 The final configuration of the SR.N1 has been altered considerably from its initial revision, having adopted a twin-jet configuration along with an estimated weight increase from 4,000lb to 6,600lb.Throughout 1958 and into 1959, work on the design and production on the SR.N1 proceeded under the leadership of Saunders-Roe's chief designer Maurice Brennan.The Saunders-Roe "SR.N1" ("Saunders-Roe Nautical 1"), initially known as the "Model A", was the world's first full-sized hovercraft.