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Aviation History
1949
1949 - 1898.PDF
664 FLIGHT, 24 November 1949 SHIPS and FLYING-SHIPS Ocean Liner and Marine-Aircraft Development Compared : A Study in Progress By Lt. Cdr. L. G. GRIFFITHS, R.N. (Ret.) IT is generally acknowledge that the behaviour of abody in air is in most respects similar to that of onein water. The relation of speed to horse-power is governed by the same basic laws, while in each case waves are created in much the same way. One might, therefore, be justified in outlining an analogy of marine transport to air transport. About 25-30,000 years ago, it is believed, Neolithic man paddled himself about on logs of wood or better still, used an inflated skin as a primitive means of river and sea transport, trusting to God and the unpredictable weather condition to arrive even- tually at his destination. „ A rather far-fetched ana- logy would appear to bring this parallel to the balloon as we know it, although some 25,000 years later, according to legend, Daeda lus manufactured a flying machine of sorts, probably a primitive glider, which came to an ignominous end by collapse in the air and . —"—"—~ ~~ " final destruction in the sea. ~ • •...- - : • ; V ' "..; f This point is made to demonstrate that, compared with aircraft, the development of marine craft has been at a great advantage in time; even so, it has not been until within the last four hundred years that we arrived at the first development of well-rigged, ocean-going sailing ships, superseding the galley with slaves sweating at the primitive oar against the forces of nature which confined their acti- vities to coastal waters. With the dawn of the mechanical age, steam began to take the place of sail about 1840; in 1851 the screw pro- peller replaced the paddle wheel, and wooden ships became obsolete with the advent of iron construction. In 1881 iron was superseded by steel, while during this long '' ex- perimental '' period the trend was a "gradual increase in range, speed and displacement (see Table I). It may be said that, during this period, the most striking enterprise was the building of the Great Eastern, of r8,gi5 tons, in 1858—a mammoth ship of her day, which had a fairly successful career in trans-oceanic cable laying; although this craft was not of the Cunard White Star fleet detailed in the table, outstanding interest attaches to her T HOUGH this comparative study of two spheres of transport is anacademic one, the author's conclusions—particularly those empha- sized in the development curves—will be of considerable interest to students of what might be called long-term design. For a variety of reasons he has confined his marine-aircraft examples to British types : had he included certain notable foreign designs, such as the Cornier DoX, the Martin Mars and the Hughes Hercules, the picture might have been somewhat changed, though his principal argument—the consistency of progress that is apparent in the two spheres—would remain substantially unaltered and demands that she be mentioned. Her success, how- ever, was not sufficiently great to justify a continuance of similar construction on a grander scale. Contrasted with this, the corresponding period of experi- mental development of aircraft commences with gliders and landplanes preceding the first seaplane built by Short's in 1912, No. 41, of wooden construction. Table II shows a plot of all-up weight, speed and rated h.p. of a number of the principal marine aircraft constructed by Short Bros., against dates and names. The Stellite, of 1924, with the first all-metal stressed-sktn hull, may aptly be com- u_^___________________ pared with the first ironship. Gradual progress was made, range, speed and all- up weight increasing until 1932, when the largest fly- ing boat of her day, the Sarafand, made her debut. This revolutionary, advance to an all-up weight of 70,000 lb. and a speed of 150 m.p.h. with six engines giv- ~ : ing a total of 4,920 h.p., •-•.-••-" --."• ..:.;: v..... •:».-..; may justifiably be compared with the appearance of the Great Eastern in 1858. Of the periods up to 1858 and 1932 in sea and air trans- port respectively, we may say that both maritime and air- craft design and construction were successfully passing through their experimental and teething stages, preparing the way for greater things to come. In 1904 the steam turbine had progressed beyond the experimental stage and was fitted in large ships. The Carmania was the first of the Cunard White Star ships to be so driven, while her twin sister, the Caronia, was fitted with reciprocating engines. Since that time, the steam turbine has become the standard marine engine, resulting in a very noticeable increase in the gradient of the shaft horse-power curve as compared with that of the preceding indicated horse-power figures. Analogous to the steam turbine of 1904, gas turbines and jet propulsion of aircraft may be said to have begun to come into their own in 1944, though it was 1947 before the first gas-turbine flying-boat, the Saro S.R. / Ai, took the air. These forms of propulsion are undoubtedly the drives of the future for aircraft and their bounds are no more Ship Britannia British Queen Persia Scotia Umbria, Etruria - Campania, Lucania Ivernia, Saxonia Caronia, Carmania ... Lusitania, Mauretania Aquitania Scythia, Samaria (Laconia class) Queen Mary Queen Elizabeth Date 1840 1851 1856 1862 1867 1881 1885 1893 .1900 I9<M 1907 1914 1920 1936 1940 Tonnage 1,154 772 3,300 3,871 2,960 7,392 7.718 12,950 10,900 each 20,000 each 32,500 each 45,650 20,000 each 81,235 84,000 TABLE 1 : FAMOUS Speed 8.5 !2.9 13 00 14.00 16.5 20.25 22.00 I6i 18.00 26.00 24* 16.00 29.00 No, of Passengers 115 cabin 250 cabin 275 cabin 430 cabin 480 cabin 750 steerage 1,000 each 1,225 each ship 1,370 each ship 2,650 each ship 1,755 each ship 2,690 1,500 each 2,000 2.200 CUNARDERS SINCE 1841 Type of Engines Common side lever Compound Common side-lever Compound Compound Compound inverted Expansion type Quad.-expansion Recip. (Caronia) Turbine (Carmania) Direct drive tur- bines Parsons turbines Brown-Curtis tur- bines Parsons turbines Parsons turbines No. of Engines One One One One One One per ship Two each Two each Two Three Four each Four Two each Four each Four each Horse-Power of Engines 740 i.h.p. 430 i.h.p. 4,570 i.h.p. 4 200 i h p 2,800 i.h.p. 11,000 i.h.p. 14,500 i.h.p. 26.000 i.h.p. 10,400 i.h.p. 21,000 s.h.p. 68,000 s.h.p. 56,000 s.h.p. 12,500 s.h.p. 158,000 s.h.pi 158,000 s.h.p. Remarks First Cunarder ; wooden First iron screw-steamer. First iron paddle-steamer. in her day). Single screw ; noted for great comfort. First steel Cunarder, single screw. Record-breakers in their day. Largest twin-screw liners in their day. Popular as passenger and freight carriers. Caronia was twin-screw. Carmania was triple-screw. Blue Riband holders. Quad, screws, four turbines. Mammoth ship in her day. Popular intermediate liners for cruising. Twin screw. • Quad, screws^ turbines. Quad, screws, turbines. B 2
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