means that checking and repairing equipment must be done by scuba-divers at sea.
This is often difficult and time consuming. All these constraints limit the efficiency
for the use of bathyscaphes for today’s scientific research.
Manned and Unmanned Submersibles
The deep-diving submersibles used for today’s oceanographic research consist of
manned and unmanned vehicles. Most modern manned deep-diving submersibles
are constructed around a sphere made of an alloy of steel and titanium about 2 m
in diameter, which can resist the high pressure found at ocean depths. The pressure
at 6 km (6,000 m) depth is about 0.75 tons/cm
2 . A sphere is the most adapted form
for resisting such high pressure. The speed of descent for a submersible is roughly
30 m/min. Thus, it will take about 90 min to reach a depth of 2,000 m. Inside the
sphere, the atmospheric pressure is at one and the passengers breathe oxygen.
Their released CO 2 and water vapor are absorbed in the sphere by means of a
system using chalk and CO 2 filters. The average autonomy for research diving
vessels is 120 h, but most dives are aimed at a total duration of only 8–10 h.
Several industrial nations have deep-diving submersibles that are used for
research : Japan has the Shinkai (Jamstec organisation), Russia has the Mir (2), the
USA has Alvin (WHOI) and Pisces IV and V (HURL = Hawaii Undersea
Research Laboratory), France has Archimède, Nautile and Cyana, Germany uses
Yago, (IFM-GEOMAR Leibniz-Institüt fur Meereswissenschaften) (Fig. 3.2).
China has recently entered in the game of deep-sea exploration by building its first
submersible called the ‘‘Jiaolong’’ that made a test dive at 7,072 m depths in the
Mariana Trench in June 2012.
Alvin
Alvin is operated by Woods Hole Oceanographic Institution (WHOI) but is owned
by the US navy and is contracted through US government funding (Fig. 3.2). It is
the submersible that has the highest record for diving, since it usually makes
between 100 and 175 dives each year. The support ship of Alvin is now the R.V.
ATLANTIS. For several years, in the 60’s and 70’s, a catamaran called Lulu was
used as Alvin’s support ship (Ballard and McConnell 1995). The submersible Alvin
has a maximum operating capability of 4,500 m deep and it weighs 16 tons. Alvin
carries one pilot and two scientists. The vessel has two lateral portholes oriented at
an angle of 45° and a frontal porthole for the pilot. Alvin is not as comfortable as
the French submersible Nautile, because the observers must sit behind the pilot
who has the best view through the front porthole. Sitting on each side of the pilot
Archimède
61
This is often difficult and time consuming. All these constraints limit the efficiency
for the use of bathyscaphes for today’s scientific research.
Manned and Unmanned Submersibles
The deep-diving submersibles used for today’s oceanographic research consist of
manned and unmanned vehicles. Most modern manned deep-diving submersibles
are constructed around a sphere made of an alloy of steel and titanium about 2 m
in diameter, which can resist the high pressure found at ocean depths. The pressure
at 6 km (6,000 m) depth is about 0.75 tons/cm
2 . A sphere is the most adapted form
for resisting such high pressure. The speed of descent for a submersible is roughly
30 m/min. Thus, it will take about 90 min to reach a depth of 2,000 m. Inside the
sphere, the atmospheric pressure is at one and the passengers breathe oxygen.
Their released CO 2 and water vapor are absorbed in the sphere by means of a
system using chalk and CO 2 filters. The average autonomy for research diving
vessels is 120 h, but most dives are aimed at a total duration of only 8–10 h.
Several industrial nations have deep-diving submersibles that are used for
research : Japan has the Shinkai (Jamstec organisation), Russia has the Mir (2), the
USA has Alvin (WHOI) and Pisces IV and V (HURL = Hawaii Undersea
Research Laboratory), France has Archimède, Nautile and Cyana, Germany uses
Yago, (IFM-GEOMAR Leibniz-Institüt fur Meereswissenschaften) (Fig. 3.2).
China has recently entered in the game of deep-sea exploration by building its first
submersible called the ‘‘Jiaolong’’ that made a test dive at 7,072 m depths in the
Mariana Trench in June 2012.
Alvin
Alvin is operated by Woods Hole Oceanographic Institution (WHOI) but is owned
by the US navy and is contracted through US government funding (Fig. 3.2). It is
the submersible that has the highest record for diving, since it usually makes
between 100 and 175 dives each year. The support ship of Alvin is now the R.V.
ATLANTIS. For several years, in the 60’s and 70’s, a catamaran called Lulu was
used as Alvin’s support ship (Ballard and McConnell 1995). The submersible Alvin
has a maximum operating capability of 4,500 m deep and it weighs 16 tons. Alvin
carries one pilot and two scientists. The vessel has two lateral portholes oriented at
an angle of 45° and a frontal porthole for the pilot. Alvin is not as comfortable as
the French submersible Nautile, because the observers must sit behind the pilot
who has the best view through the front porthole. Sitting on each side of the pilot
Archimède
61