SCIENCE AND TRAVEL

Stratford Evening Post, Issue 85, 26 June 1930, Page 8

SCIENCE AND TRAVEL

SENDING THE DIVER DEEPEK. A COMPKESSION CHAMBER IN WHICH WOHKKItS CAN BE LOWERED INTO THE SEA.sen diving from "living rooms" lowered into the ocean is a possibility suggested by a new invention. A steel chamber called a decompression chamber is the basis ni' the invention. One that has recently been constructed is 11 feet long b\ (i feet wide. There is ample room for two men.

When this is lowered into the sea the iliver inside il can dress for his work, and undress again on his return. He can havi; an attendant to await him with hot coffee and food. Once the chain ber is closed again, it can be drawn to the surface immediately-—the need for a long and tiring climb by the diver himself is eliminated. Experiments .so far have been concentrated on a chamber lowered only to "decompression point" but the future may briny a large chamber lowered to the bed of the ocean —and containing more men than two.

Until recently the investigation of what lies at the bottom of the deeper seas has been out of the question because the human frame cannot stand the strain of the enormous pressures in deep waters. A diver fakes an hour to climb up out of only 200 feet of water. He suffers from an agonizing malady, caisson disease.

This ) malady, frequently fatal, arises from too rapid return of an individual to normal atmospheric. pressure. The trouble comes from the action of the nitrogen gas always present in the blood and body tissues, in simple solution.

When a diver comes from the depths, where he has been exposed to heavy barometric pressure, the nitrogen gas is apt to form bubbles in the tissues and blood vessels.

The bubbling action is akin to that of a carbonated beverage when the, bottle is opened.

When formed in the brain and spinal cord the bubbles are especially daugcrous, causing paralysis or death.

Jh diving practice the custom is to provide careful control of the changing pressure.

When a diver ascends towards the surface he must make the upward journey by easy stages, to permit the gas to escape quietly into the blood avid thence through the lungs. Much work has been done in arranging suitable time-tables for the return to the surface, with a view to providing for the safe; '"decompression" of under-watcr workers from various pressures and depths. In spile of the precautions thus established, caisson disease often develops after exposures to high .pressures. As a rule it can be relieved, and controlled by putting the victim back under pressure for the purpose of decreasing the si/.o of the nitrogen bubbles. This is called "recompression,'' and the' symptoms disappear as soon as adequate pressure is attained. tt appears contradictory, but it is true that a diver may descend rapidly with no ill effects from the growing pressure, so long as he keeps his ears cleared. This means that he must preserve the same pressure inside the ear-drum that prevails on the outside of this membrane.

Without this precaution there is a likelihood of severe pain and possible rupture of the ear-drum. Minor symptoms of this trouble are familiar to those who pass through submarine tunnels and other channels in which there is abnormal air ■pressure. A g<3od diver experiences no difficulty in descending 100 feet within, a period of two or three minutes, or as rapidly as his tenders, at the surface, can feed out his air-hose, life-line and telephone cable, which usually are bound together in a single line

When the worker is ready to start back to the surface, the tenders haul in the line and lift him from the depths. Experienced divers can make themselves "light" by increasing ses, and this facilitates the upward journey, as far as concerns the physical effort of lifting him. There must be no facilitation, however, in the mailer of speed. The, ascent most not be continuous.

Decompression schedules call for periods of rest at various intervals of depth, to permit readjustment of the diver to the diminishing air pressure. At each stop time is allowed for the escape of the excess gas in body fluids and tissues. The '.'ivaler Ihe depth the larger is the number of stops thai must be made.

The time required for decompression increases rapidly below 100 feet. The man who has worked 1.5 or twenty minutes at a depth of 2.50 feet requires several hours fur his return journey, With a decompression chamber the diver can be brought to ihc surface at once;.

ion lakes 1)1 board the ship. The difficult ies of deep si'ii divmil; have hitherto prevented men from searching the bottom of tin sunk- and tlie art ol ancient civilizations may still be found. But is it too much to hope thai one day—very soon perhaps—decompression chambers with stores may be' lowered to the bed of the for long periods and -several men deeper ocean, so that its mysteries can be explored at leisure"