Barrack buster is the colloquial name given to several improvised mortars, developed in the 1990s by the engineering unit of the Provisional Irish Republican Army (IRA). The improvised mortar properly called "barrack buster" - known to the British security forces as the Mark 15 mortar - fired a 1 m long metal propane cylinder with a diameter of 36 cm, which contained around 75 kg of home-made explosives and had a range of 75 to 275 m. The cylinder is an adaptation of a commercial gas cylinder produced by the Cobh company Kosangas for heating and cooking, and used in rural areas across Ireland. The Mark 15 was first used in an attack on 7 December 1992 against an RUC/British Army base in Ballygawley, County Tyrone, The projectile, fired from a tractor parked near the town's health center, was deflected by the branches of a tree besides the perimeter fence. A number of civilians had to be evacuated. It took ten hours for the British Army technicians to defuse the device. A later IRA statement acknowledged that the mortar bomb had "failed to detonate properly". The following, more successful attack took place on 20 January 1993 in Clogher, also in County Tyrone, where the local RUC compound was heavily damaged, and several RUC constables wounded.

Provisional IRA's mortars

The barrack buster belongs to a series of home-made mortars developed since the 1970s. The first such mortar—Mark 1—was used in an attack in May 1972 and it was soon followed by the first of a series of improved or differentiated versions stretching into the 1990s:

Strategic impact

The intensification of the IRA's mortar campaign in the late 1980s led the British government to increase the number of army troops in Northern Ireland from its lowest ebb of 9,000 in 1985 to 10,500 in 1992. Also in the 1980s, defense authorities undertook a huge and costly plan to fortify its security facilities across the region to tackle the threat. The IRA's use of mortars combined with heavy machine guns compelled the British Army to build their main checkpoints more than a mile away from the Irish border by 1992. These mortars were also used against targets in England, such as the Downing Street attack on 7 February 1991, and the Heathrow mortar attacks in March 1994. Both attacks were intended by the IRA to put pressure on the British Government to negotiate with them.

Use by other groups

In 1972 the Official IRA developed a type of mortar which was used in attacks against several British Army installations on 5 December that year. Provisional IRA-type mortars have been used by the Real IRA, who also developed their own fuzing system, in the 2000s. In early 2000 a new type of mortar was tested by the Real IRA in County Fermanagh. The weapon was classified as a "Mark-19" by the British Army. Furthermore, what appears to be a similar or identical mortar technology known in Colombia as "cilindros" (or "cylinders" in English) have been used since 1998 by the Revolutionary Armed Forces of Colombia (FARC). ETA in Spain was in 2001 rumoured to have built mortars "very similar" to the IRA's. The possible transfer of this mortar technology to the FARC was a central issue in the arrest in August 2001 and later trial of the so-called Colombia Three group of IRA members, who were found innocent of false claims by Colombian authorities and the United States House Committee on Foreign Affairs that they “allegedly” trained FARC in the manufacture and use of this mortar technology even though there was no evidence presented at trial to prove the claim.

In popular culture

A derived term in Belfast refers to a two or three-litre bottle of inexpensive white cider.