A new submersible craft that combines high speed on the surface with the ability to submerge to significant depths has been developed in the US.

With a length of 14 metres, the HyperSub is road transportable and it has been designed to be fully self-supporting with a range of over 200 miles on the surface.

It can be deployed without the requirement for a support ship which can greatly reduce the operating costs that are normally associated with operating submersibles. The top speed on the surface is 31 knots reducing to a cruising speed of 25 knots.

On the surface the HyperSub is powered by a pair of 480 hp Yanmar diesels of type 6LY3-ETP. A snorkel exhaust system allows the craft to operate just below the surface with the diesels running either for propulsion or for battery re-charging. Below the surface the propulsion is by Innerspace electric motors with two 60 hp units which give a speed of 5.5 knots. Two further Innerspace thrusters of 10 hp each are used in a vertical mode to maintain depth.

HyperSub is based on a trimaran hull with the outer hulls having the planing surfaces necessary for speed. The craft comprises two main components, the sea frame and the dry chamber. The sea frame consists of four main components, the ballast chambers, the engines, the batteries and the dive chamber. This is the functional base unit of the HyperSub responsible for its surface and submersible operations.

The dry chamber is the crew compartment and adjustments can be made to the cabin to accommodate more passengers, cargo, crew, battery payload and any number of options designed to meet specific criteria for the end-user. Once on location the transition into a submarine is achieved through activating a few switches.

A feature called Hyper-Buoyancy controls and compartmentalises the 30,000 lbs of lift inherent in the design. This can be accessed on demand which it is claimed gives the craft unmatched safety features. These include the lift separated in 8 different compartments allowing the craft to return to the surface, in a controlled way, even in the event of total systems failure plus a very rapid ascent capability if needed in an emergency. The craft can return to the surface even if the cabin is completely flooded.

The life support system operates for 12 hours and an emergency system extends this out to 96 hours. With a steel cabin fitted the craft can submerge to 366 metres and with an acrylic cabin the depth capability is 150 metres. In standard form the HyperSub has a number of features including a periscope but the design can be adapted to meet a wide variety of specialised applications in the offshore sector. These can include pipeline surveys, hull and platform inspections and search and rescue in addition to harbour and littoral patrol. ROVs can be operated from the craft.

By Dag Pike