Titan to Titanic: A History of Deep Sea Exploration

Going Deeper Underwater: The Beginning

Diving is about pressure, because water has weight. A cubic metre of water weighs one metric tonne. Or in Imperial measures, a cubic yard of water weighs roughly 1.2 Imperial tons or 1.4 American tons. We do not have to go very deep underwater to have a ton of weight trying to crush our body. And that weight constantly increases as we go deeper.

The way people work underwater was transformed at the beginning of the Industrial Revolution with the development of the Standard Diving Dress. The development of more powerful hand-operated pumps to supply air from the surface, along with improvements to the waterproofing of flexible material, along with manufacturing techniques for copper and other components, all led to the advent of the Deep-Sea Diver—the iconic diver in the large copper helmet, lead-soled boots, chest weights and an air hose to the surface.

Deep Sea Diver
The Deep Sea Diver revolutionised how people worked underwater.

But divers in the flexible suit of the Standard Dress had to be supplied with compressed air. And the deeper they went, the higher the air needed to be compressed. The Deep-Sea Diver was soon afflicted with decompression sickness, or ‘the bends’. Inventors understood the crippling effects of decompression sickness were somehow related to breathing compressed air, and soon after the introduction to the Standard Diving Dress, inventors started to come up with ideas to protect the diver from the pressure as they went deeper. This resulted in a series of ‘armoured diving suits’ being made. These were heavy steel or iron diving suits, but they simply did not work. It is impossible to partially protect a person from pressure that surrounds them completely. Think of the tyre on a car, but in reverse. You can inflate it with air pressure, but if there is the smallest hole or weak point, the air will rush out. Surrounding the human body with a metal diving suit meant the water would get in if there was the tiniest hole, or weak point. And with metal, or ‘armoured diving suits’, there were many weak points in the moveable joints.

So the Standard Dress Diver remained the most popular way for people to work underwater for more than 100 years, until the development of practical scuba gear.

Scuba divers also breathe compressed air to stop the water pressure from collapsing their lungs. But again, the physiological effects of breathing compressed air, or more recently, mixed gases, limit the depths that free swimming divers can reach. The most highly trained and experienced mixed-gas divers cannot reach 3% of the total depth of the ocean.

For humans to go deeper, they must be sealed inside a vessel that protects them from the pressure (or weight) of the water.

Otis Barton William Beeb
In their hollow steel sphere Otis Barton and William Beebe reached a depth of half a mile.

Otis Barton and William Beebe Reach Half a Mile Deep

The first real breakthrough that enabled people to go beyond the limits of compressed air came in the 1930s, when two Americans, Otis Barton and William Beebe descended to a depth of more than half a mile (or 800 metres) in a specially built hollow sphere made of cast iron. The sphere (called a bathysphere – bathy meaning deep) weighed more than two tons and was lowered underwater on a cable. At a depth of half a mile, the cable to the ship above weighed more than a ton, and both Barton and Beebe realised they would not be able to go much deeper in a metal ball without finding a way to lower it underwater, then bring it back to the surface, independent of a steel cable.

Dropping a hollow metal sphere weighing more than two tons into the water, meant it would quickly sink to the bottom. But how could it be brought back to the surface, if not by means of a cable? The person who found the answer was a Swiss scientist, Auguste Piccard. Piccard had previously made high altitude ascents in a hydrogen-filled balloon. Piccard wanted to apply the same principles of balloon flight, to deep-sea vessels—except in reverse.

He decided he would construct a hollow metal sphere, similar to Beebe’s and Barton’s, and suspend it beneath some sort of underwater balloon that would float it to the surface. Then, once he had put it in the water, he would add extra weight to it, and sink it. Once he was at the desired depth, he would jettison the extra weight and the ‘lighter than water balloon’ would float the steel ball back to the surface.

That, in a sense, is the principal behind Deep Submersible Vessels almost 90 years later—including the Oceangate Titan that imploded while descending to the wreck of the Titanic. (Although the Titan did not have a hollow sphere.) You need a hollow chamber for the occupants, strong enough to protect them from the surrounding water pressure. You need something that is lighter than water that can float that chamber to the surface. And you need a means to attach additional weight to the vessel to sink it, then jettison the weight so the vessel will float back to the surface. And it will always be a fine balance between the positive and negative buoyancy. Too much lift and the deep-sea vessel will not sink. Not enough and it will descend to the bottom of the ocean and stay there.

Deep Sea Bathyscaphe FNRS-2
The first deep sea vessel, the FNRS-II, with the steel ball suspended below the float.

Auguste Piccard began building his vessel to take him to the deep ocean before the outbreak of World War II. He had the steel sphere cast in two sections, then joined together. For something to fill his ‘balloon’, he chose petrol, because it is lighter than water (with a specific gravity of 0.7 petrol floats on the surface of water) and being a liquid petrol will not compress. World War II interrupted Piccard’s plans and, after the war when he was ready to resume, he entered a partnership with the French Underwater Research Group, which had been established by Jacques Cousteau following the invention of the Aqualung in 1943.

Using a French ship, and the French naval base at Dakar, Senegal, on the west coast of Africa, Piccard tested what he called a bathyscaphe (deep boat). To add extra weight to sink the bathyscaphe, then release it underwater, Piccard used silos filled with steel shot. The shot was held in the silos with electromagnets, then could be released by turning off the power to the electromagnets. Turning the power off and then on, meant that the shot could be released in controlled amounts. Neutral buoyancy could be achieved to have the bathyscaphe float at any depth.

In 1948 the bathyscaphe (Piccard named it FNRS-II for the Belgian organisation that sponsored him) was tested with no one in the sphere and a timer set to automatically switch of the electromagnets. It successfully descended to, and returned from, 4600 feet (1400 metres). But problems arose trying to lift it out of the water when the float was full of petrol. The thin, lightweight float was damaged as it crashed against the side of the ship. The principal worked, but the float of the FNRS-II was irreparably damaged. As Piccard had run out of funding, his sponsors sold the damaged FNRS-II to the French Navy, and it was left on the docks of the base at Dakar.

While the float containing petrol was damaged, Piccard’s steel sphere had proven it could go much deeper that Beebe’s and Barton’s bathysphere and still not implode. It appeared to point the way downward. What needed improvement was the float to bring the sphere to the surface.

Titanic Deep Sea Bathyscaphe
The first vessel to reach the depth of the Titanic, the bathyscaphe FNRS-III. Inset shows the steel sphere suspended beneath it.

How Deep is the Titanic?

French naval officer, Georges Houot, who took over command of the French Underwater Research Group after the departure of Jacques Cousteau, decided to pick up where Piccard had left off, and redesign the float so that it would be more seaworthy. Houot had the new float designed by a submarine engineer and the rebuilt bathyscaphe eventually looked similar to a World War II submarine, with the exception that it had Piccard’s large steel sphere suspended beneath it. To continue to honour the Belgian research group that had originally sponsored Piccard, the rebuilt bathyscaphe was renamed FNRS-III.

Georges Houot began testing the rebuilt FNRS-III, then in August 1953, took it to a deeper than 2,000 metres (1.24 miles) deep and returned safely to the surface. Then in February 1954, Houot took the FNRS-III to 4,000 metres (2.5 miles) and safely returned to the surface.

The world’s most famous shipwreck Titanic, lies at a depth of 3,800 metres. Houot had travelled 200 metres deeper than the Titanic by 1954. And the world’s most notorious deep-sea submersible the OceanGate Titan, imploded trying to reach that depth almost 70 years later. So what went wrong? And how do modern submersibles repeatedly go almost three times deeper than the Titanic?

Continued in Part 2

For the full story read: THE FRONTIER BELOW: The Past Present and Future of Our Quest to Go Deeper Underwater. Released through HarperCollins.

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