Disguised as cement wagons , they were initially stationed at Whitehead and later Magherafelt .
At the same time , the War Department converted a number of GNR ( I ) wagons into diesel - engined armoured trolleys .
Disguised as cement wagons , War Department were initially stationed at Whitehead and later Magherafelt .
At the same time , the War Department converted a number of GNR ( I ) wagons into diesel - engined armoured trolleys .