 Fiat-San Giorgio "was wary about using heavy oil Diesel engines and hesitated to guarantee the success of such engines of the power required. At the same time Laurenti prepared a design with geared steam turbines having a speed of 18 knots on a surface displacement of 856 tons." His design was modified by Scotts Shipbuilding and Engineering Company, Greenock, to include guns. Swordfish kept the same main dimensions as Laurenti's original design, but had a greater displacement and less endurance.
