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Aviation History
1920
1920 - 0456.PDF
APRIL 22, 1920 The Need for High-speed Transport It cannot be too strongly emphasised that the unit in lifeis Time not Distance, and the Distance between two countries is in practice measured by Time. Out of the six main factorsin transport, the claim of aircraft for an assured future is based on speed, that is reduction in the 'lime taken by trans-port. Transport is governed by six essential factors :— (1) Safety ; (2) regularity; 3) carrying capacity ; (4)comfort; (5) speed ; (6) cost. • The relative importance of these factors varies accordingto the special object in view, and even similar goods trans- ported over the same route may require different types oftransport. The state of the existing means of transport is a vital consideration in developing any new form of transport.To compete with the existing forms of land transport, where goods can be conveyed at 60 miles an hour and over (varyingwith the state of development of the country), the speed of any new type of transport obviously must be greaterthan is necessary to compete with sea transport where the present speed is less than half as fast as on land. Tran-shipment from train to surface craft still further reduces the mean speed of existing transport and favours air transport. Meteorology and the Choice of Airship Routes The choice of airship routes depends so very largely onthe prevailing weather conditions and position of the per- manent winds that the two subjects must be dealt withtogether. I would like to emphasise the' importance of accurate meteorological information for all forms of aerialtransport. Winds of 40 m.p.h. will often be encountered. These will usually be local in area, and will vary greatly inforce and direction at different heights above the ground, ' and if accurate meteorological information is available thesewinds can frequently be used to assist the airship instead of constituting a hindrance. If full use is madp of these winds,both in regard to original choice of routes, and in the actual flying over these routes, the speed made good over the groundcan be made to exceed the actual air speed. As meteorology and our own flying experience develops, the winds shouldultimately become less of an enemy and more of a friend. Winds may be divided into two classes : permanent windsand variable winds. The permanent winds are the more important in original choice of routes, and consist chieflyof the trade winds and the westerly drifts. Generally speak- ing, the winds just north or south of the equator are easterlyand the winds near the poles westerly, so that a ship flying east would endeavour to choose a route in latitudes from150 to 300 north or south, and when flying west in latitudes between 450 and 50.° Thus, the route from England to Australia crosses theeasterly winds practically at right angles, and turns east from the Cape, making use of the permanent southern westerly-drift, or " roaring forties." The return journey is made nearer the equator to use the easterly trade winds or easterlyslants. The Atlantic route is similarly dealt with. There are also many other less important permanent winds, andalso seasonal winds, which can be made use of, and will slightly modify the routes during different periods of theyear. The variable winds are the winds which are directly due to depressions, and can only be used provided accuratemeteorological information is available. The ability to use these variable winds depends largely on the speed of theairship, as the pilot will often find it necessary to push through a narrow belt of strong wind in order to gain the advantageof a favourable wind later. As mentioned later, electrical storms form a potentialdanger to all forms of aircraft, but as the area in which such disturbances are prevalent can be very accurately charted,the routes will be chosen so as to avoid these areas and thus reduce this danger to a minimum. Reliable weather fore-casts necessitate a large number of accurate observations being taken over very extended areas, and to run an organisa-tion especially for this purpose would be extremely costl£ If, however, arrangements were made for all sea-going shipsfitted with wireless, also the various shore wireless and cable stations throughout the world, to take and transmit meteoro-logical readings, it would probably be possible, in time, to organise an adequate meteorological service for little cost,special meteorological stations only being required in a few isolated positions. . ....'.•,-,.• Commercial Capabilities of Airships Having dealt very briefly with the fundamental aspectsof sea routes, land routes, and routes over both sea and land, I now propose to consider the capabilities and limitationsof airships with regard to the essential transport require- ments. (1) Safety.—This term must, owing to the nature of allforms of transport, be purely relative. Even in the most " safe " form of transport there is always some small risk.The airship is definitely the safest method of air transport, and if the statistics are studied for the pre-War commercialairship flying in Germany, the very extensive War flying of the German Zeppelins, and the 2,500,000 miles flown bythe British airships during the War, it will be seen that, excluding enemy action, the loss of life is extraordinarilysmall. The danger in soundly-built well-equipped airships flown by competent personnel is so small that, in my opinion,it will come to be regarded as nothing more than an every- day risk. In the case of sea-going ships during the last hundred years,the safety has been very greatly increased, due mainly to the increase in size and the use of more powerful propellingmachinery, enabling the modern ship to meet the worst storms without much fear of, foundering or of being drivenon to a lee shore. The same improvements are to be expected in airships, and the larger airships of the future, fitted withmore powerful and reliable machinery, will necessarily be still safer than the airship of today. Modern airships have proved themselves capable of flyingthrough practically, any type of weather. There is, no doubt, however, as already stated, that at present the most violenttypes of electrical storms are an undoubted danger to all forms of aircraft. Fortunately, however, although thewind speed in the centre of these disturbances has been known to reach as much as 300 miles an hour, the actual speed ofsuch a storm over the ground seldom exceeds 50 m.p.h., and with ordinary navigation there is no reason why airshipsshould blunder into the centres of such storms. At the worst, the danger from violent electrical storms appears tobe less than the danger of rocky coasts and shallows to the sea-going ship. Another important factor in the safety of airships is thatall minor repairs engine can be carried out whilst flying. Also, owing to the number of separate machinery units, seriousengine failure is reduced to a minimum. . Fog does not constitute a real danger to airships. Withpresent methods of navigation it is not necessary to see the ground in order to navigate accurately between bases. Thebases, however, should be situated in localities comparatively free from fog to prevent delay in landing. (2) Regularity.—If transport by air is to possess anythingmore than a very limited future, it must be possible to know beforehand when the machine is going to leave and approxi-mately when it is going to reach its destination, Regularity in this direction is essential. The chief cause of irregularityfor airships up to the present has been wind, the main diffi- culty being the handling of ships on the ground, and theimpossibility of taking them in and out of their sheds in a cross wind of much over 20 m.p.h. This difnculty«shas nowbeen solved by the development of the mooring mast. With the mooring mast it will be possible for airships to embarkand disembark passengers and freight with sufficient ease to meet practical requirements. It will be realised, however,that the selection of the site for all landing bases should, always be largely influenced by the local weather conditions,which are not always favourable at the great centres of population. Irregularity in length of passage due to adverse windsencountered during flight is now the more serious problem. Bad weather is usually confined to small areas, and for thisreason, much greater difficulty will be experienced in main- taining regularity over short routes. For the long routes,however, the various weather disturbances will tend to even themselves out, and no insuperable difficulties are anticipatedin achieving regularity over correctly chosen routes. Ah example of regularity obtained even over a short route isafforded by the German airship Bodensee, which recently carried out 60 flights between Friedrichshafen and Berlinin 64 days, although she was a new and comparatively un- tried type of airship. Carrying Capacity * I think the carrying capacity of rigid airships can be bestillustrated by the accompanying table >— .".. Bodensee R. 34 R. 38 R. X •••••.' , - (German) (In com- (Under con- mission) struction) Length (in ft.) ... 390 639 ft. 5 in. 695 740 Capacity (in c.f.) 700,000 2,000,000 2,700,000 4,000,000 Tonnage.. ,'. 21-3 60-7 B # ' 82 ;o' 121-5 Maximum speed (in m.p.h.) .. 80 50 -• ';•- ". ^7© *• 80 456
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