TO SAVE BIRDMEN FROM DROWNING

Sun (Auckland), Volume III, Issue 868, 11 January 1930, Page 18

TO SAVE BIRDMEN FROM DROWNING

__EATK by suffocation!” This has been the |PyyVp*j official verdict proM -- _ ' nounced following so l many seaplane crashes I y. during the last few years that research experts have been devoting much time to the discovery of n solution to the cause of these disasters and the finding of a remedy. \ow, Sifter almost every conceivable bind of experimentation, putting into play the very latest knowledge that science can muster, it is believed That success is -just round the corner.” This high degree of optimism is based on the astonishing results of recent, tests-made with a tiny device, weighing somewhere between six and eight pounds, which looks like a cross between a gas mask and a headgear Tor deop-sea divers. Worn in collapsed lorm about the waist, beneath i tie ps.rachute, it in no way interferes with the. pilot’s manoeuvres at the control stick and is so simply designed that when a crash has occurred the aviator, by the mere pressure of a valve, call fill the device-with enough oxygen to keep him alive for some t ime. Moreover, the wearer s body to made so buoyant that he is" able to keep afloat until help arrives. This, ndw aviator’s safety belt was developed by two experts, whose experience and ability have made them peculiarly fitted for their task. F. M. Hobson, young civilian engineer of the United States Naval Bureau of Construction and Repairs, lias long been identified with the development of many important inventions designed to make more safe the 'lives of men who. spend, most of their time in submarines, whereas C. L. Tibbals, a chief gunner of the navy, has spent close to 20 years testing out such devices. Thus one expert represents the best theory that a highly technical background can offer, while the other represents the practical knowledge necessary to utilise that theory to the highest degree of perfection. Chief-Gunner Tibbals tells an absorbing story of how he and his friend were able to develop the apparatus that almost certainly will make aviation history. It seems that in 1917, as an authority on oxygen-breathing devices for use in saving the lives of men trapped in sunken submarines, he had reasoned that the same general principles might, some day be applied to advantage for an apparatus to save aviators from death by suffocation following a seaplane crash. The problem resolved itself into finding a way to cpmbine the safety elements of the heavy diving apparatus with the simplicity of the gas mask, such as worn by miners or carried by soldters. But Tibbals had so many other matters on his mind which were of immediate importance that his inventive dream was slow in finding a chance to materialise. Nevertheless, it did not die. During many spare moments the big fellow miglit be found piecing bits of. spare tubing together or fiddling iti seeming idleness with sections of heavy rubber. Meantime, his growing reputation as an authority on diving apparatus gave hfm freuuent opportunity to take careful note

of virtually every kind of oxygenbreathing apparatus used by the various nations. Quite unexpectedly, a few months ago, Tibbals, along with his good friend, Hobson, was given his chanee. Navy officials, disgusted with the futile efforts of many so-called aviation experts to reduce the number of deaths by drowning as the result of seaplane crashes, turned to submarine authorities for a solution of thenproblem. Just prior to this decision, quite a few tests had been made with a rubber-boat contraption, supposed to be carried by the seaplane flyer along with his ’chute. This device, made in collapsible form and including two bottles of compressed air, seemed to work well enough, but it had the great disadvantage of all its predecessors — it was too bulky and heavy, weighing, when inflated, 15 or 20 pounds.

After a series of consultations with naval parachute experts, Tibbals learned these vital points about a parachute drop; first, usually, when a flyer hits the water, he is going fecit first; second, even under the mo’st adverse conditions he rarely becomes submerged more than a few feet: third, at the moment he strikes the water s surface his velocity is about 20. feet a second —a speed that is about the same ~aS if he were to jump into the water from a height of 20 feet. Surprising, to say the least, was the discovery that a flyer rarely goes more than a few feet under the surface of the water. What, then, caused so many deaths by drowning and suffocation? The answer, as voiced by many famous navy flyers, was explainable. When an aviator crashes into the water he is liable at any moment to have one of two dangerous things happen to him—either a gust of wind may blow his ’chute upon him, thereby burying him beneath the waves, or the plane itself may bear him down. Furthermore, Tibbals found, there have been many cases where the wind has been so strong that it has swept ’chute and aviator far from shore, so : that his chance of gaining immediate help was extremely remote. What obviously was needed, then, in addition to a light, simply constructed oxygen device to protect the nose and throat, was buoyancy enough to keep a man afloat for at least an hour. Bearing this vital fact in mind Tibbals reviewed the knowledge he had picked up over many years’ experience concerning what happens physiologically to a man suddenly submerged in water. First of all, he reasoned, the air in a man’s body, just before he goes under. Is at normal, or atmospheric, pressure. The farther down he goes, however, the greater the pressure conditions. Meantime, the body pressure continues to be the same as it was on the surface, unless some device can be found that will equalise it to that of the water. At this juncture Tibbals realised | that he had ’a man-sized job on his hands. There were plenty of divers' helmets that would accomplish the dej sired result, but they were so heavy I that to attempt to make use of them | for an aviator was out of the question. | However, there was one ray of hope;

New Oxjgemi Apparatus Expected to Save Many Airmen From Graves in Lonely Seas «, . . , the fact that only in very rare cases ! is a flyer’s body forced under more than a few feet of water. A perplexing problem now presented itself. Where could the apparatus be most efficiently worn On the head? Hardly, for during the perilous downward jump with the chute the flyer must be possessed of liis complete faculties. On the arms? i No, for that position would prevent a necessary freedom of motion. The - only place left, and that seemed feasible enough, was around the waist beneath the parachute. Once the chute = was released, the device quickly could 1 be used to advantage. Tibbals and Hobson set to work to 3 put their known facts and theories 1 into definite form. For months they toiled, their greatest difficulty being in £ the direction of reducing the hulk 3 made seemingly necessary by the use L of heavy rubber. First they produced a crude-looking contraption weighing 1 about twelve pounds. Later they re- * duced it to ten, then eight, and, fiu- ; ally, to six pounds. The finished pro- ’ duct is thus described by Tibbals: “When worn, the. new safety belt , is a collapsible affair, measuring some t thirty-six inches by six inches. It is _ made of durable rubber with a stockinette cover. It includes a mouthpiece connected with two breathing tubes, one into which the wearer in- ; hales, and the other through which _ he exhales: an oxygen container, bearing enough oxygen to sustain life for • an hour and ,a-half, and a tiny bit of > soda lime for the purpose of purifying . the oxygen supply and helping equalise the body to the changing pressure 3 conditions involved in a rapid descent r into the water.

“One of our main objects in designing the new device was to keep the wearer in an upright position, not only when he struck the water, but for some little time thereafter. With this end in view we made pads on tiie side of the belt that, like the rest ■of the apparatus, ar.e readily Inflatable. Tests have shown that they afford the degree of stability desired. “Originally, we had In mind two main circumstances when tlj.e -safety belt would be useful. The first was when an aviator, unable to find time enough to use his parachute, was forced to remain with his plane, trusting pretty largely to Lady Luck as to whether he would survive the crash; whereas the other occasion was when he struck the water via the chute. We are now convinced, after numerous tests, that we were not overly ambitious in our hopes in this regard. In fact, we believe that at least six out of ten men, wearing the belt, will have a good chance of escaping a watery grave. “Of course, in this connection there are certain situations that might arise that are entirely beyond the control of man-made devices. A flyer, for instance, might, strike his head on a piece of the plane while hurtling to earth on a dizzy ride, or perhaps might even be burned to death before aid can be brought. “However, having apparently fulfilled the urgent request of the navy officials for a simply-constructed easily handled oxygen apparatus, we were delighted to discover, after numerous conferences with various experts of the different departmental branches, that the uses for our device were by no means confined to the original two that we had in mind. “An allied use, for instance, is connected with the belt’s extreme buoyancy. Assuming that a flyer, having successful landed on a body of water in chute or plane, found himself blown considerably away from immediate help, his air-filled pads would readily keep him afloat for at least one and a-half hours.”