TORPEDO-BOAT OF THE AIR.

Oamaru Mail, Volume XL, Issue 12540, 11 May 1915, Page 2

TORPEDO-BOAT OF THE AIR.

NEW BRITISH CRAFT TO FIGHT THE ZEPPELINS..

SWORDFISH v. WHALE.

Five dirigible torpedo-boats of the air, to "sink" Zeppelins, are stated to be now being built, at a cost of ■ £'20,000 apiece, by a British company in England. Their construction is under the direction of Mr Thomas'R. MaeMeehen, president of the Aeronautical Society of America, who lias just returned from Great Britain, according to a remarkable article in the New York Sun..

Mr MaeMcchen confidently predicts a spectacular attempt to raid Loudon inthe latter part of April, if not before, by Zeppelins armed with guns firing steel-capped projectiles rather than bombs, and declares, that it is principally to defend Great' Britain against this attack that the Zeppelin destroyers are being built. They will- also be used, he says, for detecting German submarines, destroying-, them, and marking their . precise position for the gunner:* of the British Fleet.

_ "These little dirigibles, which are entirely new in the history of aeronautics," says Mr MaeMechen, "will each be equipped with one torpedo gun, firing a torpedo that will explode on contact.

"Each will carry four men, a navigator, a gunner, and two engineers. Tlhe torpedo gun will fire its projectile 1600 feet point blank, true to mark.

'The?e, small rigid dirigibles which

we are building can stay in the air watching for an enemy, say. 75 miles from tbi-iir base, for at ten hours. They can wireleSsly report back to their base. "Germany's newest Zeppelins are 500 feet long. Our Zeppelin destroyer.;,' are but 230 feet long, and .only 28 feet it: diameter. The i.ittie defensive dirigibles have two engines, one forward of 75-90 'horse-power and one aft with 125 hol'se-power. Perhaps the most radical idea we have followed in building the new aircraft is that to maintain, rigidity, we have enclosed the gas compartments in an envelope of wood instead of metal like the Zeppelins. We. tise laminated spruce from Canada. Thin strips of it are wound iiv spiral from one'end to the other of the cigar-shaped hull, and they are locked into a mahogany ring at the end. The strips cross and rc-cross each other, and are copper, rivetted together. There are also fourteen straight girders. This construction is the strongest possible for the weight. "Inside of it are thefourteen gas-bags, each in a separate compartment. Outside the wood structure the whole is covered with a-weather-proof ahiminised cloth. Tt shines like a polished spoon, and will be difficult to see in the air on that account.

"There is no hanging car. The calls built right into the main structure. The navigator operates .the whole craftily .simply pressing a set of buttons on a desk in front of him. He can even take the.control of the engines out of the hands of the engineers. A set of fourteen tubes in front of the navigator ttiis liim tih/e condition of the gas in. each balloonet—as the gas bags are called —and by means of buttons he can. regulate the gas pressure in any one of the fourteen. A certain button toregulate the density of the gas will .-end hot air from the exhaust chamber up under a certain balloonet, or another will send cold! air. The sparks are strained out of t'tae exhaust, and each engine is enclosed, with its engineer, in an asbestos-lined, fire-tight compartment." Its designer believes the destroyer will play the sword-fish to the Zeppelin whale, superior speed and 1 climbing power enabling it to thrust from above into the gaseous vitals of the big diri-g-iblo. Mr Wilbur R. Kimball, formerly secretary of the Aeronautical- -Society, is. one of the engineers of the work, and is now in. New York looking for qualified men for tjhe crew to accompany him back to England.