DEEP WATER RECORDS

Evening Star, Issue 21881, 19 November 1934, Page 11

DEEP WATER RECORDS

LEAVING DIVERS FAR BEHIND The depth of 3,028 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 426 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 ‘ NewsChronicle.’

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 this armour, the work he is able to perform in this way is strictly limited. So far, with all its disadvantages, 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 leadensoled 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 170ft-180ft down, the diver had 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 he “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 eggshell—or worse;.

Danger does not end, by any means, with the maintenance of the neeessarv air pressure. Through the continual breathing of compressed air the bodv become? saturated with nitrogen; and should the diver rise too quickly from deep water the nitrogen is liable to form bubbles inside him in its haste to escape from his body. Death, paralysis, or, at the least, the agony ot “ 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 safe rate of ascent for various periods from different depths. It was found, for example, that after spending one hour at a depth of ‘2ooft, including the time taken for his descent, a diver needed two hours for bis upward journey. And if he cared to stay at work for an extra fifty minutes he would have to spend no less than tour 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 typo of dross. For the diver himself there is the wearisome business 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 atten-

dant inside, to meet him in deepwater. Within its pocket of compressed air he may have lus helmet removed and enjoy small comforts. . A much more important part or tire equipment of deep-water salvage vessels is the recompression chamber. In this ‘‘iron doctor” men who have ascended too rapidly are promptly placed in a suitable air pressure which is gradually reduced. Many lives have been saved by its aid. „ , The compressed air difficulty, alter all is only one risk among many. Divers have had their airpipes cut 01 their suits burst; and more than one man has been sucked into a pipe or buried under heavy falls of mud. And in the chill of winter seas there 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.