Enhg! into Inner Space
'
159
The self—contained diving apparatus came much later. Its
‘
important feature was a exible bag or counter—lung Which received
oxygen from a small canister. When used in the water, the pressure
on the counter—lung maintained the oxygen at the ambient pressure.
Exhaled air passed through a canister of soda lime
remove the
carbon dioxide before re—entering the counter lung for recycling.
Because there were no tell—tale bubbles of escaping air, this closedcircuit equipment was used by frogmen in the Second WOd War,
and various more sophisticated forms of closed—circuit apparatus
still very important in modern naval diving.
‘
_
ï' »
’
The type of apparatus developed specicallyfor military purposes,
however, is generally far too complicated for everyday civilian uSe
—
where a more easily maintained piece Of equipment is needed.
Therefore the closed—circuit was dispensed with in favour of a much
simpler system in which expired air is released intothe sea. ”Com—
mander Y. Le Prieur had devised such an apparatus»operaüng on
compressed air in 1926 but the valve which reduced the pressure of
theair coming from the supply cylinder had to be adjusted by hand
to compensate for changes in water pressure during a
The air
owed continuously so that, apart from the disadvantàge of a hand—
operated valVe, by no means a foolproof device, the diver' could spend
only a short time under water. The breakthrough came in the 1940s
with the design of a valve which supplied gas automatically at the
ambient sea pressure but which also conserved the gas by cutting
off the supply during exhalation. » — «
—
Two men, ]acques—YVes Cousteau and Emile Gagnan, were
responsible for developing what is now kann as the
Cousteau, an ofcer in the French
already tried m‘08t
types of apparatus available in the early» 1940s, “and as
good idea as to a diver’s requirements;i'“Gàgnan,£ an engineer specia—
lizing in gas control valves; converted «these speCieations into «a
practical piece of equipment. The essential part of their diving
apparatus was the unit cOntaining an outlet Valve placed close to a
diaphragm demand valve. When the diver; breathes out the exhaled
gases open the outlet valveallowing them to escape.
The air supply
controlled by the diaphragm demand valve is »sWitchedÎ off. The diver
then starts to breathe in. The
thesea doses the
outlet valve and pùshes»the
’
«on theair
supply. The air continues to ow
pressure
is the same on
either side of " the diaphragm which then returns to its ‘resting’
'
159
The self—contained diving apparatus came much later. Its
‘
important feature was a exible bag or counter—lung Which received
oxygen from a small canister. When used in the water, the pressure
on the counter—lung maintained the oxygen at the ambient pressure.
Exhaled air passed through a canister of soda lime
remove the
carbon dioxide before re—entering the counter lung for recycling.
Because there were no tell—tale bubbles of escaping air, this closedcircuit equipment was used by frogmen in the Second WOd War,
and various more sophisticated forms of closed—circuit apparatus
still very important in modern naval diving.
‘
_
ï' »
’
The type of apparatus developed specicallyfor military purposes,
however, is generally far too complicated for everyday civilian uSe
—
where a more easily maintained piece Of equipment is needed.
Therefore the closed—circuit was dispensed with in favour of a much
simpler system in which expired air is released intothe sea. ”Com—
mander Y. Le Prieur had devised such an apparatus»operaüng on
compressed air in 1926 but the valve which reduced the pressure of
theair coming from the supply cylinder had to be adjusted by hand
to compensate for changes in water pressure during a
The air
owed continuously so that, apart from the disadvantàge of a hand—
operated valVe, by no means a foolproof device, the diver' could spend
only a short time under water. The breakthrough came in the 1940s
with the design of a valve which supplied gas automatically at the
ambient sea pressure but which also conserved the gas by cutting
off the supply during exhalation. » — «
—
Two men, ]acques—YVes Cousteau and Emile Gagnan, were
responsible for developing what is now kann as the
Cousteau, an ofcer in the French
already tried m‘08t
types of apparatus available in the early» 1940s, “and as
good idea as to a diver’s requirements;i'“Gàgnan,£ an engineer specia—
lizing in gas control valves; converted «these speCieations into «a
practical piece of equipment. The essential part of their diving
apparatus was the unit cOntaining an outlet Valve placed close to a
diaphragm demand valve. When the diver; breathes out the exhaled
gases open the outlet valveallowing them to escape.
The air supply
controlled by the diaphragm demand valve is »sWitchedÎ off. The diver
then starts to breathe in. The
thesea doses the
outlet valve and pùshes»the
’
«on theair
supply. The air continues to ow
pressure
is the same on
either side of " the diaphragm which then returns to its ‘resting’