The SAS Regiment increased their operational focus on Northern Ireland, with a small element known as the Ulster Troop that were permanently stationed in Northern Ireland to provide specialist support to the British Army and RUC. The troop consisted of around 20 operators and associated support personnel, serving on a rotational basis. For larger pre-planned operations, Ulster Troop was reinforced by SAS personnel, often in small 2- or 3-man teams from the Special Projects Team. From 1980, the Troop served twelve-month tours instead of six-month tours, as it was felt that longer deployments allowed the operators to develop and maintain a better understanding of the key factions and senior PIRA terrorists. Surveillance became an important aspect of the Troop, with 14 Intelligence & Security Company (commonly known as "The Det") often carrying out surveillance missions that led to SAS ambushes.