Game-changing DSEND suit protects deep sea divers from pressure dangers

Game-changing DSEND suit protects deep sea divers from pressure dangers
DSEND is designed to protect the wearer against water pressure during deep dives
DSEND is designed to protect the wearer against water pressure during deep dives
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DSEND is designed to protect the wearer against water pressure during deep dives
DSEND is designed to protect the wearer against water pressure during deep dives
DSEND is lightweight and flexible
DSEND is lightweight and flexible

The US Navy recently completed tank tests of a new deep-diving suit called the Deep Sea Expeditionary with No Decompression (DSEND) system that is light and flexible, yet maintains sea-level internal pressure around the wearer even when hundreds of feet underwater.

Modern scuba gear makes diving a fun and relatively safe sport, but deep sea diving is the equivalent to doing a space walk. Working under the crushing pressures hundreds of feet down requires complex apparatus and the choice between two challenging and expensive alternatives.

One option is to use a mixed-gas diving system where the nitrogen in the air is replaced with different mixtures of helium and hydrogen, with the percentage of oxygen kept within tolerable concentrations. It's a tricky operation that requires enormous amounts of the mixture gases that have to be supplied to the diver along with a constant flow of hot water through umbilical hoses to a special suit to keep the diver from freezing to death even in 'warm' water.

It also means that the diver has to be put under pressure in a special surface chamber on the host ship, transferred to the desired depth in a diving bell, returned to the surface chamber after completing work, kept under pressure for days or weeks at a time to finish the duty tour, and then take days more to decompress.

Not only is this extremely involved, it's also expensive – not just in terms of equipment and gases, but in dive pay, which, for a civilian diver, starts the clock from the moment of entering pressure to the moment of leaving. That's a lot of cash.

DSEND is lightweight and flexible
DSEND is lightweight and flexible

The alternative is to wear diving armor, which is a metal alloy suit that keeps the diver under normal sea-level pressure for the entire dive. Because the suit has to withstand, for example, over 18 atmospheres of pressure at 600 ft (183 m), it has to be very heavy with equally robust joints in the arms and legs and articulated claws where the hands should be. Such a contraption is so cumbersome that it is often equipped with electric thrusters to move about. It also requires a ship with heavy lifting gear and assist scuba divers to help the armor diver.

The DSEND project aims at avoiding both of these choices, at least at depths under 300 ft (92 m), with a light suit made of hard, durable material with its own internal life support system. This allows the diver to not only avoid the dangers of the bends and the need to return to the surface with decompression, but to also move much more easily underwater and even swim.

Developed in partnership with Naval Sea Systems Command (NAVSEA), Naval Undersea Warfare Center (NUWC), and Naval Surface Warfare Center (NSWC) Panama City, DSEND boasts joints, grippers, and hand attachments made from novel materials and can be adjusted to fit the diver. The joints are designed to more closely mimic human ones, making them much easier to move with less concentration and effort.

The recent tests were conducted at the NSWC Carderock Division in Maryland and at the Navy Experimental Diving Unit in Florida where it was used in simulated rescue and salvage operations of an imaginary downed aircraft with a mannequin standing in as a casualty.

"DSEND is truly a game-changer because it’s a self-contained environment that keeps internal pressure steady, as a diver descends to depths with increasing external pressure," said Dr. Sandra Chapman, a program officer in the Office of Naval Research's (ONR) Warfighter Performance Department. "It increases diver safety, allows them to expand the operational envelope and would eliminate lengthy decompression times."

DSEND is currently rated to 300 ft (91 m), though efforts are being made to improve upon this.

Source: Office of Naval Research

So, how exactly does this keep you at sea level pressures when your hands are exposed to the water directly? I'm struggling to understand how you could seal that and still have circulation in the fingers wiggling about in 130psi fluid.
Bob Stuart
I knew the history of diving. I was hoping to learn more about the new tech than the title told.
@Chase, I don't see how that's big of a deal, the human body is mostly made of incompressible Water. At most the pressure difference would feel like a firm handshake, it's just a bit of constriction of the hands. I guess it the glove is firmly connected to the whole apparatus like a full body condom anyway

@New Atlas Also I guess it's technically 19 Atmospheres of pressure at 180 meters considering we need to count surface level pressure of 1 Atmosphere already (2 ata at 10 m. . . etc)
The author didn't make any mention of Nuytco Research's EXOSUIT ADS, rated up to 2000ft. The DSEND looks like a derivative of the Nuytco suit.
I agree that circulation to the hands exposed to pressure would be cut off not to mention the numbing effects of ice water but the article does mention grippers and hand attachments. So I would imagine the diver in the suit pictured is a PR photo and not an actual deep dive simulation.
Expanded Viewpoint
EXACTLY, Nobody! Anyone can see that the two men in regular dive gear are just there to assist the test diver, should the need to do so arises. It's probably just a short mobility test in the tank and a photo op for a PR piece.
I don't know if it true or not, but supposedly a deep sea diver's air supply system had failed and the check valve to keep the air in the suit didn't work, and part of his body was subsequently jammed up into the big brass helmet! Ouch. So water could be forced past the wrists and into the suit at a great depth, which would kill the diver due to a crushed respiratory system.
Deep sea diving is nothing like a space walk. A space suit only has to maintain an internal pressure of 1atm against no external pressure.
A diving suit rated for 300 feet is a lot less impressive once you realize the deepest free diver managed a depth of 700 feet without any fancy equipment.
Sándor Dávid Papp
It is meaningless to develop pressure-resistant suit for deep diving.
It is much more safe, efficient, comfortable and practical to build micro-submarines instead.
This is the same as for jetpacks.
It is much better to sit in a small vehicle, than exposing yourself to the forces of the nature.