The Ballad Of Ron Allum

In late March 2012, an oblong lime-green submersible broke the surface of the Western Pacific near Guam. On the deck of a nearby ship, the Mermaid Sapphire, an 80-person support team and a film crew cheered wildly. The team winched the peculiar-looking craft on board and released the hatch. The door swung open and, to even louder cheers, James Cameron, the legendary

Hollywood action-film director, emerged. He had just dived nearly seven miles to the deepest point in the ocean, becoming the first person to ever reach the pitch-black depths of the Mariana Trench alone.

With his seven-hour dive, Cameron achieved what the world’s top ocean explorers could not, and the eerie scenes he filmed in the frigid darkness form the basis of a documentary, Deepsea Challenge 3D, set to be released in August. But if the tale of a Hollywood director turning into a deep-sea pioneer isn’t odd enough, the story of how he got there—all but forgotten behind the news of his dive—is even stranger.

That story centers on a stocky, gray-haired figure standing shyly at the edge of the crowd that early-spring day. Ron Allum, a 65-year-old Australian broadcast technician, co-designed and built the Deepsea Challenger despite having no background in mechanical engineering, no qualifications in oceanic science, and no education beyond a trade-school certificate. For seven years, he toiled in secret on Cameron’s submersible, eventually ending up in a clandestine workshop jammed between a plumbing-supply business and a furniture maker in suburban Sydney.

How did this unknown, self-trained engineer build a sub capable of getting James Cameron to the bottom of the ocean? It’s complicated, and it involves $10 million worth of scientific research, along with a can of car lubricant and a KitchenAid cake mixer.

Before 2005, Ron Allum never aspired to build submarines. For the previous decade, he had worked with a documentary filmmaker named Andrew Wight, building the camera rigs Wight needed to shoot his subjects—crocodiles, sharks, volcanoes, and other natural hazards. The two men had forged a partnership while scuba diving in caves beneath the central Australian desert. When Cameron hired Wight to help him shoot a documentary about the sunken wreck of the German battleship Bismark in 2001, Allum joined the team as a technical assistant.

The relationship between Allum and Cameron got off to a bumpy start. “I couldn’t understand a word Ron said at first because of his thick Aussie accent, and he’s so damned quiet,” Cameron says. But the director quickly realized how valuable his new team member would be. Early on, he watched Allum fix an electrical problem aboard their support ship by jury-rigging five malfunctioning circuit boards into a single working one. Allum fast became the troubleshooter on complex problems. On another occasion, Cameron needed a biodegradable compound as packing for a fiber-optic cable box; Allum stuffed the box with sliced bread from the ship’s galley. And after Cameron bought two mini submarines in 2004 for his film Aliens of the Deep, Allum refitted their electronics and thruster systems.

“Ron will figure out solutions that are so off-the-wall when you first hear them,” Cameron says. “Then they slowly reveal their brilliance and their elegance as you get into them.”

During their long days at sea, Cameron often talked with Allum about a fantasy he’d had since childhood: taking a submarine to the bottom of the Mariana Trench. Inspired by his deep-ocean film projects, which include a live-broadcast dive on the Titanic, Cameron saw a mission to the trench as equal parts research expedition and movie shoot. His submarine would need Hollywood-ready 3-D cameras and LED systems along with a hydraulic arm to collect scientific samples. At the end of 2005, as the director prepared to start work on Avatar, he commissioned Allum to build the craft.

The Ballad Of Ron Allum

Built in secret, the Deepsea Challenger was the first submersible to reach the bottom of the Mariana Trench in 52 years.

It was the Everest of underwater challenges. Only one manned vehicle had ever reached the bottom of the Mariana Trench, a submersible called the Trieste. In January 1960, it carried the Swiss oceanographer Jacques Piccard and U.S. Navy Lieutenant Don Walsh there for a fleeting 20 minutes. But that brief mission faced problems. At a depth of almost seven miles, the weight of the ocean reaches nearly 200,000 tons, and the pressure cracked Trieste‘s Plexiglas window. No manned sub had ever repeated the journey.

Technical challenges aside, the project would be dauntingly expensive, even for someone of Cameron’s means. The world’s most advanced deepwater submersible, the Japanese Shinkai 6500, had cost $60 million to build and couldn’t descend much further than four miles. The U.S. Navy’s submersible, Alvin, maxed out at about two-and-a-half miles, and scientists estimated the cost of replacing it at nearly $22 million.

“I was expecting a world-class workshop and machine shop. But it was basically Ronnie’s shed, scaled up.”

The mission would also come with unexpected competition. In 2005 another millionaire, Tennessee-born businessman Steve Fossett, had likewise fixed his sights on a solo dive into the trench, potentially eclipsing Cameron’s bid. Fossett had hired Graham Hawkes, a leading oceanic engineer, to build his submersible. Hawkes had founded five technology companies, engineered remote-controlled vehicles for NASA, and said that he’d had the blueprint for a submarine capable of diving to seven miles since 1993. Allum had neither the designs nor even a workshop. His research started in the laundry room of his Sydney home, where he tested the tolerance of a high-density battery system using a hand-primed pressure pump.

From the very beginning, Allum and Cameron took an unorthodox approach to the Deepsea Challenger‘s design. Most subs have a horizontal orientation and move through the water like a gliding bird. Allum and Cameron instead decided to build the Deepsea Challenger along a vertical axis so that in the water, it resembled a gigantic cigarette lighter with stumpy fins at each end. It would descend quickly, then move across the seabed like a seahorse with the aid of small thrusters. They also rethought the sub’s basic construction. Rather than use an expensive titanium shell, like most other submersibles have, they would build the chassis of their craft almost entirely from syntactic flotation foam, a buoyant material made from epoxy resin embedded with tiny glass spheres. They would then nest a steel pilot sphere just large enough for Cameron and the controls within it. The foam would adjust to the pressure automatically, and Allum could build the lights, batteries, cameras, and thrusters directly into it.

The first hurdle would be to find the right foam. Allum requisitioned a number of samples, but at 16,500 pounds per square inch, most of them failed—a bad sign for his boss. After months of frustration, he resolved to invent his own. Allum had a hunch that the foam would be strongest if the glass microspheres were evenly distributed throughout a thick, doughlike resin. After ordering canisters of various gases and bulk containers of small glass balls and resin, he drove to his local shopping center and bought a cake mixer to blend them, opting for a top-of-the-line $500 KitchenAid. “It was just before Christmas,” he recalls, “and the saleslady said, ‘Boy, your wife’s going to be happy!’ ” After months of trials, he arrived at a formulation that passed the pressure test.

Then he had to build Cameron’s steel pilot sphere. It needed to be small enough to minimize weight but large enough to fit a 6’2″ auteur and his control systems. Allum found a metallurgist in Melbourne to press two seven-ton ingots of steel into “pennies” seven feet in diameter and five inches thick, then mold and weld them into a sphere. He also recruited the Tasmanian structural engineer Phil Durbin; they’d met while playing underwater hockey, a grueling sport in which swimmers push a 1.5-kilogram lead puck around the bottom of a swimming pool while holding their breath. Durbin created a computer model of the sphere and foam frame to measure the anticipated stress. Then he and Allum shipped the sphere to a U.S. Navy laboratory at Pennsylvania State University, where it passed its final pressure test.

From 2008 to 2010, Allum beavered away in a 2,000-square-foot workshop in Sydney while Cameron took breaks from filming and editing Avatar to study technical specs and conduct Skype conferences with him. By May 2010, Allum had acquired more staff and moved into a larger workshop on a small industrial lot. Dave Goldie, an Australian special-effects engineer brought in as an assistant, was a little surprised when he saw the well-used cake mixer. “I was expecting a world-class workshop and machine shop,” Goldie says. “But it was basically Ronnie’s shed, scaled up.”

The Ballad Of Ron Allum

Allum created the submersible’s portal from a single piece of acrylic; it was the only material that wouldn’t crack under 1,100 atmospheres of pressure.

Getting finely calibrated equipment to operate deep underwater and at intense pressure brought up seemingly endless technical problems. For instance, different parts of the sub contracted differently under pressure. At 16,500 pounds per square inch, the foam hull shrank 6.4 centimeters in length, while the steel pilot sphere contracted at a much slower rate. To fix this, Allum suspended the sphere inside the foam housing on a system of elastic polyester straps, allowing it to float freely. Meanwhile, Allum was also having trouble with the “window” Cameron was supposed to peer through—a conical slab of clear acrylic 30 centimeters thick: It kept cracking within its steel housing during testing. Allum surmised that the lubricant surrounding it was failing to protect the Lucite from the pressure, even though it was the standard formulation recommended by the American Society of Mechanical Engineers. So he walked to his local Repco auto-parts outlet and bought a handful of automotive lubricants. Through trial and error, he discovered an aerosol spray called Dry Glide that did the job for $14.

By early 2011, Cameron had announced his intention to dive to the trench, and more personnel arrived in Allum’s workshop to refine the sub’s sonar system, communications, and hydraulics. Then came another surprise. In April, the Virgin Group’s founder, Richard Branson, announced that he and millionaire Chris Welsh were joining forces with designer Graham Hawkes. The mission would pick up where Hawkes had left off following the death of his patron, Steve Fossett, in a plane crash in 2007. Around the same time, Eric Schmidt, then chief executive of Google, announced that he was funding his own “cutting-edge” submarine, Deepsearch, for the same purpose. Once again, the race was on.

In November 2011, Cameron flew to Sydney, booked himself a suite at the Four Seasons hotel, and rented an office adjacent to the Deepsea Challenger workshop. For the next four months, the famous director lived in the city anonymously, holding strategy meetings in the boardroom of the nearby plumbing-supply business as various parts of the submersible were shipped in at all hours (except for the structural beam, which came in under the cover of darkness to avoid attention). “We were hiding in plain sight,” recalls Cameron. “Our roller door was open all the time, and yet no one had a clue what we were doing. It just seemed so improbable. I’m wandering around there every day, going to restaurants and cafes, and nobody realized.”

“I always said if I ever had to go to Mars and I could only take one person with me, I would take Ron. He would just rebuild the spaceship in flight.”

In the final week of January 2012, the Deepsea Challenger was loaded onto a truck at night and taken to the Sydney Naval Dockyards, where it was winched onto the pipeline-inspection ship_ Mermaid Sapphire_ for its first test dives. The sub’s odd appearance doubtless helped with the secrecy. A week later, the ship headed out to the ocean with its support team of engineers, robotics specialists, biological scientists, and filmmakers. Then tragedy struck. Cinematographer Mike deGruy and Andrew Wight—the man who had brought Allum and Cameron together more than a decade before—were killed in a helicopter crash on takeoff at a rural airstrip.

Devastated, Allum and Cameron talked about calling off the mission. But Wight and deGruy’s families urged them to carry on, and within weeks the Mermaid Sapphire chugged 2,000 kilometers north, heading to Guam. On March 26, James Cameron became the first human in history to tweet from the bottom of the sea: “Just arrived at the ocean’s deepest pt.,” he typed while crammed inside his tiny pilot sphere. “Hitting bottom never felt so good.”

The Ballad Of Ron Allum

Director James Cameron piloted the Deepsea Challenger to a depth of nearly seven miles, collecting scientific samples and footage for an upcoming film.

The dive was not without hitches. As Allum watched from the control room of the Mermaid Sapphire, he saw that the sub’s hydraulic arm and sample door were malfunctioning. And although Cameron had planned to make multiple descents, his scheduled appearance at the premiere of Titanic 3D in London meant that only hours after resurfacing, he would board a charter flight from Guam to Heathrow Airport. By the time he returned, three days later, bad weather had put an end to things: The expedition, which National Geographic and Rolex were underwriting, had already cost $20 million, and Cameron had spent an estimated $10 million on the submersible itself.

Cameron says the problems were not disastrous. Some sediment samples were lost, but his science team identified 68 new species and made potentially big discoveries about deep-ocean ecology. And the film Deepsea Challenge 3D will still consist largely of 3-D footage shot on the expedition. Last June, Cameron took Deepsea Challenger on a road show across the U.S., appearing before the Senate to plead for more oceanic-research funding before delivering the submersible to the Woods Hole Oceanographic Institution in Massachusetts. Allum is now refining his deep-sea systems in collaboration with Woods Hole, whose $8 million submersible Nereus was lost in May when it apparently imploded at a depth of 6.2 miles in the waters off New Zealand. He has also patented his flotation foam, Isofloat, and formed a business with Cameron’s financial backing to commercialize it for industrial and military use. “It can take a bullet, and it floats,” says Allum, who has already sold a batch to the Australian defense department.

To Cameron, Allum is an unsung engineering genius. “I always said if I ever had to go to Mars and I could only take one person with me, I would take Ron, because he would just rebuild the spaceship in flight,” says the director. Whether the two men will get to share another deep-ocean adventure is unclear, though—Cameron has to make Avatar 2, 3, and 4 before he can put his submariner’s hat back on, which could take five years or more.

For Allum, who never got to dive the Mariana Trench, that is the unfinished business of his Deepsea Challenger adventure. Asked if he’d like to make the dive one day, his eyes light up. “I’d do it in a heartbeat,” he says.

Science at Depth

When James Cameron surfaced from the Mariana Trench, he came back with more than bragging rights. He carried with him hours of video, samples of sediment, microbes, and even some crustaceans. Since then, scientists around the country have been examining the material. The expedition’s chief scientist, microbiologist Doug Bartlett, describes the discoveries thus far. —Erin Biba

Bartlett’s team has already identified a number of new amphipods—small crustaceans, some about the size of a thumbnail—and a jellyfish that could be related to moon jellies. They also have dozens of microbial cultures under high pressure (15,000 pounds per square inch) whose DNA they will scan for new species.

New Species.

Bartlett’s team has already identified a number of new amphipods—small crustaceans, some about the size of a thumbnail—and a jellyfish that could be related to moon jellies. They also have dozens of microbial cultures under high pressure (15,000 pounds per square inch) whose DNA they will scan for new species.

Giant Amoebas

Although single-celled, xenophyophores are not micro-scopic. They can grow to the size of a hand. The unusual organisms have been spotted far underwater in other locations, but the Mariana Trench is the deepest sighting.

Microbial Mats

In the trench’s subduction zone, where a tectonic plate plunges into the Earth’s mantle, scientists have found large beds of single-celled organisms. They likely live off chemical compounds seeping up from the depths. With no need for sunlight, they may expand scientists’ understanding of the requirements for life.

Pillow Lava

Before Cameron dived the Mariana Trench, his team did some shallower tests in the New Britain Trench, located off the coast of Papua New Guinea. Scientists had expected a flat, silty seafloor but found large, lumpy pillow lavas instead. The formations could help explain how the trench was formed.


Of the five dozen amphipods collected, one has already yielded a surprise: Its tissue contains scyllo-inositol, a compound normally found in coconuts, not animals. “It may be that they’re making these molecules because they help counteract the influence of pressure,” Bartlett says.

This article originally appeared in the August 2014 issue of _Popular Science._