A dry deck shelter (DDS) is a removable module that can be attached to a submarine to allow divers easy exit and entrance while the boat is submerged. The host submarine must be specially modified to accommodate the DDS, with the appropriate mating hatch configuration, electrical connections, and piping for ventilation, divers' air, and draining water. The DDS can be used to deploy a

SEAL Delivery Vehicle The SEAL Delivery Vehicle (SDV) is a crewed submersible and a type of swimmer delivery vehicle used to deliver United States Navy SEALs and their equipment for special operations missions. It is also operated by the Royal Navy's Special Boat S ...

submersible A submersible is a small watercraft designed to operate underwater. The term "submersible" is often used to differentiate from other underwater vessels known as submarines, in that a submarine is a fully self-sufficient craft, capable of ind ...

, Navy divers, or

Combat Rubber Raiding Craft The Zodiac Milpro Futura Commando 470 or in short FC470 Combat Rubber Raiding Craft (CRRC), also known as the "Combat Rubber Reconnaissance Craft," is a specially fabricated rubber inflatable boat often used by the U.S. Navy, U.S. Marine Corps ...

(CRRC).

Active and future DDS-capable submarines

Royal Navy

In UK service it is formally named the Special Forces Payload Bay (SFPB) and was procured under ‘Project Chalfont’ Training is conducted at the purpose-built Chalfont Shore Facility (CSF) constructed by

BAE Systems BAE Systems plc (BAE) is a British multinational arms, security, and aerospace company based in London, England. It is the largest defence contractor in Europe, and ranked the seventh-largest in the world based on applicable 2021 revenues. ...

HMNB Clyde His Majesty's Naval Base, Clyde (HMNB Clyde; also HMS ''Neptune''), primarily sited at Faslane on the Gare Loch, is one of three operating bases in the United Kingdom for the Royal Navy (the others being HMNB Devonport and HMNB Portsmouth). It ...

. It is used by the .

United States Navy

The

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

's DDSs are long and high and wide, add about 30 tons to its host submarine's submerged displacement, can be transported by trucks or

C-5 Galaxy The Lockheed C-5 Galaxy is a large military transport aircraft designed and built by Lockheed, and now maintained and upgraded by its successor, Lockheed Martin. It provides the United States Air Force (USAF) with a heavy intercontinental-ran ...

airplanes, and require one to three days to install and test. They have three

HY-80 HY-80 is a high-tensile, high yield strength, low alloy steel. It was developed for use in naval applications, specifically the development of pressure hulls for the US nuclear submarine program and is still currently used in many naval applicati ...

steel sections within the outer

glass-reinforced plastic Fiberglass (American English) or fibreglass (Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass cloth ...

(GRP) fairing: a spherical

hyperbaric chamber A diving chamber is a vessel for human occupation, which may have an entrance that can be sealed to hold an internal pressure significantly higher than ambient pressure, a pressurised gas system to control the internal pressure, and a supply of ...

at the forward end to treat injured divers; a smaller spherical transfer trunk; and a cylindrical hangar with elliptical ends. The hangar can support a

(SDV) submersible, six

Navy SEALs The United States Navy Sea, Air, and Land (SEAL) Teams, commonly known as Navy SEALs, are the United States Navy, U.S. Navy's primary special operations force and a component of the United States Naval Special Warfare Command, Naval Special Wa ...

to man the SDV, and a crew of Navy Divers to operate the DDS and launch the SDV; or 20 SEALs with four

(CRRC). The SDV release team consists of 2 officers, 2 enlisted technicians, and 18 divers. SEAL Delivery Vehicle loading

The two SEAL delivery vehicle teams report to

Naval Special Warfare Group 3 Naval Special Warfare Group 3 (NSWG-3), based at the Naval Amphibious Base Coronado in California, was one of six constituent formations of the United States Naval Special Warfare Command. Until 2008, NSWG-3 was composed of two SEAL Delivery Veh ...

. There are currently six portable dry deck shelters in use by the USN, the first one built by

Electric Boat An electric boat is a powered watercraft driven by electric motors, which are powered by either on-board battery packs, solar panels or generators. While a significant majority of water vessels are powered by diesel engines, with sail pow ...

. The first, designated DDS-01S ("S" for starboard opening outer door), was completed in 1982. The remaining five, DDS-02P ("P" for port opening), -03P, -04S, -05S, and -06P, were built between 1987 and 1991 and were built by

Newport News Shipbuilding Newport News Shipbuilding (NNS), a division of Huntington Ingalls Industries, is the largest industrial employer in Virginia, and sole designer, builder and refueler of United States Navy aircraft carriers and one of two providers of U.S. Navy ...

. The shelters are maintained by a combined effort of Navy divers stationed on the teams and workers of the maintenance company

Oceaneering International Oceaneering International, Inc. is a subsea engineering and applied technology company based in Houston, Texas, U.S. that provides engineered services and hardware to customers who operate in marine, space, and other environments. Oceaneering's ...

. They have expected useful lives of about 40 years each. The first submarine to have an operational dry deck shelter was the , which was fitted with the DDS in 1982 and first deployed with it in 1983. It is deployed on the , the, the :, and the . The ''Ohio''-class SSGNs are capable of supporting dual dry deck shelters.

Marine nationale

Barracuda-class submarine (France) The Barracuda class (or ''Suffren'' class) is a nuclear attack submarine, designed by the French shipbuilder Naval Group (formerly known as DCNS and DCN) for the French Navy. It is intended to replace the s. Construction began in 2007 and the ...

Former DDS-capable submarines

Former US Navy DDS-capable submarines include: : * * : * * * * * * : * * Note: The ''Benjamin Franklin''-class special operations attack submarines were capable of supporting dual dry deck shelters. Five s were also fitted to carry the DDS.

References

{{reflist Submarine components United States Navy SEALs