Pulling another pin would arm the firing mechanism and the user would attempt to attach the grenade to an enemy vehicle.

They experimented with different lengths of bicycle inner tubes filled with plasticine to represent explosives, fit them with wooden handles, and dipped them in rubber solutions to make them sticky.

Jefferis was in charge of the MIR(c) department, tasked with developing and delivering weapons for use by guerrilla and resistance groups in occupied Europe.

He obtained a 150-Watt light bulb to demonstrate that a spherical glass flask inside a sock of woven wool would be rigid when thrown.

[10] The grenade needed a delay for the thrower to get clear, so the woollen sock was covered in a sticky substance, ensuring the bomb stayed in place immediately prior to denotation.

[14] The prime minister, Winston Churchill, who was concerned with the state of the country's anti-tank defences, learnt about the grenade and urged its development.

[18] Two days later, Anthony Eden, then Secretary of State for War, added a scribbled note to a cabinet minute that recorded the order to go ahead with the bomb: In spite of top-level pressure, arguments carried on.

Trials were disappointing, it was impossible to get the bomb to adhere to any surface that was wet or covered with even the thinnest film of dried mud "a customary condition of tanks" as Major-General Ismay, on 27 June, pointed out.

[19] Churchill was disappointed: General Ismay, I understand that the trials were not entirely successful and the bomb failed to stick on tanks which were covered in dust and mud.

There were concerns over the explosive charge, pure nitroglycerin is susceptible to the slightest knock, but the mixture developed by ICI proved to be safe even if it should get into the hinges of the storage boxes.

74 grenade Mk II – was accepted by the Ordnance Board; it was put into full-scale production, and became service issue.

[28] On 14 May 1941, Lieutenant-General Sir Ian Jacob reflected: The most extraordinary feature of the whole business, however, was the fact that the Secretary of State for War, in a minute addressed to the Prime Minister on 25 November 1940, said that the Director of Artillery and the Ordnance Board had only just been able to obtain from ICI the details of the explosive contained in the bomb.

The War Office seems to be to blame in that, up to the end of April 1941, no sticky bombs had been issued to any unit, nor had any dummies been provided for training.

[30] The grenade consisted of a glass sphere containing 1.25 lb (0.57 kg) of semi-liquid nitroglycerin, covered in stockinette (a kind of fabric) and coated with birdlime.

[32] The handle also contained two pins and a lever, which were pulled out to make the casing fall away and activate the firing mechanism.

[36] "It was while practising that a H[ome]G[uard] bomber got his stick [sic] bomb stuck to his trouser leg and couldn't shift it.

According to a War Office training pamphlet dated 29 August 1940, the sticky bomb should be regarded as a portable demolition device which can be "quickly and easily applied".

It could be dropped from an upstairs window or applied in place by hand, with sufficient force to break the glass creating a greater area of contact.

[13] "A section of the Royal Durban Light Infantry used these bombs to great effect in what amounted to a battle between men and tanks.

The South Africans waited until the leading tank was 10 paces away and then pelted it with sticky bombs, setting fire to it and forcing out its crew, who were all shot down.

[38] Macrae credits the Australian Army with developing the technique of applying a sticky bomb directly onto a tank instead of throwing it from a relatively safe distance.

[40] Although the Ordnance Board had not approved the grenade to be used by regular army units, a quantity were provided for training purposes.

[16] However, a number of sticky bombs did find their way to British and Commonwealth units participating in the campaign in North Africa and were used as anti-tank weapons.