Technicians of the Atomic Energy Authority are making final preparations for two underground test explosions at Greenside lead mine at Glenridding, Westmorland. Only conventional explosives will be used in the explosions which will take place, half an hour apart, probably late this evening.
The tests are the first of a series designed to give information on the detectability of small underground nuclear explosions. Similar tests are to be carried out at a mine in Cornwall*, but the Greenside tests will be bigger and deeper; also the geological structure here is different.
In each of the firings, about a ton of TNT-type explosive will be set off more than a thousand feet underground. The precise figures are kept secret, although the results may eventually be published.
The explosions will be recorded by seismograph on the spot and at a number of stations up to fifty miles away. The scientists hope to learn not only how far away the explosion can be detected, but whether the seismographic record of a nuclear explosion can be distinguished from that of a conventional one. This question has been fiercely disputed at Geneva.
The site of the explosions in the hills two miles above Glenridding on the edge of Ullswater is one of the oldest lead, and formerly silver, mines in Britain. But it was due to close soon because of a fault in the vein. Only fifty miners are left now to help as many technicians. Although the mine will not be made unusable, it is thought unlikely to be worked again.
Glenridding is taking its explosions with complete calm. Some ex-residents have written from the South as if Armageddon was at hand, and initially there was a mistaken fear of radio-active fall-out. But this has been dispelled, and a common reaction among villagers is to say that they have never noticed explosions from the mine and they do not expect to notice this one.
The only detectable disquiet owes more to politics than science. Two miners, quoted by a leading local Conservative about the shifts in Labour policy, are said to have replied gravely to their tormentor that at least that was better than having a house at Glenridding built as his was upon the rock.
Note: The above newspaper clipping is believed to be from a ‘local’ paper, covering Cheshire, Cumbria and Lancashire. It probably dates from 1959/1960, as that was the period during which the Atomic Weapons Research Establishment were running their tests. The AWRE finally left Greenside mine in August 1960.
The tests in Cornwall were carried out in the Excelsior Tunnel under Kit Hill where a series of spherical chambers made for the tests can still be seen. Some appear to be unfinished, while others may have been used!
One of the Excelsior chambers. (Kelvin Lake)