SEAPLANE CARRIER

New Zealand Times, Volume XLIV, Issue 10298, 5 June 1919, Page 2

SEAPLANE CARRIER

SHIP WITHOUT OBSTRUCTION OR TUNNELS ON DECK.

One of the most interesting skips added to the British Navy during the war was the seaplane-carrying ship Argus, built by .Messrs William Bearctraore and Co.. Limited, a t their works at Dalmuir on the Clyde. It is true that the Admiralty adapted the battle-cruiser Furious to accommodate seaplanes and to permit theui to rise froru the deck. and this vessel, with her W.OjO-h.p. geared turbine machinery, had a speed or 32 knots, which gave her a great advantage over the Argus in point .of speed. Further, there' is now being built specially for the same duty the cruiser Eagle, also of high speed and specially adapted to enable seaplanes to rise from her deck. The Argus, however, has the advantage that there is absolutely no obstruction on the flying deck, not even funnels, and that she has under this deck space for the accommodation and repair of seaplanes. She is therefore a floating hangar, the space given up for this purpose being 330 ft long. 6Sft wide over all. and 48ft clear, with a clear height of about 20ft. Hoists are provided from this hangar to the flying dec:, and cranes are available for lifting the seaplanes from the water on to the hangar deck. The structural arrangements in the ship to meet these abnormal conditions involved problems of design and construction which were admirably worked out and proved thoroughly successful. Perhaps, however, the most novel feature is the arrangement of the uptakes from the funnels, so that the boiler furnace .gases could be .discharged over the stern. Here also gratifying success has been achieved, and the results reflect credit not only on the technical officers of the Admiralty, but on thoso responsible for the biiiluing of the ship, and her mahinery at Messrs Beardmore's works. The aeroplane carrier was laid down originally as a first-class passenger and pargo steamer for the Lloyd Sabaudo Company, of Genoa, but work on her was discontinued at the outbreak of war. In U)l6, however, the Admiralty decided, to have her completed as a seaplane carrier, although the construction of the hull was in an advanced .state* and it was not possible therefore so to alter it as to ensure a high speed. . Modifications, however, were made to increase the power and raise the speed from 18 knots under normal sea conditions to 20J knots for short coriods and 20 knots on service m ordmarv wenther. As originally designed and built the vessel was 535 ft lon* between perpendiculars, of a moulded breadth of 68ft, with a height of 40ft. to the shelter dock. The original form, structure and decks were retained up to the shelter deck, which it was decided should constitute the floor of the hangar. Thus all above the shelter deck was modified to provide hangar, workshops, stores and a flying deck. . In the early stages of the design of the superstructure work the method of supporting the flying deck was carefully con. sidered. A Jin scale model of the ship according to the proposed method of construction was sent to the National Physical laboratory at Teddington to be tested in the air tunnel there. Exhaustive experiments on this model were carried out for the purpose of discovering the eddymaking effect of the structural work below and above the flying deck, and also about the after end, through which air eddies the aircraft had to pass when flighting on the deck. The result of these experiments showed that to ensure the minimum of air disturbance it was necessary that the space between the hangar roof and flying deck should be as open as possible. On account of this it was decided to make the-hangar troof strong : enough ;to withstand the greatest hogging-.and :..6agging stresses tilcely 'to come on the struoture and to support the flying deck._by very light lattice work. Further, it was discovered that the emission of the hot gases through vertical funnels above the flying deck produced such serious air disturbance that the safe landing on the deck would be extremely difficult. This necessitated the fitting of the horizontal smoke ducts below the flying deck which carry the gases right aft away from the stern.—" Engineering."