- Dry deck shelters transformed the mission of U.S. military submarines.
- The DDS is a large room where SEALs are launched from underwater for missions.
- The photo shows underwater special operations facilitated by a dry deck shelter.
Dry deck shelters on U.S. military submarines play a critical role in naval operations, turning hidden ship hunters into mother ships for Navy SEAL raids.
Photos show special operations facilitated by dry deck shelters, such as launching Navy SEALs more efficiently and covertly in submersibles.
A Dry Deck Shelter (DDS for short) is a long cylindrical lockout module installed on the deck of a U.S. Navy submarine near the sail.
Before DDS, a small airtight compartment called a lockout trunk could accommodate only one diving pair and trunk operator at a time. The process of pressurizing the chamber for just two divers took him as long as 10 minutes, greatly hampering efficiency and making the submarine vulnerable to attack if an entire squadron had to be deployed. Ta.
In the 1960s, the USS Greyback, a once decommissioned diesel-electric submarine, was returned to active service to improve inefficiencies.
After Greyback was decommissioned in 1964, the submarine was repurposed four years later, with empty hangar bays converted to dry and wet compartments for storing equipment and launching divers and SEAL transport vehicles, respectively. Ta.
Greyback's modified missile bay streamlined special operations, making it easier to quickly and covertly deploy platoons. This design was later adopted for what became his DDS.
The DDS is approximately 9 feet tall and wide by 38 feet long and can carry approximately 30 tons of displacement, in addition to the submarine's displacement.
It is large enough to accommodate an entire crew of Navy SEALs, divers, a rubber boat called a Combat Rubber Raiding Craft (CRRC), and even an underwater vehicle known as a SEAL Delivery Vehicle (SDV). .
SEAL transport vehicles provide underwater propulsion for transporting small teams and their weapons and equipment over long distances, reducing the chance of detection if they are in small boats.
The SDV is a small, freely submersible submersible that can carry up to six SEALs for transportation. SEALs in combat gear breathe either through compressed air through underwater breathing apparatus or through an internal life support system aboard the SDV.
Excerpts from a then-classified 1952 report on “underwater swimmers” emphasized the importance of SDV in special operations on submarines, stating that they were “used in areas near enemy-controlled coasts in the absolute secrecy possible. Whenever it is necessary to conduct operations in the water, the target must be made underwater.”
According to the report, “The first part of the approach could be made by fleet-type submarines, but these 1,500-ton vessels cannot operate in water shallower than 60 feet, and depths less than 150 feet are considered dangerous. It is said that “The final underwater entry must be made by swimming or in a small submersible.”
The DDS consists of three compartments: a high-pressure operating bay, a transfer trunk, and a lockout chamber.
The hyperbaric chamber at the front of the DDS is used to treat injured combat divers.
A centrally located transfer trunk serves as an entryway for equipment and personnel to other rooms in the DDS and the rest of the submarine.
The aft lockout chamber operates similarly to Greyback's refurbished hangar and is used to rapidly position and deploy divers, SDVs, and CRRCs.
All three chambers of the DDS are constructed from HY-80 military grade steel with glass fiber reinforced plastic, and each chamber can withstand at least 130 feet of water pressure. The dry deck is filled with water for diver access.
Expected useful life is at least 40 years.
Many submarines are specially equipped with DDS. In 1982, the Sturgeon-class attack submarine USS Cavalla was the first submarine to be equipped with DDS. Other vessels in the class equipped with DDS include the USS Silverside, William H. Bates, Tunney, and L. Mendel's Reverse.
Two Ethan Allen-class ballistic missile submarines, the Sam Houston and John Marshall, were equipped with DDS, as were the Benjamin Franklin-class Kamehameha and James K. Polk.
The flagships of the Los Angeles class submarines, USS Los Angeles, USS Philadelphia, Dallas, La Jolla, and Buffalo, were capable of carrying DDS. It is also aboard the Seawolf-class attack submarines, the USS Jimmy Carter, and several Virginia-class hulls.
Four ballistic missile submarines, the Ohio-class USS Ohio, Michigan, Georgia, and Florida, were reclassified as guided missile submarines and modified to comply with DDS.
Having one DDS on board a submarine has proven advantageous, but having two is even better.
Until the early 2000s, most submarines equipped with DDS carried only one, but four, USS Sam Houston, USS John Marshall, USS James K. Polk, and USS Kamehameha, were equipped with twin carriers. was.
Kamehameha was the last of the twin carrier submarines to be retired in 2002, leaving the Navy to consider which ship would replace it.
Instead of creating a new group of dual-DDS platforms, the Navy turned to its existing fleet of Ohio-class nuclear-powered ballistic missile submarines (SSBNs).
The 1994 Nuclear Posture Review found that the Navy only needed 14 of the 18 SSBNs, replacing the first four Ohio-class SSBNs with guided missile submarines (SSGNs) that fire long-range Tomahawk attack missiles. ) became possible.
The flagship of the class, Ohio, entered the shipyard in November 2003 to convert its capabilities to SSGN, including a host of DDS.
Ohio's Trident missile launch tubes were repurposed into lockout chambers and equipment storage to accommodate submarines, divers, unmanned vehicles, or Tomahawk ground-attack missiles.
Ohio completed her conversion to SSGN in December 2005 and first deployed two years later in October 2007.
USS Florida was also originally an Ohio-class ballistic submarine and was refitted in 2006. The 560-foot submarine is equipped with four torpedo tubes and up to 154 Tomahawk ground-attack missiles. This is the most for any U.S. warship.
More recently, Florida has become one of the firepowers used by the U.S. military in attacks. against Houthi military targets Last month in Yemen. More than 80 Tomahawks were used as part of the attack against Houthi rebels, but it was not immediately clear how many came from the USS Florida.
Then the strike came repeated warnings of retaliation Attacks on commercial ships in the Red Sea by Iranian-backed rebels.
In addition to Florida and Ohio, USS Michigan and USS Georgia were also converted to guided missile boats.
The glory days of SSGN converts are coming to an end.
In 2021, the Navy announced a 30-year plan to build more than 400 new ships by 2051 and retire 304 current ships, including the Ohio-class SSGN, in the process.
The reclassified submarines are scheduled to be retired between 2027 and 2040, but this could be extended due to potential delays for the Virginia-class Block V nuclear-powered attack submarines that replace them.
The Navy is seeking to modernize its submarine fleet by incorporating more manned and unmanned underwater vehicle operations.
While large UUVs can be launched from land and controlled on long-duration missions, some medium-sized UUVs can only be deployed and recovered in dry deck shelters. This means that the hull installation may remain in the Navy's fleet for a little longer.