BMEWS
As a result of plans laid in the late 1950s three huge radar stations, each with a range of 3,000 miles, were built to give the US administration early warning of Soviet trans-polar nuclear missile attack. Only one of these radars, at Clear, Alaska, were built on American soil. The others were sited at Thule in Greenland and on Fylingdales Moor in Yorkshire, England. As these radars were in many ways the pivots upon which US nuclear strategy revolved their presence in Greeland and the UK rendered the host countries dangerously vulnerable strategic targets in their own right. The original FPS50 'billboard' radars and the FPS49 parabolic radars were replaced in the early 1990s by solid-state phased-array systems which have much the same range but are far less succeptible to jamming.

ABOVE - the famous Fylingdales 'golfballs', each containing an 84-foot diameter radar dish
RIGHT - In the foreground can be seen Fylingdales' replacement phased-array radar, with the disused 'golfballs' in the background. These were demolished in 1995

ABOVE LEFT- the original 'billboard' radar at Thule, Greenland in 1960, with the replacement phased-array tower on the right
BELOW:- Clear, Alaska, phased array radar with the earlier 'billboard' antennae below