HEA Coal Hopper Mainline Blue 360620The HAA wagon successfully filled the role of delivering coal to power stations. A new design of wagon was also required for other coal traffic, to replace the large fleet of mineral wagons and hoppers. In 1975 the prototype 32. 5 ton HBA (360000) was unveiled at Shildon Works. It was fitted with manually operating discharge doors. The hopper body was painted initially in Bauxite. An order for 2000 wagons to be built at Shildon was placed. Two small