Flotation piece

Date2005-2012

Object number00055457

NameFlotation piece

MediumSyntactic Foam, Isofloat, Microglass / epoxy

DimensionsOverall: 487 × 580 × 175 mm, 30 kg

ClassificationsTools and equipment

Credit LineAustralian National Maritime Museum Collection gift of Ron and Yvette Allum

Terms

DescriptionHeavy white trapezoidal block of foam developed by Ron Allum for James Cameron's DEEPSEA CHALLENGER. One of a number of pieces used to construct a model of the submersible.HistoryThese blocks each represent a full size block 1/5 scale. The original concept was to build the DEEPSEA CHALLENGER in layers like putting bricks together. This set of trays is a concept model. The blocks bonded together by special technique that forces glue into the join, which creates a homogenous layer. Building the chassis from foam instead of metal meant that the vehicle could be lighter overall. James Cameron didn’t want the DEEPSEA CHALLENGER to have a metal chassis. He wanted the chassis to be foam. Ron Allum recalls: “Flotation for submersibles is usually made up of a mix of hollow glass microspheres and epoxy resin which sets solid like a brick but floats. Again I turned towards the US and requested quotes and samples. Again I hit a wall. It was either no-response or the samples I tested were not homogeneous or offered an insufficient factor of safety, especially for a piloted vehicle. With their standard foam we would have to incorporate a chassis that would make our sub too heavy. Not to mention, if a foam block failed during a dive the pilot and sub might not ascend. Rather than abandon the project I went to Kitchen Warehouse in Marrickville and bought a food mixer. It took me 12 months to come up with a structural flotation material that we could use. From there we designed a manufacturing plant and commenced production in February 2011.” Each block represents a full size block 1/5 scale the original concept was to build the DEEPSEA CHALLENGER in layers like putting bricks together. This set of trays is not quite how was built in the end but is a concept model. Blocks bonded together by special technique that forces glue into join. This model is six metres long and constructed in five different sections. Built vertically, the way it would dive. Each block 1200 x 270 x 270 with biggest block off the shelf is about a cubic foot. The Isofloat process and bigger equipment and mixers could make bigger blocks. The blocks have machined and radiused corners which help to relive stress as when block subjected to hydrostatic pressure, they bend like a banana. SignificanceOn 25 March 2012, James Cameron piloted the submersible DEEPSEA CHALLENGER to the bottom of the Marina Trench in the first solo dive to this depth. Australian inventor and deep-sea pioneer Ron Allum began work on the project in secrecy in 2005 in his workshop in Leichhardt, New South Wales. Allum patented Isofloat foam system that allowed the submersible to withstand the pressure of full ocean depth.