tons, the receiving antennae were 75 ft high strung between 350 ft transmitting masts, Bowen’s task was to miniaturize the whole system and produce
a transmitter that weighed just 200 lbs with a receiving antenna that could fit
inside an aircraft’s nose or belly ‘blister’. The first trials of a complete system
installed in a Heyford bomber (transmitter, receiver and display operating at
6.7 m and *45 MHz
17
), were conducted by Bowen in March 1937. By
August of that year, the wavelength, and hence the size of the antenna had
been reduced and installed in an Avro Anson for flight trials at Martlesham
Heath. This setup demonstrated ranges of a few miles
18 and formed the basis
for all the wartime airborne radars. Subsequently, the first-hand built
examples of AI Mk.I (now 1.5 m, 200 MHz) were installed in six Blenheim
fighters of No. 25 Squadron at Northolt in August 1939,
19 whilst similar
examples of ASV Mk.I—using ‘micropups’ as a power source
20
—were fitted
to a very small number of Coastal Command aircraft. When the war broke
out in September 1939 therefore, Britain had working versions of both terrestrial and airborne radars.
After the success of RAF fighter command in the ‘Battle of Britain’ in the
summer of 1940, it was quickly anticipated that the Luftwaffe would resort to
night bombing. The battle of course was fought in daylight, ‘CH’ and ‘CHL’
directing intercepts to the general area of the enemy aircraft which were then
engaged by sight. At night, or in adverse weather conditions, a ‘blind’
interception mechanism was urgently needed by the RAF and the need for
the widespread adoption of Bowen’s AI system became acute. ‘Taffy’ Bowen
worked closely with the GEC during the war—Paterson describing him as ‘a
fine chap …’ in his war diary entry of 16 January 1940—and whereas the
‘micropup’ did stirling work, when the new E1189 magnetrons began coming
through the workshops at Wembley in July 1940,
21 they were immediately
deployed for AI radar. One was also flown to the USA on the ‘Tizard mission’
22 in late September 1940 and demonstrated there to the amazement of
the Americans. Such was its importance, James P. Baxter, the official US
historian of science developments in the second world war, described it later
thus;
When the members of the Tizard Mission brought one [E1189] to America in
1940, they carried the most valuable cargo ever brought to our shores. It
sparked the whole development of microwave radar and constituted the
most important item in reverse lend-lease ….
14
If only for the development and manufacture of the E1189 then, Wembley
staff were at the forefront of the scientific war against Germany. Naturally, its
17 The GEC Laboratories 1939–1949
409
a transmitter that weighed just 200 lbs with a receiving antenna that could fit
inside an aircraft’s nose or belly ‘blister’. The first trials of a complete system
installed in a Heyford bomber (transmitter, receiver and display operating at
6.7 m and *45 MHz
17
), were conducted by Bowen in March 1937. By
August of that year, the wavelength, and hence the size of the antenna had
been reduced and installed in an Avro Anson for flight trials at Martlesham
Heath. This setup demonstrated ranges of a few miles
18 and formed the basis
for all the wartime airborne radars. Subsequently, the first-hand built
examples of AI Mk.I (now 1.5 m, 200 MHz) were installed in six Blenheim
fighters of No. 25 Squadron at Northolt in August 1939,
19 whilst similar
examples of ASV Mk.I—using ‘micropups’ as a power source
20
—were fitted
to a very small number of Coastal Command aircraft. When the war broke
out in September 1939 therefore, Britain had working versions of both terrestrial and airborne radars.
After the success of RAF fighter command in the ‘Battle of Britain’ in the
summer of 1940, it was quickly anticipated that the Luftwaffe would resort to
night bombing. The battle of course was fought in daylight, ‘CH’ and ‘CHL’
directing intercepts to the general area of the enemy aircraft which were then
engaged by sight. At night, or in adverse weather conditions, a ‘blind’
interception mechanism was urgently needed by the RAF and the need for
the widespread adoption of Bowen’s AI system became acute. ‘Taffy’ Bowen
worked closely with the GEC during the war—Paterson describing him as ‘a
fine chap …’ in his war diary entry of 16 January 1940—and whereas the
‘micropup’ did stirling work, when the new E1189 magnetrons began coming
through the workshops at Wembley in July 1940,
21 they were immediately
deployed for AI radar. One was also flown to the USA on the ‘Tizard mission’
22 in late September 1940 and demonstrated there to the amazement of
the Americans. Such was its importance, James P. Baxter, the official US
historian of science developments in the second world war, described it later
thus;
When the members of the Tizard Mission brought one [E1189] to America in
1940, they carried the most valuable cargo ever brought to our shores. It
sparked the whole development of microwave radar and constituted the
most important item in reverse lend-lease ….
14
If only for the development and manufacture of the E1189 then, Wembley
staff were at the forefront of the scientific war against Germany. Naturally, its
17 The GEC Laboratories 1939–1949
409