Beneath the shimmering lights on the water’s surface, a U.S. Navy diver navigated through the depths of a sprawling tank. Clad in a specially designed diving suit capable of withstanding the immense pressure of the ocean, the diver reached her objective—a mannequin representing a human body. This exercise was part of a simulated mission to recover a crashed aircraft, testing the capabilities of the Deep Sea Expeditionary with No Decompression (DSEND) system. The DSEND system consisted of a lightweight yet durable atmospheric dive suit equipped with rotating and detachable joints, providing the diver with enhanced dexterity, flexibility, and maneuverability.
Sponsored by the Office of Naval Research (ONR) in collaboration with the Naval Sea Systems Command (NAVSEA), Naval Undersea Warfare Center (NUWC), and Naval Surface Warfare Center (NSWC) Panama City, the DSEND system recently underwent demonstrations at the NSWC Carderock Division in Maryland and the Navy Experimental Diving Unit in Florida.
Dr. Sandra Chapman, a program officer in ONR’s Warfighter Performance Department, highlighted the groundbreaking nature of DSEND, stating, “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. It increases diver safety, allows them to expand the operational envelope, and would eliminate lengthy decompression times.”
The Navy frequently undertakes diving missions involving deep ocean salvage operations, underwater rescues, explosive ordnance disposal, ship hull maintenance, and recovery of sunken equipment. However, as divers descend to greater depths, they face heightened risks due to the escalating water pressure. To mitigate these dangers, Navy divers employ a saturation system, or diving bell, which is pressurized with gas to match the external pressure.
The drawback of this approach is that when divers resurface, they must ascend slowly and pause at intervals to prevent decompression sickness. This condition, caused by the formation of gas bubbles in the blood and tissues due to the decrease in pressure, can be fatal. While this gradual ascent ensures the safety of divers, it limits the duration they can spend at a particular site.
The DSEND system offers a solution to this challenge by providing a one-atmosphere environment. With its self-contained life support system, the DSEND suit envelops the diver in a stable pressure cocoon throughout the entire dive. This enables divers to work at significant depths for extended periods and ascend without the protracted decompression process.
Paul McMurtrie, NAVSEA diving systems program manager, explained, “Because DSEND maintains one consistent pressure atmosphere, the diver is never exposed to the negative physiological effects associated with deep diving, such as decompression sickness, cold, and wet exposure. A diver can work for long periods of time in deep water and rapidly return to the surface.”
Despite its sturdy construction, the DSEND suit is lightweight and allows users to swim and walk on the seabed with ease. This represents an improvement over the conventional atmospheric diving suits previously utilized by the Navy, which were bulkier and powered by attached thrusters, hindering mobility.
Moreover, the DSEND suit is easier to don and remove and can be adjusted to fit individual divers. It incorporates joints, grippers, and hand attachments made from innovative materials that are both strong and lightweight, replicating the natural movements of human joints and reducing diver fatigue.
Tom Hansen, a research engineer at NUWC Division Newport, expressed his excitement, stating, “DSEND will allow divers to conduct harder missions by going deeper, executing faster, and operating longer, all while being protected by a sensorized suit of armor. It feels like we’re developing the futuristic smart armor you see in movies.”
During the demonstrations in Maryland and Florida, DSEND divers successfully completed various exercises to showcase the capabilities of the system. These exercises included retrieving a mannequin from an aircraft fuselage, rigging a piece of wreckage for salvage, and maneuvering through simulated tunnels representing sunken vessels.
Looking ahead, Dr. Sandra Chapman hopes to see further development of the DSEND system, including conducting at-sea demonstrations in realistic operational environments within the next year.
Navy Master Chief Jericho Diego, a master diver and the senior enlisted leader at NUWC Division Keyport, expressed his optimism about the potential benefits of the DSEND system for Navy divers. He emphasized that eliminating the need for decompression would enhance safety, and the more flexible arm attachments would enable divers to retrieve targets and perform their tasks more effectively.
In summary, the DSEND system represents a significant advancement in deep-sea diving technology, offering increased safety, extended dive durations, and enhanced maneuverability for Navy divers. With its innovative design and promising performance, the DSEND system holds great potential for revolutionizing underwater missions and ensuring the success and well-being of Navy personnel.
Source: Office of Naval Research