LEAVING DIVERS BEHIND

Greymouth Evening Star, 15 November 1934, Page 10

LEAVING DIVERS BEHIND

MODERN APPLIANCES. The depth of 3028 ft reached by Dr. Beebe in his bathysphere has made all other deep-water diving records seem like child’s play. Until the American scientist began exploring the life of the ocean deeps, no man had ever dared to go below 71 fathoms, or 462 ft. it was at this depth that the salvaging of gold from the liner Egypt was directed by the Italian divers of the Artiglio, writes Douglas Capper in the “News-Chronicle.” . Their feat was made possible only by the use of the modern rigid type of “shell” diving-dress. Like Dr. Beebe in his steel ball, they acted merely as observers as they swung in their steel chambers at the end of a cable below their ship. Their eyes, and not their hands, were needed.

Although some types of the “shell” dress allow the diver to operate mechanical “fingers” from inside his armour, the work he is able to perform in this way is strictly limited. So far, with all its advantages, no satisfactory substitute has yet been invented for the older kind of flexible rubber suit—the diving-dress with the fascinating copper helmet and the loaden-soled boots.

Probably the record depth at which manual work has''ever been carried out was during the salving of silver bullion from the Skyro, off the Spanish coast. Working at 170-l Soft down, the diver hacj to withstand a pressure of 951 b per square inch on his body, and he eventually spent many months in hospital in consequence. Unlike the diver in the “shell” dress, who is able to breathe normally within his armour, the wearer of the flexible suit has to breathe what is literally compressed air. The deeper he goes the greater must be the compression. Unless the pressure of air inside his suit (and therefore inside his lungs) is equal to the pressure of water outside, he will be “squeezed,” as it is called. And if the pressure outside is suddenly increased by a fall into deeper water, or from some other cause, he will be . crushed like an - egg-shell—or worse.

DISEASE RISKS. Danger does not end, by any means, with the maintenance of the necessary air pressure. Through the continual breathing of compressed air, the body becomes saturated with nitrogen; and should the diver rise too quickly from deep water, the nitrogen is liable to form bubbles inside hiin in its haste to escape from his body. Death, paralysis, dr, at the least, the agony of “bends” (diver’s palsy) will be the result.

; To obviate these risks, exhaustive tests were carried out some years ago. A table was drawn up which gives the isafe rate of ascent for various periods from different depths; It was found, tor example, that after spending one hour at a depth of 2fiof t, including the time taken for his descent, a diver needed two hours for his upward journey. And if he cared to stay at work for an extra fifty minutes he would have to spend no less than four hours on his way up.

The short periods for which a deepwater diver can work, compared with the time lost in lowering and raising him, is one of the handicaps of the flexible type of dress. For the diver himself there is the wearisome busi-

ness of idly waiting at stipulated intervals, on a rope or a staging, until he can safely emerge above the surface.

Recently the waiting has been made less irksome for him by the use of a bottomless steel cylinder, which is lowered, like a diving-bell, with an attendant inside to meet him in deep water. Within its pocket of compressed air he may have his helmet removed and enjoy small comforts. A much more important part of the equipment of deep-ivater salvage vessels is the recompression chamber. In 1 this “iron doctor” men who have ascended too rapidly are promptly'

placed in a suitable air pressui*e which is gradually, reduced. Many lives Have been saved by its aid. The compressed-air difficulty, after all, is only one risk among many. Divers have had their airpipes cut or their suits, burst; and more than one man has been slicked into a pipe or buried under heavy falls of mu,d. And in the chill of winter seas thefe is always the chance of pneumonia, as a less sensational danger., Certainly the deep-water diver has quite enough potential trouble without the giant octopus that novelists and film scenarios thrust upon him.