, anxiety at the constant negotiations, despair as weather halts progress at crucial moments, dismay at the increasing doubts of those around him, and jubilation at small victories.  All the while the costs involved are becoming higher and higher.

Particularly poignant are his Christmas Eve entries, in which he reflects on the last year:

1953: ‘A year ago today Cementation were struggling around the hundredth pile. Today in brilliant sunshine only Wades are on site putting in the drain pipes […] There has certainly been some progress between these two Christmasses, but there will have to be a good deal more by Christmas Eve 1954 if the instrument is to be ready for use in 1955.’ [MS_870_0251]

1954: ’Since the diary note on the eve of Christmas a year ago the site of the telescope has been transformed […]  Above all, and in spite of the 1000 tonnes of steel on the site, the future is dark with financial anxiety. But surely now it will be finished, perhaps even in 1955.’ [MS_870_0350]

1955: ‘Another Christmas without the telescope – but surely not next year! […] Still, we have a good deal more than a year ago, including the control building, although the control room is still empty.’ [MS_870_1_3_0032]

The delays were not entirely out of Lovell’s hands. During construction he requested a number of design changes for scientific reasons, the most significant of which was replacing the original wire mesh dish with a solid surface, to enable the telescope to work at shorter wavelengths. This was in response to the 1951 discovery of the 21cm hydrogen line; a hugely significant development in radio astronomy. It was part of a suite of design changes in 1955 that necessitated an additional 440 tonnes of steel and brought the telescope £250,000 over budget.

What becomes apparent throughout this story is Lovell’s unshakable commitment and vision. At all points of the project he was encouraged to abandon. At the beginning of 1954 Lovell wrote to Husband to ask him to ‘obtain some big erection on site as soon as possible. Many people are still taking every opportunity of saying the project must be cancelled‘. As early as 1953 Patrick Blackett, Lovell’s lifelong mentor, expressed extreme annoyance at Lovell’s ‘blind ambition’ and the delays it was to cause, stating that the cream of the research would be skimmed off by places with ‘less ambitious apparatus’.

Above: The telescope rises out of the mud, c. 1955 (Jodrell Bank collection, copyright University of Manchester)

But Lovell was single-minded, and the giant telescope slowly rose up out of the Cheshire mud. On the 2nd of August 1957 the telescope made its first recordings of the sky, the moment that is referred to as ‘first light’. As Lovell recalls in his autobiography Astronomer By Chance: ‘The recording was of no particular scientific importance, but for us it was an inked trace on a paper chart symbolizing an end to five years of massive engineering and a beginning to the researches that we had planned and dreamed of for many years.’  

The telescope wasn’t fully operational until 1958, and the debt remained until 1960, by which time the telescope had become wrapped up in the space race and matters of international defence… And that’s another story!