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Страна: Великобритания

Год: 1913

H.King Sopwith Aircraft 1912-1920 (Putnam)

'Three-seaters' and Derivatives


   So it came about that on the occasion of the 1913 Olympia Aero Show, held in February of that year, the designation 'Sopwith Three-seater', jointly with that of ‘Bat Boat’, borne by Britain's first successful flying-boat, as later shown, removed the name and fame of ‘Sopwith' - the image as it would be termed today - from the sporting and promotional scene to that of original design and construction. It would, in fact, be hardly overstating the matter to declare that the 1913 Three-seater marked the true inauguration of the 'all-Sopwith' range of tractor landplanes and floatplanes, the lineage whereof will be traced through many pages to follow. More explicitly, the "hybrid' represented an archetype, whereas the design now under scrutiny was a prototype in the accepted sense.
   Of even greater significance in a broader sense, the present writer would go so far as to proclaim the early-1913 Sopwith 'land tractor' (as it was sometimes called) as the true begetter of a line of British transport biplanes built - with notable success to a characteristic formula: that is, with the passengers in a forward fenestrated compartment, with the pilot behind them, and having no more engine-power than was strictly necessary to perform (jointly with generous wing-area) a rigorous operation with exemplary economy. The line of aeroplanes one has in mind came to full fruition in the well-nigh incomparable de Havilland series of the inter-war years, culminating in the little Fox Moth.
   So evident, in any case, were the merits of Sopwith's new tractor that they were acclaimed even in their time - for pioneers and prophets pre-1914 went frequently unhonoured, even though meticulous records were supposedly maintained to chart aeronautical progress. So true was this last assertion that publication (for instance) of Octave Chanute's Progress in Flying Machines stood as a beacon on the very course it charted.
   Less renowned than such a bible - and less well-known even than Flight or The Aeroplane - was the English journal Aeronautics which, in August 1913, made this declaration: If one were asked to give the name of the most successful machine in existence, at least one of British design and construction would be among the claimants for place among those for final selection. How many constructors would undertake to build a machine which, when fitted with an 80-h.p. Gnome, is satisfactorily capable of carrying pilot and two passengers in addition to four hours' fuel? The Sopwith biplane can accomplish this and, at the same time, fly within a wide range of speed. This range, naturally, is not so great as the range obtained when the standard load of three hours' fuel and one passenger is carried, but reasonably large nevertheless." Having mentioned also the Bat Boat, the journal continued: 'The Sopwith Aviation Co. have undertaken an enormous amount of work, and though this fact might have tended to cause a lack of thoroughness in the firm's productions, no trace of this is visible.'
   As exhibited at Olympia in February 1913 the Three-seater differed very noticeably from its hybrid precursor bearing, in fact, much the same relationship to it as did the Avro 504 of 1913 to the Avro Type D of 1911. Staggered wings were only one of its identifying features. The tail and landing gear were altogether new, and most striking of all the novelties - three big non-inflammable celluloid panels were let in to each side of the forward fuselage, to improve the downward-and-sideways (and in some degree forward) field of view for the three occupants.
   One contemporary assessment tantalisingly invited elucidation. This was to the effect that the new machine was 'similar to the one recently supplied to the Admiralty' (meaning, presumably, the hybrid) - excepting that it had staggered wings and an 80 hp Gnome engine (instead, it was implicit, of a 70 hp unit of the same type). Clearly, though, here was a machine calling for detailed study even in its day, and even more so on this present occasion. Thus may history be honoured, and today's investigations be satisfied, by the following first-hand appraisal:
   'Staggered planes are used, and these appear to be of such a camber as would permit the machine to be of an exceedingly fast description. An 80-h.p. Gnome is fitted in front, driving a tractor propeller.' (Present writer's note: Clearly, the observer under quotation wished to impress on his readers that this aeroplane was of tractor form, though in order to acquit him from naivety or tautology it must be recalled that certain types of the period had the engine in front, though driving a pusher propeller. The Mersey Military Trials Monoplane of 1912 was a case in point, likewise the Grahame-White Type 6 Military Biplane - exhibited at Olympia in 1913, as was the Sopwith now reviewed). To continue the contemporary appraisal under quotation:
   'The main chassis consists of a pair of wheels mounted on what may best be described as a V inclined forward, while a pair of smaller wheels are mounted on another pair of struts in front. The whole strikes one as being amply qualified for resisting any shock, within limits, to which it may be subjected, and the fitting of an additional and non-weight-carrying pair of wheels forward has found favour in certain quarters, on account of its tendency to prevent any possibility of the machine's complete inversion should a somewhat steep landing be made. The interplane struts situated at the point where the planes abut upon the fuselage, and the fuselage uprights, are one and the same member - this naturally reducing weight and head resistance to a considerable extent.
   'The reduction of these two bugbears, in fact, has obviously been the end and aim of the designers. Their efforts to minimise the former can be seen everywhere and are distinctly worthy of emulation. In almost every instance, not only in fuselage longitudinals and uprights and in the ordinary struts, but even in the thin members which support the fabric in the various members of the tail, has weight been brought down by channelling to what in some cases almost approaches an I section. In other cases, where this method of procedure has been impossible, the spars and struts are built up hollow, the centre being flat and composed of ash, and surrounded on each side by a curved section of spruce. They are bound at intervals with oil-silk ribbon. The lightness of the spars is astonishing, while their rigidity and strength should leave nothing to be desired. It is interesting to note that the ash centres of the main spars are of approximately the same-sized section as that of the wing-spars on the standard 70-h.p. Bleriot, though in the latter case they are not strengthened by spruce coverings! This is another instance of the fact that, though the reduction of unnecessary weight has been one of the chief aims of the designers, this has not been accomplished at the expense of the strength of parts. One may at first question the necessity of drilling eighteen to twenty holes in a steel clip which is only five inches by about two or three inches in dimensions, for the weight of a single example cannot be greatly reduced thereby, but one realises eventually that, if this is done to every clip upon the machine, the desired effect is produced to a considerable extent. Sonic of the clips are really the most remarkable that the writer has yet seen, representing as they do the outcome of most thoughtful design, while the labour and expense that must necessarily have been involved is by no means inconsiderable. The most remarkable of these clips is a socket which holds no fewer than four members, viz, the main-plane spar, the inter-plane strut, the fuselage upright, and one of the undercarriage struts! Even the small clips for attaching the fuselage uprights and longitudinals together are carefully drilled, and are of the pattern introduced by the Hanriot Company, i.e., are actually clipped to the wood by compressing it, no bolts in consequence piercing it.
   'A novel and extremely laudable point is the employment of steel tube for the trailing edge and extreme tips of the planes. This, in the latter case, permits the camber to extend right up the whole length of each wing, which fact must obviously give greater efficiency. The struts for the undercarriage are also constructed of steel, though in this case they are of 18-gauge steel plate bent into a tube of marvellous sections.
   'One point which will undoubtedly pass unnoticed by the majority of those who examine the tractor-biplane is not really of any great structural importance, though it shows the care which has been devoted to the small details of design, and will be appreciated by those who have to make any adjustments or alterations to that part of the machine referred to. The tail-plane, as mentioned, has its outer framework constructed of steel tube, the latter being attached to the longitudinals by U-bolts. The minor, though all-important feature of this attachment, however, is that the bolt is kept from falling out when the nuts on its top extremities are loosened.'
   The general conclusion was that the two new Sopwiths - the Three-seater landplane and the Bat Boat pusher flying-boat-represented 'the last word' in aeroplane construction. Yet conservatism lingered, and lateral control on both machines was by wing-warping, the warping pulleys being ingeniously combined with the rear-spar hinges, and actuated by a warp-wheel on a vertical 'elevator column'. Ailerons came later, on developed versions; and certainly by August 1913 there were at Brooklands 'two Sopwith tractor biplanes-one fitted with warping wings and the other with ailerons."
   'Last word' or not, it was the 1913 Three-seater that not only put Sopwith in business as an aircraft constructor in general, but, in particular, as a supplier to the Services; for more or less coinciding with the Olympia exhibition of February 1913 (the displayed example having already been tested by Sopwith himself, and shown to be capable of over 70 mph) came orders for two Naval specimens of the same general type. The show-machine itself, in fact, was actually the first to be delivered to the Navy, the pilots to whom it was handed over on 1 March, 1913 – being that breezy pair Lieuts Spenser Grey and L'Estrange Malone. To this same aeroplane the Service number 103 was allocated, and Spenser Grey, with Lieut Bigsworth as passenger, was reported as having looked in at Hendon with the 'Naval 80 hp Sopwith Tractor' on 24 May.
   During May also Harry Hawker flew the Navy's No. 104 to Farnborough, to demonstrate for the War Office such useful attributes as a speed range of 35-75 mph. As Aeronautics had already noted, the standard load (for Service use, certainly) was one passenger only, with fuel for three hours; and it was assuredly not as a three-seater that No. 104 was to be found at Eastchurch in January 1915 on 'Zeppelin stand-by".
   Nor was the prewar public in ignorance of the (nominally) Three-seater's capabilities: for with Hawker as pilot, an aircraft of the type won the Cross-country Race at Brooklands on Whit-Monday 1913, then climbed to 7.500 ft in 15 min. Whereafter things got better still, for on 31 May the 'great Harry' set a (solo) British height record of 11.450 ft.
   Matters then progressed from excellent to better still, for on 16 June Hawker look a single passenger to a breath-taking 12,900 ft, and on that same day (half an hour later, in fact) carried two passengers to 10,600 ft. Even with three men, in addition to his slender self, he managed 8,420 ft - on 27 July, 1913.
   Nevertheless the Sopwith Tractor Biplane (potential seating capacity going unacknowledged) was chiefly used not for passenger transport, but as a general-duties two-seater, by both the RNAS and the RFC.
   Cannibalisation - as the term was to become current in air-service jargon - was rife, as was modification; and certainly distinctive in this regard was the second example constructed (or reconstructed) for this had a deeper fuselage and windows with rounded corners.
   The transformation from three-seater to two-seater must not be passed over without noting a clear intention that a military application was foreseen for the former layout. Thus a contemporary declaration: 'The machine is arranged to seat three, two observers side by side at the centre of gravity, and the pilot some little distance behind them. The bottom plane being staggered back by 1 ft, the observers are able to obtain a good view of all that is happening below them. The pilot can get a good view below him too, for the trailing edges of the planes on either side of him are cut away for that purpose.'
   For the shapely Olympia-pattern rudder a more angular form was substituted, reminiscent of the earlier hybrid in that the area was distributed above and below the fuselage. But still there was no fin. For competition work, and Service testing also, a 100 hp Green water-cooled engine was fitted experimentally, and in this instance an Integral propeller, instead of a Levasseur or Chauviere, was tried. The petrol tank (on a typical Three-seater, at least) was under the passengers' seat.
   Although passing references have already been made to the landing gear, it must now be stressed that the agglomeration of struts, wheels and skids tended to obscure one particular feature that was eventually incorporated that is, the so-called 'split axle’, which was to become almost a Sopwith trademark on the later and better-known war machines (a design with each wheel mounted on a half-axle, the inner ends whereof were pivoted at the mid-points of the spreader-bar, or bars). There were, in fact several variations in landing gear, notably with two massive tailskids; but the following description appears to have applied early in 1913:
   'The landing chassis is of the combined wheel and skid type. The body of the machine is supported from two long hickory skids by six spruce struts. The two pairs of rear struts are assembled to the skid by a welded steel fitting which is also slotted to take the axle of the two landing wheels. The latter are strapped with rubber cords to the skids. Miniature skid-tip wheels are fitted. They are 13 ins. in diameter, and are each supported by a pair of beaten steel fittings. The main skids, the sides of which are hollowed out for lightness, are continued back 3 ft. or so behind the rear chassis struts, in such a manner that there is no necessity to provide a rear tail skid. These continuations of the rear skids have the advantage that they act as most efficient land brakes when it is required to pull the machine up quickly
   Apart from Nos.103 and 104. already mentioned as going to the Navy, that same Service had No.906 (after it had served as Sopwith's hack and demonstrator) and other recorded numbers for these Sopwith Tractors were 248, 315, 319, 324 and 325 all these for the RFC. That cannibalism and modification was rife in respect of these biplanes has already been observed, and even the number built remains open to question, though in September 1913 it was reported, apparently with good authority, that: 'The Sopwith Co at Kingston continues to test its many machines at Brooklands before their delivery to the two Services. Nine 80-h.p. tractor biplanes, standard type [sic] were recently ordered for the Army, while delivery of two was requested by the Admiralty." The inference was rightly drawn that 'these two sets of orders are only the beginning of a long period of prosperity for Messrs Sopwith' - rightly, that is, if one reckons the 1914-18 war and its immediate aftermath as 'long'.
   Before the coming of that war the great event for the Royal Flying Corps (Military Wing) was, of course, the 'Concentration Camp' at Netheravon the description having no sinister implication, but being analogous with the Naval Review, or mustering, of the same period. Respecting the 'M.W.' camp, I have examined a duplicated typed sheet once possessed by the Camp Commandant himself. Pencilled-in, and detailing one particular 'task for aircraft', could be perceived - after the listing of Bleriots, Farmans and B.E.s - the addition '& Sopwiths".
   Two or three years later a typical RFC Order of Battle might have listed 'Sopwiths (& other types)'. Need more be said?


'Three-seater' (as at early 1913) (80 hp Gnome)

   Span 40 ft (12.2 m); length 29 ft 6 in (9 m); wing area 365 sq ft (33.9 sq m). Empty weight 1.100 lb (500 kg); maximum weight 1,750 lb (790 kg). Maximum speed 70 mph (112 km/h). Climb 500 ft/min (152 m/min); ceiling (with one passenger) 12,900 ft (3,930 m).

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Описание:

  • H.King Sopwith Aircraft 1912-1920 (Putnam)
  • M.Goodall, A.Tagg British Aircraft before the Great War (Schiffer)
  • P.Lewis British Aircraft 1809-1914 (Putnam)
  • J.Bruce British Aeroplanes 1914-1918 (Putnam)
  • O.Thetford British Naval Aircraft since 1912 (Putnam)
  • Jane's All The World Aircraft 1913
  • Журнал Flight