USS SSN-686

Dry Deck Shelters (DDSs) provide specially configured nuclear powered submarines with a greater capability of deploying Special Operations Forces (SOF). DDSs can transport, deploy, and recover SOF teams from Combat Rubber Raiding Crafts (CRRCs) or SEAL Delivery Vehicles (SDVs), all while remaining submerged. In an era of littoral warfare, this capability substantially enhances the combat flexibility of both the submarine and SOF commandos.
The concept of a detachable Dry Deck Shelter with the ability to house, deploy, and retrieve SDVs, was born in the late 1970s. The Electric Boat Division of General Dynamics Corporation completed DDS-01S in 1982. [Note: The number indicates its order of construction, and the “S” indicates that its outer hangar door opens to the starboard side.] Newport News Shipbuilding completed the construction of DDS-02P, -03P, -04S, -05S, and -06P between 1987 and 1991. The following submarines once accommodated DDSs but have since been decommissioned: USS Silversides (SSN 679), USS Archerfish (SSN 678), USS Cavalla (SSN 684), USS Tunny (SSN 682),USS William H. Bates (SSN-680), USS L. Mendel Rivers (SSN-686).
Overall, the DDS is 9 feet wide, 9 feet high, 38 feet long, and displaces 30 tons. It consists of three interconnected compartments made of HY-80 steel within a fiberglass fairing, each capable of independent pressurization to a depth of at least 130 feet. The forward-most compartment, a sphere, is the hyperbaric chamber which is used for treatment of injured divers. In the middle compartment, or transfer trunk, operators enter and exit the submarine and/or either of the other compartments. The third compartment, the hangar, is a cylinder with elliptical ends which houses either the SDV or up to 20 SOF personnel with CRRCs.
The DDS may be transported to its host ship by barge, trucked over land, or flown via C5A aircraft. Each DDS has a specially designed truck called a “transporter” for this purpose. Complete on-loading and testing to make the DDS ready for manned operations at-sea takes from 1-3 days.