RMAS Magnet (A114)  RMAS Magnet (A114) was the eponymous Magnet class Royal Navy degaussing ship. She was completed in 1979 by Cleland. As well as the "Magnet", a sister ship, RMAS Lodestone (A115) was built by Cleland in 1980. The Magnet class was developed to replace the Ham class minesweepers that had been converted for degaussing. They are 828 tons gross register tonnage (GRT) and have a top speed of 14 knots. They measure 55m x 12m x 4m.