the corporation was founded as a result of the aircraft and shipbuilding industries act 1977, which nationalised 27 major shipbuilding and marine engineering companies in great britain. a further 6 ship repair companies and a further shipyard were also acquired by the corporation, with british shipbuilders initially comprising 32 shipyards, 6 marine engine works and 6 general engineering plants. collectively, british shipbuilders accounted for 97% of the uk's merchant shipbuilding capacity, 100% of its warship-building capacity, 100% of slow speed diesel engine manufacturing and approximately 50% of ship-repair capacity. harland & wolff, the only shipbuilder based in northern ireland was deemed to be a special political case and remained out of the control of the british shipbuilders' management, despite it also being in state ownership from 1977.