(CODE or "Davis-drifter" )
The Technocean
Argo Drifter (sometimes called the "SCULP","Shallow
Water" or "Davis Drifter") was designed to be a
surface level (1 meter) Lagrangian drifter which can report position
(and sea temperature if this option is exercised) via the Argos
satellite-based data collection system. Locations by GPS are available
as an option. The unit consists of a central sealed tube which
contains the electronics and power pack. On top of the tube is a folding antenna which
protrudes through the water surface when deployed.
Around the central core on top and bottom are eight spring loaded arms which upon deployment form two intersecting orthogonal, vertical, planes made of cloth with an area approximately 1 meter square - the central tube forming the vertical axis. Four ball-shaped foam floats approximately 10 cm. in diameter are attached by 25 cm. tethers from the outer ends of the upper arms. These floats provide net positive buoyancy to the unit.
Packaging
and Activation
When shipped, the arms, floats
and antenna are folded and the entire assembly is placed in a
"coffin" shaped cardboard box about 110 cm long and
25 cm square at its maximum dimension. Each box weighs approximately
9 kg. and contains a clearly marked "rip cord" which
is used to remove the magnet which activates the transmitter and
enables operation prior to deployment. However, this magnet cannot
be replaced without opening the packing box. If the rip cord is
not manually pulled the magnet will automatically separate after
the unit is deployed in water.
For air deployed units, a small spring loaded clip is provided to attach the parachute prior to deployment. If placed in the water the box components will separate and the unit will deploy in approximately 40 - 60 minutes.
Deployment
From a vessel
The
box may simply be dropped in the water and the unit will automatically deploy in under 1 hour. If preferred, the unit may be removed from the box and
then the magnet can be removed and replaced at will. Make certain
that the magnet is replaced in exactly the same spot, since this
location is NOT indicated on the tube. The location can be determined
by choosing a place directly opposite the antenna through point
and 2 cm. below the cap edge.
From
an aircraft
The parachute is shipped in a paper bag with the soluble release
tail protruding. The spring clip should be placed somewhere between
the round soluble element and the paper bag just prior to deployment.
The parachute bag and the instrument box should be jettisoned
from the aircraft while holding the parachute bag against the
top of the box. Minimum altitude should be approximately 1,500
ft. (450 m.) and maximum airspeed about 120 knots.
Construction
Technocean products are optimized
to meet requirements of the intended application. This means
they are neither underbuilt (delivering inadequate performance)
or overbuilt (excessively expensive). Materials such as
ABS and stainless steel provide strength and corrosion resistance
where needed and are optimal for the marine environment.
Construction techniques have evolved along with product design
resulting in products of high standard at relatively low cost.
All Technocean products use sophisticated electronic components
obtained from established vendors or developed in-house.
Products are tested for quality at various stages of construction
and before leaving the Technocean plant.