Dry Deck Shelter

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.

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History

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 construction of one unit in 1982. Newport news Shipbuilding built 5 units between 1987 and 1991. Submarines currently configured for DDS use are USS L Mendel Rivers (SSN 686), USS Kamehameha (SSN 642), and USS Dallas (SSN 700). Four additional Los Angeles (SSN 688) Class submarines are slated for conversion to be DDS host ships. To date, modifications are nearly complete on USS Los Angeles (SSN 688) and USS Buffalo (SSN 715). Conversion of USS Philadelphia (SSN 690) has begun, and work on USS La Jolla (SSN 701) will commence in Fiscal Year 2000.

Description

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.

Two shelters can be installed aboard USS Kamehameha (SSN 642) while fast attack submarines can accommodate one. To serve as a host ship numerous modifications must be made to the host submarine. These include mating hatch modifications; addition of electrical penetrations, valves, and piping for ventilation; divers' air; and draining water.

The two major mission areas for the DDS are SDV launch and recovery, and Mass Swimmer Lock-Out (MSLO). For SDV missions, Mark 8 Mod 0 or Mod 1 SDVs are generally used, although the DDS can also accommodate the Mark 9 SDV. The miniature wet submersible sits on a cradle within the DDS hangar until ready for use. After flooding the hangar and equalizing it with outside pressure, the DDS operators open the hangar's large outer door and wheel out a track onto the topside surface of the submarine. The cradle and SDV roll out on the track, and the SDV departs. DDS operators then return to the submarine or may remain outside. After conducting their mission, SDV operators locate the submarine by means of an active pinging sonar. When the SDV returns, divers secure it to its cradle, winch it back into the DDS, and shut the hangar outer door.

MSLO operations may be performed with the submarine surfaced, submerged, or awash. Generally, the SOF team uses CRRCs, large rubber rafts with outboard motors. The rafts are stored rolled up within the hangar until ready for use, and then are inflated on deck. Though less clandestine than SDVs, CRRCs can insert more commandos into an area more quickly, an advantage for some missions against particular threats.

DDSs are operated and maintained by members of SDV Team One in Pearl Harbor, Hawaii, and SDV Team Two in Little Creek, Virginia. The SDV Teams report to Navy Special Warfare Groups One and Two, which report to Naval Special Warfare Command in Coronado, California. U.S. Special Operations Command, a joint command in Tampa, Florida, oversees all of these organizations. Memoranda of Agreement (MOAs) provide the proper interface between the SOF community and the submarine crews, squadrons, and submarine Type Commanders.

The portable DDS is designed for temporary installation on modified host submarines. 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.