AP 118 · No. 10 Section II · Aircraft Plate 70 / 264

Plate 70 of 264 · Between the wars · Medium day bomber

Boulton Paul Overstrand

Overstrand Mk I, K4556, painted as K4556, a Boulton Paul Overstrand of No. 101 Squadron RAF at Bicester, which crash-landed on 4 November 1936 and whose nose the Boulton Paul Association has recreated for the Norfolk & Suffolk Aviation Museum: Boulton Paul’s twin-engined day bomber, the first RAF aircraft with a fully enclosed, power-operated gun turret, a two-bay biplane of 72 ft span with the outer wing panels swept back, two 580 hp Bristol Pegasus IIM3 engines in polygonal Townend rings between the wings driving four-bladed wooden propellers, a slim fuselage with the pneumatically driven nose turret, an enclosed pilot’s cockpit and a dorsal gunner’s position behind a tall windscreen, and a tall fin and horn-balanced rudder with a Flettner servo rudder on outriggers, shown standing tail-down on its main wheels and tail wheel: aluminium dope overall with the metal nose, cowlings and turret base a shade darker, roundels on the fuselage sides, above the upper wing and under the lower wing, a large dark grey ‘F’ and the squadron badge on the nose, ‘101’ in blue ahead of the fuselage roundel, and ‘K4556’ in black on the rear fuselage and fin (shape from the Johan Visschedijk collection’s Overstrand three-view, checked against the dimensioned Sidestrand drawing in NACA Aircraft Circular 71; the nose markings follow the museum’s replica, and the rest follow period photographs of other 101 Squadron Overstrands, since no photograph of K4556 itself has been found); no Overstrand survives, and the Norfolk & Suffolk Aviation Museum displays a replica of K4556’s nose and cockpit.

3D model

Turn it over

A procedural model built in Blender from published dimensions, drawings and photographs, painted as K4556, a Boulton Paul Overstrand of No. 101 Squadron RAF at Bicester, which crash-landed on 4 November 1936 and whose nose the Boulton Paul Association has recreated for the Norfolk & Suffolk Aviation Museum: Boulton Paul’s twin-engined day bomber, the first RAF aircraft with a fully enclosed, power-operated gun turret, a two-bay biplane of 72 ft span with the outer wing panels swept back, two 580 hp Bristol Pegasus IIM3 engines in polygonal Townend rings between the wings driving four-bladed wooden propellers, a slim fuselage with the pneumatically driven nose turret, an enclosed pilot’s cockpit and a dorsal gunner’s position behind a tall windscreen, and a tall fin and horn-balanced rudder with a Flettner servo rudder on outriggers, shown standing tail-down on its main wheels and tail wheel: aluminium dope overall with the metal nose, cowlings and turret base a shade darker, roundels on the fuselage sides, above the upper wing and under the lower wing, a large dark grey ‘F’ and the squadron badge on the nose, ‘101’ in blue ahead of the fuselage roundel, and ‘K4556’ in black on the rear fuselage and fin (shape from the Johan Visschedijk collection’s Overstrand three-view, checked against the dimensioned Sidestrand drawing in NACA Aircraft Circular 71; the nose markings follow the museum’s replica, and the rest follow period photographs of other 101 Squadron Overstrands, since no photograph of K4556 itself has been found); no Overstrand survives, and the Norfolk & Suffolk Aviation Museum displays a replica of K4556’s nose and cockpit. Drag to orbit, scroll or pinch to zoom · download .glb (1.0 MB)

Data plate

Specification

First flight, number built and top speed are for the whole family (Overstrand); engine, crew and dimensions are for the Overstrand Mk I, K4556 modelled here.

History

The Overstrand

Boulton & Paul of Norwich built the Sidestrand, a fast twin-engined biplane day bomber named after a village on the north Norfolk coast, for the RAF in the late 1920s. It served with only one unit, No. 101 Squadron, and was quick and agile for a bomber, but at its top speed the gunner standing in the open nose could hardly aim or even stay upright in the slipstream. Boulton & Paul’s answer was to enclose him. The company’s armament designer, H.A. Hughes, devised a glazed turret that turned through a full circle on pneumatic motors, fed by air bottles that an engine-driven compressor kept charged, while the gunner raised and lowered his Lewis gun by hand.

The turret was fitted to a rebuilt Sidestrand, at first called a new mark of Sidestrand and then renamed Overstrand, after the next village along the coast from Sidestrand. It first flew in 1933. As well as the turret it had an enclosed cockpit for the pilot, a glazed shelter for the dorsal gunner, more powerful Bristol Pegasus engines in drag-reducing Townend rings, and outer wing panels swept back to balance the heavier nose. The prototype went to No. 101 Squadron for trials in February 1934. Four Sidestrands were converted and 24 new aircraft built, 28 in all.

No. 101 Squadron began to receive Overstrands in January 1935 and flew them from Bicester. They carried up to 1,500 lb of bombs and Lewis guns in the nose turret, the dorsal position and a ventral hatch, and in 1935 one of the squadron’s crews won the Sassoon Trophy for reconnaissance. By then the monoplane bombers were coming, and in 1938 the squadron re-equipped with the Bristol Blenheim. The surviving Overstrands went to the armament training camps as gunnery trainers, and the last were retired in 1941. The powered turret they pioneered went on to arm the RAF’s monoplane bombers and Boulton Paul’s own Defiant fighter.

This airframe

Overstrand K4556 of No. 101 Squadron

K4556The airframe modelled

K4556 was one of the new-build Overstrands delivered to No. 101 Squadron at Bicester, and according to the Norfolk & Suffolk Aviation Museum it crash-landed on 4 November 1936. No Overstrand survives. The Boulton Paul Association built a full-size replica of the nose turret, cockpit and forward fuselage, painted as K4556, and it is displayed at the Norfolk & Suffolk Aviation Museum at Flixton. The model shows K4556 complete as it would have looked in squadron service in 1936, standing tail-down on its main wheels and tail wheel: aluminium dope overall, with the metal nose, cowlings and turret base a shade darker, roundels on the fuselage sides, above the upper wing and under the lower wing, a large dark grey ‘F’ and the squadron badge on the nose, ‘101’ in blue ahead of the fuselage roundel, and ‘K4556’ in black on the rear fuselage and fin. No photograph of K4556 itself has been found, so the nose markings follow the museum’s replica and the rest follow period photographs of other 101 Squadron Overstrands, among them K4546 and K4549; the blue of the squadron number is taken from the replica. The shape follows the Johan Visschedijk collection’s Overstrand three-view, checked against the dimensioned Sidestrand drawing in NACA Aircraft Circular 71.

See it at Norfolk and Suffolk Aviation Museum

Where to see one

In the gazetteer

The gazetteer records the Overstrand in one UK collection. The airframe modelled here is marked.

Every airframe and serial All 264 plates

Profiles and models are procedural interpretations built in Blender from published dimensions, three-view drawings and photographs of each airframe. Treat the museum aircraft as the reference.