An analysis of fragments of a timing device recovered at the scene of the explosion revealed the device may have been set to detonate up to one hour before the explosion. As the vehicle had stopped in Oldham, Manchester Chorlton Street coach station, and finally Huddersfield to collect returning service personnel and their families prior to travelling towards Catterick Garrison, a possibility existed the device could have been placed in the vehicle in any of these three locations, although the timing of the explosion indicated the device would unlikely have been placed upon the vehicle in Huddersfield. The construction of the explosive device was typical of those used by the IRA.