Design and development Vickers Warwick

1 design , development

1.1 origins
1.2 changes , redesigns
1.3 flight
1.4 production

design , development
origins

in october 1932, british industrial conglomerate vickers-armstrong decided tender own design in response british air ministry s release of specification b.9/32, called development of twin-engined medium bomber. during late 1934, point company in midst of developing type 271 design meet needs of specification b.9/32, vickers received draft requirement larger bomber. draft specification developed air ministry specification b.1/35, sought twin-engined heavy (by standards of day) strategic bomber. aircraft intended make use of more powerful engines, in range of 1,000 hp, being developed; these enable bomber both faster , carry heavier bombload earlier b.3/34 specification. amongst requirements of specification b.1/35 speed of no less 195 mph while flying @ 15,000 feet, range of 1,500 miles while carrying payload of 2,000lb of bombs, along limitation on wingspan less 100 feet, while engines furnished variable-pitch propellers.

the warwick designed in parallel smaller wellington, both aircraft having been derived vickers type 271 design developed conform demands of specification b.9/32. end of july 1935, air ministry able consider 8 designs; design proposed vickers, designated 284, powered pair of bristol hercules engines, had generously exceeded specifications requirements. accordingly, on 7 october 1935, vickers received order single prototype produced; air ministry ordered prototypes of designs tendered armstrong whitworth (known aw.39, development of armstrong whitworth whitley) , handley page (known hp.55). however, prior these alternative designs being built, cancelled - both handley page , armstrong whitworth preferring work upon newer specifications released medium (p.13/36) , heavy (b.12/36) bombers.

changes , redesigns

as specification b.1/35 considered heavier complement specification b.9/32, thought there no need produce new mock-up of type. however, on 14 march 1936, in light of major design changes being submitted, production of complete mock-up authorised. around same time, decided allocate vickers 284 designation project, while redesigned b.9/32 design (which become wellington) designated vickers 285. consequence of relaxation of restrictions imposed 1932 geneva disarmament conference, weight of both vickers 284 , 285 expanded gradually, until 285 approached original specified weight specification b.1/35.

during 1936, specification b.1/34 modified require aircraft have greater fuel , bombload capacity. during january 1937, rolls-royce vulture liquid-cooled x engine named aircraft s alternative powerplant, , adopted in late 1938. vulture, had been prioritised rival avro manchester bomber, subsequently determined unlikely available in sufficient numbers warwick, being unreliable. in recognition of engine s disappointing performance, on 2 july 1937, order second prototype placed air ministry insurance measure against vulture s potential failure.

the second prototype (l9704) designed use napier sabre engines; however, development of sabre slow, partially consequence of available production capacity being urgently required keep manufacture of hawker typhoon fighter, l9704 instead fitted bristol centaurus radial engines. in addition engine issues, other aspects of design proved troublesome, such defensive gun turrets, official doubts on geodesic airframe structure proposed type, latter having been pioneering design element british aircraft designer barnes wallis.

in february 1939, decided not proceed development beyond pair of prototypes consequence of troublesome situation vulture engine; however, position reversed following january. in late june 1939, following completion of high-level review , resubmission of programme data, work resumed. while vickers chose continue project, negative perceptions, fuelled progress having been slowed work on wellington , lack of suitable engines, led growing official expectation design surpassed later aircraft.

into flight

on 13 august 1939, first prototype (serial k8178), powered vulture engines, made maiden flight brooklands. initial flight, flown test pilot joseph summers, lasted few minutes due defect in carburettor linkage. point, smaller wellington bomber had made maiden flight 3 years earlier , quantity production of type had started 18 months prior. when equipped, calculated all-up service weight of first prototype 42,182lb, double of weight given vickers in initial tender design. initial flight tests prototype revealed type possess unfavourable characteristics, being slow, underpowered, , unable maintain altitude when flown on single engine.

fitted centaurus engine, second prototype performed first flight on 5 april 1940. in addition change in powerplant, second prototype had incorporated various improvements design, such re-profiled elevator, improve handling. in comparison first prototype, there definitive improvement in performance; according aviation author norman barfield, second prototype claimed faster hawker hurricane, contemporary british fighter aircraft, @ altitudes. while centaurus-powered prototype viewed being more promising, development of centaurus engine @ stage , again in relatively short supply. various alternative arrangements explored power type. in october 1939, proposed design reconfigured four-engined aircraft, powered either rolls-royce merlin xx or bristol hercules he7sm engines; after study, use of 4 engines discarded after found produce serious negative impact in aircraft s range , payload.

another proposal made use of american pratt & whitney double wasp radial engine. performance projections showed similar performance hercules iii-powered wellington bomber, greater payload; engines available due cancellation of contracts placed french government. explore option, second prototype converted use r-2800-s14a4-g engines; first flew in form in july 1941. double wasp installation considered inferior centaurus engine, nonetheless, aircraft ordered pratt & whitney engine.

on 3 january 1941, initial production order placed 250 warwicks, consisting of 150 double wasp-powered mk aircraft , 100 centaurus-powered mk iis; deliveries scheduled commence in november year. @ point proposed aircraft received name; in accordance air ministry s practice of naming bombers after british towns , cities, , vickers own practice of using w initial letter (to indicate designs of barnes wallis), warwick selected @ type s official name.

production

the large initial production contract gave programme relative sense of security, there still need resolve troubles warwick s centaurus engine. double wasp engine, furnished three-bladed 15-ft diameter hamilton standard-built propeller, therefore became engine of choice type. due time took double wasp engines reach vickers facilities in britain pratt & whitney s production lines in u.s., delays unavoidable.

during 1941, second prototype engaged in flight trials support manufacturing effort, such in-flight testing of alternative tail configuration, determined have improved warwick s handling. prototype refitted production standard engines , propellers; revealed problems engine ignition, resolved revised booster coil. during time, warwick subject high level of investigation aim of keeping type relevant rapidly changing circumstances of conflict; out of process relatively orderly progression towards standardised production made.

due persistent engine shortages , changes in policy, 16 of planned 150 bomber-configured warwicks completed. first bomber aircraft being completed @ vickers weybridge facility, type s capabilities below air staff s requirements bomber aircraft, result of rapid advances in field rather faults of design itself. bombers being required carry ever-greater bombloads on greater distances; point, decision had been made re-equip raf bomber command exclusively new generation of four-engine bombers. earlier wellington displaced bombing missions other roles, newly emerged warwick likewise re-directed other activities, including air-sea rescue, troop , cargo transport, long range anti-submarine patrols, general reconnaissance, , operational crew training.

by january 1943, total of 57 warwick mk aircraft had been completed; same month, decided predominant platform performing transport , air-sea rescue missions warwick. during mid-1943, single warwick mk converted become warwick mk ii prototype; principal difference fitting of centaurus iv engines. total of 219 warwick mk aircraft constructed, last 95 of these 2,000 horsepower (1,500 kw) r-2800-47 engines.

during 1942, order 14 transport-orientated warwicks, designated warwick c.mk.i , vickers 456, made british overseas airways corporation (boac), civil operator. prescribed operational requirements carriage of mail, freight, , passengers (in order of priority) between bathurst in south africa , cairo in egypt, complementing boac s flying boat operations between england , bathurst. order met converting existing b.mk.i warwicks, removing military equipment, fairing on gun turret positions, along installation of cabin windows, freight floor, long-range fuel tanks, , exhaust stack flame dampers (for night flights).

the warwick used barnes wallis geodesic airframe construction pioneered in wellesley , wellington. in system, network of intersecting structural members made duralumin covered wired-on fabric. load distributed amongst structure, providing great redundancy in event of damage, @ expense of complexity of construction.