Hawkins grenade

73 grenade and the sticky bomb. • Illustration — Battle patrol of the 1st East Surreys rest after returning from enemy territory in Italy, 16 December 1943. The soldier in the centre is holding a Hawkins grenade It was rectangular, about 150 mm in length and 75 mm in width, containing approximately 0.45 kg of explosive. When a vehicle drove over the grenade, it cracked a chemical igniter and leaked acid onto a sensitive chemical, which detonated the explosive. Multiple grenades were often used to destroy tanks or disable their tracks, and the grenade could also be used as a demolition charge. It was used by the British Army and the United States Army, with the former using it until 1955 and the latter also creating their own variant, the M7 anti-tank mine.

• Name — Hawkins grenade • Origin — United Kingdom • Type — Anti-tank hand grenade/anti-tank mine • Is Explosive — yes • Is Uk — yes • Service — 1942 - 1955 • Used By — United Kingdom, United States, Canada • Wars — World War II • Production Date — 1942-? • Variants — United States M7 anti-tank mine • Weight — 1.02 kg • Length — 150 mm • Width — 75 mm • Filling — Ammonal/TNT • Filling Weight — 0.45 kg • Detonation — Crush igniter

With the end of the Battle of France and the evacuation of the British Expeditionary Force from the port of Dunkirk between 26 May and 4 June 1940, a German invasion of Great Britain seemed likely. However, the British Army was not well-equipped to defend the country in such an event; in the weeks after the Dunkirk evacuation it could only field twenty-seven divisions. The army was particularly short of anti-tank guns, 840 of which had been left behind in France and only 167 were available in Britain; ammunition was so scarce for the remaining guns that regulations forbade even a single round being used for training purposes. As a result of these shortcomings, a number of new anti-tank weapons had to be developed to equip the British Army and the Home Guard with the means to repel German armoured vehicles. Many of these were anti-tank hand grenades, large numbers of which could be built in a very short space of time and for a low cost. They included the No. 73 Grenade, which was little more than a Thermos-sized bottle filled with TNT, and the grenade, hand, anti-tank No. 74, also known as the "sticky bomb", which was coated with a strong adhesive and stuck to a vehicle. A more versatile grenade appeared in 1942 in the form of the grenade, hand, anti-tank, No. 75, more commonly known as the "Hawkins grenade", which was designed so that it could be used in a number of roles.

The grenade was rectangular in shape and approximately 150 mm in length and 75 mm in width, and weighed about 1.02 kg. Its explosive content consisted of around 0.45 kg of blasting explosive, which was usually either ammonal or TNT. On the top of the grenade was a plate, under which the user would insert a chemical igniter, which would act as the weapon's fuse. When a vehicle drove over the grenade, its weight crushed the plate, which in turn cracked the igniter; this then leaked acid onto a sensitive chemical which detonated the charge. The grenade was designed so that it could either be thrown at a vehicle like an ordinary anti-tank grenade, or placed at a location when used as an anti-tank mine. It was also fitted with areas where blasting caps or cordtex could be placed, so that it could be used as a demolition charge. When the grenade was used, it was recommended that the user be within a short distance of their target, ideally concealed within a trench; if the target were an armoured vehicle, then the best areas to target were the sides and rear, where the engine compartment was located and armour was generally thinner.

• Illustration — 1st Lieutenant Wallace Strobel, speaking with SHAEF commander General Dwight D. Eisenhower, has a Hawkins grenade strapped to his leg Introduced in 1942, the grenade saw service with the British Army until 1955. The United States Army also used the grenade, as well as developing their own variant, the M7 light anti-tank mine. When used in an anti-tank role, a number of the grenades could be strung together in a "daisy chain" at intervals of around two feet before being placed across a road. It was particularly effective at damaging the tracks of tanks. When sufficient grenades were grouped together, they were capable of disabling a medium tank. The Hawkins was also used in other roles, such as breaching walls, and its small size enabled its placement into the "web" of a railway line to destroy a section of track. The weapon received the nickname "Johnson's Wax tin" due to its appearance to a commercially produced floor treatment product. In the Battle of Ortona Canadian troops used them as demolition charges to "mousehole" between buildings.

Users of the grenade included: • United Kingdom • Canada • United States