Ron Allum is a cave diver, engineer and deep-sea explorer whose quiet determination transformed a film director's dream into engineering reality. In 2012, James Cameron piloted the Deepsea Challenger to the Challenger Deep, the deepest part of the Mariana Trench, taking with him technology created almost entirely by Allum and his team in a small Sydney workshop.
The undertaking was extraordinary in its scope. Allum had been involved in Cameron's deep-sea expeditions since 2001, and commenced work on the Deepsea Challenger submersible in 2005, researching and overseeing the building of the pressure sphere that forms its core. The engineering team spent seven years building the unique manned submersible.
The technical challenges were staggering. When engineers tested the two "full-ocean-depth-rated" foams that were on the market, they proved not to be adequate. In fact they cracked, warped, and compressed, losing buoyancy, and did not have nearly the tensile strength required for the new vehicle to operate under extreme conditions. Rather than abandon the project, Allum spent 18 months designing a new type of syntactic foam, which has since been dubbed ISOFLOAT and patented.
His approach was unconventional. 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 depth. Allum's unique, pressure-balanced, oil-filled electronic systems and other innovative ideas kept the submersible's weight to a minimum while maximising its ability to do science and imaging work in the world's deepest spots.
The submersible features a pilot sphere, large enough for only one occupant. The sphere, with steel walls 64 mm thick, was tested for its ability to withstand the required 114 megapascals of pressure in a pressure chamber at Pennsylvania State University. Yet the submersible contains over 180 onboard systems, including batteries, thrusters, life support, 3D cameras, and LED lighting. Each system required custom engineering; little could be bought off the shelf.
Allum's background made him suited to this work. His fondest memory is of leading a 1983 expedition to Cocklebiddy Cave on Australia's Nullarbor Plain, where the expedition achieved a world record push of 3.88 miles into the cave system. During his early work with Cameron, his quiet manner and unique ability to adapt, design, and build special equipment earned him the title of "The Professor" aboard ship.
The 2012 dive vindicated the engineering. On 26 March 2012, Cameron reached the bottom of the Challenger Deep, the deepest part of the Mariana Trench. The maximum depth recorded during this record-setting dive was 10,908 metres. More significantly, it was the first solo dive and the first to spend a significant amount of time, three hours, exploring the bottom. This extended exploration was only possible because Allum's designs allowed the submersible to descend faster and operate more efficiently than its 1960 predecessor.
Since the historic dive, Allum has continued his work. He founded Ron Allum Deepsea Services in 2013, based in Taren Point NSW, and continues developing specialist underwater systems for deep-sea exploration and research. In 2012 he was awarded the New South Wales Senior Australian of the Year in recognition of his outstanding contributions.
The Deepsea Challenger remains a testament to what independent engineering creativity can achieve. Built in Sydney, Australia, the submersible includes scientific sampling equipment and high-definition 3-D cameras and reached the ocean's deepest point after two hours and 36 minutes of descent from the surface. It is a reminder that Australia's contributions to exploration and innovation extend far beyond what international headlines typically acknowledge.