January 2018: Anniversary of the Bathyscaphe Trieste
On 23 January 1960, the Bathyscaphe Trieste journeyed to the bottom of the Challenger Deep in the Mariana Trench. It was the first manned vessel to reach this depth of 10,911 metres – the deepest known part of the ocean. The Trieste was designed by Swiss physicist, Auguste Piccard and largely built in the town in Italy it was named after. It was manned by Auguste Piccard’s son, Jacques Piccard, and US Navy Lieutenant Don Walsh.
This excursion proved that deep-sea exploration was possible, but it required nearly every piece to be custom designed, even down to the bolts used. The innovation required for developing the Trieste and its consequent success led to many engineering breakthroughs, including the first manipulator arm, the first deep-sea, color-TV camera system, the first high-pressure housings and connectors and the design of the first remotely operated vehicle.
A variety of raw materials made this development possible. The Trieste had walls 12.7 cm thick to withstand the enormous pressure it endured, and it weighed 12.25 metric tonnes (on land). For a ballast, 9 metric tonnes of magnetic iron pellets were places on the craft. These weights were held in place by electromagnets, so if there was an electrical failure, these would be released and the vessel would automatically float to the surface. The entire vessel was powered by batteries, which often contain a number of materials such as nickel, zinc, graphite and manganese dioxide.
The air system was similar to those used in space. As exhaled air passed through soda-lime canisters, it was scrubbed of carbon dioxide. The two men could only observe their deep-sea surroundings through a single block of acrylic glass (Plexiglas) as this was the only known transparent material that could withstand the extreme pressure. External lights on the vessel were made of quartz arc-light bulbs.