Airborne Cigar (abbreviated ABC) was a World War II electronic countermeasure (ECM) system developed by the British Telecommunications Research Establishment (TRE). It was designed to jam Luftwaffe ground-to-air radio communications operating in the very high frequency (VHF) band, making enemy night fighter communications nearly impossible when used effectively.
Development and Purpose
The system grew out of an earlier jamming effort called "Tinsel," which targeted German HF-band communications. As German night fighters increasingly shifted to VHF bands, Bomber Command requested a solution in April 1943. A ground-based version called "Cigar" was first deployed at Sizewell on the night of 30/31 July 1943, but its range was limited to approximately 140 miles (230 km) due to VHF signal propagation. An airborne version was ordered on 6 May 1943 by Air Commodore Sidney Osborne Bufton, becoming known as "Airborne Cigar," with the original retroactively termed "Ground Cigar."
Technical Specifications
The system consisted of a wide-band receiver and three tunable transmitters, each producing about 50 watts of output. The transmitter electronics were packaged into a large cylinder weighing 275 kilograms (606 lb) and required approximately 3,000 man-hours to install. The bomb load was reduced by about 1,000 pounds (450 kg) to accommodate the equipment. Two 7-foot (2.1 m) antenna masts were mounted above the wing, with a specialized receiver and shorter antenna near the tail.
A motorized tuner swept the receiver through the entire VHF band 25 times per second. Detected signals appeared as vertical "blips" on an oscilloscope, with the horizontal position indicating the signal's frequency. A German-speaking Special Duties Operator (SDO) would then tune a conventional receiver to that frequency, identify ground controller transmissions, and direct one of the three transmitters to broadcast noise on that frequency.
Operational History
ABC was first tested on 4–6 September 1943 and entered operational service on the night of 7/8 October 1943. It was primarily operated by No. 101 Squadron RAF, part of the specialist No. 100 Group RAF. Because the system was effective only over a range of about 50 miles (80 km), ABC-equipped Lancasters had to be spread throughout the bomber stream, requiring many such aircraft on every mission. This resulted in very high losses for No. 101 Squadron: seventeen aircraft were lost between 18 November 1943 and 24 March 1944, including seven on the night of 30/31 March 1944 during the Nuremberg Raid.
Many of the Special Duties Operators were Yiddish-speaking refugees who had escaped from Germany before the war. The Germans referred to ABC as "dudelsack" (German for bagpipes), in reference to the warbling sound of the jamming.
Countermeasures and Later Use
The Germans attempted various countermeasures, including rapid frequency hopping, using female controllers, transmitting Morse code on HF bands, and using captured ABC sets to send deceptive jamming signals. These efforts had limited effect. The Morse code countermeasure was quickly countered by a new system called "Drumstick," first used on 21/22 January 1944.
ABC was eventually supplanted by the "Jostle IV" system, which broadcast 2,000 watts of noise across the entire ground-to-air band and required no operator intervention. Jostle IV entered service on 30 June 1944. ABC systems were moved to No. 462 Squadron RAAF in March 1945.
Post-War Service
ABC remained in use after the war. No. 199 Squadron RAF fitted four ABC transmitters to their Avro Lincolns, de Havilland Mosquitos, English Electric Canberras, and later Vickers Valiants. When No. 199 stood down in 1958, the Valiants were transferred to the newly reformed No. 18 Squadron RAF. The exact retirement date of the last ABC systems is not recorded.
