Westwood Works 1903-2003

Westwood Works in World War 2

Baker Perkins and 'Window'

This might seem a rather tenuous connection but Baker Perkins had made another input into the capacity of the Allies to wage effective war. During the second half of WW2, with mounting losses of aircraft over Germany, one of the methods used by Bomber Command to jam German radar was 'Window' - strips of aluminium foil backed with coarse paper which were dropped from British bombers and created false blips on the enemy's radar screen - "appearing to the radar operators as if thousands of bombers suddenly filled the sky, making it impossible to detect the real planes amidst the sea of moving dots." Pioneered by the brilliant physicist R.V. Jones in early 1942, 'Window' was not used over Germany until mid-1943, the fear in the minds of many at Bomber Command HQ being that the enemy could easily copy the new development with disastrous results for British cities under threat from German raids. However, the rising losses being experienced by Bomber Command precipitated the use of 'Window' on a massive raid over Hamburg at the end of July 1943 which proved to be an enormous success with a loss rate of only 1.5% - significantly below the previous loss rates.

The metal strips, measuring approximately six inches long and an inch wide - Window' was manufactured in varying dimensions to match different frequencies - were produced by the Sun Engraving Company. After trimming, they were bundled into parcels. A Lancaster would carry 50 of these parcels on a trip over Germany - a total of around 1.3 million strips. It is interesting to note that 'Window' was produced on a printing press made at Westwood Works - a 58-inch Baker Perkins "Sungravure" press supplied to Sun Engraving just prior to WW2 (see here )

Black ink was printed on both sides of the aluminium foil, and the drying technique had to be modified because the metal didn't absorb the volatile ink. They called it "the black stuff" and the ink came off very easily.Often, when pushing the bundles of 'Window' into the bomber's discharge chute. the strips would be blown back into the fuselage. If they blew against any of the turrets it would leave a dirty smear, restricting the gunner's vision.

For the full story on 'Window', click here.

[NOTE: For information on Rose Brothers (Gainsborough)'s role in winning the air war over Germany see here