В.Кондратьев Самолеты первой мировой войны
СОПВИЧ "ПОЛУТОРАСТОЕЧНЫЙ" / SOPWITH 1/2-STRUTTER
Цельнодеревянный биплан с полотняной обшивкой. Самолет отличался рядом передовых технических решений, таких как тормозные щитки на нижнем крыле и стабилизатор с регулируемым в полете углом возвышения. Кроме того, "полуторастоечный" был первым самолетом союзников с синхронной установкой пулемета.
С октября 1916 года "Сопвич" применялся в качестве разведчика и легкого бомбардировщика на западном фронте, в Палестине и Македонии. Выпускались три основные модификации машины: Sop.1A2 - двухместный разведчик, Sop.1B2 - двухместный бомбардировщик и Sop.B1 - одноместный фронтовой бомбардировщик. Интересно, что последняя версия, как по внешнему виду, так и по оснащению (синхронный пулемет) больше соответствовала классу истребителя.
Массовые поставки "полуторастоечных" бомбардировщиков на западный фронт начались только в апреле 1917-го, когда эта машина, разработанная полутора годами ранее, уже начала устаревать. Тем не менее, на фоне архаичных "Фарманов" и "Вуазенов" аппарат выглядел совсем неплохо.
Его начали строить по лицензии во Франции и России. Большинство воевавших на фронтах первой мировой войны "полуторастоечных" были французской постройки. К осени 1917 года они преобладали в дневных бомбардировочных эскадрильях французских ВВС. Правда, из-за довольно скромной бомбовой нагрузки их боевая эффективность нередко вызывала сомнения. Часто звучало мнение, что "Сопвич" больше подходит для воздушного туризма, чем для войны. В результате, уже в январе 1918-го "полуторастоечные" начали переводить с фронтов в учебные части. Всего на них успели повоевать 30 французских и три бельгийских эскадрильи, а также 3 разведдивизиона RFC, два авиакрыла RNAS и три дивизиона AEF.
"Сопвичи" повсеместно участвовали в гражданской войне в России. Их активно использовали как красные, так и белые авиачасти. В частности, в 1919 году в составе колчаковской армии на этих машинах летал французский разведывательный авиаотряд.
Цельнодеревянный одностоечный биплан с полотняной обшивкой. Центроплан верхнего крыла скреплен с лонжеронами фюзеляжа дополнительными диагональными подкосами - "полустойками", за которые самолет и получил свое название.
Самолет разработан в декабре 1915 года конструкторским коллективом фирмы "Сопвич Эвиэйшн Компани" (Sopwith Aviation Company) под руководством ее владельца и главного конструктора Томаса Сопвича - одного из основоположников британского самолетостроения. Машина отличалась рядом передовых технических решений, таких как тормозные щитки на нижнем крыле, значительно сокращавшие посадочную дистанцию, а также - стабилизатор с регулируемым в полете углом установки. Кроме того, "полуторастоечный" был первым серийным самолетом союзников с синхронным пулеметом.
Аэроплан запущен в серию в феврале 1916 года. Вскоре машиной заинтересовались французы и также начали ее серийный выпуск по британской лицензии. В дальнейшем именно они стали основным производителем и эксплуатантом "полуторастоечных", однако французские "Сопвичи" применялись, в основном, в качестве легких бомбардировщиков. Всего за годы войны было построено более 4600 экземпляров машины, из них 1513 - в Великобритании, около 3000 - во Франции и несколько десятков - в России. Самолет выпускался в одноместной и двухместной модификациях с различными двигателями и вариантами вооружения. Наряду с истребительными существовали и бомбардировочные версии машины.
На "полуторастоечные" устанавливали 110-сильные ротативные моторы "Клерже" 9Z или 120-сильные "Клерже" 9Ba или 130-сильные "Клерже" 9Be или "Роны" 9J той же мощности, хотя иногда применялись и иные ротативные двигатели.
Первые серийные машины поступили на вооружение 5-го дивизиона RNAS в апреле 1916 года и применялись в качестве истребителей сопровождения. Такой характер применения обуславливался их большим радиусом действия. В следующем месяце "полуторастоечные" начали поступать в дивизионы RFC.
Британские пилоты отмечали хорошие пилотажные качества машины и легкость управления. Но когда осенью 1916 года на западном фронте в большом количестве стали появляться новые германские истребители, более скоростные и маневренные, чем "полуторастоечный", его пришлось переклассифицировать в бомбардировщик и ночной истребитель ПВО.
В 1917 году 517 машин передали американскому экспедиционному корпусу в Европе. Еще около 150 машин отправили в Россию. Лишь некоторые из них успели принять участие в боях Первой мировой, зато остальные - очень активно воевали на стороне Красного воздушного флота в Гражданской войне. Кроме того, в 1917-18 годах "полуторастоечными" оснастили две румынские и три бельгийские эскадрильи.
ОСНОВНЫЕ ИСТРЕБИТЕЛЬНЫЕ МОДИФИКАЦИИ
Одноместный вариант - передняя кабина заделана, на ее месте - дополнительный топливный бак. вооружение -два несинхронных пулемета "Льюис", направленных под углом вверх, на лафете Стрейнджа. Построено 70 экземпляров. Применялся в британской ПВО в 1917 году для борьбы с дирижаблями.
Двухместный вариант - вооружение - один синхронный "Виккерс" и один подвижный "Льюис" в задней кабине на турели "Скэрф" (британские и поздние французские машины) или "Этев" (самолеты ранней французской сборки).
(Сопвич-полуторастоечный, с двигателем "Клерже" 9Ba, 1916 г.)
Размах, м 10,20
Длина, м 7,70
Высота, м 3,12
Площадь крыла, кв.м 32,80
Сухой вес, кг 592
Взлетный вес, кг 975
мощность, л. с. 130
Скорость максимальная, км/ч 164
Скорость подъема на высоту
2000 м, мин.сек 9,10
Дальность полета, км 600
Потолок, м 4270
Экипаж, чел. 2
А.Шепс Самолеты Первой мировой войны. Страны Антанты
"Сопвич полуторастоечный" (1 1/2-Strutter) 1916 г.
Кроме истребителей фирма "Сопвич" во время Первой мировой войны выпускала разведчик "Сопвич-двухместный". Из-за необычного расположения межкрыльевых стоек он назывался также "Сопвич-полуторастоечный".
Эта машина конструктивно выполнена по той же схеме, что и другие самолеты фирмы "Сопвич" того времени.
Отличался самолет большими размерами. Увеличены размеры и площадь оперения. Фюзеляж, крылья и оперение имели каркас из дерева и были обтянуты полотном. Стойки крыла и шасси были деревянные. Расчалки выполнялись из стальной ленты (на английских машинах) или троса (на машинах, строящихся по лицензии во Франции и России). Капот двигателя аналогичен самолету "Пап". Шасси с резиновой амортизацией.
На самолетах, строившихся в России, в зимнее время устанавливалось лыжное шасси. На самолетах устанавливалось 2 пулемета: синхронный 7,69-мм "Виккерс" и на турели у наблюдателя - 7,62-мм "Льюис". Выпускались и одноместные машины без задней кабины.
Двигатели ставились различные. На английских машинах в основном 9-цилиндровый, воздушного охлаждения, звездообразный "Клерже-9b" (130 л. с.). На французских и российских экземплярах кроме того ставили 7-цилиндровый, воздушного охлаждения, ротативный, звездообразный "Рон" (120 л. с.).
В России самолеты "Сопвич-полуторастоечный" строились на заводах "Дукс" и В. А. Лебедева. Построено более 100 машин, которые состояли на вооружении до 1923 года.
В.Шавров История конструкций самолетов в СССР до 1938 г.
"Сопвич-разведчик" ( "Сопвит" , "Сопфит" , "Сопвис" , "Сопуит" - двухместный разведчик с двигателем "Клерже" в 130 л. с. (иногда "Рон" в 120 л. с.), один из основных типов самолетов советской авиации в гражданской войне. Его строили у нас серийно на протяжении 1917-1923 гг. Это была настоящая "рабочая" машина.
Самолеты "Сопвич-разведчик" поступали в Россию по поставкам в 1917 г. в небольшом количестве, более 100 экземпляров их было построено и некоторое количество самолетов взято в качестве трофейных в 1919-1920 гг. По схеме это был одностоечный биплан с характерными наклоненными кнаружи стойками центроплана, из-за чего англичане называли его "полуторастоечным" бипланом. Расчалки коробки крыльев были двух типов: на английских экземплярах - профилированные стальные ленты, на французских - парные тросы с планкой между ними, обмотанные тесьмой. На самолетах русской постройки расчалки были одиночные тросовые. Вооружение - два пулемета.
Была одна модификация "Сопвича" с двигателем "Оппель" в 185 л. с. и шасси от трофейного самолета "Румплер". Конструктор этой модификации - инженер В. П. Григорьев, заведующий мастерскими Киевского политехнического института.
Двигатель , марка||<Клерже>
мощность, л. с.||130
Длина самолета, м||7,7
Размах крыла, м||10,2
Площадь крыла, м2||32,8
Масса пустого, кг||593
Масса топлива+ масла, кг||148
Масса полной нагрузки, кг||382
Полетная масса, кг||975
Удельная нагрузка на крыло, кг/м2||29,7
Удельная нагрузка на мощность, кг/лс||7,5
Скорость максимальная у земли, км/ч||149
Время набора высоты||
Потолок практический, м||4700
Продолжительность полета, ч.||3,5
H.King Sopwith Aircraft 1912-1920 (Putnam)
1 1/2 Strutter (land versions)
In more ways than one the 1 1/2 Strutter was the most significant of all the Sopwith 1914-18 aeroplanes - not in the military and technical senses alone, but in its international acceptance as a novel and uncommonly efficient airframe (dependent though it was to remain throughout its life upon French-designed engines). In Great Britain, its country of origin, it had the additional significance of being the first Sopwith type to be sub-contracted on a truly vast scale.
Here one draws attention to a parallel which, though quite remarkable in its closeness, seems to have passed unnoticed in the annals of the air: that is, the relationships which undoubtedly existed between this classic type of two-seat tractor fighter and the Vickers Gun Bus the classic type of two-seat pusher fighter. This is true not only in the military sense, but also in the international sense; for the Gun Bus, like the new Sopwith, was licence-built in France and was dependent on French rotary engines. In the purely Service sense the parallels are even stronger, for Admiralty interest was very marked in both instances not in the airframe alone (for both machines embodied novelties - the Gun Bus, for example, in its partly metal structure) but in the development of suitable armament. Both types, moreover, were tested and developed at Brooklands, and both were at one time intended to have a Smith radial engine; but even in 1915 it was declared of the Gun Bus: 'A most painstaking, and often disheartening, series of experiments were made with a view to making this pusher type machine the equal of the tractor type of aeroplane, and a measure of the success obtained can be gauged by the fact that it has now flown in a wind against which scarcely any headway could be made.’
Certainly, compared with the 1 1/2 Strutter the Gun Bus was to make very little headway of any sort at all.
Although in its definitive military form (and it will soon be clear that 'definitive' is used here solely for convenience) the design of the 1 1/2 Strutter is generally ascribed to late 1915, the time might be more truly set much earlier in that year, or even in late 1914; and that 'two-seater scout' was a description already current in the early summer of 1915 for the 'Sigrist Bus' (to use a familiar appellation) will be clear from a quotation that shortly follows. First it must be explained, however, that in the course of this quotation (describing the setting-up of a new British altitude record by Harry Hawker on 6 June, 1915) the qualified barograph reading of 'about 20,000 ft' proved inaccurate, thus accounting for the apparent discrepancy concerning Norman Spratt's unofficial performance on a B.E. - for Hawker's true height was 18,393 ft (5,606 m). Thus the quotation ran:
'An altitude record is of distinct value for several reasons. First and foremost it connotes reserve of power. Secondly, provided it is made with a standard machine, not specially designed for the purpose, with neither pilot nor engine doped,' [a portent for Olympic Games to come?] 'it affords a direct standard of efficiency. Neither of these conditions was fulfilled in the case of the world's record held by the Germans. On July 14, 1914, Oelerich reached a height of 26,200 ft. in Germany, but his machine had been specially designed for the occasion; it was a 120 h.p. Beardmore-A.D.-engined D.F.W. biplane, and both pilot and engine were doped.’ (Sic: Does one detect here a tang of wartime propaganda, especially as the figure quoted for the German effort appears to be on the low side?).
‘Hawker's new British record' (continued the quotation) 'though inferior in actual height, is of a very different nature. It was made on a standard Sopwith two-seater scout, engined with an 80-h.p. Gnome of the ordinary type. True, the machine is slightly different in minor points of design from the Schneider Cup craft, notably in the chassis, with a single central skid and a new diagonal strut arrangement, of which it might he indiscreet to give particulars.'
It was then recorded that 'The first 10.000 ft. were climbed in twenty minutes - 500 ft. per minute up to 10.000 ft. is some going went on steadily in the clear air and the intense cold, until the barograph needle had gone right off the chart, marked up to 6,000 metres, when the revolutions fell off to 1.100, and the climbing angle became exaggerated to the point of stalling. At this point Hawker deemed it expedient to come down; switching on and off, he made a long spiral, at the rate of 1,000 ft. a minute right over the aerodrome.' (This was Hendon - the Sopwith having flown there from Brooklands that morning). 'His vol plane lasted twenty minutes from a height of 20.000 ft. Switching on again, he made two splendid circuits over the course at full speed, having, curiously enough, lost none of his touch' (Hawker's hands were 'icy cold' even in the 'sweltering heat of the aerodrome") 'and finally alighted. His sealed barograph showed about 20.000 ft, subject to official correction. Thus Lieutenant E. F. Briggs' unofficial record (14.920 ft at Eastchurch. March 11, 1914, on an 80-h.p. Gnome Bleriot), and the unofficial record of Lieutenant Norman Spratt, amounting to some 18,900 ft., on a B.E., were both handsomely beaten, to the manifest delight of Tom Sopwith, who watched the while with perfect confidence.'
The speed of this aircraft was given as 'upwards of 90 m.p.h.'. Its central-skid landing gear has already been mentioned though not the fact that this fitment was at some stage in the aircraft's career used to contain adjustable lead ballast (possibly when the machine was flown as a single-seater); but it was the 'diagonal strut arrangement, of which it might be indiscreet to give particulars' that was the essential novelty, the two halves of the top wing being braced by the W-form strut system, the outer arms (or struts) whereof reached so far outboard that their attachment-points might well have received a second pair of normal interplane struts (there was one pair in any case, further outboard) and thus suggesting the name '1 1/2 Strutter' - for did not the French have '1 1/2-wingers", or sesquiplanes, and were not both the Sopwith company, and Hawkers after them, much given to trying new biplane fighters with alternative single-bay and two-bay wings?
With his usual professional touch Harald Penrose thus summarised the salient facts: 'At Kingston, Tom Sopwith's great factotum, the dour determined Fred Sigrist, as a result of discussion with Hawker on the possible form of a replacement two-seater with enhanced performance and safer characteristics, modelled a new fuselage on the 807 [see 'Folder Seaplane'] using a bigger fin having a rounded nose of bent tube, and stiffened the main wing spars in order to employ a single bay with outward-raking struts, shortening the lower wing proportionately [N.B. The 'Sigrist Bus', unlike the 'definitive' 1 1/2 Strutter, had wings of unequal span]. To reduce bending moments of the upper wing he used steel centre-section struts steeply sloping from the top longeron to a point well out in the spar bay, and then braced the centre-line juncture of port and starboard spars within inverted V-struts arranged like a trestle, resulting in a widespread transverse W. The machine had been growing slowly in a corner of the old Kingston Skating Rink, for Sigrist was preoccupied with production matters, and it would be another month or more before the framework was ready for covering. Meanwhile it was jocularly referred to by the workmen as 'Sigrist's Bus’.
Further, it may now be pointed out, although it is sometimes correctly observed that the French Hanriot HD-1 fighter had a similar arrangement of inboard struts, it is no less cogent to remark that these struts braced far less of the span; and it might be more valid to submit that the 1 1/2 Strutter was a half-way step to full Warren-girder bracing - associated especially with Fiat and Handley Page - and that the centre portion of the W was to be seen on the Hawker Horsley and Hornbill. Far more remarkable, however, is the analogy of the Fiat C.R.42, the finest biplane fighter of the Second World War, an aircraft which had not only Warren-girder bracing for the outer wings but the 1 1/2 Strutter-style W bracing inboard. (Still one is left pondering how best might be described, in fractions, the centre-section struts of the 'progressively' modified Gloster fighters of the Gamecock era - culminating in the Goldfinch, with an N system instead of the W, though full Warren-truss bracing was nevertheless used for the ribs!).
Whatever the full implications of the matter may be (and, all things considered, perhaps the RAF's homely Armstrong Whitworth Atlas affords the closest parallel, embodying, as it did, the inverted-V struts of the RFC's 'Little Ack' and 'Big Ack' with additional long splayed-out members) in the particular instance of Sopwith's 1 1/2 Strutter the novel wing-bracing arrangement for a biplane having no centre section was a peculiarly happy one. Certainly it differed radically from the arrangement on the Gordon Bennett single-seater (wherein the inboard struts were splayed in side elevation only) and it was one, furthermore, which helped to gain for the 'Strutter' - as it soon became known - not only military fame but its international acceptance also, the French themselves building 4,200 examples, some of which went to the Americans.
Construction on this scale in France was, in itself, some tangible repayment of the debt accumulated by British aircraft-builders over the years to the Farmans (though Henri was a British citizen until 1937), to Bleriot and Voisin - and certainly not forgetting the flow of French engines, to which, as already noted, 1 1/2 Strutters were (so to speak) to remain permanently attached.
While thus engaged in a general assessment of the 1 1/2 Strutter one must next reaffirm one’s contention that - its bombing and naval applications aside - this aeroplane is ‘justly remembered as the archetype of the classic two-seat fighter (pilot with fixed gun, gunner with free gun).' As for bombing and naval use, one might with equal justification have devoted separate chapters to fighters, bombers and chip's aeroplanes' (as they were called), as comprising the 1 1/2 Strutter spectrum; but one has plumped for compactness, and thus proceeds with development for land-based use, with fighting foremost - for we have already noted the early-1915 description of the aircraft as a 'scout'.
Felicitously one can record at this point a visit by Harry Hawker to Hendon on 8 April, 1916, (the best part of a year after the one already mentioned) in what Flight described as 'the new two-seater ‘bullet'; and as at that period the terms 'scout' and 'bullet' were generically and loosely applied to the class of aeroplanes latterly known as 'fighters' it may reasonably be supposed that this aeroplane can be identified with the production-type 1 1/2 Strutter, built to the order of the RNAS, and capable of being armed to the requirements of that pioneering Service.
This appearance by Hawker on the new Sopwith two-seater followed shortly upon another event which may now be seen to have been of no less significance in the history of the aircraft and the company alike. This event was a dinner given in the preceding January (1916) by the Sopwith employees for the directors, and graced by the presence of the Mayor of Kingston, who remarked that the occasion was something of a birthday party, for it was three years since the company had made a start at their Kingston works. Mr Sopwith declared that credit for the successful machines produced belonged to 'the fellows who had the getting out of the machines’, mentioning (evidently in the order now given) Mr F. G. Sigrist, Mr H. Hawker and 'the drawing office and charge hands'. Mr R. O. Carey, in his directorial turn (and before leading the Sopwith Works Band in a rendition to which he himself added a violin solo) referred to 'the excitement created by certain newspapers about the Fokker machine'. They must realise, said Mr Carey, 'that this kind of machine was a purely defensive one, and didn't worry our people a bit' because 'this country possessed something which would successfully outstrip a Fokker any day.' He then referred to the great kindness and consideration shown by 'the Naval resident inspectors'. Thus one may reasonably suppose that the unworried people mentioned were the Sopwith staff, and that the 'something' was the 1 1/2 Strutter, which was certainly an offensive, as well as a defensive machine; could indeed outstrip the Fokker (though by a narrow margin); and could certainly outfight it. And, in any case, the Pup was already well advanced.
A special word will be in order here concerning 'the Naval resident inspectors' to whom Mr Carey rendered such grateful tribute; for numbered among these in 1915 was R. A. Bruce who, in that same year, joined the Westland Aircraft Works (founded during that April). To many people in the aircraft industry the name of Mr Bruce - together with that of Harald Penrose - was well-nigh identified in later years with Westland, and Bruce's eventual appointment as the company's managing director was a measure of his calibre. In this present instance it is fitting to note that the Westland-built Sopwith 1 1/2 Strutters were among the better-built examples.
With fighting as our foremost concern in considering the 1 1/2 Strutter, we turn attention first to armament and then to the airframe - which embodied unorthodox features apart from the peculiar strut-arrangement. Thus, respecting armament, of particular importance were the guns, the mode of their installation and their manning.
The pilot's fixed Vickers gun was mounted on the centre line of the fuselage, with the firing lever (when the Sopwith-Kauper synchronising gear was fitted, at least) projecting from the back of the gun. A Sopwith patented padded windscreen was fitted (to protect the pilot when he was taking aim) and plain open sights, or ring-and-bead sights, were mounted on the gun itself. This was the normal arrangement, though at least one early specimen had the Vickers gun mounted on the port upper longeron, with the breech casing lying under the built-up coaming of the cockpit. The ammunition (as was then standard for the Vickers gun, as for the Maxim gun from which it had been developed) was fed from the right, and a metal plate on the left, forward of the feed block, served to prevent the canvas belt from twisting in the slipstream before re-entering the protection of the fuselage. (The Prideaux disintegrating-link metal belt had not yet arrived). On some early examples the rear of the gun was partly faired.
The 1 1/2 Strutter being primarily an RNAS aircraft (the first contract having been placed by the Admiralty in time for deliveries to start in February 1916 and the first operational machines being in action with No.5 Wing, RNAS, before April of that year was out) the entire gunnery scheme must be acknowledged largely to the experts of that Service (notably Warrant Officer Fredrick W. Scarff) but also to Sopwith themselves particularly in the person of Harry Kauper. Both the fixed-gun and the free-gun installations at first varied quite extensively, and apart from what has already been said about the Vickers gun scheme, it must be added that the first machines for the RFC (A and B Flights of No.70 Squadron, which went to the war a few weeks after the RNAS machines already mentioned) had gun-synchronising gear of the Vickers type, though C Flight of the same unit had aircraft which had been transferred from RNAS contracts, and which were fitted with the Scarff-Dibovsky gear developed for that Service. On a small scale, gears of Ross type were fitted to Strutters; and seemingly on a larger scale the Sopwith-Kauper gear, which is now rightly our concern.
Harry (H. A.) Kauper - at one time foreman of the Sopwith fitters and already something of a hero in the earlier chapter on the Circuit Seaplanes - was the man chiefly responsible for this mechanical gear, which proved so successful that it lived on well into the Camel era. 3,950 sets having been supplied to the flying Services and 2,750 installed. The gear was developed in 1916, and there were several variations. Sopwith themselves once described it in the context of a cam operating a mechanism 'which directly caused the actuation of the firing lever of the gun’, at the same time remarking on 'the difficulty of obtaining a high rate of speed with these devices' because 'the inertia of the moving parts tends to prolong the period during which the automatic gun may repeat its movements and fire again, with the resultant risk of damage to the propeller.’ The essential components were, in fact, the cam already mentioned, and which allowed the actuation of a spring, which itself operated the firing mechanism. The cam was mounted on the engine 'in such a manner that it can oscillate the tappet rod in order to synchronise with the passage of the blades of the propeller past the line of fire of the gun, alternatively holding off or preventing the fire and then permitting the fire by means of the spring.’
As for the 1 1/2 Strutter's free-mounted Lewis gun, the Scarff No.2 ring-mounting, with which the aircraft became almost identified and which Gen Trenchard quickly requested as standard on all future 1 1/2 Strutters for the RFC, was designed by Warrant Officer F. W. Scarff of the Air Department of the Admiralty, and in its development Sopwith played some part, the nature and extent of which is indeterminate. This most famous of all aircraft gun mountings was mainly constituted by an elevating-arm, or bow, which carried a Lewis gun, and a rotatable ring. It was contemporarily described as follows:
‘The elevating-arm and the rotatable ring are locked in their adjusted positions by devices which are actuated simultaneously, or in succession, to effect unlocking by a single control wire operated by a handle on the elevating-arm. When operated in succession, the ring is released before the elevating-arm. Elastic cords balance the turning moment in a vertical plane due to the weight of the elevating-arm and the parts carried thereby. The rotatable ring is mounted on ball or roller bearings.' Not mentioned in the foregoing concise description were the two upward-projecting pairs of toothed segments, or quadrants, each pair being engaged by a locking pin carried by the elevating-arm and moving into or out of engagement with the teeth of the segments. Of this basic form of Scarff ring-mounting there were several variations, not only British but foreign also, the best-known related foreign counterpart being the French T.O.3.
This last-named mounting differed very greatly from the French-designed Nieuport type used on some early 1 1/2 Strutters, though the Nieuport mounting was itself basically of ring type. It had, nevertheless, a very distinctive appearance, by reason of its great height and peculiar form, these features resulting from a pair of upward-projecting arms, between which the Lewis gun was carried on a cross- member.
Far less obtrusive was the British Strange mounting, a cranked-pillar pattern with which was associated a crescent-shaped toothed quadrant; but neither the Nieuport nor the Strange mounting was extensively fitted on the 1 1/2 Strutter - such was the demand for the Scarff, when it became available in quantity.
One Sopwith contribution was a special seat for the gunner, capable of all-round movement about an eccentric pivot on a fixed stand, and having means for unlocking itself when relieved of the gunner's weight, enabling it to be freely rotated in its socket. Largely negating such refinements however (which were intended to enhance fighting efficiency) was the wide separation of the two cockpits by the fuel tank - a legacy from earlier Sopwith tandem two-seaters already described.
For the Vickers gun of the 1 1/2 Strutter the belt held 300 rounds of .303 in ammunition, and for the Lewis gun a maximum of five 'double' (97-round) drums could be taken. Early 1 1/2 Strutters were sometimes supplied with 'single' (47-round) drums. Supplementary armament on one aircraft of B Flight, No.70 Squadron, was an 'automatic' (self-loading) pistol with oversize magazine, attached to the starboard landing gear struts to fire outside the propeller arc. Sopwith 'Two- seaters', as the 'fighter' versions of the 1 1/2 Strutter were sometimes called, sometimes had bomb-rails under the lower wings, possible loads being four or eight bombs of 20 lb or two of 65 lb.
The airframe of the two-seat 1 1/2 Strutter was a remarkable combination of convention and novelty, the latter having been already instanced by the strut arrangement, though the wooden construction (with steel tubing used for tips and trailing edges) conformed with standard Sopwith practice. Three features that command special mention were the air brakes handwheel - actuated trailing-edge panels in the bottom centre section, pivoted spanwise to rotate upwards through 90 deg; the large adjustable tailplane (which, though having as a primary purpose compensation for gunners of different weights, was later popular with pupils, when numbers of 1 1/2 Strutters were used for training, because it enabled the trainees to fly with their chilly hands in their pockets); and third, the use of all-steel tubular construction for the elevators, fin and rudder.
The unhappy separation of the pilot and gunner has been mentioned, but the pilot's upward view was also poor, though adequate forwards and downwards, while the siting of the gunner's cockpit, jointly with a top-wing cutout, afforded a wide field of fire for the Lewis gun. Somewhat disappointingly (for so much care had gone into the design) the 1 1/2 Strutter was officially declared to be 'rather heavy and slow on controls'; yet. even so, this aircraft marked a new departure in military-aircraft design, and was clearly capable of development and adaptation.
After Hawker's early spectacular demonstrations (he was then flying solo) performance was never remarkable, either with the original 110 hp Clerget engine, or the later-standardised 130 hp Clerget (nor, for that matter, with any other Clerget or Le Rhone rotary, as fitted in some French-built machines), and this deficiency in performance, jointly with mediocre manoeuvrability, clearly militated against combat effectiveness - and, of course, the armament was quickly matched. Nevertheless, the type was in first-line service until late in 1917, by which time the Sopwith single-seaters had quite outclassed it in fighting performance. This being so it is the more regrettable that a project of September 1916, involving the fitting of an American-designed 150 hp Smith Static ten-cylinder radial engine, was never realised - and at that time there was no comparable A.B.C. radial available. (Clearly, a long inline engine would have spoiled the basic concept of the design).
The foregoing reference to a ten-cylinder engine is a reminder that, however confusing were the Service or makers' designations of the rotary types actually fitted, these - for British operational service at least - invariably had nine cylinders, whereas the Pup sometimes had a seven-cylinder unit. The British-built 1 1/2 Strutters had either the 110 hp Clerget (makers' suffix 9Z) or the 130 hp Clerget (9B), but French-built examples had either Clergets of the 9B series (9Ba 135 hp, 9Bb 135 hp or 9Bc 145 hp) or the Le Rhone 9J (110 hp) or 9Jby (135 hp). French-built trainers sometimes had the 80 hp Le Rhone 9C, a type so popular in British operational Pups. The standard annular cowling on British 1 1/2 Strutters had a segmental slot at the bottom and was of special Sopwith design (see under Pup. in Harald Penrose's account).
Development and adaptation now being our concern it is fitting to consider the special single-seat fighter version of the 1 1/2 Strutter developed for Home Defence. In this instance the Vickers gun was dismounted, the front cockpit was faired over, the pilot was moved to the rear, and a Lewis gun was mounted over the top wing to fire above the propeller and obviate the risk of using sensitive and temperamental 'special' ammunition in a synchronised gun. Presumably to exploit the '45-degree shot' upward-firing formula, on which much investigatory work was done, one aircraft at least had two upward-firing Lewis guns in a special installation forward of the cockpit, and in another application of two Lewis guns these were carried on a twin mounting of Foster (sliding block on curved track) type.
Yet of far greater significance than these specialised single-seat fighters were the no less specialised single-seat bombers (as distinct from bomb-carrying two-seaters already mentioned). In essence the bomber transformation was simple: bombs were internally stowed in a compartment which took the place of the gunner's cockpit. On typical British 1 1/2 Strutter single-seat bombers, four 50 lb or 65 lb bombs were stowed horizontally. Beneath the bomb compartment were four trapdoors that were opened by the weight of the falling bombs (probably with scant effect on bombing accuracy) and were closed again by shock-absorber cord. In each side of the compartment were two inspection and access panels. The Vickers gun, was retained, and occasionally a Lewis gun firing over the top wing was additionally fitted though strictly as 'secondary' armament, for the ammunition magazine could not be changed in flight. Nevertheless, the possibility of abandoning the Vickers entirely may well have been in mind, for the later Sopwith B.1 bomber (another single-seater) had a single Lewis only.
1 1/2 Strutter (Ship's)
Although the part played by Sopwith aircraft generally in the development of British Naval flying has been extensively recorded by other writers (and properly so) the contribution made by the 1 1/2 Strutter in particular has not, one feels, been fully recognised. In the 'Ship's Strutter' (as the basic form concerned was sometimes known, though commonly adapted from a landplane fighter or bomber) we see not merely an aeroplane capable of operating from a platform on a ship (or from a carrier's deck) but one that could perform in the pre-eminent roles that the Navy so urgently demanded should be filled: namely those of spotting fall-of-shot for the big guns of the Fleet(s) and of reconnaissance in general - aided by 'wireless'.
Between the specially prepared shipborne versions of the 1 1/2 Strutter and the original form of the aircraft were analogies that were strikingly in parallel with those existing between the Hawker Hart of over ten years later and its Naval derivative the Osprey; and this was evident even in external appearance, for both could be seen with jury struts where the outer wing-panels were (on some Ship's Strutters) detachable or (on all Ospreys) foldable. Further, although in the Osprey there existed (supposedly at least) a 'fighter' element the official classification being 'fleet fighter-reconnaissance' - the pilot's armament was only half that of the corresponding specialised land-based fighter variant of the Hart (this, the Demon, having two Vickers guns and the Osprey one only) whereas on the shipborne 1 1/2 Strutter there was no Vickers gun at all, having regard to the pressing requirement to keep the aeroplane light while carrying its all-important wireless and other Naval appurtenances. By the same token, the Parnall Panther, which was specifically (and very ingeniously) designed to undertake essentially the same duties as the Ship’s Strutter, had a fixed Vickers gun in prototype form only, this being absent on production versions - with even more weight being saved by the adoption of a special pillar mounting for the defensive Lewis gun, instead of the generally adopted Scarff ring.
To conclude the Ship's Strutter/Osprey analogies, even the apparently basic difference - the fitting of floats on the Osprey in its catapulted form - was, in fact, far from being as basic as appearances suggested; for catapults were not widely fitted to British Naval vessels until the 1930s, the two possible launching methods formerly used from battleships, battle cruisers and craft other than specialised aircraft carriers being the 'flying-off platform' built over a gun turret and rotating with it, or the technique of lowering a floatplane into the water by derrick and hoisting it back again.
Herein lies the full Significance of the Ship's Strutter - it gave the Navy ears as well as eyes and claws; for on 4 April, 1918, (immediately after the formation of the RAF) an aircraft of this type, flown by Capt F. M. Fox of the new Service, and carrying an observer, W/T equipment and an Aldis signalling lamp was successfully launched from a platform on Q turret of the battle cruiser HMAS Australia. 'Successfully' here is emphasised, for an earlier trial from another battle cruiser (MHS Repulse, in March) had failed. Thus battleships and battle cruisers carried a two-seat reconnaissance aircraft (typically a 1 1/2 Strutter, though a Parnall Panther was used, for instance, from HMS Revenge) on a forward-turret platform, with a single-seat fighter (generally a Camel) on a rear-turret platform. By the end of the war, in fact, the Grand Fleet had over 100 platform-borne aircraft, 22 cruisers having themselves been given platforms - though not, of course, rotatable atop the turrets of big guns.
The extent and importance of these provisions were little appreciated at the time by reason of wartime secrecy, but shortly after the Armistice a Naval officer gave this concise account: 'My ship carried one Camel and one 1 1/2 Strutter. These were carried on our broadside turrets. The 1 1/2 Strutter was used for spotting purposes, and the Camels in the squadron performed formation flying. The method of release is effected by a "quick-release". When about to fly off, the ship steams at about 30 deg. to the wind and the turret is trained 30deg., thereby pointing into the wind. The clamps are taken off the ailerons, elevators and rudder, and the quick-release attached. The pilot then starts his engine, and gradually works up to the maximum revolutions. When he waves his hand, the men holding on to the leading edge of the lower plane let go and stand clear, and at another signal, usually dropping a flag, given by the executive officer, the A. M. [air mechanic] pulls sharply on the quick-release and thus frees the machine, when the pilot runs along, and takes-off from, the platform. All the time when the engine is running the quick-release alone holds the machine. A tail guide of about 2 ft. length keeps the tail from dropping at the start. The greatest length of run for taking-off is not more than 30 ft.'
This helpful little note is given here, rather than in the context of the Camel, with deliberate intent, for reconnaissance and spotting, rather than fighting, were (as noted in this chapter's opening paragraph) pre-eminent among the Navy's requirements. A brief word, too, on terminology may not be superfluous.
First, the term 'broadside turret' must not necessarily be construed as archaic or tautologous, for not all turrets during 1914-18 were on the ship's centre line. Second, the Camels' 'formation flying' may reasonably be construed as 'flew in formation (or in company) with the 1 1/2 Strutters" just as, in later years, the single-seat Hawker Nimrods were dependent on the slower two-seat Ospreys for navigation (and found station-keeping a hindrance to their purpose). Last, even when flying-off platforms had become obsolete on Naval ships, the essential launching technique described was perpetuated in the aircraft carriers Furious, Courageous and Glorious for launching their 'slip-flight' fighters - sometimes using a quick-release - straight out of their hangar and over the bows below the level of the main flying-deck.
Conversely, it is worth pondering the true origins of training the launching platform by a rotary mechanism; and here it may be noted that torpedo-tubes were mounted on turntables just as guns were mounted in rotating turrets. This being so one may further remark that well before the end of the 19th century a humorous fictional reference had been made to launching a flying machine from a ship of the Royal Navy by means of a veritable torpedo-tube. A relevant passage ran: '... the navigatin' commander give the correc' course to the torpedo lootenant, who trained the toobe by compass, an' fired.... (But perhaps this was a precursor of the aircraft catapult).
To the earlier-quoted account by a Naval officer of how Sopwith aircraft were operated aboard 'his ship' it may be added that a technique was also developed whereby the aircraft was launched, as it were, in reverse, the guns being elevated to give a sleep run down the platform, but still into wind. A method involving downward launching from a ship had, in fact, been patented long before the war in the names of Capt F. M. Sueter, Lieut F. L. M. Boothby and Engr-Lieut H. G. Paterson, this method being applied jointly with a launching trolley, which was to drop into the water and be hauled on board again. Acceleration of the aircraft was assisted by a Wright-style falling weight. In the purely practical sense, Lieut C. R. Samson, on 10 January, 1912, had used a sloping staging, built over the forward gun turret (thus rendered unworkable) of HM Africa, to accelerate his pusher Short and secretly, it was said, 'Sammy' had done the job in the previous December.
In the preceding chapter it was affirmed that 'On the Naval side' (and distinct from work described in this present chapter) 'bombing was pre-eminent'; and this particular theme may now be taken up by remarking that 1 1/2 Strutters were used for anti-submarine patrols not only in home waters but in the Mediterranean area also, the home-based patrols beginning in April 1917 and those in the 'Med’ about two months later. Thus, on 17 September of that year (by which time the 1 1/2 Strutter had been in service for about 1 1/2 years) an Otranto-based aircraft of this type was claimed to have sunk a U-boat with a 65 lb bomb.
As a summation of other developments and as a basis for further comment one acknowledges this excerpt from Owen Thetford's British Naval Aircraft since 1912: 'At the Armistice some 170 Sopwith 1 1/2 Strutters remained in service with the R.A.F. and nearly 40 of these were at sea with the Grand Fleet. Indeed, when, in March 1918, HMS Furious was made the flagship of the Flying Squadron of the Grand Fleet her complement included fourteen 1 1/2 Strutters. For deck flying the 1 1/2 Strutter was used both with the normal wheeled undercarriage and with a special skid undercarriage first developed in trials at the Isle of Grain; the latter version usually had a hydrovane mounted at the front end of the skids to prevent the aircraft nosing over if forced into the sea. This device, as well as the inflatable air-bags located either side of the engine, remained a feature of naval aircraft until about 1923, when flotation equipment was mounted inside the rear fuselage instead.'
To these remarks one would add that, before ditching a 1 1/2 Strutter, it was advisable (one experienced pilot said 'necessary') for the pilot - seated as he was under the centre section - to get out on the bottom wing. Further points that one now makes revert to the earlier Sopwith/Hawker analogies and to the development of flotation gear generally. Whereas the Hawker Nimrod and Osprey had (in common with other Fleet Air Arm types of their period) air-bags of the officially-styled 'permanent atmospheric-pressure type' as part of their normal equipment, the land-based Hart bomber was not thus endowed. So, when over-water dive-bombing became a requirement, flotation gear had to be provided as an 'extra' - just as it had been on the 1 1/2 Strutter and although this gear took two quite distinct forms (inflatable bags in under-wing containers, or a Youngman dinghy, as fitted on some Ospreys, and housed at the root of the top starboard mainplane, between the spars) both forms were inflatable again as on the 1 1/2 Strutter.
Another fitment of the general type which was to reappear on the Nimrod and Osprey was the arrester hook with which experiments were made on the dummy deck at the Isle of Grain (particularly associated with Harry Hawker's compatriot Harry Busteed) in June 1918. The 1 1/2 Strutter used was a skid-equipped single-seat bomber, though the significance of this fact should not be over-estimated, for many types of aircraft were used as experimental 'hacks', and the absence of a gunner and internal bombs may have been deemed especially beneficial respecting c.g. position and flying weight, for the hook was attached far forward under the fuselage. These considerations notwithstanding, the claim by Vice-Admiral Richard Bell Davies that the idea of 'detachable-wing 1 1/2 Strutters' of 'the long-range single-seater bomber' type was his own (for attacking Zeppelin bases) is not to be ignored.
Clips on the landing gear spreader-bar were ultimately favoured to effect arrest, and were to be generally used on British carrier-borne aircraft pending the return of the under-fuselage hook. The pilot who pioneered this 'clip' technique has, in fact, already been named in a loftier rank: he was Lieut Col R. Bell Davies, VC, DSO, and the aircraft concerned - on 1 October, 1918 was 1 1/2 Strutter F2211, which, when flown from and landed aboard HMS Argus, had a special propeller guard.
The full extent of Naval experiments with the 1 1/2 Strutter may never be known; but one that must clearly be recorded is that wherein fore-and-aft troughs, as developed at the Isle of Grain, laid along a special deck on HMS Vindex received the landing-gear skids of another experimentally-employed single-seat bomber. This particular aeroplane was the Westland-built N5601, and there is ample evidence that more than one aircraft from the same batch was used for Naval experiments of various kinds with inflatable air-bags for instance. Westland's own first major contribution to British Naval flying was, as matters transpired, an adaptation of another of their products the Walrus, for which the D.H.9A provided the basis, but which utilised the hydrovane landing gear and inllatable air-bags as developed on the 1 1/2 Strutter.
To the 1 1/2 Strutter the US Navy, as well as the British, owes a debt for pioneer experiments and operations. Apart from a single specimen shipped to the USA and numbered there A5660, twenty-one additional examples were obtained from the US Army after the war. Thus the 'yellow rose' that bloomed on the turret platform of the USS Texas in 1919 was really planted at Kingston, Surrey, England.
At the very outset of this account deliberate allusion was made to 'specially prepared shipboard versions' (plural) of the 1 1/2 Strutter; and any attempt at a precise definition of the common appellation 'Ship's Strutter' (or Ship Strutter) would be hazardous. However, that the Isle of Grain should have primary credit for the detachable wings, skid-type landing gears, hydrovanes, flotation gear - even, perhaps, for that all-important 'wireless' (W/T) - used by aircraft of this general denomination is likely. That conversion sets were later ordered from the Gosport Aviation Co. is hardly less credible, though this order appears to be quite unconnected with the fact that Sopwith's R. J. Ashfield had joined Gosport around the turn of 1917. With the Isle of Grain also was associated the development of a special lightweight gun-mounting for the Ship's Strutter, though whether this was of the pillar type fitted to the Parnall Panther or of a specially lightened Scarff pattern (the Scarff, in any case, taking many forms) is uncertain. With Grain development, too, was associated a Clerget engine having a nominal output of 140 hp - in which regard it may be noted that the 9BF pattern was described by Gwynnes Ltd, of Hammersmith (‘Sole licencees for the British Empire’) as having a stroke of 172 mm (that of the 130 hp 9B being 160 mm) and a nominal power of 150 hp. (For French ratings see previous chapter). Concerning the long-stroke Clerget it may also be pertinent to note in the present context that in February 1918 an official Information Circular was issued comprising notes on the conversion of the 9B engine to what was designated (verbatim) 'the 9B.F. (Long Stroke) Clerget Engine’. As no Vickers gun was fitted to the Ship's Strutter any increase in cowling diameter would be of small consequence.
F.Manson British Bomber Since 1914 (Putnam)
Sopwith 1 1/2-Strutter Bomber
Design of the Sopwith 1 1/2-Strutter probably began quite early in 1915 although, being in effect a private venture at the outset, manufacture of a prototype at Kingston was accorded less urgency than to aeroplanes being prepared to specific Admiralty orders. As with most of the early Sopwith aircraft, delineation of design responsibility was nebulous, frequent informal discussions on new designs being held between Thomas Sopwith himself, his works manager Fred Sigrist, and his chief pilot Harry Hawker, with R J Ashfield and Herbert Smith representing their respective design offices.
Being almost exclusively involved with Admiralty requirements, Sopwith would have been familiar with that Ministry's shift towards bombing aircraft during 1915 (away from purely torpedo-carrying seaplanes), yet no less aware of the Army's desperate shortage of effective light tactical bomb-carrying aeroplanes, and in particular such aeroplanes capable of defending themselves in the presence of German fighting scouts.
The 1 1/2-Strutter (so called on account of the shortened inboard wing struts being attached to the upper longerons and not extending down to the lower wing spars) was therefore deliberately intended to attract both Admiralty and War Office orders for a self-defensible light bomber. Designed initially as a two-seater, it was provided with a Lewis gun on the rear cockpit and later a fixed, front Vickers gun, firing through the propeller, made possible by the Vickers and Scarff-Dibovski synchronizing gears. The former gear was preferred by the War Office, the latter by the Admiralty.
Structurally the 1 1/2-Strutter was entirely conventional by Sopwith standards, that is to say it was of all-wood construction with ply and fabric covering; ailerons were fitted to upper and lower wings, which were of equal span. Early aircraft were fitted with the 110hp Clerget engine, but also came to be powered by the 130 and 135hp Clergets and Le Rhone engines of similar power.
The aircraft featured two interesting innovations which served to demonstrate the efforts made to alleviate any handling difficulty that might arise when carrying and dropping bombs. These were a pair of rudimentary airbrakes set in the lower surfaces of the wing centresection, and a variable-incidence tailplane, adjustable by a control wheel in the pilot's cockpit to compensate for variations in trim. The latter innovation was patented by Harry Hawker and, in 1920, when the Sopwith company went into liquidation, the patent rights were determined in favour of the H G Hawker Engineering Company. (The variable-incidence tailplane was to be a feature of most Hawker aircraft produced between 1926 and 1935, as well as others)
The prototype, No 3686, was placed on an Admiralty contract, and probably first flew at the end of December 1915 or early the following month. It was followed by numerous production contracts - which were widely subcontracted - from the Admiralty (where the aircraft was referred to as the Type 9700) and War Office, the majority of the former being for bombers, and the latter for fighters. The 50 naval aircraft of the first production order, built by Sopwith, were two-seaters, but it was quickly decided that, when carrying the normal bomb load (of up to four 65 lb bombs in an internal fuselage bay), it was necessary to fly without the observer/gunner, with the result that all subsequent Admiralty orders for bombers required the rear cockpit to be deleted altogether, and faired over. The front gun was, however, retained. A total of 172 naval single-seat bombers was built by Sopwith, Westland, and Mann, Egerton.
It is perhaps worth recording here that it was Warrant Officer F W Scarff at the Admiralty Air Department who drew up the design of the front gun synchronizing gear from proposals made by a Russian, Lt-Cdr V V Dibovski, and that Scarff it was who also designed the gun mounting ring that was to carry his name in the RAF for a quarter century. Some 1 1/2-Strutters were fitted with a Nieuport ring of French origin, but when two-seater naval aircraft were transferred to the RFC at the time of the great summer battles o f 1916, General Trenchard ordered all his Service's 1 1/2-Strutters to be converted to have Scarff rings, so superior were they found to be.
The arrival of the 'Strutter' bomber in the RNAS was intended to be central to the build-up of a bombing campaign by No 3 Wing, based at Luxeuil, but this plan was severely delayed when the Admiralty agreed to transfer more than 70 of these aircraft to the RFC to help make good the losses being suffered during the Somme battle of July.
Despite these delays, naval 1 1/2-Strutters flew a number of outstanding bombing attacks during the summer of 1916, including raids on the airships stations at Evere, Berchem Ste Agathe and Cognelee, an ammunition dump at Lichtervelde and the shipyards at Hoboken, serving with Nos 5 and 8 (Naval) Squadrons.
Apart from anti-submarine coastal patrols, which 1 1/2-Strutters flew as stopgap equipment from such stations as Mullion, Pembroke and Prawle Point, the aircraft gave long service with the RNAS in the Mediterranean both as anti-submarine aircraft and bombers in Italy, Macedonia and the Aegean (probably sinking an enemy submarine with a 65 lb delayed-action bomb on 17 September 1917).
The aircraft were also supplied to a number of Allied air forces, in most instances as two-seat fighters or reconnaissance aircraft, although France (where the 1 1/2-Strutter was also licence-built by Liore et Olivier and Hanriot) also received single-seat bombers.
Type: Single-engine, single- and two-seat, single-bay biplane light bomber.
Manufacturers: The Sopwith Aviation Co Ltd, Kingston-upon-Thames, Surrey; Mann, Egerton & Co Ltd, Prince of Wales Road, Norwich, Norfolk; Morgan & Co, Leighton Buzzard, Bedfordshire; Westland Aircraft Works, Yeovil, Somerset.
Powerplant: One 110hp Clerget 9Z or 130hp Clerget 9Bc nine-cylinder rotary engine driving two-blade propeller.
Dimensions; Span, 33ft 6in; length, 25ft 3in; height, 10ft 3in; wing area, 346 sq ft.
Weights (Clerget 9Z): Tare, 1,354 lb; all-up (with four 56 lb bombs), 2,362 lb.
Performance (Clerget 9Z): Max speed, 104 mph at sea level; climb to 10,000ft, 26 min 55 sec; service ceiling, 12,500ft.
Armament: One synchronized 0.303in Vickers machine gun on nose decking; bomb load of four 65 lb bombs or equivalent weight of lighter bombs carried internally in bay aft of the pilot's cockpit.
Production: No special bomber prototype. Of the total of 1,513 Sopwith 1 1/2-Strutters recorded as having been ordered for the RFC and RNAS, 172 were built as single-seat bombers: Sopwith, 145 (Nos 9651, 9652, 9655, 9657, 9660, 9661, 9664, 9666-9673, 9700, 9704, 9707, 9711, 9714, 9715, 9718, 9720, 9723, 9724, 9727, 9729, 9732, 9733, 9736, 9738, 9741, 9742, 9745 and 9747; A6014 and A6015; N5088 and N5089; N5120-N5179; N5500-N5537 and N5550-N5559); Morgan, 2 (A6014 and A6015); Mann, Egerton, 20 (N5200-N5219); Westland, 5 (N5600-N5604).
Summary of Service: Sopwith 1 1/2-Strutter single-seat bombers served with 3rd and 5th Wings, RNAS, in France, and with RNAS units in Italy (at Otranto), Macedonia and the Aegean, including 'F' Squadron which flew a number of bombing raids in the Smyrna area.
O.Thetford British Naval Aircraft since 1912 (Putnam)
Sopwith 1 1/2 Strutter
The claims of the Sopwith 1 1/2 Strutter to historical fame are many. It was, of course, the first of the Sopwith breed to achieve widespread use as a fighting aeroplane and hence the precursor of a justly renowned series. In addition to this it was the first British aeroplane to enter service already equipped with a synchronising gear, enabling the fixed front gun to fire between the revolving blades of the airscrew, and also the first two-seater which gave the pilot a chance to use his gun effectively as well as the observer. It thus established what came to be a classic formula, that of the two-seat fighter, later exemplified in the Bristol Fighter and the Hawker Demon.
Nor did the 1 1/2 Strutter's pioneering tendencies end here. In 1916, with the 3rd Wing of the RNAS at Luxeuil. 1 1/2 Strutters became the first British aircraft ever to take part in bombing raids of an avowedly strategic nature, attacking German industrial centres and providing, as it were, a prelude to the heavier blows struck later by the squadrons of the RAF's Independent Force. Finally, in the sphere of shipboard flying, it was a 1 1/2 Strutter that became the first two-seater to take off from a British warship, in April 1918.
The Admiralty had from the earliest beginnings of the RNAS shown interest in the products of the Sopwith Company, and it was therefore only logical that the 1 1/2 Strutter should be first ordered for naval service, though it later entered the RFC as well. The prototype (No.3686) was completed at the end of 1915, and first deliveries of RNAS Strutters began early in 1916, against an Admiralty contract for 150. Some of the first to enter service equipped part of No.5 Wing at Coudekerque in April 1916. NO.5 Wing was formed in March 1916 for long-range bombing duties and was equipped primarily with Caudrons and Farmans. The 1 1/2 Strutters were able to provide a welcome escort, as well as operating in the bombing role themselves. As related in the narrative on the Caudron G.4, a 1 1/2 Strutter was on 2 August 1916 used to control a No.5 Wing bombing formation by firing Very lights, a sort of forerunner of the master bomber technique of the Second World War. A few days later, on 9 August, two of NO.5 Wing's 1 1/2 Strutters flown by F/Sub-Lts R H Collet and D E Harkness made bombing attacks on the Zeppelin sheds at Evere and Berchem Ste Agathe; another attack followed on 25 August, this time on the sheds at Cognelee. Subsequently the 1 1/2 Strutters of No.5 Wing participated in many important raids on enemy aerodromes and ammunition dumps, as well as naval targets such as U-boat bases and the Tirpitz battery.
Meanwhile, plans for the establishment of NO.3 Wing. RNAS (which was to have received 20 1 1/2 Strutters by 1 July 1916). had been delayed due to the Admiralty's agreement to forgo its Strutters in favour of the RFC, which was desperately short of aircraft with which to fight the Battle of the Somme. Eventually No.3 Wing's 1 1/2 Strutters started their raids in October 1916 and, though severely hampered by winter weather conditions, bombed industrial targets at Hagendingen, Oberndorf, Dillingen and other towns in the Saar where the Admiralty believed steel for U-boats was being manufactured in large quantities. It is interesting to note that No.3 Wing's base at Luxeuil was close to Belfort. from whence the RNAS Avros had taken off in November 1914 to raid Friedrichshafen.
Two distinct versions of the 1 1/2 Strutter were supplied to the RNAS, where the type was officially known as the Sopwith Type 9700. As well as the normal two-seater, the RNAS used a single-seat bomber without the rear cockpit, with provision for 12 bombs stowed internally. It is recorded that, of some 550 1 1/2 Strutters supplied to the RNAS, about 420 were two-seaters and the remainder single-seaters.
Although by 1917 the 1 1/2 Strutter was outclassed as a fighting aircraft on the Western Front, it continued to give extensive service with the RNAS in other theatres of war. The RNAS was, in fact, the only service to operate the type outside France. In Macedonia, particularly, the naval Strutters saw a lot of action in bombing raids between April and September 1917, when they hit targets such as aerodromes, ammunition dumps and railway communications behind the enemy lines on the Struma.
The Sopwith 1 1/2 Strutter's versatility extended also to anti-submarine patrols, both in home waters and in the Mediterranean area. The home-based patrols started in April 1917 and those in the Mediterranean in June 1917. On 17 September 1917 a 1 1/2 Strutter based at Otranto claimed the sinking of a U-boat by attacking it with a 65 lb delayed-action bomb.
At the Armistice some 170 Sopwith 1 1/2 Strutters remained in service with the RAF and nearly 40 of these were at sea with the Grand Fleet. Indeed, when, in March 1918, HMS Furious was made the flagship of the Flying Squadron of the Grand Fleet her complement included 14 1 1/2 Strutters. For deck flying the life Strutter was used both with the normal wheeled undercarriage and with a special skid undercarriage first developed in trials at the Isle of Grain: the latter version usually had a hydrovane mounted at the front end of the skids to prevent the aircraft nosing over if forced into the sea. This device. as well as the inflatable air-bags located either side of the engine nacelle, remained a feature of naval aircraft until about 1923, when flotation equipment was mounted inside the rear fuselage instead.
Numerous experiments in deck-flying were made with 1 1/2 Strutters. One aircraft (N5601) fitted with skids was flown off a railed deck aboard HMS Vindex, and the first successful landing aboard HMS Argus using the early form of deck arrester gear was made by Wg Cdr Bell-Davies, Vc, in F2211 on 1 October 1918. A further development of 1918 was the introduction of 1 1/2 Strutters for two-seat reconnaissance duties aboard capital ships. This involved flying off a short platform mounted above the forward gun turret and became standard practice aboard battle cruisers after the first successful take-off had been achieved from the Australian warship HMAS Australia by Capt F M Fox on 4 April 1918, carrying an observer and full wireless equipment.
Nos.2, 4, 5, 7 and 8 Squadrons, RNAS (Western Front); Maccdonian units: 'A' Squadron (Thasos). 'B' Squadron (later No.23 (Naval)) (Mitylene). 'C' Squadron (later No.20 (Naval)) (Imbros and Mudros). 'D' Squadron (Stavros). 'E' Squadron (Hadzi Junas). 'F' Squadron (Amberkoj). 'G' Squadron (Mudros) and 'Z' Squadron (Thasos). NO.225 Squadron (Italy). RNAS coastal air stations at Dover, Great Yarmouth, Mullion, Otranto, Pembroke and Prawle Point. RNAS training schools at Cranwell and Manston. Aircraft-carriers: Argus and Furious. Battleships: Australia, Barham. Courageous, Glorious, Indomitable, Inflexible, Malaya, Queen Elizabeth, Renown, Repulse, Valiant, and Warspite. Seaplane carriers: Campania, Vindex and Vindictive.
TECHNICAL DATA (1 1/2 STRUTTER)
Description: Single-seat bomber, or two-seat bomber, fighting and reconnaissance aircraft for shore-based or carrier-borne operations. Wooden structure, fabric covered.
Manufacturers: Sopwith Aviation Co Ltd, Kingston-on-Thames (Nos.9376 to 9425, 9651 to 9750, 9892 to 9897, N5080 to 5179, and N5500 to 5537) Sub-contracted by: Mann, Egerton & Co Ltd, Norwich (N5200 to 5219, N5220 to 5249 and N5630 to 5654) and Westland Aircraft. Yeovi1 (N5600 to 5624). Also 70 French-built 11/2 Strutters converted for ship-board flying in 1918 and serialled F2210-2229 and F7547-7596.
Power Plant: One 110 hp or 130 hp Clerget.
Dimensions: Span, 33 ft 6 in. Length, 25 ft 3 in. Height. 10 ft 3 in. Wing area, 346 sq ft.
Weights (two-seater with 110 hp Clerget): Empty, 1,259 lb. Loaded, 2,149 lb. (single-seater with 130 hp C1erget): Empty, 1,316 lb.
Performance (two-seater with 110 hp Clerget): Maximum speed, 106 mph at sea level; 92 mph at 12,000 ft. Climb, 1 min 20 sec to 1,000 ft; 10 min 50 sec to 6,500 ft; 20 min 25 sec to 1,000 ft. Endurance, 4 1/2 hr. (Single-seater with 130 hp C1erget): Maximum speed, 102 mph at 6,500 ft. Climb, 12 min 40 sec to 6,500 ft; 24 min 35 sec to 10,000 ft. Service ceiling, 13,000 ft.
Armament (single-seat bomber): One Vickers machine-gun forward and four 65 lb bombs. (Two-seater): One Vickers machine-gun forward and one Lewis machine-gun aft. Two 65 lb bombs for anti-submarine patrol.
H.King Armament of British Aircraft (Putnam)
1 1/2 Strutter. Although justly remembered as the archetype of the classic two-seat fighter (pilot with fixed gun, gunner with free gun), this biplane of 1915/16 was also constructed as a specialised bomber and as a 'ship's aeroplane'. In all three forms the armament differed. While the fighter and bomber had a fixed Vickers gun, the third variant did not. The prototype and some production aircraft were flown without armament, the reason in part being a shortage of Vickers guns. While at least one early specimen had the gun mounted on the port upper longeron, with the breech casing lying under the built-up coaming of the cockpit, on all standard production fighters and bombers thereafter the gun was mounted on the centre line of the fuselage immediately ahead of the pilot, with the firing lever projecting from the gun above the control column. The Sopwith patented padded windscreen was fitted, and plain open or ring-and-bead sights were mounted on the gun. The ammunition was fed from the right, and a metal plate on the left, forward of the feed block, served to prevent the canvas belt from twisting in the slipstream before entering the protection of the fuselage. On some early examples the rear of the gun was partly faired. The first machines for the RFC (A and B Flights of No.70 Squadron) had gun-synchronising gear of the Vickers type, but C Flight of the same unit had aircraft intended for the RNAS and fitted with the Scarff-Dibovsky gear developed for, and standardised by, that Service. Gears of the Ross and Sopwith-Kauper types were also fitted. The advantages of the Vickers gun, with its continuous belt feed, over the drum-fed Lewis, which demanded the breaking-off of an engagement for the changing of drums, was quickly apparent.
That the Scarff No.2 ring-mounting for the Lew is gun was developed with the assistance of the Sopwith company is not generally known, and it is with this most famous of all aircraft gun mountings that the 1 1/2 Strutter is most intimately associated. Early examples, however, had either a Strange cranked pillar mounting or a ring-mounting of the French Nieuport type. The Scarff No.2 mounting was first introduced in the ex-RNAS aircraft of C Flight. No.70 Squadron, already mentioned in connection with the Scarff-Dibovsky gear. It was mourned directly on the top longerons, and thus below the fuselage top line, and its diameter was slightly greater than the fuselage width. Standard ammunition provision on the 1 1/2 Strutter two-seater was 300 rounds in a fabric belt for the Vickers gun and five double drums for the Lewis gun. On one aircraft of B Flight, No.70 Squadron, an auxiliary armament of an automatic pistol with oversize magazine was attached to the starboard undercarriage struts to fire outside the airscrew arc. On certain Home Defence aircraft, the Vickers gun was dismounted, the front cockpit was faired over, the pilot was moved to the rear and a Lewis gun was mounted over the top wing to fire above the airscrew and obviate the risk of using 'special' ammunition in the synchronized gun. One aircraft had two upward-firing Lewis guns mounted forward of the cockpit in a special installation, and another carried the same armament on a twin mounting of Foster type.
Apart from its Scarff ring-mounting and Sopwith padded screen, the 1 1/2 Strutter was notable also for its tailplane incidence-adjusting gear, a primary purpose of which was to compensate for gunners of different weights. For this aeroplane, also, Sopwith developed a special gunners seat, capable of all-round movement about an eccentric pivot on a fixed stand. Means were provided for automatically locking the seat to the stand when the seat was occupied and for unlocking the seat when it was relieved of the gunner's weight. A wooden frame carried a vertical pivot having a toothed ring which was pressed, by the weight of the gunner acting against a spring, into engagement with a toothed ring carried by a fixed socket supported by legs. The engagement between the teeth served to fix the seat in the desired position, but disengagement automatically took place under the action of the spring when the gunner raised himself, and the seat could then be freely rotated in the socket.
No fighting aeroplane ever introduced as many novel armament features as this Sopwith two-seater.
Bomb rails were sometimes fitted beneath the lower wings and/or fuselage of 1 1/2 Strutter two-seaters, and possible loads were four or eight 20-lb or two 65-lb. The potential of these aircraft as long-range bombers was quickly recognised by the RNAS; indeed the 1 1/2 Strutter had been originally designed for bombing and has a place in history as one of the first truly 'strategic' bombers. A specialised single-seat bomber type was developed, and this carried its bombs internally in a compartment which took the place of the gunner's cockpit. Official rigging notes indicate that the rear flying wires on bombers were shorter than on fighters. The standard load was four 50-lb or 65-lb bombs, horizontally stowed. The four trapdoors beneath the bomb compartment were opened by the weight of the falling bombs and were closed again by shock-absorber cord. Two small inspection and access panels were let in to each side of the bomb compartment. On the single-seat bomber, 500 rounds were provided for the Vickers gun. Occasionally a Lewis gun was fixed to fire over the top wing of bombers as auxiliary armament, but the drum for this could not be changed in flight. The 'Sopwith Bomber (Clerget)' was declared obsolete in an Air Ministry Order of 1921.
G.Swanborough, P.Bowers United States Military Aircraft Since 1909 (Putnam)
The Sopwith “1-1/2- Strutter”, so named by the British because of its extra centre section struts, was a notable military aircraft before American entry into World War I. The French obtained large quantities of the two-seat observation version, which they named Sopwith 1A2, and the single-seat bomber version 1B1, by purchase and license manufacture. When the A.E.F. desperately needed aeroplanes in 1917/18, the French sold 514 Sopwiths (384 As and 130 Bs) to the Americans.
Span, 33 ft. 6 in.; length, 25 ft. 4 in.; area, 353 sq, ft.; weight, 2,061 lb.; speed, 95 m.p.h.
G.Swanborough, P.Bowers United States Navy Aircraft Since 1911 (Putnam)
SOPWITH 1 1/2-STRUTTER
Among the Navy's British purchases during World War I were two-seat Sopwith 1 1/2-Strutters, widely used as observation and training types by both France and Britain. The one example shipped to the States received serial A5660. An additional 21 obtained from the US Army after the war became A5725-A5728 and A5734-A5750. These were used as light observation types. Power plant was a 130 hp Clerget. Span, 33 ft 6 in; length, 25ft 3in; gross weight, 2,150 lb; max speed, 100 mph.
L.Andersson Soviet Aircraft and Aviation 1917-1941 (Putnam)
Sopwith 1 1/2-Strutter
The single-bay biplane known as the 'Sopvich' in the Soviet Union had long sloping struts between the fuselage and the upper wing and was originally named Sopwith 1 1/2-Strutter because of these extra centre section struts. Developed in 1915 primarily for the Royal Naval Air Service, it was delivered to that Service from February 1916, but was soon accepted by the Royal Flying Corps as well. The Sopwith was an immediate success in the reconnaissance, patrol and day bombing roles. The pilot's fixed Vickers machine-gun was mounted on the centre line of the forward fuselage and it was one of the first British aircraft fitted with a machine-gun firing through the propeller arc by means of interrupter gear. Furthermore the famous Scarff gun ring-mounting was first developed for the 1 1/2-Strutter.
Apart from the strut arrangement and the armament the 1 1/2-Strutter was of conventional design for its period. A circular cowling enclosed the rotary engine which drove a two-blade wooden propeller. The pilot's cockpit was located well forward of the leading edge of the lower wing, while the rear cockpit was behind the trailing edge of the upper wing. The rudder and elevators were unbalanced and the fin had a peculiar rounded forward end. The staggered wings were straight and of parallel chord and unbalanced ailerons were fitted. British- and French-built versions had different wire bracing arrangement. The undercarriage was of normal V type.
In addition to the reconnaissance version there were single-seat and two-seat bomber versions and many aircraft were built as trainers without the gun ring in the rear cockpit. Over 1,500 were produced in Great Britain and more than 4,000 in France, as the Sopwith 1A2, Sopwith 1B2 and Sopwith 1B1 (single-seat). The 1 1/2-Strutter was also used by Belgium, Russia and the USA. After the war it served with the air forces of Japan and Romania and, in small numbers, also in a few other countries.
Some 125 Sopwith 1 1/2-Strutters were delivered to Russia from Great Britain and a number was built under licence. At least thirty-four were taken over by the RKKVF in 1917 and several were captured in 1919-1920, both British- and French-built examples. The Soviet Latvian Air Force had seven in 1918-19. Some were captured from the RKKVF in 1919 - at least one by Latvian troops, one by Estonia and one by Lithuania (A 1527, which became the first aircraft of that country's air force). Most Sopwiths used by the RKKVF had 130hp Clerget engines, but some were fitted with the 120hp Le Rhone. The Sopwith was one of the most numerous aircraft types in the RKKVF before 1922 and many were also built by Duks in Moscow, later GAZ No. 1 Aviakhim. One was modified by V P Grigorev at the Kiev Polytechnic Institute and fitted with a 185hp Opel engine and an undercarriage taken from a Rumpler.
At the end of 1920 a total of 130 Sopwiths were in service, of which eighty-two remained one year later. In 1921 they served in all military districts but the largest numbers were assigned to the Eastern Front district, North Caucasia, Caucasia, the Ukraine, Kiev, Khar'kov, Turkestan and the 5th Army in Siberia. A few aircraft were added to the inventory, the last batch built by GAZ No. 1 in 1922 consisted of about twenty-five machines (c/ns 2322-2346 probably). The Sopwith served with the following RKKVF units:
Until 1922: the 3rd, 9th, 11th, 15th and 18th Aviaotryady
Until 1923: the'15th Otdel'nyi razvedivatel'nyi aviaotryad at Smolensk (120 and 130hp Sopwith lA2s) and the 1st Razvedivatel'naya eskadril'ya of the Aviatsionnaya eskadra No. 2 at Kiev (2nd otryad only initially)
Until 1924: the 7th Otdel'nyi razvedivatel'nyi aviaotryad at Klin (from 1923), the 10th Otdel'nyi razvedivatel'nyi aviaotryad at Rostov (from 1922, also had Halberstadts and Rumplers), the 16th Otdel'nyi razvedivatel'nyi aviaotryad at Irkutsk (from 1922) and the 17th Otdel'nyi razvedivatel'nyi aviaotryad at Chita (1924 only)
Until 1925: the 18th Otdel'nyi razvedivatel'nyi aviaotryad at Chita (from 1922).
Single examples were used by many other units and by the NOA. Relegated to second-line roles the Sopwith was assigned to the aviabazy and in small numbers to the 1st Military School of Pilots at Kacha, the Higher Military School of Aerial Observers in Leningrad, the Strel'bom school at Serpukhov, the 1st Higher School of Military Pilots, the School of Military Photography and the Training eskadril'ya in Moscow. Sixty-nine remained by October 1924. Many were written off in 1925 but about ten were retained, some until 1929. In December 1928 there were two with the 50th Aviaotryad (c/ns 189 and 8746) and two at the 2nd Voennaya shkola letchikov (c/ns 2322 and 2328).
Some were exported to Afghanistan (one in 1921 and a few more in 1925) and others were handed over to the ODVF late in 1924 and in 1925. These included the following aircraft:
Tomich, flown by Bazhenko and Maslennikov at Tomsk and Novonikolaevsk, Siberia. C/n 1786, flown at Novgorod.
Krasnaya zvezda, flown by Fadeev for the first time after assembly on 8 October 1925 at Yakutsk. Officially presented to the ODVF in November 1925.
Krasnoyarets, flown by Baturin at Krasnoyarsk in 1925.
Stalinets, flown at Stalingrad. Written off in 1926 and given to a museum.
One flown at Orenburg, Bashkiriya, in 1925.
Known identities of Soviet Sopwith 1 1/2-Strutters:
(British- and French-built aircraft) 352/3, 4/H, 5 to 7, 9, 10, 18, 34, 35, 37,39,123,125,126,171,175,189, 200, 214, 219, 238, 241, -/252, 257, 4/258, 260, 296, 298, 299, 301, 302, 306, 326, 339, 402, 418, -/514, 1202/536, 1786, 2000, 2316, 2341-2343, 2357, 2360, 2366, 2368, 2379, 2403, 2407, 2410, 2523, 2557, 2595, 2723, 3131, 3159, 3191, 3407, 4056, 4065, 5760, 4C6078, 6804 and 7046.
(Mostly British-built aircraft) 985, 1000, 1002, 1003, 1006, 1010, 1013, 1015, 1017-1022, 1527, 1552/538, 2383, 2395, 2396, 2398, 2411, 5219, 5247, 5248, 5975, 6925, 6930, 6934, 6950, 8179, 8204, 8266, 8312, 8316, 8323, 8324, 8744, 8746 and 8749 (prob- ablv/possibly including ex-A985, A1527, A1552, N5219, A5247, A5243, A5975, A6925, A6930, A6934, A6950, A8179, A8204, A8266, A8312, A8316, A8323, A8324, A8744, A8746 and A8749)
Aircraft in the 2322-2338 range were probably GAZ No. 1-built.
Span 10.2m; length 7.7m; height 3.12m; wing area 32.8m2
Empty weight 593kg; loaded weight 975kg
Maximum speed 149km/h; climb to 1,000m in 4.4min; ceiling 4,700m; endurance 3'zhr
W.Green, G.Swanborough The Complete Book of Fighters
SOPWITH 1 1/2-STRUTTER UK
Deriving its extraordinary appellation from a characteristic arrangement of cabane struts - a name that was initially unofficial, but came to be accepted as a result of common usage - the 1 1/2-Strutter was both the first British aircraft to be built with a synchronised gun as standard equipment and the first true two-seat fighter to see RFC service. Designed and built for the Admiralty, the unarmed prototype was completed in December 1915, and series deliveries to the RNAS followed from February 1916. A single-bay biplane of wooden construction with fabric skinning, the 1 1/2-Strutter featured air brakes in the lower wing and an adjustable-incidence tailplane. At an early production stage, armament was standardised on a synchronised 0.303-in (7,7-mm) gun with a second weapon of similar calibre on a Scarff ring mounting in the rear cockpit. The 1 1/2-Strutter was used by the RNAS in both escort and (without observer) bombing roles, and 77 of the first 150 aircraft ordered by the Admiralty were transferred to the RFC owing to the exigencies of the times. A single-seat bomber version of the 1 1/2-Strutter was built in parallel, some examples of this variant being converted as two-seat fighters. Initial production aircraft were powered by the 110 hp Clerget 9Z nine-cylinder rotary engine, but, in the autumn of 1916, this gave place to a 130 hp Clerget 9B. At least 1,513 1 1/2-Strutters were built in the UK (by the parent company, Fairey Aviation, Hooper & Co, Mann, Egerton & Co, Ruston, Proctor & Co, Vickers Ltd, Wells Aviation and Westland Aircraft). The 1 1/2-Strutter was licence-built in France as a single- and two-seat bomber (SOP 1B1 and 1B2) and two-seat reconnaissance aircraft (SOP 1A2), primarily with the 110 hp and 135 hp Le Rhone 9J and 9Jby nine-cylinder rotaries, 4,500 allegedly being produced by Liore et Olivier, Hanriot, Amiot, Bessoneau, Darracq, REP and Sarazin Freres. The US government procured 514 from France, and others were supplied to Belgium and Imperial Russia. The following data apply to the 130 hp Clerget-engined model.
Max speed, 100 mph (161 km/h) at 6,500 ft (1 980 m).
Time to 6,500 ft (1 980 m), 9.15 min.
Endurance, 3.75 hrs.
Empty weight, 1,305 lb (592 kg).
Loaded weight, 2,150 lb (975 kg).
Span, 33 ft 6 in (10,21 m).
Length, 25 ft 3 in (7,69 m).
Height, 10 ft 3 in (3,12 m).
Wing area, 346 sqft (32,14 m2).
Flight, February 6, 1919.
THE SOPWITH MACHINES
The 1 1/2-Strutters. (December 12, 1915, and June 7, 1916)
The Sopwith 1 1/2-Strutter has claims to great historical distinction, not only for its great capabilities for use as a fighter, but because, indirectly, it set a new fashion in aerial fighting, being the first British aeroplane to carry a synchronized gun firing through the propeller. The Sopwith-Kauper synchronisation gear which made this possible was developed at the Sopwith works, and was as much a product of this firm as was the machine in which it was installed. It was also fitted with the Scarff gun ring for the gunner, which has since become such a well-established feature on all fighters. The 1 1/2-Stnrtter was originally designed as a high-performance two-seater fighter, with a 100 h.p. Clerget engine. At the time of its introduction it was justly regarded as an extraordinarily good 'bus, having an excellent performance and a good manoeuvrability. Incidentally it established a world's altitude record for an altitude of 23,980 ft. In view of its good performance, coupled with its (for the times) excellent armament, the 1 1/2-Strutter had a tremendous success, and it is not surprising that many machines were built to the order of the Governments of Roumania, Russia, America and Belgium. In addition, it might be mentioned that the French Government has manufactured under licence no less less than 4,500 machines of this model. In addition to the novel points connected with the mounting and firing of the guns carried, the 1 1/2-Strutter was interesting in several other respects. Thus the wing bracing - which gave it its name - was very unusual, and in a modified form set a new fashion, so to speak. The top plane was in two halves, bolted to the top of a central cabane, while the spars were provided with an extra support in the shape of shorter struts running from the top longerons to the top plane spars some distance out. In the single-seaters to follow this bracing of the top plane was generally adopted, with the exception that the central cabane was done away with, the outer struts of the W formation having a slightly less pronounced slope, and supporting a separate top plane centre section. Aerodynamically the 1 1/2-Strutter is of interest in being fitted with, an air brake in the form of adjustable flaps in the trailing edge at the lower plane adjacent to the fuselage. These flaps could be rotated by the pilot until they were normal to the wind, thus helping to pull the machine up when about to land.
A more successful innovation incorporated in this machine was the trimming gear, by means of which the angle of incidence of the tail plane could be altered during flight. In this manner the difference in weight of the passenger carried could be counteracted by the tail setting, and also the tail could be adjusted for high speed, climbing, &c. This feature has since become universal practice on passenger-carrying machines.
The 1 1/2-Strutter Bomber
Originally designed as a two-seater fighter, the 1 1/2-Strutter was later adopted as a single-seater bomber, and it is the machine which has been so successful in bombing, with good results, such towns as Essen, Munich and Frankfort. For bombing work the 1 1/2-Strutter was equipped with a 130 h.p. Clerget, which afterwards took the place of the 110 h.p. Clerget in the standard two-seater fighter model. It might also be mentioned that fairly recently the French Government converted a large number of two-seaters into school machines with dual controls. These machines are fitted with 80 h.p. Le Rhone engines.