4 October 1952 An atomic weapon of British manufacture was exploded in the Montebello islands early yesterday. There was a flash, a double bang, a blast of wind, and a cloud unlike the usual mushroom-shaped one
The sound and the appearance of yesterday’s atomic explosion in the Monte Bello Islands have caused speculation that Britain may have produced a new type of atomic weapon.
Observers on the mainland report that they heard a double explosion, the second louder than the first. This could be accounted for, it is stated, by the trigger effect of a “conventional” atomic weapon exploding some other material as in a hydrogen bomb. It could also be produced by a new method of exploding a “conventional” bomb.