UK Air Ministry fooled German bombers with fake burning cities

Colonel John Turner had run a decoy programme for RAF airfields and factories since 1939 ('Q' sites), using dummy structures and controlled lighting to draw night bombers away from real installations. It worked on isolated military targets, but whole cities were a different problem: a city cannot be hidden, disguised, or moved, and its blackout discipline was only ever partial — a single lit window or an accidental fire was enough to give a bomber's crew a usable aiming point in the dark.

The November 1940 Coventry raid made the gap urgent: incendiaries dropped first, and once the city was burning, the fires became a beacon that later waves of bombers simply flew toward, regardless of blackout discipline elsewhere. Turner was tasked with extending his decoy logic to major cities: not concealment, but competition — give the bombers a more convincing fire to aim at than the real one.

Starfish (SF) sites were built a few miles from real cities and factories in open countryside, using controlled bonfires timed to build and flare like incendiary damage, electrically powered 'glow boxes' simulating lit streets and rail yards, and staged light patterns mimicking blackout failures — all triggered from a control bunker once real bombing began nearby, so a decoy 'ignited' in sync with the actual raid and looked, from altitude at night, like the fire already taking hold in the real target. By the end of the war 237 Starfish and related decoy sites protected 81 towns and cities.

Built fake burning cities nearby that ignited in sync with real raids, so bombers aimed at the decoy's fire instead of the real target's.

Bombers aimed at fires, not verified targets, so a convincing fake fire drew them away.

Decoys were triggered in sync with real raids, making them look like the genuine fire.

Crews under time pressure couldn't distinguish decoy from real fire, so many bombs hit empty land.

When you can't hide a target, build a more attractive fake of the same signal to absorb the attack.

Historian Colin Dobinson, in Fields of Deception (English Heritage, 2000), collated Turner's own wartime estimates and concluded Starfish decoys diverted roughly 968 tons of German bombs onto empty countryside — a figure that is Turner's own contemporaneous assessment rather than an independently audited count, and effectiveness varied by site: a 1992 archaeological survey of the original Black Down (Bristol) site found no bomb-crater evidence there specifically.