Bathyscaphe Race to the Deep

PART 1: The Underwater Balloon

At the end of World War II, no one had been deeper than half a mile underwater, and divers were still using copper helmets, lead boots and an air hose to the surface. Yet within the next 15 years people dove seven miles to reach the bottom of the ocean. The opening of our ocean depths is one of the great untold stories of human exploration. It is the story of clashing personalities, national rivalries, and a race between two versions of the same remarkable invention: what was originally called an ‘underwater balloon’, but came to be known as a bathyscaphe.

In the 1930s, two Americans, Otis Barton and William Beebe, had demonstrated that to descend to the depths of the ocean, humans needed to be sealed inside a steel sphere, so that the enormous weight of the water was spread evenly over the surface. Barton and Beebe had descended to a depth of half a mile (3,028 ft / 923 m) suspended on a steel cable. The weight of the steel cable, and the stresses on the winch and the boat on the surface, meant that it would be almost impossible to go deeper, while still suspended from the surface. Beebe had Barton had revealed half of the solution to going deeper underwater: a hollow steel sphere was the ideal shape to protect people from water pressure. The other half of the problem was how to lower a heavy sphere into the water, then bring it safely back to the surface, if not on the end of a steel cable?

Auguste Piccard Finds an Answer

The man who suggested a possible answer was a Swiss physicist, Auguste Piccard. In the 1930s, while Barton and Beebe had dangling on a cable to go deeper, Piccard had been ascending to the stratosphere in the aluminium gondola slung beneath a helium-filled balloon. Piccard had been sponsored by the Belgian Belgian Fonds National de la Recherche Scientifique (FNRS – National Fund for Scientific Research) and as a consequence, has called his high-altitude balloon FNRS. Towards the end of the 1930s, Piccard turned his attention from ascending higher, to descending deeper.

It would be possible, the Swiss scientist believed, to take the principles of lighter-than-air craft and use those principles underwater. Piccard’s idea was to take a strong hollow steel sphere, similar to what Beebe and Barton had used, but instead of suspending it on a cable, to suspend it under a ‘balloon’ that was lighter than water, and therefore positively buoyant. Once the ‘underwater balloon’ was ready, a person (or persons) could climb inside the sphere, and the whole lot put in the water. Then extra weight could be added so the sphere and balloon would sink to the bottom. Once there the weight would be dropped, so the balloon would return to the surface.

Piccard called his idea a bathyscaphe (Greek for deep boat’), and successfully sought sponsorship again from the Belgian FNRS. In 1937, Piccard was given a laboratory at the University of Brussels and set about making his idea a reality. He visited William Beebe at his laboratory in New York, and inspected the sphere that Beebe and Barton had taken to a depth of half a mile. Then he had a sphere made with an internal diameter of 6ft 6 in (2 m). It also had one porthole with the portlight made of the newly-invented Plexiglass. Piccard’s sphere was built in two halves, which were then pressed together. In that way the two halves could be X-rayed for imperfections before they were joined. The halves were made from steel, alloyed with nickel-chromium molybdenum. After the halves were cast and pressed together, the sphere weighed 10 tons. Getting it to sink would not be a problem. Satisfied his sphere would withstand the pressure at a depth of 13,000 ft (4,000 m), Piccard turned his attention to what would lift his balloon back from the depths to the surface. He decided on gasoline (petrol). Gasoline had a specific gravity of 0.7 (depending on temperature and refinement) and is only partially compressible.

In 1939, Piccard was at his laboratory at the University of Brussels, designing a gasoline-filled float that could pull his 10 ton sphere to the surface, when World War II broke out. Building his bathyscaphe was put on hold for the next six years.

Enter Jacques Cousteau

During World War II, Jacques Cousteau, along with another Frenchman, Emile Gagnan, invented what became known as the Aqualung—a workable scuba system that was lightweight, easy to use, and revolutionised diving. At the end of the war, Cousteau was still a Captain in the French Navy, and along with Commander Philippe Tailliez, formed the Underwater Research Group, a specialist group within the navy, dedicated to promoting the Aqualung for different underwater applications.

Meanwhile, Auguste Piccard completed his bathyscaphe, which to honour the organisation which had sponsored him, he named FNRS-II. He also toured, giving lectures about his invention, to raise more sponsorship money. In December 1946, Piccard was in Paris when he gave a lecture that was attended by Jacques Cousteau. After the lecture, Piccard and Cousteau met, and Cousteau told Piccard how he was fascinated by the idea of a deep sea vessel. Piccard explained that his bathyscaphe was already built. All he needed to do was raise more money to pay the cost of shipping it to deep water and trying it out. He also asked Cousteau if he would like to be present when the test was undertaken, and swim down in an Aqualung to film the bathyscaphe underwater.

Jacques Cousteau with members of the Underwater Research Group in 1947
Jacques Cousteau (left) with members of the Underwater Research Group in 1947

Jacques Cousteau, as head of the Underwater Research Group, was able to offer much more. He told Auguste Piccard that he could ask the French Navy to make a ship available, along with the naval base at Dakar, Senegal, so the tests could be carried out in the water off the west coast of Africa. The two men agreed to cooperate. It seemed an ideal collaboration: the Swiss inventor of the bathyscaphe and the French inventor of the Aqualung. As events would transpire, the honeymoon did not last long.

In August 1948, Jacques Cousteau, Philippe Tailliez, and members of the French Underwater Research Group, arrived at Dakar to wait for Auguste to arrive with the bathyscaphe. A few weeks later the Piccard arrived in a Belgian ship, Scaldis, and the French naval officers and divers saw Piccard’s bathyscaphe for the first time. Tailliez later recalled that they were both excited and alarmed when they first saw the ‘underwater balloon’. The idea was brilliant, but what concerned them was the flimsiness of the gasoline-filled float. It did not appear to be strong enough to withstand rough seas. The French divers were all navy men and understood the needs of sea vessels.

The First Bathyscaphe Test

Nevertheless, despite their concerns, they decided to test the bathyscaphe in the lee of Boavista Island. Next, Jacques Cousteau was surprised when Auguste Piccard did not invite him to join Piccard on the shakedown dive. He believed, because of the assistance that the French had generously provided, he should share the honour of co-piloting the first dive of the bathyscaphe. Instead, Piccard insisted everyone associated with the project draw straws to see who would accompany him. The winner was Théodore Monod, a French naturalist who was in Africa looking for meteorites.

Bathyscaphe FNRS-II in the Hold of the Scaldis
Bathyscaphe FNRS-II in the Hold of the Scaldis

Preparing for the test dive, problems immediately became apparent. There was no hatchway, so the occupants of the sphere could not enter or exit it while the bathyscaphe was in the water. They needed to climb inside while the bathyscaphe was still in the hold of the Scaldis, and then the lot would be lifted into the water. Plus, it would need to be lifted out of the water before the occupants could get out of the sphere. This caused more complications, because the crane on the Scaldis was not powerful enough to lift the FNRS-II in or out of the water if the float was full of gasoline.

On 23 October 1948, Piccard and Monod climbed into the cabin of the FNRS-2 and the hatch was sealed shut. The FNRS-2 was lowered into the water, and bobbed on the surface while gasoline was pumped into the float. That took three hours. During that time Aqualung divers dove to the sphere dangling under the float and looked in the window to see Piccard and Monod sitting patiently playing chess.

Finally, the float was full. Iron pellets were poured into the silos and the FNRS-2 slipped beneath the surface. It sank to 200 feet (60 m) where it settled on the bottom. Then  Auguste Piccard switched off the electromagnets, emptied the ballast, and the bathyscaphe returned to the surface. It had been underwater for sixteen minutes. The principle of the underwater balloon worked.

The petrol could not be pumped from the float back to the Scaldis. For the next five hours the gasoline was emptied into the sea, before the crane could lift the FNRS-II. It was almost midnight before the hatch was opened and Piccard and Monod were able to exit the sphere.

The Bathyscaphe FNRS-II
The Bathyscaphe FNRS-II Being Lowered From the Scaldis

With the successful (but slow) test dive, Auguste Piccard, Jacques Cousteau and the rest of the team agreed that it was now time to try the bathyscaphe deeper. They planned an unmanned descent to 4,200 feet (1.3 km). A mechanical clock would be wound and set for 11 hours. The idea was that the FNRS-2 would be lowered into the water, filled with gasoline and then the iron shot added. It would sink to the bottom and after 11 hours the clock would switch of the electromagnets holding the shot and release it. The bathyscaphe would then (theoretically) return to the surface.

On 26 October, the cabin was sealed shut and the bathyscaphe was lifted into the water. Next the float filled with gasoline and the silos filled with shot. That process took 10 hours, during which time the clock was ticking. Finally, 40 minutes before the deadline, the bathyscaphe slipped underwater. Aqualung divers followed for the first part of its journey.

Everyone waited anxiously and watched the surface of the water. Would Auguste Piccard’s invention really open the way to the deep ocean? Thirty minutes later the FNRS-2 broke the surface. The crew of the Scaldis tried to tow the FNRS-2 back to port, but found when the bathyscaphe was full of gasoline and sat low in the water, it was impossible to tow. There was no option but to empty the float. As it was the last of the gasoline, the crew did not want to empty it into the sea. Instead they decided to siphon the highly flammable liquid into drums. The task took all night and during that time rough seas were smashing the FNRS-II against the side of the Scaldis. By the time the bathyscaphe was lifted back into the hold of the Scaldis, the float was irreparably damaged.

When the hatch was eventually opened, it was found the FNRS-II had reached, and returned from, 4554 feet (1400 m). Auguste Piccard and Jacques Cousteau were encouraged. It had worked, but there were obviously a number of issues with Piccard’s design. Firstly, the float needed to be stronger, and shaped more like a boat to withstand rough seas. Secondly, the occupants needed to be able to get in and out of the sphere when the bathyscaphe was in the water. Had Auguste Piccard, or anyone else, been in the cabin on the unmanned test dive, they would have died because the oxygen in the rebreathing system would have run out long before the hatch was opened.

The damaged FNRS-2 was taken back to Dakar, where it was left on the docks of the naval yard. Auguste Piccard returned to Switzerland, conscious that he would be getting no more sponsorship from Belgium, and no more support from the University of Brussels.

Jacques Cousteau was happy to leave the FNRS-2 at Dakar, and turn his attention to a new idea; making underwater documentaries. In fact, six months after the failed bathyscaphe test, Cousteau left the French Navy, bought the Calypso and commenced shooting the films that would make him world famous.

The damaged FNRS 2
The damaged FNRS-II on the docks at Dakar

The appointed person to take over the work of the Underwater Research Group was Georges Houot, a career naval officer who ironically, because he had contracted polio as a child, was forbidden to go into sea water. Nevertheless, Houot took to his new role with enthusiasm, and studied the work of the specialist branch of the French Navy. He learnt that the FNRS-2 was still sitting on the docks at Dakar, and decided to investigate whether it would be possible to restart the program of deep sea exploration. Realising the future of the bathyscaphe was in doubt, and that it was owned by the Belgian Government, Houot proposed the French Navy buy it, so he could rebuild it. The navy and the Belgian Government agreed, and a contract of sale was signed on 9 October 1950.

The sale did not please Auguste Piccard, who felt betrayed, not only by the Belgian Government, but by the French Navy as well. With his son, Jacques, August Piccard immediately raised the money to build another bathyscaphe, this time in Italy.

Suddenly two bathyscaphes were being constructed. One was being built by the French Navy using the sphere and parts from August Piccard’s FNRS-2. The other was being built in Italy by the man who had conceived the idea of the ‘underwater balloon’. A bitter rivalry and a race to reach the depths of the ocean was about to begin.

Part 2 will be published 15 January 2023.

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