Patrol Flying Boat
In March 1936, the RAF Ministry of Aviation issued the R.1 / 36 specification for the creation of an all-metal flying monoplane boat to replace the Saro London and Supermarine Stranraer biplanes. The competition was attended by aircraft from three firms: S.36 Saunders-Roe (Saro), Type 314 Supermarine and B.20 Blackburn Aircraft. As a result, the choice was made in favor of the S.36 project by Saro, developed under the leadership of G. Knowler.
Lerwick was distinguished by a rather high fuselage, thereby ensuring the rise of the wing with engines installed on its leading edge to a safe distance from the water. Machine gun armament, which consisted of seven 7.7 mm (0.303 inch) machine guns, was housed in three Nash & Thompson turrets (1 × Vickers K 0.303 inch in the bow turret, 2 × Browning 0.303 inch in the upper turret and 4 in the tail turret), with the bow performed sliding inward of the fuselage - this freed up the area for mooring work. The designers abandoned the external suspension of the bombs, equipping the bomb bays in the engine nacelles. The total mass of the bomb load was 907 kg - 2 × 227-kg or 4 × 113-kg bombs in each of the two compartments.
As a power plant, they ultimately chose 14-cylinder air-cooled engines Bristol Hercules II (2 × 1375 hp on 9 aircraft) or Hercules IV (2 × 1650 hp on 8 aircraft), which were the moment of its creation the most powerful in the world.
In April 1937, a batch of 10 Lerwick seaplanes was ordered. The first serial prototype went for testing in early November 1938. The results were not very encouraging - the flying boat was distinguished by poor hydrodynamic characteristics, unsatisfactory takeoff and landing qualities and instability in the air.