Saturday, 30 June 2012

R.J.Mitchell's Walrus – 'he looped the bloody thing'

Supermarine Seagull III (from painting by author)
The Walrus  owed its origin to a 1933 Australian order for a replacement for the Supermarine Seagull IIIs which the Royal Australian Air Force had been operating since 1926.
In view of the deck landing limitations and porpoising characteristics of the obsolescent Seagull [see my Blopost:"Precursors of R.J. Mitchell's Walrus"], the new machine would have to be a complete re-design – and so the move to metal structures, slab-sided fuselages, and the experience of the intervening years, produced a quite distinct type within the older formula.
   One important example of the re-design was the employment of a fully retracting undercarriage, for the first time. A more obvious aspect of the redesign of the Seagull predecessor was the hull – it now shared the more aggressive, slab-sided, features of the Scapa and the later Stranraer but did not have their upward sweep to the tail unit. But, whilst the direct attachment of the lower wings to the hull was similar to these two aircraft, the upper centre section had a less than tidy trailing edge, as it had to be cut back for clearance of the pusher propeller and cut back again for the folding-wing arrangement. The engine nacelle also contributed to the somewhat ‘minimalist’ appearance of the new design by being quite noticeably off-set to counteract the corkscrew pressure of the propeller slipstream on the fin.
Supermarine Seagull V/Walrus from a painting by the author
   Thus the new machine was clearly no beauty and when, in June 1933, the prototype was seen by the Air Ministry Director of Technical Development, he said to Clifton: ‘Very interesting; but of course we have no requirement for anything like this’. Perhaps this reaction had some bearing on the test pilot’s performance at the second SBAC Show at Hendon. The Aeroplane described the event:
This boat made its maiden flight on 21 June, five days before its first public appearance, but Mr. Summers [Vickers chief test pilot]  proved its qualities by throwing it about in a most carefree manner. Of its performance little is known but there can be little doubt about its amiability and general handiness in the air and on the ground. One must be prepared to see all sorts of aeroplanes looping and rolling with abandon nowadays, but somehow one has, up to now, looked to the flying-boat to preserve that Victorian dignity which one associates with crinolines, side whiskers, bell-bottom trousers and metal hulls. The Seagull V destroyed all one’s illusions.
Henry Knowler, Chief Designer at Saunders Roe who watched the display in the company of Mitchell, reported the designer’s understandable surprise and anxiety at the low level antics of the five-day old prototype. ‘He looped the bloody thing,’ Mitchell kept repeating to everyone he met.
The Seagull V, as it was known to the Australian government, then underwent modifications and trials. Summers had criticised the rigidity of the undercarriage and its steering capacity and, after these deficiencies had been put right it went to the Marine Experimental Establishment at Felixstowe, five weeks after its maiden flight. Evaluation tests then lasted until the end of October, after which the Seagull went to the Royal Aircraft Establishment at Farnborough for the catapulting trials required by the Australian Government.
    Despite lengthy trials, including the successful catapult trials for the Australian order, no Air Ministry order was expected and so it would appear that the future of Mitchell’s design would rest solely with the Australian Government’s requirement. However, movements were afoot nearer to home, as reported in Caspar John’s Foreword to The Supermarine Walrus by G. W. R. Nicholl:
To the late Rear Admiral Maitland W. S. Boucher, D.S.O., Royal Navy [at that time serving in the Naval Air Division], goes the initiative for the introduction to the Fleet Air Arm of this somewhat improbable looking, yet highly successful flying machine.
He said to me one day in late 1933, ‘I’ve just been to Supermarines. I’ve seen a small amphibian. It looks handy, tough and versatile … something the Navy needs. I want you to put it through its service trials. Off you go.' With a Supermarine Southampton flying-boat course at Calshot and some tests at Felixstowe intervening, off I went to Woolston to collect Seagull V  N.2 early in 1934.
Caspar John, son of the artist Augustus John and later Admiral of the Fleet, took the Seagull to Gibraltar for rough weather take-offs and landings and for fleet co-operation exercises. The aircraft was then taken back to home waters for the continuation of trials at Sheerness and in the Solent until May when it was returned to Supermarine for the fitting of re-designed wing-tip floats to give better buoyancy, the removal of the wheel brakes for lightness and for an improved layout of the observer’s compartment. Further fleet operation trials continued, including landings in 30-knot winds and six-foot waves off the Kyles of Bute and underway recovery onto a warship making up to 13 knots through rough water. As a result, on the 27th of August, the Australian government ordered 24 production Seagull Vs, A2-1 to A2-24.
    Thereafter, the prototype was renumbered K4797 and, on New Year’s Day, 1935, handed over to the Fleet Air Arm. As the prototype had first flown in June, 1933, it is clear that the Admiralty had needed time to be convinced that open sea and catapult operation from their capital ships would work smoothly. In all probability, the earlier Australian initiative and the developing international situation had helped to overcome any doubters in the Admiralty and so an initial order was placed on 18 May, 1935, for 12, serial numbers K5772 to K5783, shortly followed by a second for eight, K8338 to K8345, and then a much larger order for twenty-eight, K8537 to K8564.
   A name was now to be chosen for the British machine, unlike the Australian one – which retained the Seagull V appellation. In the past, Supermarine amphibians and flying boats had been favoured mainly with reasonably attractive seabird names: Sea Eagle, Sheldrake, Seamew, etc. whilst the name Sea Lion was a nod in the direction of the engine used. It is thus an interesting comment on what Caspar John had called its ‘somewhat improbable’ appearance that the far less glamorous name "Walrus" was now chosen. Nevertheless, it was not only the first of its type to be catapulted with a full military load but also the first British-designed military aircraft with a retracting undercarriage. The first British batches of 48 aircraft ordered was increased dramatically in 1936 with the requirement for another 168 machines, L2169 to L2336. Despite its initially very doubtful future and backward-looking appearance, the Walrus then became the last and the most successful of all Mitchell’s reconnaissance amphibians and the navy's standard fleet spotter.


For reference sources, see my Blogpost: “Source Material and References" – an extended bibliography is included in my R.J.Mitchell at Supermarine; Schneider Trophy to Spitfire (details below) which also provides material for wider reading, grouped according to specific areas of interest. 

More information on the Seagull V/Walrus, photographs and a three-view drawing, as well as a full account of all Mitchell's completed designs and of the man behind them, will be available in a few weeks' time:
Advance Notice – 
R.J.Mitchell at Supermarine; Schneider Trophy to Spitfire.
This is a much expanded, completely up-to-date, second edition of my earlier work with 50% more photos, and 25% more text – 380 pp. instead of 250. There are general arrangement drawings of Mitchell’s 21 main aircraft types which flew, as well as 40 other drawings. There are 24 photographs, featuring or including Mitchell, as befits the first fully detailed and, I hope,  definitive account of the man and his work at Supermarine.
To obtain a copy at pre-publication prices, please enquire via the contact form in the sidebar.



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