The sticky bombs used during World War II were originally produced by the United Kingdom. These hand grenades were designed as a solution to the shortage of anti-tank guns, which was evident after the Dunkirk evacuation.
Development of the Sticky Bomb
It is believed that Major Millis Jefferis began thinking about an anti-tank weapon as early as 1938. His idea was to have an explosive charge deform so it could cover a substantial area of close contact with a target’s surface. Once detonated, the charge would create far greater destruction in a more condensed area making it capable of rupturing a thick armored plate. This type of explosive device was known as a ‘poultice’ or ‘squash head’.
Eventually, he enlisted the help of Dr. Bauer and Dr. Schulman from the Colloid Science Department at Cambridge University. The men began experimenting with various lengths of bicycle inner tubes, filling them with a type of modeling clay to represent the explosive. Next, wooden handles were fitted on the tubes and then dipped into a rubber solution causing them to become sticky. They soon discovered their prototypes were not only difficult to aim, but they also did not adhere to the metal bins used in the trials to represent the tanks.
By 1940, after the incident at Dunkirk, a German invasion of the UK seemed imminent. The British Army was not properly equipped for such an invasion. Among other things, they were short on anti-tanks guns. The 840 they had in France had been left behind, leaving them with only 167, for which ammunition was scarce.
Jefferis realized his sticky bomb idea may now have general applications for the British Army. But problems still remained with developing this device. In searching for solutions, he turned to Robert Stuart Macrae, who realized a flexible bag capable of holding an explosive gel would be required. This design, in theory, would allow for better adhesion on the target. At trials though, difficulty throwing the bag was still an issue.
Next, Gordon Norwood, who was a master printer and happen to overhear the problems being experienced, had an idea. He secured every day light bulbs in an effort to demonstrate his theory that a spherical glass flask placed inside a sock of woven wood is rigid enough to allow a good throw. However, upon making contact, the glass breaks allowing the bomb to bend and adhere to the necessary shape. In order to provide the thrower time to create a safe distance between himself and the explosive, a sticky substance was used to cover the bomb which allowed it to remain in place a few seconds before detonation.
The development of the sticky bomb continued to be refined and arguments over a number of issues persisted. The War Department refused to grant approval for the British Army to use this devise. However, Prime Minister Churchill intervened and production of the bomb commenced. Between 1940 and 1943, more than 2.5 million were made. During World War II, in addition to the United Kingdom, the sticky bomb was also used by Canada and Australia.