the Deepsea Challenger. The sub was
built in Sydney, Australia by the
research and design company,
Acheron Project Pty Ltd in a secret
The 12 ton/24 foot long DeepSea
Challenger shown in the drawing in
Figure 9 was equipped with two
booms for a lighting system and a
camera, a high-definition 3D IMAX
camera, vertical and horizontal
thrusters for maneuvering, a bank of
low power but high intensity LEDs for
lighting, and a large bank of lithium-ion batteries all managed by a
programmable automation controller.
Cameron reached the deepest
part of the oceans. The Challenger
went deep for two hours
on March 26, 2012, and
stayed on the bottom for
another three hours.
Figure 10 shows the
unique sub while in the water and
Figure 11 shows the sub being
retrieved after a dive. At six foot two
inches, Cameron was crammed into a
small 43” diameter steel pilot’s sphere
with a thickness of only 2-1/2” to
protect him from the eight tons per
square inch of crushing pressure.
Figure 12 shows Cameron emerging
through the small hatch.
The core of the sub is composed
of a special structural syntactic foam
called Isofloat that has a specific
gravity of 0.7, or 7/10 of what the
same volume of water would weigh.
Syntactic foam and other noncompressible material is used in many
ROVs for buoyancy, and derives its
lightness from millions of tiny ceramic
hollow ‘microspheres’ embedded in an
epoxy-like medium. Cameron was able
to jettison 1,100 pounds of steel
ballast to ascend to the surface this
way, as typical ballast tanks would not
function at that extreme depth.
Figure 13 shows the only two
Figure 10. DeepSea Challenger shown
Bathyscaphe Trieste in
1960 and James
Challenger in 2012.
SERVO 08.2014 79