It used to be that if you were stuck aboard a downed submarine, your best bet for rescue was to grow a set of gills -- fast. Now, however, the US Navy can reach and extract sailors who are in over their heads with this deep-diving 16-passenger ROV.
The Submarine Rescue Diving Recompression System (SRDRS) is a 180-tonne remotely operated rescue vehicle (ROV) capable of diving 600m below the waves, mating with virtually any nation's disabled submarine, and ferrying up to 155 crew members per operation to the surface. The SRDRS has been developed to replace the less capable Mystic class Deep Submergence Rescue Vehicle (DSRV), the US Navy's existing sub rescue system, which requires tethering to a mother submarine and takes much longer to deploy in the event of an emergency.
The new system consists of four parts: the Assessment/Underwater Work System (AUWS), the Submarine Decompression System (SDS), the pressurised Rescue Module System (PRMS) and various PRMS Mission Support Equipment. The AUWS includes the Atmospheric Dive Suit 2000 (ADS2000), a one-man pressurised hard suit that allows a first responder to quickly locate and inspect the downed sub on the seafloor, then find and clear the rescue hatch.
A PRMS, such as the US Navy's PRM Falcon, is then launched from a floating mother ship to descend to the wreck. Once it has mated with the rescue hatch, two attendants help evacuate and transport sailors from the sub directly to the surface at up to a pressure of five atmospheres (which saves loads of time waiting to decompress each shuttle-load on the way back up top). Once topside, evacuees are loaded into the self-contained SDS, which consists of a hyperbaric transfer chamber connecting a pair of 36-person deck-mounted decompression chambers.
And at just 180 tonnes, the SRS is small enough to fit on most commercial and military transport aircraft and seafaring vessels, which allows the system to move from its home port at the Deep Submergence Unit at the Naval Air Station San Diego, California, via land, sea or air, and arrive at the emergency site within 72 hours, anywhere in the world. [Wikipedia - Oceaneering - Global Security - Defense Media Network - US Navy - Naval Engineering]
Image: US Navy