The Bangalore torpedo was first devised by Capt R. L. McClintock, of the Royal Engineers while attached to the Madras Sappers and Miners unit of the Indian Army at Bangalore, India, in 1912. He invented it as a means of blowing up booby traps and barricades left over from the Second Boer War and the Russo-Japanese War. The Bangalore torpedo could be exploded over a mine without a sapper having to approach closer than about 3 m (10 ft).
Bangalore torpedoes were manufactured until 2017 by Mondial Defence Systems of Poole, UK, for the UK and US armed forces. An improved version called the Advanced Performance Bangalore Torpedo was developed by Chemring Energetics UK, part of the Chemring Group, in response to a British Ministry of Defence requirement issued in 2008; the APBT was chosen by the MOD following competitive performance trials and is also in use with the militaries of Australia, the Netherlands, and New Zealand.
In World War One
By the time of World War I the Bangalore torpedo was primarily used for clearing barbed wire before an attack. It could be used while under fire, from a protected position in a trench. The torpedo was standardized to consist of a number of externally identical 1.5 m (5 ft) lengths of threaded pipe, one of which contained the explosive charge. The pipes would be screwed together using connecting sleeves to make a longer pipe of the required length, somewhat like a chimney brush or drain clearing rod.
A smooth nose cone would be screwed on the end to prevent snagging on the ground. It would then be pushed forward from a protected position and detonated, to clear a 1.5 m (5 ft) wide hole through barbed wire. During the 1917 Battle of Cambrai, British Royal Engineers used them as diversions to distract the enemy from where the real battle was to be fought.
In World War Two
The Bangalore torpedo was later adopted by the U.S. Army during World War II, as the “M1A1 Bangalore torpedo”. Bangalore torpedoes were packed in wooden crates that contained 10 torpedo sections, 10 connecting sleeves, and 1 nose sleeve; the total weight of a crate was 176 pounds. Each torpedo section was 5 feet long, 2.125 inches in diameter, and weighed 13 pounds. Each end of the torpedo was filled with 4 inches of TNT booster, while the middle section contained an 80-20 amatol mixture; the explosive charge weighed about 9 pounds. Each end of the torpedo had a recess to accommodate a standard Corps of Engineers blasting cap. Torpedo sections could be attached together via spring clip-equipped connecting sleeves, and a blunt nose sleeve was provided so that the assembled torpedoes could be pushed through obstacles or across terrain without getting stuck.
Post-World War II development Bangalore torpedoes continue to be used today in the little-changed M1A2 and M1A3 versions (United States Armed Forces) and the modified Advanced Performance Bangalore Torpedo version primarily to breach wire obstacles. Combat engineers have also been known to construct similar field versions of the Bangalore by assembling segments of metal picket posts and filling the concave portion with plastic explosive. The PE is then primed with detonating cord and a detonator, and pickets are taped or wired together to make a long torpedo, producing fragments (aka “shrapnel”) that cut the wire when detonated. This method produces results similar to the standard-issue Bangalore, and can be assembled to the desired length by adding picket segments.
Video courtesy of http://www.periscopefilm.com