Aviation of Word War II

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Lerwick

Patrol Flying Boat

Saunders-Roe

Saro Lewrick

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.



Lerwick Mk.I
Crew 6-9
Dimensions
Length, m 19.40
Height, m 6.10
Wing span, m 24.64
Wing area, m² 78.50
Weight, kg
Empty 12,880
Gross weight, kg 15060
Powerplant
2 × PE Bristol Hercules II, power, h. p. 2 × 1375
Performance
Maximum speed, km/h 345
Cruising speed, km/h 267
Rate of climb, m/min 270
Service ceilling, m 4,270
Service range, km 2,480

A number of changes were made to the design of the L7248 prototype, eventually installing a double keel instead of a single keel. The propellers were replaced with new ones with an increased diameter from 4.11 m to 4.42 meters. However, the changes made to the design did not allow for a radical improvement in the characteristics of the machine. Nevertheless, production continued, until the final discontinuation of production in March 1941 built 21 aircraft.

Photo Description
Drawing Lerwick Mk.I

Drawing Lerwick Mk.I

Lerwick on the sea

Lerwick on the sea

Bibliography

  • "Flying boat Saro "Lerwick"/Evgeny Aranov/
  • "All seaplanes of the Second World War" /Andrey Kharuk/
  • "British Flying Boats" /Peter London/