Complete Technical Data Package (Mortar bomb & Launch Assembly)

#Standard Improvised Munitions

The MK 10A mortar bomb includes a striker fired, time delayed fuze (MK10/2) in an attempt to increase reliability. As the bomb leaves the launch tube, a detent (attached to a length of steel wire secured to the launch frame) releases a spring loaded striker against a .22 rimfire cartridge which in turn ignites a length of safety fuse providing a short delay until landing and detonation. The MK 10A often includes a longer and larger diameter propelling spigot allowing for an increased black powder charge to be held internally.

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The Provisional IRA Mark 10 mortar system was first introduced in March 1979 and ecompasses bombs with both electrically as well as later developed mechanical and impact initiated fuzing mechanisms. Each of the bombs contain approximately 20.5kg of improvised explosive (either loose or in bags). This is usually ammonium nitrate / nitrobenzene (ANNIE) although SEMTEX-H has occasionally been used. Attacks have ranged from the use of a single, man-portable tube, to banks of up to 18, the base-plate bolted to a launch platform - usually a flat-bed lorry or van with a section of the roof removed and camouflaged using spray painted cardboard. The base-plate consists of a H section steel girder into which are set the launch tubes supported by a launch frame fabricated from steel box tubing or angle iron. The launch tubes are invariably made from 7" diameter industrial gas cylinders from which the valve assemblies are removed. The bombs themselves are constructed from 6.5" overall diameter rolled steel pipe of an approximate 1 meter length and again, these are usually cut-down gas cylinders - often oxy-acetylene welding or Guinness gas bottles sourced from pubs. Three MK 10 mortars were used to attack 10 Downing Street in London while British Prime Minister John Major’s War Cabinet were meeting on February 7th 1991

The propellant unit is in the form of a steel pipe or spigot with several vent holes drilled into it which is screwed to the base of the bomb via a coupling. Early models contained a sodium chlorate and sugar mix but this soon changed to a fine improvised black powder, the quantity and quality determining range. The remaining space in the spigot tube is packed with a tissue paper wadding. The propellant powder is ignited by a flash bulb - the wires protrude through a hole in the bottom of the spigot and are connected from there to the firing pack.

The firing angle is set at approximately 45 degrees and range has varied from 50 to 350 meters. The launch tubes are often set at varying angles to maximize target coverage and timed to fire at two second intervals, alternating far left to far right to maintain balance of the vehicle. The MK10/1 bombs are not point detonating and rely on the delay of the burning safety fuse and they sometimes air burst, fail to launch and explode in the tube or fail completely due to the overall simplicity of the system. If they land on target however they can cause devastating damage. The weapon is ambitious but lethal with very good shrapnel effect. Initiation in the past has included command wire, radio control and timers. When fired from a truck or van the wires are fed through a hole into the cab to a Timing & Power Unit placed on the passenger seat. The driver positions the vehicle using a permanent known feature in the landscape (such as a radio mast in the case of an Army base), often using a strip of black tape on the windscreen to align. He then only need flip two switches and remove two pegs from the TPU to arm the system and escape.

Highly accurate EOD reference model + diagrams and photos.