AIRSHIPS FOR TRANSPORT

Greymouth Evening Star, 24 June 1937, Page 12

AIRSHIPS FOR TRANSPORT

OUTPACED BY FLYING-BOATS The deplorable disaster that has so suddenly overtaken Germany’s giant airship Hindenburg must raise again the question whether the airship can ever be made safe if it is operated with hydrogen as its lifting gas (writes Cmdr. Sii - Charles Denriistoun Burney in the London “Daily Telegraph”). Hydrogen, as everyone knows, forms an explosive anixture if diluted with air, and consequently there is the ever-present danger of this dilution taking place in a structure such as an airship. The only ’ other lifting gas soj far' knowii which gives a lift comparable with that of hydrogen is helium. Helium is an inert gas’ and cannot form an explosive mixture when diluted with air, and it would, of course, be used to the exclusion of hydrogen if it were .not for the difficulty of-ob-taining and transporting it and also, of course; the economic disadvantage of its high cost. Germany has 'Siiown'thaf "a“safe and" regular service across both the north and south Atlantic can be maintained in so far as navigation and ordinary flying practice are concerned: but this disaster must qualify any optimistic view of the future of airship transport. Great Britain closed down British airship construction after the RlOl disaster. Although the circumstances of the two accidents are different, hydrogen was ultimately ignited both in the case of RlOl and the Hindenburg, and it was the fire and explosion of the ignited hydrogen that cost so many lives in both cases. It would seem that there are two questions to examine if an estimate is to be made of the place that airships may take in the future of aviation. Can an economic service be op-, erated on helium, an'd, if it can. is the airship likely to compete with the

heavier-than-air machine ? The United States has operated its naval airships on helium for several years, and the U.S. Naval authorities have fairly accurate figures as to the cost of that gas. In a naval service,

where cost is not o£ prime impor- . tance, the decision has been made to operate on helium. The U.S. was in a favourable position. Supplies of helium in any quantity can only be obtained in that country. It is from the gases obtained in certain oilfields and, having been separated and extracted, has to be compressed into steel cylinders for transportation. Even in the United States the cost of inflating a ship the size of the Hindenburg would be not less than £20,000, and if the helium had to be transported to Europe, in order to make up losses on the voyage, the cost of its handling and transport would have to be added. This is no small charge. The weight of metal containers numerous enough to hold sufficient helium to inflate the Hindenburg would be some hundreds of tons. Another disadvantage of helium is that its actual lift is some 7 per cent, less than that of hydrogen, and the whole of this has to come off the ( pay-load- Therefore, assuming a payload of some 11 per cent, of the dis- i placement, a change from hydrogen j to helium would reduce the pay-load i to 50 per cent, of.what is possible with hydrogen. It is easy to see why the Zeppelin Company has used the j utmost ingemiity of its designers in i trying to make a hydrogen ship safe 1 rather than use helium. Assuming, however, that an inert gas such as helium could he used upon an economic basis, what are the prospects of the airship competing with the large flying-boat on ocean I

crossings? All that aviation has to sell to the travelling public is higher speed, and the difference in speed both* actual and potential between the airship and the flying boat is considerable. It is unlikely that an airship can be constructed with a higher speed than 90 m.p.h. The Hindenburg had a top speed of 84 m.p.h. and a cruising speed of about 75-77 m.p.h., whilst the new Imperial Airways flying-boats have a top speed of 200 m.p.h. and a cruising speed of 160 m.p.h.

TWICE AS FAST. In otheV words the flying-boat is twice as fast as the airship to-day and if development proceeds at the present pace it would not be unduly optimistic to predict that within a few years flying-boats of 250 m.p.h. cruising speed will be practicable. Again the difference in accommodation for passengers between the fly-ing-boat and the airship will tend to narrow. The larger the flying-boat the better the accommodation, and today more than one American firm have flying-boats on the stocks double the size of the Imperial Airways’ latest type. In these latest designs tlie accommodation will be but little inferior to that of the Hindenburg, and when the great difference in speed is considered it would seem that travellers in a hurry would be more inclined to book their passages by flying-boat than by airship. If speed is not a vital factor the competition of the crack liner such as the Queen Mary becomes a pertinent consideration. The Hindenburg has crossed the Atlantic in less than 48 hours, but its average time is about three days against the Queen Mary’s five days, and the possible 24 hours or less of the aeroplane when the flying-boat service is in existence. In speed, therefore, the airship ranks midway between the flying-boat and the ocean liner. Its one advantage over both is its smooth and silent passage through the air and lack of motion. No airship passenger need fear seasickness or airsickness,

and to bad sailors this would have a great appeal. \ Again, however, as the flying-boat increases in size this advantage may become correspondingly less, as there is no doubt that the larger the flyingboat the less it is affected by the air conditions. It might be said that the greater radius of action of the airship should enable it to fill a role that the flyingboat. cannot fill. This, again, is a moot point. Air transport on regular

scehdule is to-day economically possible only between considerable cen- , tres of population, and the richest ocean routes are undoubtedly the European-South American and Euro-pean-North American routes. Airships have flown on both; the flyingboat or heavier-than-air craft on the former, while plans are in progress to test it upon the latter. In neither case should the more restriHed radius factor prevent the flying-boat service being operated. ■ One ik forced, therefore, to the con-] elusion that the airship has been de-1 veloped. and could perhaps have been [ further developed, as an ocean transport to serve for a short era. That, era would seem to be the period re- ' quired for the flying-boat to develop sufficiently to become, capable of fast,: regular and reliable oceanic services, i Once the flying-boat is sufliciently de-1 veloped the airships’ chances of econ-1 omic survival would seem to be precarious. FOR ECONOMIC GAIN ! I It should have perhaps another decade or even two, of usefulness but if, and only if, a safe lifting gas can be used, is this possible? It may be. As the airship increases in size it be-' conies more efficient, and consequent-

ly the handicap of the reduced lift o helium would be minimised. More over, the cost of operating the vesse would not increase in direct propoi tion to the increase in size. It ina; be, therefore, that if a ship double tin size of the Hindenburg were built an< operated on helium its operating cos per passenger-mile might be no mori than the Hindenburg’s cost operate* upon hydrogen. One could no doubt have full con : fidence in the ability of the Zeppelii Company to build and operate a ves sei of so large a capacity, but it wouh take perhaps three years to build tin first and six to build a fleet. In six years a regular daily flying boat service 1 will probably be operat ing between New York and Southamp ton and the-question of competitii would have to be faced. Technically a safe airship service can in all prob ability be achieved. Financially ii must depend upon whether the Ger man Government desires to maintaii the service it has inaugurated and de velop it to a higher degree of safety One doubts whether private capita would be attracted, as flip airshii seems to have only a limited span ol life. If a consistent policy of devel opment had been pursued in Britain and Germany since the war, regulai services by airship would by now have been in operation and might have last ed until the 1950’s and fulfilled a use

mi row. i u-uctj, uuwcvci, K/wmvi not advise this country again to entertain them, as it would have to be done with public money and the money would be better expended in fostering the development of the ocean living-boat. Whatever the future of the airship the sympathy of this country and the world will go out to Dr. Eckener, head of the Zeppelin Company, as his enthusiasm, doggedness and perseverance in face of great difficulties have been the admiration of the world. He has developed a wonderful technical instrument that has played its part in the development of world aviation. His name and that of his brilliant lieutenant, Capt. Lehmann, will secure a place in history.