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OK, and now something completely different. One of the
units used for deep diving in the 70"s is called the Tethered Arawak system.
It is a pleasure to offer this information to my readers. The Arawak system
is a incredible high tech system when the depth involved taken in
perspective. The system is used for depth up to 500 meters. Later models
like the SLS system and the BOSS system are improved models of this
innovative technology. This article could only be made thanks to many people
but most of all I want to thank Jan de Groot of Nautiek Diving. Don't
hesitate to check his website, by clicking his logo! |
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"27 February 1968"
Abstract of the disclosure
Diver apparatus includes an inhalation breathing bag and
an exhalation breathing bag with a breathable gas mixture being supplied by
pressure source to the inhalation bag through the inlet valve. The
exhalation bag is connected to a suction source through an outlet valve with
the apparatus including a flexible hose connected between the breathing bags
and having a suitable mouthpiece and valving arrangement for diver
breathing. The inlet valve opens up to supply the gas mixture when the
inhalation breathing bag collapses due to a diver inhalation or a descent,
and the outlet valve opens to allow removal of the exhaled breath when the
exhalation breathing bag expands due to an exhalation or an ascent. One
valving arrangement utilizes wire bales extending within the respective
breathing bags an another arrangement utilizes valve chambers with
diaphragms having on one side the water pressure and on the other side
either the inhalation breathing bag pressure or the exhalation breathing bag
pressure. The valves are biased to insure that they are not simultaneously
opened.
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General Description: (Penzias & Goodman 1973)
The Tethered ARAWAK Sytem
This
apparatus is used for lateral, and limited vertical, excursions from
subsurface diving bases. Supply and vacuum pumps (compressor-depressor),
situated inside the diving habitat, provide chamber gas to the diver and,
via a second hose, return it to the habitat for carbon dioxide removal and
processing with the atmospheric purification equipment located there. The
Arawak gas circuit constitutes a satellite appendage of the subsurface base:
it is a rebreathing apparatus without carbon dioxide removal capability, and
is a closed-circuit mixed-gas apparatus without self-monitoring devices or
automated mixture control. The compensatory advantages which this system
provides include the following: simplicity of predive preparation, diver
monitoring, and post-dive maintenance; economy in procedurement and
operational costs; augmentation of diver safety, conferred both by
restrictions implicitly imposed with a tether, as well as by engineering
features already mentioned.
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History of development.
The
Arawak system is designed by Wilbur J. O’Neill assignor of Westinghouse
Electric Corporation, Pittsburg. The equipment is sold by Emerson and later
by Reimers Engineering. Finally Divex UK bought the Arawak system
Wanted information:
The system seems to have two backup
systems. One of them seem to work as a semi-closed system. Since the goal of
the system is to not have the diver wearing a scrubber this seems strange to
me. I would like to have the user manual or detailed photos of the system
and backpack of the diver. I would like to invite everybody to sent me
additional information! Most wanted are actual photos of the divers using
this system.
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Introducing the ARAWAK V
Patented 1968 3,370,585
The Divex designed ARAWAK V is a
closed circuit (push-pull) diving system that supports the saturation diver
in depth of water from 200 to 1,500 feet. (~65 – 500 meter). Using the 15
years of Emerson and Westinghouse closed circuit pump and valving technology
recently acquired by Divex as a point of departure, the Arawak V is a
advanced closed circuit system designed for commercial use. The first
operational application of this push-pull concept was during Sealab I and II
in the Arawak I and II equipments. With Divex improvements, Arawak V is a
linear descendent of that Arawak family of diving systems.
In the Arawak V, breathing gas is
taken from the atmosphere of a saturation system, whether PTS or
submersible, and pumped to the diver through an umbilical. Diver exhaust
gas, in turn, is pumped back to the bell for CO2 scrubbing, reconstitution,
and reuse. The system employs gas heating in the supply line. Two
independent emergency gas systems are provided. In addition to the
supply and return hoses. Major concerns in system design are diver safety,
comfort, and mobility. The basic system is configured for one diver, and
multiple systems may be employed in a specific application.
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Characteristics |
Operational: |
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Gasflow |
4.5 ACFM |
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Depth |
Minimum |
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200 FSW |
Maximum |
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1500 FSW |
Excursion (Bell) |
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Up |
33 FSW |
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Down |
100 FSW |
Physical Weight |
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Surface |
In water |
Helmet |
20.5 lbs |
neutral |
Backpack |
52.0 lbs |
neutral |
Pump |
380.0 lbs |
neutral |
Dimension Pump module
60”x15” dia |
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- Latch Mechanism
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- In the pictures to the left and below the ARAWAK
V helmet latch mechanism is shown in both the open upper, and closed
lower, positions. A single motion of the locking bar will lock the
helmet in place. Five distinct actions are required to remove the helmet
from the diver, indicative of the safety inspired redundancy built into
Arawak V.
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closed |
closed |
open |
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Latch Mechanism
In the pictures above the ARAWAK V
helmet latch mechanism is shown in both the open upper, and closed lower,
positions. A single motion of the locking bar will lock the helmet in place.
Five distinct actions are required to remove the helmet from the diver,
indicative of the safety inspired redundancy built into Arawak V.
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- Backpack
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- The backpack, upper left, includes the exhaust
gas accumulator, the emergency bottles, ans a gas heat exchanger. The
accumulator acts as a buffer between the return pump and the helmet
exhaust system, acting to dampen the exhaust gas flow. The emergency
bottles are off-the-shelf components adapted to the Arawak V. A gas
heater is included in the system.
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- Valve Ring:
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- All valving and swivel fittings are integrated
into a single valve ring casting, lower left.
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- Pump Module
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- The pump module, lower right, is designed to
minimize power requirements and package size. The pump module valving
and the exhaust gas accumulator in the backpack, working together,
reduce exhaust flow requirements. The result is a small return pump and
a requirement for less power. The module is normally mounted on the
exterior of a PTC for space, noise, and cooling considerations.
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IMAGINE DIVING @ 500 METER! |
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