M314 ALTA former Royal Norwegian Navy Minesweeper is now a museum ship in Oslo|Length: 144 feet|Beam: 28 feet|Draft: 8.5 feet|Displacement: 333 tons|Armament: One twin 20 mm Oerlikon gun|Minesweeping equipment: Magnetic, Acoustic and Mechanical |Launched: January 31, 1953 At: Hodgdon Brothers, Gowdy & Stevens, East Boothbay, Maine