Biard also describes the visit of the Prince of Wales to Supermarine, and to the Swan in particular, on 27 June in the same year. On being invited to climb the 10ft steel ladder to the cabins (see drawing on p.73), he declined because of his dress sword.
By the time of the prince’s visit, the Swan’s two 360hp Rolls-Royce Eagle engines had been replaced by Napier Lion engines, each developing 90hp more than the Rolls-Royce units, thereby increasing the Swan’s top speed by 13mph. The folding of the wings and the leading-edge cut-outs had also been dispensed with. Plans for an RAF version of the Swan were also being actively pursued at this time – which may have had some influence on the change to the fixed-wing layout and possibly throws more light upon the decision to terminate the development of the military Scylla.
Meanwhile, the first of the N4 specification aircraft, the Fairey Atalanta, had made its maiden flight, but its 139ft wingspan and four 650hp Rolls-Royce Condor engines made it a less attractive proposition for the drastically reduced post-war services. In comparison, the Swan had only half the wingspan, two smaller engines and yet was only 10mph slower; it also embodied the Linton Hope type of hull in which the Air Ministry was interested.
Successful trials of the Swan at the Marine Aircraft Experimental Establishment, Felixstowe, followed which were to have important results for the fortunes of Supermarine. On its return to Supermarine, it was now fitted out for its passenger-carrying role. Company publicity pointed out that the machine was not only the first twin-engined commercial amphibian but that the provided accommodation set new standards:
This is the first twin-engined amphibian flying boat to be built in the world and it may also be fairly claimed to be the first twin-engined commercial flying boat.
An important feature of this machine is that the whole of the hull is devoted to passenger accommodation. There are no internal obstructions of any kind, and the amount of room in the saloon far exceeds that of any commercial land plane. The internal accommodation consists of one large passenger saloon, elaborately furnished and upholstered and with every comfort. Forward of the saloon is the luggage compartment, fitted with racks for the stowage of passenger baggage. Aft of the saloon is the buffet, with all necessary fittings to supply light refreshment during the journey. Still further aft are the lavatories, which are efficiently and fully equipped.
As such, it was registered as G-EBJY and first flew on 9 June 1926, carrying a representative of the newly formed Imperial Airways and eight excited female employees of the company among its passengers. A slight reduction in passenger seating further allowed Supermarine to set new standards in passenger accommodation, which Biard fully confirmed: ‘the Swan, then the world’s largest amphibian … was a real cabin-liner of the air, with comfortable armchairs, big porthole windows, a commodious passage along the centre of the living accommodation, and all sorts of luxuries and refinements which were very new to aircraft at that time’.
A more neutral observer from the Aeroplane agreed, saying that ‘the appointments are exquisite’ with ‘a commodious passenger saloon padded luxuriously and in which there are ten cosy armchairs. An ample porthole is provided for each chair.’
Cozens describes a later, and more mundane use for the passenger compartment in the course of his recollections of this aircraft:
Both Rolls-Royce Eagles and Napier Lions were tried but the Lions were finally chosen. The writer recalls this machine when it was used in the colours of Imperial Airways as a freighter to bring bags of early potatoes and boxes of daffodils from the Channel Islands. The large mid-section made this possible and highly suitable for bulky cargoes. I remember seeing the horse drawn market carts down on the slipway being loaded from the Swan.
The aircraft had been loaned by the Air Ministry to Imperial Airways in order to supplement the service of Supermarine’s remaining two smaller sisters, the Sea Eagles, on their Channel Islands service. It operated during 1926 and 1927 but, as the Guernsey Evening Press reported, ‘during the normal rigorous inspection prior to leaving Southampton on 12 April, a structural defect was discovered which necessitated the stripping of the whole machine’. As a result, the Swan was scrapped.
The Swan, later, without wing cut-outs or undercarriage. (Courtesy of E.B. Morgan)
Imperial Airways’ next long-distance seaplane was not to be the Swan, however, and so the machine’s main significance remained that of providing the prototype for the Royal Air Force’s next standard maritime reconnaissance aircraft, the far more attractive Supermarine Southampton of 1925.
(For the sake of completeness, it ought to be mentioned that, at this very time, Mitchell was also required to design his first land plane, the Sparrow I. In complete contrast to the bulky Swan and even the medium-sized Scarabs, it had a mere 34ft wingspan and was designed to compete in an Air Ministry light aircraft competition. Owing to the poor performance of the engine fitted, it was unsuccessful. In the following year, 1925, as Sparrow II, it was configured as a parasol monoplane to test the effectiveness of wings with different aerofoils.)
ANNUS MIRABILIS
Southampton Mark IIs. (From a painting by the author)
DESIGNING THE NAVY’S STANDARD RECONNAISSANCE MACHINE
It is surely no exaggeration to identify 1925 as the year when two of Mitchell’s aircraft stood out dramatically from what had preceded them. While he had had early successes, incrementally improving on conventional machines, this year marked his full emergence as a designer who had transcended the design conventions that he had inherited and who was now striking out boldly into the future.
The young man who had joined his aero firm in 1916 at the age of 21, assisting with the designs of others, nine years later produced the first standard naval reconnaissance aircraft since the end of the First World War and the racing floatplane that set the basic design configuration for all subsequent Schneider Trophy machines.
By this time, the need to find a suitable replacement for the Felixstowe military flying boats was becoming critical, let alone the possibility of creating aerial links with the outposts of Empire – as the Secretary of State for Air, Sir Samuel Hoare, recorded: ‘In 1922, there were no aeroplanes capable of maintaining a long-distance service. The existing heavier-than-air machines were low-powered, very noisy and uncomfortable. Flying boats had almost ceased to exist and there was no plan for an Empire air line of any kind.’
And the first responses to the Admiralty specification for a flying boat to replace the Felixstowe machines were not such attractive propositions in terms of design or in the post-war ‘anti-waste’ climate. The Fairey Atalanta, which had made its maiden flight in 1923, had a 139ft wingspan and four 650hp Rolls-Royce Condor engines; the English Electric P5 Kingston, which flew in the following year, was essentially a continuation of the old N3 specification of 1917; and the Short S2 of the same year, while being forward-looking because of its metal hull, utilised the old F3 flying surfaces.
In view of this unsatisfactory situation, the Air Ministry authorised, also in 1924, the building of six airships initially to provide a service to Egypt, but the project became an embarrassment because of many delays. The success of the trials of the more compact, twin-engined Swan was very welcome news to the Air Ministry officials, who had previously been very impressed by the standards set by the Sea Eagle in 1923. Their appreciation of the new standards in flying boat performance now being established by Mitchell led to the very unusual step of ordering (no doubt with considerable relief) straight off the drawing board a reconnaissance flying boat based on the Swan amphibian passenger carrier. It was fortunate for Supermarine that the Estimates of January had, at the expense of those for the navy and for the army, provided for an increase of £2.5 million for the RAF.
The Southampton
Supermarine received specification R18/24 in the August of 1924,for a modified and slightly enlarged Swan type flying boat, and Mitchell’s main response was to have the Swan hull lines redrawn to improve its streamlining.
Although the new machine continued the planing configuration that Mitchell had been developing since 1923 with the Sea Eagle, it now became a part of one of the most elegant hulls that Mitchell had ever been responsible for. Indeed, the transformation of the lines of its prototype, the Swan, was dramatic. The more utilitarian requirements of a military machine allowed the removal of the ad hoc looking, high-drag crew compartment above the Swan’s lower wing and for the passenger baggage compartment to be utilised for the pilot and navigator, seated in tandem in open cockpits. He also streamlined the Swan nose and dramatically upswept the rear of the hull to keep the tail unit well clear of the water (see photograph overleaf).
While this upsweep had been seen earlier on both the small FBA and the Latham Schneider aircraft, as well as on the First World War Grigoravich machines, its incorporation in the much larger Southampton hull was a novel and bold move – of which Mitchell must have been aware, as a 1924 patent on behalf of himself and Supermarine draws explicit attention to the fact that ‘the hull is curved upwardly and rearwardly’.
Elsewhere, in larger hull designs, Curtiss and Sikorsky moved from the previous Felixstowe unswept approach to the employment of ‘canoe’ type hulls with the empennage attached by booms subtended from the wings and supported by girders from the hull.
In contrast, the elegance of Mitchell’s sweeping lines was emphasised and complemented by the redesign of the Swan fins, which were now swept back in a single curve, resulting in the new Southampton being regarded as ‘probably the most beautiful biplane flying boat that had ever been built’ and ‘certainly the most beautiful hull ever built’.
The Sikorsky S-40.
The first Southampton flying boat.
Cozens gives some interesting contemporary information, particularly about the construction of the Southampton hull:
Many considered the Southampton’s wooden hull to be the ultimate in design and craftsmanship, in its shape and purpose Mitchell combined his experience in building with Captain Biard’s reports on flying and this was recognised by the people of Southampton who subscribed and had a silver shield with the Southampton coat of arms fixed to the bow of N9896.
It was about this time that Scott-Paine and his co-director Commander Bird had a tremendous quarrel which ended with Scott-Paine leaving Supermarine with a fortune which he used to begin the British Power Boat Company at the old boat sheds at Hythe, where the May, Harden and May company built the Felixstowe flying boats of the Great War period.
The late Mr Conrad Mann, who worked on the wooden Southamptons, told me they were built bottom side up so that the two steps and the curved keel, which had been a feature of the Swan, could be built. He said there were six men and two apprentices on each hull and the contract price agreed by them for each hull was £483 19s 4d, so that the money worked out as follows:
Contract price for 6 men to build 1 hull
£483 19s 4d
Wages for 6 men to build 1 hull
£357 19s 4d
Balance
£126
This was shared among the men giving each £21
The two apprentices were paid by the company.
This arrangement seemed to work very well, giving both the management and the men every encouragement to build the machines as quickly as possible, and most of the men bought their bicycles with the lump sum bonus …
Extracts from letters about the Supermarine Southampton which appeared in the Southern Evening Echo:
‘Southampton people had good cause to remember and honour that machine because it brought a good deal of prestige and a steady flow of work to the factory where it was built.’
This was the time of the Depression and the General Strike, when a machine was finished there was an order for another one. With a steady wage and the prospect of another bonus, the workforce was fortunate and happy. This air of well-being, stimulated by the success of the Schneider Trophy Races, made the firm, and Woolston generally, a vigorous and active area.
About 20 [twenty-four, in fact] of the wooden flying boats were made and, as there was not enough floor space at Woolston, the main components were put on barges and ferried across to the boatsheds at Hythe for assembly. There were often three or four machines moored on the Hythe buoys, their varnished hulls and white wings making a picture that those who saw them would never forget.
This was brought to mind when a Group Captain who saw the picture of the wooden Southampton in the Echo remembered his early days on Flight 48[0], an RAF conversion flight stationed at Calshot to train pilots to fly Southamptons, looked in his logbook and found that he had flown that same machine in about 1928. He said that one day a second pilot wanted to change into the first pilot’s seat and left his own seat and went to the one behind him, passing between the two propellers … At the nearest point the two propellers were only 9in apart!
Cozens mentions several times the importance of Biard’s advice to Mitchell during these early years, and this would have been especially important to Mitchell when there was little theory to guide designers. As Cozens was a neighbour of the test pilot, it would seem very likely that he heard of particular instances where advice was given – and listened to willingly (see Chapter 1).
No doubt the new machine’s ability to maintain height on one engine, as well as its maximum range of 500 miles, was more important in Air Ministry minds than any aesthetic considerations. Additionally, there was the extreme practicality of the design. Warren girders (as with the Swan) supported the centre section of the wings without the need for wire bracing, thus enabling a change of engine or servicing to take place unimpeded and without interference to the airframe. This centre-section was plywood covered, again for ease of movement by mechanics, and the leading edges of the outer wing panels were also sheeted for a smoother aerodynamic entry.
It is also notable that the lower wings were not joined to the boat hull, as might be expected; instead, the wing superstructure had attachment points on the top of the hull (see photograph on p.194) and was stabilised laterally by struts from reinforced frames in the hull. In this way, Mitchell retained as much flexibility as possible in the Linton Hope type hull and avoided the cracking around the wing fixing position, experienced at this position by other companies’ designs.
In the Swan, this fuselage structure had provided unusually good passenger space for the time and, in the Southampton, it enabled particularly good communication between crew members. Ahead of the pilot was a cockpit for a gunner and, a little further back from where the Swan pilot had been situated, were two staggered positions for rear gunners, one on each side of the centre line. Basic cooking, lavatory and sleeping facilities were also provided, so beginning the provision for equipping the RAF with naval aircraft that could be generally self-sufficient for reasonable periods of time. The siting of petrol tanks in the upper wing centre-section, which Mitchell had established with the Seagull II, was a contributory factor to the improvement to crew conditions, as well as giving a reliable gravity feed to the engines.
The extent of the modifications to the original design were such that a completely new name was considered more appropriate than, say, ‘Swan Mark II’. Since the Swan was built as a commercial aircraft, it had not been subject to the ‘Aircraft Nomenclature Committee’, which required the names of water fowl for small multi-seat amphibians and names of ‘seaboard British towns’ for larger seaplanes. ‘Southampton’ was chosen, albeit an estuary port not a seaboard town.
In negotiating this name, the company was now proclaiming Supermarine’s increasing status in the community whose dignitaries had welcomed the return of the company’s 1922 Schneider Trophy winner from Naples. Cozens’ information that a silver shield with the Southampton coat of arms was fixed to the bow of N9896, the first of the batch, can be confirmed in the preceding photograph.
Supermarine thus marked the firm’s increasing importance in the industrial community of the area, particularly in view of the Air Ministry order, substantial
by the criteria of the day, for six standard military aircraft (N9896–N9901) and an experimental one, N218, to be fitted with a metal hull. These aircraft were also the largest production machines yet to come from Supermarine – the Seagulls and Scarabs had had a wingspan of 46ft, whereas the Southampton spanned 75ft (6ft 4in more than the Swan).
Air Ministry officials must surely have been impressed by the promptness of the delivery of the first of the Southamptons, as Supermarine recorded:
Something of a record in design and construction was achieved with the first machine of this class, for it was designed and built in seven months, was flown for the first time one day and delivered by air from Southampton to the RAF at Felixstowe the next day [11 March 1925].
Three Southamptons over Southampton Docks (with the Mauretania in the foreground) and about to overfly the River Itchen and the Supermarine factory at Woolston. (Courtesy of RAF Museum)
Nor could its reputation have been harmed when, after sustaining damage there in a collision with a breakwater, it was taxied by sea all the way back to Woolston for repairs. Pilots thereafter reported that it ‘never gave the slightest trouble … and was a joy to fly’; it was ‘a great step forward, a delight to fly and operate’ – summed up by Penrose when he reported for the year 1925 that ‘it was the beautiful new Supermarine Southampton flying boat which was receiving unstinting approbation from RAF pilots’.
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