Самолеты (сортировка по:)
Страна Конструктор Название Год Фото Текст

Sopwith Dolphin / 5F.1

Страна: Великобритания

Год: 1917

Истребитель

Sopwith - Cuckoo / T.1 - 1917 - Великобритания<– –>Sopwith - Hippo / 3F.2 - 1917 - Великобритания


В.Кондратьев Самолеты первой мировой войны


Сопвич 5F.1 "Дельфин" / Sopeith 5F.1 Dolphin

  Самолет спроектирован Гербертом Смитом весной 1917-го в попытке создать более совершеный истребитель, чем РАФ SE.5, с использованием того же 200-сильного мотора "Испано-Сюиза". При этом основная ставка делалась на улучшение обзора и усиление вооружения. Для решения первой задачи верхнее крыло было вынесено назад и опущено почти до фюзеляжа. Летчик сидел между лонжеронами, а его голова возвышалась над крылом. В результате обзор вперед, вверх и в стороны получился великолепным.
  В мае-июне 1917 года первый прототип под заводским обозначением 5F.1 успешно прошел испытания. Его летные данные были признаны вполне удовлетворительными, и в следующем месяце с фирмой "Сопвич" заключили контракт на постройку 500 штук, а затем у фирм "Даррак Мотор Компани" и "Купер энд Компани" заказали еще по 200 экземпляров истребителя.
  "Дельфин" представлял собой цельнодеревянный двухстоечный биплан с полотняной обшивкой всех поверхностей, за исключением передней части фюзеляжа, покрытой съемными дюралевыми капотами. Конструкция крыла, фюзеляжа и оперения аналогична предыдущим истребителям Герберта Смита. Вооружение - два синхронных пулемета "Виккерс".
  Поначалу многие "дольфины" выходили из заводских цехов с двумя дополнительными "льюисами", установленным в наклонном положении перед кабиной для стрельбы поверх винта. Однако пользоваться ими было неудобно, поэтому в частях "льюисы" нередко снимали, а в дальнейшем от них вообще отказались. На ряде машин оборудовали подвески для четырех 11-килограммовых противопехотных бомб системы Купера под нижним крылом.
  Из-за задержек с поставками двигателей первые серийные "дельфины" поступили на фронт только в январе 1918 года. Самолет не пользовался популярностью у летчиков из-за тесной неудобной кабины и риска получить увечья при капотировании машины (что в те годы случалось не редко, особенно - на кочковатых полевых аэродромах) или просто при грубой посадке. Такова оказалась плата за улучшение обзора. Летчика можно было в значительной мере обезопасить путем установки над кабиной противокапотажной рамы, однако, почему-то этого так и не сделали.
  Несмотря на отсутствие существенных преимуществ перед SE.5 и весьма сдержанные оценки пилотов, схема "Дельфина" считалась перспективной. В 1918 году последовали дополнительные заказы на машины этого типа, а всего до конца войны построено 1533 экземпляра истребителя. В середине 1919 года "дельфины" были сняты с вооружения и отправлены на слом. Помимо англичан, на них успел повоевать один канадский дивизион.


ЛЕТНО-ТЕХНИЧЕСКИЕ ХАРАКТЕРИСТИКИ

  Размах, м 9,90
  Длина, м 6,78
  Высота, м 2,60
  Площадь крыла, кв.м 24,50
  Сухой вес, кг 640
  Взлетный вес, кг 911
  Двигатель: "Испано-Сюиза"
   мощность, л. с. 200
  Скорость максимальная, км/ч 192
  Скорость подъема на высоту
   2000 м, мин.сек 6,30
  Дальность полета, км 300
  Потолок, м 5790
  Экипаж, чел. 1


А.Шепс Самолеты Первой мировой войны. Страны Антанты


Сопвич "Долфин" (Dolphin) 1917 г.

  Появление этой машины было вызвано необходимостью борьбы с германскими высотными бомбардировщиками "Гота" и "Штаакен", участвовавшими в налетах на территорию Англии. Поскольку на высоте более 4000 м ротативные двигатели теряли мощность, новый истребитель получил рядный двигатель жидкостного охлаждения "Испано-Сьюиза" мощностью 233 л. с. Самолет во многом повторял конструкцию своих предшественников, однако из-за более тяжелого двигателя пришлось удлинить фюзеляж, а верхнее крыло имело отрицательный вынос. Кроме двух синхронных "Виккерсов" в кабине пилота, расположенной между верхними крыльями, устанавливался пулемет "Льюис", стреляющий вперед-вверх. Радиаторы устанавливались по бортам фюзеляжа. Всего было построено около 1500 самолетов 5F.1 "Долфин".


H.King Sopwith Aircraft 1912-1920 (Putnam)


5F.1 Dolphin

  In several respects the Dolphin was the most remarkable (though by no means the most renowned) of all the Sopwith fighters. The backward-staggered two-bay high-aspect-ratio wings, by which it was chiefly distinguished, conferred upon it (having an area roughly the same as the Snipe's, and appreciably more than the Camel's) an especially good high-altitude potential, or alternatively the ability to carry an exceptionally heavy armament. The pilot's view for combat was the prime consideration in providing backward stagger, while the invariable use of an efficient Hispano-Suiza water-cooled engine conferred additional advantages - not least for further development, with French encouragement for the ‘Dauphin' being shown in the more exotic variants. (In describing Hispano-Suiza engines as 'efficient', which in a purely technical sense they surely were, one is not oblivious to the faults of some when fitted with reduction gear).
  To Sopwith the significance of the Dolphin was not, however, merely technical, for they themselves were given orders for well over a thousand of the 1.500 built before the Armistice, with production at Kingston succeeding that of Camels and preceding work on Snipes at Ham. Even so, as production went ahead the parent firm continued to set the pace for airframe and engine development. That only four squadrons were Dolphin-equipped reflects little diminution in the merits of the type, already emphasised. Though no Naval version is known to have existed, night-flying for Home Defence was an area of specialised application; and so successful and adaptable did the Dolphin prove as an 'all-round' fighter and so full of promise did it remain in spite of its defects (real or imagined) - that American interest ran high, and French, perhaps, even higher. Curiously, the last Dolphins on active service equipped some Polish units in the fighting with the Russians during 1920, when Polish forces penetrated deep into the Ukraine. Less surprisingly, a single Dolphin only came upon the British Civil Register, though even this (G-EATC) was a demonstrator for Handley Page. The few two-seat trainer Dolphins were Service conversions.
  Like so many other aeroplanes, the Dolphin suffered badly at the mouths of rumour-mongers, their tales of woe and terror being aggravated by recollections of the similarly back-staggered D.H.5; by the Dolphin's unusual spinning characteristics; the vulnerability of the pilot's head in a landing accident; engine difficulties; and prejudice in any case against the unconventional. (Even the sloping nose of the Service type was sometimes regarded not so much as an aid to the pilot's outlook as a feature detrimental to his flying ability - in that he was unable to 'keep the nose on the horizon"). The fact that advantages were rarely set against these strictures is understandable; likewise that the Dolphin was never acclaimed in its time - as it has been by later commentators as 'the world's first multi-gun fighter', for not only was there secrecy to be observed, but the full complement of guns was seldom mounted.
  The Dolphin's back-stagger having been mentioned as a salient feature, with concomitant advantages to pilot-view, a word on the fuller significance of this feature is in order. Although it is well known that the D.H.5 of 1916 was the first operational aeroplane of any note to have a negative, or backward, stagger, and that the dubious reputation of that fighter, especially respecting the stall, was attributed to this same feature, one is none the less left wondering why, in his autobiography Sky Fever, Sir Geoffrey de Havilland made no allusion whatsoever to the "5", though types of lesser fame are there. Perhaps the unusual wing-arrangement was officially inspired (though Harald Penrose attributes it to 'D.H.'s' own 'daring', and Oliver Stewart to his 'genius'). But whatever the facts of the matter, the staggering of wings in either direction was not entirely novel, for even in 1902 there was a mention in Wright/Chanute correspondence of" 'staggering surfaces back' - or 'arranging the surfaces in steps' as Wilbur put it. Nevertheless, the D.H.5, Dolphin wing-arrangement in a fighting aeroplane (with the upper wing supposedly blanketed in a spin by the lower one) was something to which initially high accident rates for both types were sometimes ascribed. Little did pilots know that America's 'Staggerwing Beech' was to remain in production from 1933 to 1948! To Sopwith moreover back-stagger meant not only "Dolphin" alone, but Hippo, Snail and Cobham also - while even the D.H.6 trainer received a slight degree of negative stagger, jointly with other 'improvements'.
  Whatever the arguments for and against back-stagger, it was officially affirmed that 'A negative stagger increases the interference between the planes and is therefore only employed when, for overwhelming reasons, some property such as unobstructed upward view is required.’
  The first Sopwith 5F.1, later named Dolphin, was apparently designed more or less in parallel with the Hippo, and was cleared by Sopwith's Experimental Department on 23 May, 1917. It carried no identifying number, and differed from the production form in notable respects. Most notable of all, it had a frontal radiator (instead of flanking surfaces) though the particular radiator fitted, which was to be officially criticised as 'inefficient', was far too deep and narrow for the common description 'car-type' so deep, in fact, that even the high-set thrust-line of the geared 200 hp Hispano-Suiza engine was well below the upper lip. Of such a depth, moreover, was the whole nose ahead of the top wing that the two Vickers guns were contained wholly within it, while behind the wing the fuselage was similarly deep, meeting as it did the rear steel-tube cross-member of the open 'centre-section'. The tail resembled a Camel's though its small size was largely disguised by the lengthy lever-arm of the sharply tapered fuselage.
  This first Dolphin was flown by Harry Hawker at Brooklands before May 1917 was out; was officially tested - with plywood decking extended aft - at Martlesham Heath in the following month, when it was deemed to be nose-heavy and was ballasted accordingly; and on the 13th of that same month (June 1917) was flown to St Omer for Service trials. The ferry pilot was H. T. (later Sir Henry) Tizard, who had joined the RFC from the army in 1915 and who did so much not only for ‘Martlesham methods' but in founding the station itself.
  At the end of June (confirming how well the Dolphin was regarded - being faster than the Camel and more manoeuvrable than the S.E.5) five hundred Dolphins were ordered from Sopwith themselves, with contracts quickly following to the Darracq Motor Engineering Co Ltd, and Hooper & Co Ltd. both of which firms were London-based. The name Darracq must be especially remembered here for at least two reasons. First, this same company had earlier received an order for two hundred examples of the D.H .5 back-staggered fighter; second, as the Dolphin was built to lake a vee-8 engine of 200 nominal horsepower, it may be recalled that Darracq had made a racing-car engine of these same characteristics though far heavier as early as 1905. (That a young man named Moore-Brabazon had been apprenticed to the company is possibly less relevant). Hooper, of course, were famed for their fine coachwork, and already had Sopwith associations through the 1 1/2 Strutter and Camel. Thus was Dolphin production centred round Surrey and South London.
  The first Dolphin, with its unmistakable deep frontal radiator, having earlier received attention in this chapter, it can now be recorded that the second machine of the type embodied new features which went some way to meet Service desires, notably respecting pilot-view, but met new problems of its own. Most notable on this second specimen, the seemingly simple frontal radiator was abolished, the cooling for the engine being now provided by two small triangular surfaces, set one near the root of each upper wing, and revised at least once. However inefficient, this new system (apart from being in the top wing rather than the bottom one) did at least presage the twin-radiator installation tried on the Hornbill - Hawker's very first 'water-cooled' fighter, though as the Hornbill's Condor gave nearer 700 hp than 200 the radiators were in greater prominence.
  Though the Dolphin's new wing-mounted radiators were not themselves successful, they did allow incorporation of a downward-sloping nose, which was in essence to become so characteristic of the type in service and which left the two Vickers guns partly exposed, though in the second form of Dolphin, now discussed, the top of the cowling retained its great depth at the rear. The enhanced field of view conferred by the sloping nose was supplemented by large cut-outs in the bottom wings; and had these spaces served to accommodate radiators (as they might well have done in the ultimate) then the Hornbill analogy would be all the more apt.
  Also to be seen on the second form of the Dolphin were a new fin and a horn-balanced rudder, this last-named feature having been officially proposed because the first Dolphin had been tiring to fly by reason of the coarse left-rudder required at full throttle.
  Clearly, however, the radiator system was the Dolphin's real bete noir, and the third form of the aircraft had an altogether new arrangement, for although this was again based on the use of two surfaces, these were now of deep block form, mounted not in the wings but on the fuselage sides, well aft, and in line with the rear of the cockpit. Just forward of each block was a shutter for varying the cooling area exposed. The fin was now enlarged, so that the horn-balanced rudder was matched to its contour. Ahead of the cockpit the decking was at one stage somewhat lowered; but interest lay very largely in the armament, which, although it was not exactly 'doubled' as is sometimes averred, comprised two Lewis guns (drum-fed, and mounted on the tubular, front, centre-section spar) in addition to the two fuselage-mounted synchronised Vickers guns (belt-fed, with Prideaux disintegrating links). Here then, we have the inception of what has sometimes been termed, as earlier noted, the 'world's first multi-gun fighter'; though of Dolphin armament there will be more to say.
  On the fourth pre-production form of the Dolphin (circa October 1917) the fuselage behind, as well as forward of. the cockpit was shallower, and the cockpit rims cut deeper into the fuselage sides, giving a generally 'leaner' look; though the landing gear struts were still of sturdy ash, and not of thinner steel-tube as later, on production machines. The backward stagger, too, remained unaltered at 13 in (330 mm), though on production Dolphins this was reduced to 12 in (305 mm).
  As Dolphin production was to run in parallel with that of the similarly engined S.E.5a of the Royal Aircraft Factory one of the pre-production Dolphins was tried (though unsuccessfully) with a four-blade S.E.5a propeller; but a two-blade Lang pattern was standardized - one advantage of such a form being not merely in respect of propulsive efficiency, but in the synchronising of the two Vickers guns.
  By the end of 1917, production of the Dolphin was so well advanced that 121 had been delivered, the first unit equipped being No.19 Squadron (January 1918). Together with Nos.79, 23 and 87, No. 19 remained Dolphin-equipped until the war was over, and perpetuated thereafter in its unit badge was the image of a Dolphin. (The name and symbol of the Elephant, of course, was stolen from the Sopwith 'Zoo' by No.27 Squadron, while the Fox, Hind, Hart and Gamecock passed in due time to the custody of Nos. 12, 15, 33 and 43 respectively).
  From the armorial, however, to the harder facts of armament; for in the Dolphin special problems had been presented by the closely concentrated masses of two fixed Vickers guns and two movable Lewis guns. The solution of these problems had, in fact, been discussed at a meeting between Sopwith and Service personnel held as early as June 1917 - shortly after completion of the very first Dolphin, which had two Vickers guns only, as had the standard Camel. Soon after the meeting just mentioned there was another, and on this occasion the RNAS was represented as well as the RFC - the first-named Service by Engineer Lieutenant F. W. Scarff (note promotion to commissioned rank since the early days of the 1 1/2 Strutter). Details of how the Lewis guns were to be installed were apparently the primary concern of Sopwith's Mr Allman, and to limit the training of these guns a three-position ratchet was the fitting approved. The extent to which two Lewis guns were actually fitted as well as the two 'built-in' Vickers - either at the manufacture or the service stage - remains unclear; for although a single Lewis gun was far more normal in the field, a familiar photograph of Sopwith production shows C3786 at least, prominently in the foreground with both Lewis guns fitted, while C3787 and others far beyond along the lines have their Vickers guns only, complete with C.C. hydraulic synchronising gear.
  Special mountings for six Home Defence Dolphins were apparently the responsibility of the Royal Aircraft Factory; but to Lieut 'Guns' Knight of No.87 Squadron credit is evidently due for the design of the fixed installation of two Lewis guns on the bottom wings - each gun about 18 in (460 mm) inboard of the inner pair of interplane struts, though with the lines of fire outboard of the propeller arc, so that synchronising gear was not required. Though ground attack may well have been the primary object of the outboard wing-mounting scheme referred to, which certainly preceded that on the Snark though we must not too readily dismiss the American scheme of 1917 referred to under 'Triplanes (Hispano-Suiza)' - the Dolphin weapon-load for low attack could be augmented by the usual 'four twenty- pound Cooper' bombs. These little anti-personnel bombs (the targets officially prescribed were, in fact, 'personnel and aerodromes') were crutched in a carrier under the fuselage.
  For work at the higher altitudes the Dolphin's inherent attributes showed clearly at their best - a warm cockpit being not the least among them; thus for Home Defence duties at night the type was much to be desired, especially so with the German raiders coming over at great heights, and with defending fighters having difficulty not only in merely intercepting them and keeping them clearly in view, but in reaching their level at all (at least, with sufficient time in hand for effective attack).
  Militating against the Dolphin's safe employment at night, however, were not only engine difficulties (relative slowness in warming-up, persistent unreliability by reason of reduction-gear troubles and other factors) but the pilot's obvious vulnerability in the event of an accident. ('This would be an unpleasant machine in which to turn over on the ground' was Oliver Stewart's first remark on entering the cockpit, later explaining: 'The pilot's head came above the top plane, and he was completely surrounded by longerons, spars, cross-bracing wires and tie rods, and the feeling of being boxed in with the head exposed in a vulnerable position was experienced at once. With the engine in his lap and the petrol tanks in the small of his back, it seemed to the pilot that he had little chance of escaping injury in the event of a bad landing').
  Not for nothing was 'Blockbuster' one vulgar name conferred on Sopwith's fine new fighter, and - much as on the Bristol M.1 monoplane - special pylons or 'cabanes' (or even a so-called 'rolling hoop') were in requisition, though whether the mounting of a single Lewis gun on one particular form of crash pylon above the cockpit was primarily anti-German or pro-British remains conjectural. Half-hoops of steel above the attachments for the inner pairs of interplane struts were a feature of Sopwith's own ‘Dolphin Night Flyer', shown in a photograph. Although no aircraft-number is visible on the fuselage, the fin is stencilled C3858, and, of more technical interest, this surface is associated with a variable-incidence tailplane. (Rigging instructions for the standard Dolphin remarked that normal incidence was zero, adding that 'any adjustments can be made after tests').
  In the happy event of a Dolphin pilot surviving a bad upset, he might, with luck, find his escape facilitated by specially modified centre-section bracing or even by a removable cockpit-side panel, with quick-release. As used by No. 141 Squadron at Biggin Hill (a unit not already numbered among the Dolphin-equipped squadrons, for it used only a few of the type) flare-brackets were fitted under the lower wings, though there is no evidence of flame-damping exhaust tailpipes possibly because these last might impede the pilot's exit.
  Operational requirements aside, the Dolphin's development was very closely linked with powerplant vicissitudes, and it was, in fact, a shortage of Hispano-Suiza engines which precluded the operational fulfilment of at least one other Dolphin squadron (No.90) early in 1918.
  The engine for which the Dolphin was designed was the compact vee-8 200 hp Hispano-Suiza, which, although it had reduction gearing, nevertheless possessed an excellent power weight ratio. In France this engine was built by many companies, and eventually in other countries also, the wartime total of engines of this general pattern reaching nearly 30,000. In Britain the 200 hp Hispano-Suiza was made by Wolseley Motors Ltd, who called it (in developed form) the Adder; but from French production - notably Mayen - came other units of the type in big numbers. As is well known, crankshaft failures plagued the Wolseley-built geared engines; but there was far more to the story than this, and the following official notes, prepared just after the war of 1914-18, are relevant.
  Wolseley had received a British contract for 100 direct-drive 150 hp Hispano- Suiza engines, but also (now to quote the official notes) 'for a much larger number of engines of similar type but provided with a reduction gear and adapted to run at 2000 r.p.m. developing over 200 h.p. at this speed. This particular geared model was based upon drawings supplied by the French, but no engines of this kind had at that time been built. The reduction gear consisted of a pair of large diameter spur gears (with helical teeth of an angle of 4 50 ) which raised the propeller shaft above the crankcase, and the shaft was hollow so that a machine gun could tire through it. The Wolseley Co. obtained permission to modify the drawings in the direction of fitting a scavenger oil pump and employing a different method of securing the reduction gear on the propeller shaft.
  'The French at the same time were working on a 200 hp geared engine without the scavenger oil pump and with the propeller shaft gear wheel keyed on a taper on the propeller shaft. This method of fixing gave considerable trouble and the reduction gears on the French engine were the cause of frequent failure due partly to the high tooth pressure and partly to the use of air hardening steel. The Wolseley Co. used a 5% nickel case hardening steel for both gears and had little or no trouble ... The feature of firing through the propeller shaft was not used however.
  'The 150 hp engines of both French and English manufacture gave practically no trouble. In a short time the compression was raised from 4.7 to 5.3 to 1 and the speed raised to 1750 r.p.m. resulting in about 200 hp under these conditions.
  'The first difficulty to arise in the manufacture of the Hispano engines in this country concerned the propeller hub fixing ... The remedy finally adopted was to use a different taper for the hub from that of the shaft ... The tests are still (Dec, 1918) continuing at the Isle of Grain as this trouble was found most serious on Seaplanes.
  'The cylinder holding down studs frequently broke and to meet this difficulty the studs at each end of each block were lengthened and either a long nut or nuts and deep collars were used.
  'When about ten 200 hp engines had been delivered from the Wolseley Works, an epidemic of crankshaft breakage was experienced.’ (Then followed a lengthy account of measures taken) and it was later recorded:
  ‘In view of the crankshaft failures, and the trouble with the propeller hubs, and the serious failures of reduction gears on French engines, it was considered necessary to reduce the number of geared English built Hispanos, and turn out an ungeared engine capable of a normal speed of 2000 r.p.m. This was the "Viper", which without doubt proved the most satisfactory of the Hispano series ...
  'The French 200 hp engine evidently did not receive the required care in manufacture as is evidenced by the fact that individual engines gave exceedingly good results, particularly from the point of view of weight/power ratio, but the majority require continual overhaul, chiefly owing to the difficulty in maintaining the required oil pressure ... It should be recognised that the 200 hp Hispano engine was a development of a very satisfactory 140 hp engine, but that certain features, including the oil pump, were pushed beyond their capacity in the higher powered engine.'
  In February 1918 (at which time Dolphins were arriving in France in some numbers) the Ministry of Munitions Department of Aircraft Production issued a Report upon Troubles with 200 h.p. French Hispano in Service, touching especially on excessive vibration and defective lubrication and largely relating to the 'SPAD Bitrailleuse' (or 'Bi-mitrailleuse' as it was otherwise called in the same document) and the 'SPAD two-seater'. Like these French fighters and the British S.E.5 series, the Dolphin was wedded to the Hispano-Suiza form of engine (an installation of the Sunbeam Arab was schemed, if not tried) and the end of the war found the following British Marks of the Dolphin in being - all distinguished by their engine: Dolphin I with 200 hp geared Hispano-Suiza engine; Dolphin II with the new 300 hp Hispano-Suiza, of which more later; Dolphin III with engine essentially as Dolphin I though with reduction gear removed. (N.B. An officially styled '200 h.p. Mayen Hispano Engine Converted to Direct Drive’, when tested at the Royal Aircraft Establishment in the summer of 1918, 'ran satisfactorily throughout' and gave 201 hp at 1,800 rpm and 220.5 hp at 2.000 rpm. Some geared engines also delivered about 220 hp).
  Of the three Marks of Dolphin listed the Mk.II is now of greatest interest - and equally it interested the French, who made the first installation in D3615 and placed the new combination in production. The presence of the new engine was distinguished by the greater bulk of the cowling (with the two Vickers guns completely submerged beneath it); by exhaust tailpipes extended further aft than usual, and thus having to be cranked to clear the tops of the radiator blocks on the fuselage flanks; and by a telescopic carburetter-air intake (intended to reduce the risk of a carburetter fire) the front whereof was prominent between the cylinder banks.
  The number of 300 hp Hispano-Suiza installations made is uncertain; but what is sure is that Harry Hawker went over to fly the first conversion. Though snags were suspected or known, Hawker did rolls and spins. Later the structure was strengthened for production. As for the engine itself, a Mayen-built example was tested at Farnborough, and in July 1918 was the subject of the following interim report on calibration tests:
  'The engine was dismantled for examination, then reassembled and placed on a test bed for calibration tests. The maximum power obtainable after tuning up was 280 h.p. at 1800 r.p.m. although on previous tests on a similar engine (150 m/m stroke in both cases) 316 h.p. was obtained at 1800 r.p.m. On trying the compression three cylinders were found to be O.K., three had poor compression, and on the remaining two there was no evidence of compression, when the engine was turned by hand. The cylinder blocks were therefore removed and were found to be leaking badly round several of the spark plug adaptors ...'
  As for the supercharged Hispano-Suiza engine much earlier mentioned in passing (‘Other Men's Aeroplanes') this was nominally of 220 hp. but had a Rateau "turbocompresseur", which gave the Dolphin thus powered its best performance at considerable heights. The maximum speed of 130.5 mph (210 km h) was, in fact, attained at 8.700 ft (2.650 m), but at low level the speed was reduced to only 119 mph (192 km/h).
  For the 300 hp Hispano-engined Dolphin, as intended for French and American use, a variable-incidence tailplane was standardised, partly owing to the large petrol capacity demanded and the distribution of its changing weight. (Petrol and oil systems for the Dolphin varied widely, but the 200 hp versions typically called for 27 gal (123 litres) of petrol and 4 gal (18 litres) of oil). Like the British, the French experimented with various propellers (typical for a 200 hp British Dolphin was a Lang of over 9 ft diameter) though for 'Sopwith Dolphin C1 No.3618, 300 h.p.' designs by Lumiere, Gallia, Ratmanoff and Levasseur were tried. The best speed measured in one series of trials was apparently with a Gallia - 221 km/h (137 mph) at 4,000 m (13,120 ft) though the best climb was afforded by a Ratmanoff - 4,000 m (13,120 ft) in 12 min 13 sec. Ceiling with several patterns of propeller was quoted as 7,500 m (24,600 ft).
  Thus we perceive the Dolphin positively entering the 'postwar’ performance bracket; and in furtherance of this perception it can be noted that one Dolphin was experimentally fitted (and flown to France) with a Calthrop parachute, stowed in the top decking, and that another (Sopwith-built D3747) had a jettisonable petrol tank. Even so, one is left with a feeling that, like its namesake in nature, this fighter may not, even yet, have yielded up all its secrets; though in partial proof of our contention at the outset that the Dolphin was one of the most remarkable of all the Sopwith fighters there may be instanced the victories of No.79 Squadron's aircraft alone - 64 enemy aircraft and eight kite-balloons destroyed.
  Nevertheless, ferocious though it was in combat the Dolphin was in its way tame, Martlesham Heath, for instance, crediting one of the first experimental models (with the first Hank radiators) with an unstick run of 60 yd (55 m) and the ability to 'pull up with engine stopped' in 90 yd (82 m).
  Production orders for the Dolphin were as follows:
  Sopwith C3777-C4276; D3576-D3775; E4424-E4623; E4629-E5I28.
  Darracq C8001-C8200; F7034-F7133 (J1151-J250 were cancelled).
  Hooper D5201-D5400; J1-J150 (order not completed).


Dolphin I (200 hp geared Hispano-Suiza)

  Span 32 ft 6 in (9.9 m); length 22 ft 3 in (6.7 m): wing area 263.25 sq ft (24.7 sq m). Maximum weight (with two Vickers guns and one Lewis gun) 1,959 lb (889 kg). Maximum speed at 10.000 ft (3.050 m) 121.5 mph (195 km/h); maximum speed at 15,000 ft (4,570 m) 114 mph (183 km/h): climb to 10,000 ft (3,050 m) 12 min 5 sec; climb to 15,000 ft (4.570 m) 23 min: service ceiling 20,000 ft (6.095 m).


Dolphin II (300 hp direct-drive Hispano-Suiza)

  Span 32 ft 6 in (9.9 m): wing area 263.25 sq ft (24.7 sq m). Empty weight 1.566 lb (710 kg): maximum weight (two Vickers guns only) 2.358 lb (1.068 kg). Maximum speed at 10,000 ft (3.050 m) 140 mph (225 km h); maximum speed at 16.400 ft (5.380 m) 133 mph (214 km h): climb to 10.000 ft (3.050 m) 8 min 20 sec; climb to 16,400 ft (5.380 m) 12 min 10 sec; service ceiling 24,600 ft (8.050 m).


Dolphin III (200 hp direct-drive Hispano-Suiza)

  Span 32 ft 6 in (9.9 m): wing area 263.25 sq ft (24.7 sq m). Empty weight 1.466 lb (655 kg); maximum weight (two Vickers guns only) 2.000 lb (907 kg). Maximum speed at 10.000 ft (3.050 m) 117 mph (188 km/h); maximum speed at 15.000 ft (4.570 m) 110 mph (177 km/h); climb to 10.000 ft (3,050 m) 11 min 20 sec; climb to 15,000 ft (4.570 m) 21 min 50 sec; service ceiling 19.000 ft (5,790 m).


O.Thetford Aircraft of the Royal Air Force since 1918 (Putnam)


SOPWITH DOLPHIN

  The Dolphin followed the Pup, Triplane and Camel in the Sopwith family, but preceded the Snipe. It first entered service with No. 19 Squadron in January 1918 and was notable for its back-staggered wines. In October 1918 it equipped Nos. 19, 23, 79, 87 and 90 Squadrons of the R.A.F. One 200-h.p. Hispano-Suiza engine. Loaded weight, 2,000 lb. Max. speed, 131 1/2 m.p.h. Climb, 855 ft. min. Service ceiling, 21,000 ft. Span, 32 ft. 6 in. Length, 22 ft. 3 in.


H.King Armament of British Aircraft (Putnam)


Dolphin. From the standpoint of armament, as from other aspects, the Dolphin of 1917 was a fighter of exceptional interest. By reason of the fact that it carried two free Lewis guns in addition to two fixed Vickers guns, it has been correctly described as the world's first multi-gun single-seat fighter. Yet the first Dolphin, with its deep car-type frontal radiator, gave scant evidence of being armed at all. The Lewis guns were not, in fact, fitted on this machine, although the Vickers guns were present beneath the cowling, as proclaimed by the breech casings visible in the cockpit, ejection chutes, and two small ports in the nose cowling. The link chutes were above the cylinder-bank fairings and the case chutes behind the exhaust pipes. When lateral radiators were adopted, the cowling was lowered accordingly and the forward portions of the Vickers guns protruded. In the Dolphin Mk.II (300-hp Hispano-Suiza engine) the guns were again submerged.
  The rear ends of the Vickers guns were padded and came far back in to the sides of the cockpit at the level of the pilot's shoulders. The windscreen was far ahead of the cockpit and the centrally-mounted Aldis sight passed through it, being bracket-mounted at a point behind the screen and to the cross-tube which carried the Lewis guns. A ring-and-bead sight was mounted to starboard. C.C. gear Type B was fitted, and the guns had Hyland Type A or B loading handles. A prominent feature of the C.C. gear installation was the gear ring attached to the rear flange of the airscrew boss and the smaller gear wheel meshing with it below. Beneath the smaller gear wheel were two apertures in the cowling each exposing part of the box-type generator used with the Hispano-Suiza engine and a short length of the hydraulic pipeline leading to the trigger motor.
  The two Lewis guns were swivel-mounted on brackets attached to the ends of the cross member which was officially known as the 'front spar tube'. They pointed upwards at about 45 degrees and were restrained from firing into the airscrew by two cams, which nevertheless permitted their being trained to some extent outboard. The spade grips were removed, and the guns were fired by Bowden cable. Norman vane sights were sometimes fitted. When the guns were trained parallel, they were clamped above the pistol grips by fittings attached to the upper wing roots. The Lewis gun installation was not popular among pilots by reason of the guns' intrusion into an already cramped cockpit, and inevitably they affected performance. To fly the Dolphin, keep observation, operate the radiator, and use the Lewis guns as well as the Vickers guns was a one-man-band operation that few could have mastered. One or both guns were frequently removed, although a single Lewis gun was regarded as standard. In No. 87 Squadron the guns were transferred to fixed mountings on the lower wings, somewhat inboard of the inner pairs of interplane struts, where they fired outside the airscrew arc. There were probably other schemes, and certainly a fixed Lewis gun was fitted on the upper wing. Other non-standard installations were an Aldis sight attached to the front spar tube and a Lewis gun on the cross-bar of a crash pylon above the open centre-section. For night work, Hutlon illuminated sights were fitted. Four 20-lb bombs could be carried under the fuselage.


W.Green, G.Swanborough The Complete Book of Fighters


SOPWITH 5F.1 DOLPHIN

  Designed to provide the pilot with the best possible view in tactically important directions, the 5F.1 Dolphin was unusual in being a two-bay equi-span biplane with negative stagger. The pilot was seated with his head in the open framework connecting the upper mainplanes. Primarily of fabric-covered wire-braced wooden construction with an upper centre section of steel tube, the Dolphin was powered by a 200 hp Hispano-Suiza geared eight-cylinder water-cooled engine in its initial production form. Armament consisted of two fixed and synchronised 0.303-in (7,7-mm) guns and either one or two guns of similar calibre mounted over the wing centre section and movable, but usually firing forwards and upwards. The prototype was flown in late May 1917, the first production contract was placed in the following month, on 29 June, and quantity deliveries to the RFC began late in the year. The first Dolphin squadron was deployed to France in February 1918, and the decision was taken to licence-build a version for the US Air Service in France. This, the Dolphin Mk II powered by a 300 hp Hispano-Suiza engine, was to be manufactured by the SACA (Societe Anonyme des Constructions Aeronautiques) and the Air Service anticipated taking delivery of 2,194 by mid 1919. In the event, only a few Dolphin Mk IIs were completed before the Armistice prompted cancellation of all contracts. Difficulties with the reduction gear of the original 200 hp engine led to the conversion of many to direct drive, aircraft fitted with the modified power plant being designated Dolphin Mk III and some engines having their compression ratio raised to boost output to 220 hp. Production of the Dolphin totalled 1,532 aircraft, of which all but 121 were built during 1918. Both Dolphin Mks I and III were finally withdrawn from RAF service mid 1919. The following data relate to the Dolphin Mk III.

Max speed, 128 mph (206 km/h) at 6,500 ft(1 980 m).
Time to 6,500 ft (1980 m), 6.33 min.
Empty weight, 1,466 lb (665 kg).
Loaded weight, 2,000 lb (907 kg).
Span, 32 ft 6 in (9,90 m).
Length, 22 ft 3 in (6,78 m).
Height, 8 ft 6 in (2,59 m).
Wing area, 263.25 sq ft (24,46 m2).


Журнал Flight


Flight, February 6, 1919.

"MILESTONES"

THE SOPWITH MACHINES

The Sopwith "Dolphin." (May 23, 1917)

  Two principal objects were borne in mind in the design of this single-seater fighter - firstly, to make good use of the 200 h.p. Hispano-Suiza engine (which had reached a productive stage), and, secondly, to afford the pilot a range of vision greater than that of any other existing aeroplane. The former necessitated a departure from the usual lines of the Sopwith fuselage, the upper surface of which in the rear of the cockpit is more pronouncedly arched than in previous types. The span of the planes was increased beyond that of the "Camel," and a double-bay arrangement of struts adopted in order to provide great structural strength. At the same time the gap was slightly diminished, and, what forms a strong characteristic of the type, a negative stagger was adopted, with the object of placing the main spar extensions of the top plane in such a position as not to interfere with the complete freedom of movement of the pilot, who occupies the rectangular space formed by them. On these tubular steel spar extensions - which are supported by four short vertical struts from the fuselage - are mounted two Lewis guns, capable of being aimed independently of the direction of the machine. Two fixed Vickers' guns firing through the propeller are arranged along the top of the engine, and are partially covered in by this cylinder fairing. The general arrangement of the front part of the fuselage is particularly neat, and its formidable appearance is well supported by the "Dolphin's" offensive capabilities. The radiator is divided into two portions, each carried on one side of the fuselage level with the pilot's cockpit. In front of each radiator is arranged an inclined and adjustable deflector, allowing the whole or any part of the cooling surface to be obstructed. Among other features of the "Dolphin" will be noted an empennage design differing markedly from that of previous Sopwith types. The fin is of a more upright shape and the rudder is balanced.

The 300 h.p. "Dolphin."

  In connection with this type it is of considerable interest to note that at the signing of the Armistice it was being built in quantities by the French Government, for themselves and the American Government in France. It is fitted with the 300 h.p. Hispano-Suiza, and an adjustable tail plane is employed, since the variable load is considerable, the French and American Governments calling for a very large quantity of petrol to be carried. The machine was reinforced in certain respects to allow for the considerable addition of power, and it had every promise of being an extremely formidable proposition.
  In general outline it was very similar to the 200 h.p. Hispano-Suiza "Dolphin." The guns were completely concealed under the cowling, being fitted in tunnels, and the air intake of the carburettor was fitted with a telescopic-type gas tube direct into the front cowl, considerably diminishing the risk of carburettor fire.

В.Кондратьев - Самолеты первой мировой войны
Сопвич "Дельфин" капитана Фредерика Жиллета из 79-го дивизиона RAF, октябрь 1918г.
В.Кондратьев - Самолеты первой мировой войны
Сопвич "Долфин", 79-й дивизион RFC, пилот - капитан У.М.Фрай, 1918г.
А.Шепс - Самолеты Первой мировой войны. Страны Антанты
Истребитель Сопвич 5F.1 "Долфин" 79-го дивизиона RFC (1917г.)
В.Кондратьев - Самолеты первой мировой войны
"Дельфин" из школы воздушного боя в Мэрске. На фюзеляже и нижних плоскостях - номера "124"
Сайт - Pilots-and-planes /WWW/
The unmistakable first form of the Dolphin (with frontal radiator and deep fuselage to match). The original aircraft at Brooklands, May 1917
Сайт - Pilots-and-planes /WWW/
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At right, with an RFC officer, is Tom Sopwith
Сайт - Pilots-and-planes /WWW/
Сайт - Pilots-and-planes /WWW/
View of the revised Dolphin, again with emphasis on the radiator.
Форум - Breguet's Aircraft Challenge /WWW/
Sopwith Dolphin prototype revised
H.King - Sopwith Aircraft 1912-1920 /Putnam/
Certainly not emphasising the radiator, but nevertheless bearing witness to the very deep fuselage with the cockpit coaming actually slightly above the front 'centre-section' steel-tube spar, is this unfamiliar Sopwith photograph, captioned: 'S.129 - Sopwith Dolphin - 200 hp Hispano Suizo[sic] - Type 5.F.1 - 1917 - 1st Machine'.
Сайт - Pilots-and-planes /WWW/
The second prototype
Сайт - Pilots-and-planes /WWW/
Three aspects of the Dolphin in its exceptionally interesting second form with radiators let in to the roots of the upper wings, cut-outs in the bottom wings, and with horn-balanced rudder.
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The radiators themselves are barely visible, even in a revised, larger, and more forward form (front view), though the 3/4 rear view shows associated fairings having vents projecting from their peaks.
Сайт - Pilots-and-planes /WWW/
In the front view (Sopwith No. S.132, captioned '2nd Machine') the rear cut-outs in the bottom wings may be transparent, with the horizontal tail surfaces showing dimly through them. Nevertheless, they mark a definite 'kink' in the trailing edge. (In this view also there are vibration-preventers for the inner main bracing wires).
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Second prototype at Brooklands
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Second prototype at Martlesham Heath
Сайт - Pilots-and-planes /WWW/
Cockpit of the second prototype
H.King - Sopwith Aircraft 1912-1920 /Putnam/
The third form of the Dolphin had flank radiators, a revised fin and rudder and two Lewis guns, as seen in these two views (not to mention a coy little spinner). The front and port-side pictures respectively bear the Sopwith numbers S.136 and S.139, though only the frontal one carries the legend '3rd Machine".
Сайт - Pilots-and-planes /WWW/
The third prototype at Brooklands
Сайт - Pilots-and-planes /WWW/
Сайт - Pilots-and-planes /WWW/
The third prototype at Martlesham
Сайт - Pilots-and-planes /WWW/
The White square on the fuselage of this Dolphin (C8049) identifies it as being assigned to No 79 Squadron at Bickendorf during March 1918. The aircraft carries the individual identification letter Y in White, which is repeated on the upper fuselage cocking
Сайт - Pilots-and-planes /WWW/
Though not instantly apparent (perhaps because of the distracting Lewis guns) the fourth form of the Dolphin had a shallower fuselage fore and aft of the cockpit. This form set the pattern for production. B6871
В.Кондратьев - Самолеты первой мировой войны
Сайт - Pilots-and-planes /WWW/
B7855 of No.19 Squadron at Bertangles
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Lt. H E Snyder of No.79 Squadron in B7927 at Ste-Marie-Cappel
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C3778
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C3778
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Сайт - Pilots-and-planes /WWW/
RNAS's C3785
Сайт - Pilots-and-planes /WWW/
RNAS's C3785
H.King - Sopwith Aircraft 1912-1920 /Putnam/
Dolphin C3786. This machine has special mention in the text by reason of its armament. In the views it is without Lewis guns.
H.Cowin - Aviation Pioneers /Osprey/
First flown at the end of May 1917, the Sopwith 5F Dolphin started life as a high altitude single-seat fighter design, but saw service as a close air support machine, with trench and ground strafing as its primary role. Built around its 200hp geared Hispano-Suiza, that was to prove so troublesome, the Dolphin incorporated a set of backward, or negatively staggered wings. Highly thought of by officialdom, the machine was ordered into quantity production shortly after its operational evaluation in mid-June 1917. By 31 December 1917, 121 Dolphins had been delivered to the RFC, whose No 19 Squadron was the first unit to re-equip with the type in January 1918. In operational service, the type was not best loved by its pilots, their criticisms centring on the lack of head and neck protection in the event of the machine 'nosing-over', coupled to the flexible crossbar' mounting of two upward-firing Lewis guns. This rather cumbersome device had the major drawback of allowing the guns to swing and strike the pilot in the face, not the ideal situation in any circumstances and particularly not when flying at low level. As these guns supplemented twin, synchronised fixed Vickers guns, they were removed from most operational aircraft, with the exception of No 87 Squadron, who repositioned theirs atop the lower wings and outside the propeller arc. Top level speed of the Dolphin was 131mph at sea level. In October 1918, five Dolphins had been ordered for evaluation by the American Expeditionary Forces, but the cessation of hostilities soon afterwards ended this interest. At the time of the Armistice, while the engine-related problems had been overcome, only 600 or so of the 1,500 Dolphins airframes built by then had actually been delivered, the large part of the remainder awaiting the supply of engines. The image seen here is of the fourth prototype Dolphin and the first to incorporate the Dolphin's definitive shape.
Сайт - Pilots-and-planes /WWW/
C3786
H.King - Sopwith Aircraft 1912-1920 /Putnam/
Dolphin C3786. The pictures show how the Lewis guns could be trained.
Jane's All The World Aircraft 1919 /Jane's/
Three-quarter Front View of the Sopwith "Dolphin" (200 h.p. Hispano-Suiza engine).
H.King - Armament of British Aircraft /Putnam/
The view of the same aircraft below left shows the 'crossbar' mounted, upward-firing Lewis guns that could prove so dangerous. The windscreen is perforated for an Aldis sight, but the sight is not installed. Note also gear ring behind propeller hub, smaller gear wheel below it and part of generator and pipeline for starboard Vickers gun.
Сайт - Pilots-and-planes /WWW/
C3797
Сайт - Pilots-and-planes /WWW/
C3803 of No.141 Sqn.
Сайт - Pilots-and-planes /WWW/
Unidentified Sopwith Dolphin (possibly C3816) at Beaulieu in early 1918. As an operational type the aircraft replaced Spads in a number of fighter Squadrons; some were armed with two Vickers plus two Lewis guns giving them a formidable armament.
Сайт - Pilots-and-planes /WWW/
C3854 of No.2 School of Aerial Fighting and Gunnery, Marske
Сайт - Pilots-and-planes /WWW/
C3858, February 19 1918
H.King - Sopwith Aircraft 1912-1920 /Putnam/
Although this night lighter Dolphin (C3858) has protective half-hoops of steel above the wings and appears to be armed with a single Lewis gun only, provision for the Vickers guns is denoted by the case and link chutes behind the engine. Maker's caption: 'S.189 - Sopwith Dolphin Night Flyer - Type 5.F.1 - Feb, 1918'.
Сайт - Pilots-and-planes /WWW/
C3862 of No.141 (Home Defence) Squadron
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Sopwith 5F.1 Dolphin C3872 'D' of 23 Sqn showing typical markings carried by the squadron
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C3900 of No.79 Squadron
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C3901 with No.79 Squadron
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This Dolphin (C3905) was captured and stripped of its wheel covers and tires. The aircraft was formerly assigned to No 23 Squadron. The Squadron marking was a White individual letter on a Black disc
Сайт - Pilots-and-planes /WWW/
C3942 of No.141 (Home Defence) Squadron
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C4033
Сайт - Pilots-and-planes /WWW/
Dolphin C4147, "S" of No.23 Squadron
Сайт - Pilots-and-planes /WWW/
C4168 of No 87 Squadron
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C4172 at Gosport
K.Delve - World War One in the Air /Crowood/
This May 1918 shot shows Dolphin C4172 in service with the School of Special Flying at Gosport.
Сайт - Pilots-and-planes /WWW/
C4191 September 2 1919
Сайт - Pilots-and-planes /WWW/
C8043 with No.79 Squadron, RAF, at Bickendorf in 1919
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C8043 with No.79 Squadron, RAF, at Bickendorf in 1919
Сайт - Pilots-and-planes /WWW/
C8154 a home-based aircraft of a training unit
Сайт - Pilots-and-planes /WWW/
Dolphin III with 'de-geared' 200-hp Hispano-Suiza engine
Сайт - Pilots-and-planes /WWW/
Assigned to No 79 Squadron this Dolphin (D3584) was built by Hooper, a builder of customized car bodies. The aircraft was flown by F.W.Gilette
Сайт - Pilots-and-planes /WWW/
D3615, with 300-hp Hispano-Suiza engine
Сайт - Pilots-and-planes /WWW/
"Дельфин" из 87-го дивизиона RAF, август 1918 г.
The Sopwith Dolphin was designed to give the pilot the best possible field of view - hence the low setting of the upper wing - early trials showed great promise in speed and manoeuvrability (the first Martlesham tests having taken place in mid 1917). It was January 1918 before the first fully equipped unit, 19 Squadron, was operational in France. D3775 is seen here with 73 Squadron.
Supine S marking on No.87 Squadron Dolphin which had two outboard Lewis guns, one on each lower wing
Сайт - Pilots-and-planes /WWW/
C3824
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C3828 with a Peugeot-made engine
Сайт - Pilots-and-planes /WWW/
D5261 of No.30 TDS Northold
O.Thetford - Aircraft of the Royal Air Force since 1918 /Putnam/
W.Green, G.Swanborough - The Complete Book of Fighters
The Sopwith Dolphin, a service example showing upward-firing guns.
Сайт - Pilots-and-planes /WWW/
The Dolphin's normal armament consisted of twin forward firing Vickers .303 machine guns aimed with the aid of an Aldis gunsight
Журнал - Flight за 1919 г.
"RULES OF THE AIR-MEETING ANOTHER MACHINE." - If a change of course is necessary, turn to the right.
Журнал - Flight за 1919 г.
Side elevations of the Sopwith machines
Журнал - Flight за 1919 г.
Front elevations of the Sopwith machines
Журнал - Flight за 1919 г.
Plan views of Sopwith machines
H.King - Sopwith Aircraft 1912-1920 /Putnam/
Official Dolphin drawings.
Сайт - Pilots-and-planes /WWW/
W.Green, G.Swanborough - The Complete Book of Fighters
The Sopwith Dolphin with two guns
В.Кондратьев - Самолеты первой мировой войны
Sopwith Dolphin