Deepsea Challenger

Drawing of the DCV1, based on imagery from the Deepsea Challenger website (not to scale)
History
Australia
Name:	Deepsea Challenger
Builder:	Acheron Project Pty Ltd
Launched:	January 26, 2012
In service:	2012
General characteristics
Type:	Deep-submergence vehicle
Displacement:	11.8 tons
Length:	7.3 m (24 ft)
Installed power:	electric motor
Propulsion:	12 thrusters
Speed:	3 knots (5.6 km/h; 3.5 mph)
Endurance:	56 hours
Test depth:	11,000 m (36,000 ft)
Complement:	1

Deepsea Challenger (DCV 1) is a 7.3-metre (24 ft) deep-diving submersible designed to reach the bottom of Challenger Deep, the deepest-known point on Earth. On March 26, 2012, Canadian film director James Cameron piloted the craft to accomplish this goal in the second manned dive reaching the Challenger Deep. Built in Sydney, Australia by the research and design company Acheron Project Pty Ltd, Deepsea Challenger includes scientific sampling equipment and high-definition 3-D cameras, and reached the ocean's deepest point after roughly two hours of descent from the surface.

Deepsea Challenger was secretly built in Australia, in partnership with the National Geographic Society and with support from Rolex, in the Deepsea Challenge program. The construction of the submersible was headed by Australian engineer Ron Allum. Many of the submersible developer team members hail from Sydney's cave-diving fraternity including Allum himself with many years' cave-diving experience.

Working in a small engineering workshop in Leichhardt, Sydney, Allum created new materials including a specialized structural syntactic foam called Isofloat, capable of withstanding the huge compressive forces at the 11-kilometre (6.8 mi) depth. The new foam is unique in that it is more homogeneous and possesses greater uniform strength than other commercially available syntactic foam yet, with a specific density of about 0.7, will float in water. The foam is composed of very small hollow glass spheres suspended in an epoxy resin and comprises about 70% of the submarine's volume.

The foam's strength enabled the Deepsea Challenger design to incorporate thruster motors as part of the infrastructure mounted within the foam but without the aid of a steel skeleton to mount various mechanisms. The foam supersedes gasoline-filled tanks for flotation as used in the historic submarine, Bathyscaphe Trieste.

Allum also built many innovations, necessary to overcome the limitations of existing products (and presently undergoing development for other deep sea vehicles). These include pressure balanced oil filled thrusters; LED lighting arrays; new types of cameras; and fast reliable penetration communications cables allowing transmissions through the hull of the submersible. Allum gained much of his experience developing the electronic communication used in Cameron's Titanic dives in filming Ghosts of the Abyss, Bismarck and others.