Fairmile D motor torpedo boat

The Fairmile D motor torpedo boat was a type of British motor torpedo boat (MTB) and motor gunboat (MGB), conceived by entrepreneur Noel Macklin of Fairmile Marine and designed by naval architect Bill Holt for the Royal Navy. Nicknamed "Dog Boats", they were designed to be assembled in kit form mass-produced by the Fairmile organisation and assembled at dozens of small boatbuilding yards around Britain, to combat the known advantages of the German E-boats over previous British coastal craft designs. At 35 metres (115 ft) in length, they were bigger than earlier MTB or motor gunboat (MGB) designs (which were typically around 21 metres (70 ft)) but slower, at 30 knots (56 km/h; 35 mph) compared to 40 knots (74 km/h; 46 mph).