During the late hours of 30 April, a group of four Provisional IRA members held a family hostage in Killeen, County Armagh, and stole a mechanical excavator.

At the same time, other IRA members stole a dark-painted Renault Master[1] van in Dundalk, County Louth, which was then loaded with 2,200 lb (1,000 kg) of home-made explosives.

[4] The South Armagh Brigade had examined the compound and realised that the railway side of the fortified position was lacking of blast wall protection.

[1] A British Army patrol from the 2nd Battalion Royal Regiment of Fusiliers 300 yards (270 m) south of the outpost heard what sounded like a train approaching the checkpoint.

[5] The first tip that something was wrong was when a passer-by told another patrol, led by Lieutenant 'Zippy' Allanach, that his vehicle had been diverted by hooded men at one of the IRA checkpoints.

[1] The British Army's official report about this incident stated: "This was a well-planned and well-executed attack indicative of the imaginative, innovative and capable nature of South Armagh PIRA".

[7] Former British Army Brigadier Peter Morton put in question the wisdom of these fixed military compounds along the border by comparing the bases with "Crusader castles showing the flag on every Ulster road and hillside, (they) are sitting targets for the terrorists, to be reconnoitred in safety and attacked at leisure.