The US Navy's Undersea Rescue Command is located in San Diego. Its mission: To rescue sailors of all nations during a submarine casualty.
The URC's goal is to reach a distressed submarine within 96 hours. For this to happen, the Pressurized Rescue Module (PRM), Atmospheric Diving System (ADS) and associated equipment are loaded onto transport aircraft and brought to the closest capable vessel. The two launch and recovery systems (the LARS and the LRS, which are two different things even though they have similar names) are then installed on the deck. When you see how much equipment this is, it's really impressive that it can be transported and assembled so quickly.
The ADS, or Atmospheric Diving System, is a self-contained, single-person submersible that can handle depths up to 2,000 feet. It’s designed to assess distressed submarines, communicate with their crews, clear hatches, and provide emergency life-support stores.
This is a training pool for the ADS. The Launch and Recovery System (LRS) – the blue equipment - lowers the human operator (the pilot), who is inside the ADS suit, into the pool. In an actual rescue, the LRS is what tethers the pilot to the surface ship.
The ADS is a diving suit that is essentially a remotely operated vehicle capable of descending to a depth of 2,000 feet. The suit has an umbilical for power and communications, 24 hours of life-support, self-contained breathing (O2/CO2), thrusters for maneuvering, video and sonar capability and articulated joints.
Although the ADS has 24 hours of life support, mission length is limited by the endurance of the human operator (pilot). Typically, this is about 3 to 4 hours, since the suit has no heating or cooling system, and in cold water it quickly cools to the ambient ocean temperature, which can be just below 32 degrees F. (Salt water freezes at a lower temperature than fresh water.) Also, though the arms and legs do move, they are not easy to maneuver.
These are McCann rescue chambers, which date from World War II and are still used today. The McCann bell made its debut in the rescue of 33 sailors from the USS Squalus in 1939. It can rescue up to 6 persons at a time and has a depth limit of 850 feet.
The Atmosphere Control Station at the end of a hyperbaric Submarine Decompression Chamber (SDC) where rescuees are transferred after being brought to the surface. The operator of the control station monitors the life-support systems inside the SDC. You can see the interior of the chamber through the small hatch (the Medical Transfer Lock).
This is the Medical Transfer Lock (MTL) in the SDC, in-between the Atmosphere Monitoring Station at one end of the SDC and the hyperbaric chamber. The MTL is used as a transfer lock. There is a door on each end, and you can open one door, place medicine or other supplies inside, pressurize (or depressurize) the small lock, then open the other door.
This is the inside of one of the two SDCs. Each SDC can treat 36 people (32 submarine crew members and four "attendants" -- Navy divers who accompany the Pressurized Rescue Module (PRM) down to the submarine and back to the surface, depressurizing personnel from up to five atmospheres within 12 hours (The PRM can carry 18 people -- 16 submarine crew members and two attendants, and each SDC can accommodate two transfers from the PRM.)
This is the Deck Transfer Lock (DTL), which connects the Pressurized Rescue Module (PRM) to the two Submarine Decompression Chambers (SDCs) via a flexible manway to the PRM and connection tubes to the SDCs.
This is the Modified Transfer Lock (MTL, not to be confused with the Medical Transfer Lock), which is an entry/exit point to the Submarine Decompression Chamber, used by the attendants monitoring personnel inside the SDC. Each MTL can accommodate up to four personnel.