Reveal made at vSOFIC 2020
James Smith, Acquisition Executive for United States Special Forces Command (USSOCOM) stated at virtual SOFIC 2020 (virtual because of the COVID-19 Shelter-in-Place) that the Dry Combat Submersible (DCS) is close to twelve months from Initial Operating Capability (IOC) for USSOCOM’s U.S. Navy SEALs.
According to U.S. Navy Lt. Cmdr. Tim Hawkins, a spokesman for U.S. Special Operations Command, “IOC is a major production and development milestone where an initial level of capability will be achieved for the submersible’s deployment and operation by trained personnel.” LCDR Hawkins confirmed via phone that IOC will be for just one DCS undergoing sea trails and testing at this time.
USSOCOM’s Dry Combat Submersible Overview
For decades, the U.S. Navy SEALs have primarily used “wet” SEAL Delivery Vehicles (SDV) midget submarines where the passenger compartment is flooded to the temperatures and operational environmental conditions of the waters outside and the riders have to wear SCBA masks for breathing. To address SOCOM’s emphasis on BioTechnology and special forces Operators’ overall health and well-being, having a submersible with a pressurized dry interior allows for better Operator endurance, especially, for example, in the colder waters such as the Arctic. USSOCOM has tried fielding a dry combat submersible before with the Advanced Seal Delivery System, canceled in 2006.
Torpedo-shaped, the DCS should keep SEALs dry during transit, bolstering their endurance and readiness rate before they reach the DCS’s transit objective area and emerge out of the DCS to deploy “wet” by swimming to the target area. Obviously, many details of the United Kingdom’s MSubs Ltd™ (Marlin Submarines LtdM) designed and manufactured S351 “Nemesis,” which SOCOM DCSs are based off of, are classified; however some open source information can be ascertained.
S351 “Nemesis” Specifications (which the USSOCOM DCS is based off of):
• Length: 12 meters (39 feet). Height: 2.4 meters (7.9 feet)
• Weight: 14 tons (31,000 lbs) fully loaded
• Displacement: 28 tons (62,000 lbs)
• Shipping size: Transportable in a 40-foot shipping container
• Crew: two–a pilot and a co-pilot/navigator
• Passengers: Eight fully-equipped SEALs
• Interior Environment: All pressurized “dry” (not flooded “wet”) with three sections: forward compartment transport for SEAL passengers, amidships swimmer Lock-in/Loc-out trunk, and aft command section for pilot and co-pilot. (USSOCOM declined comment on if the interiors are lighted and heated).
• Performance:
o Diving depth: 100 meters (330 feet)
o Range: 60 nautical miles (110 KM, 69 miles) with Lithium-ion (longer with aluminum-seawater)
o Speed: 5 knots (9.3 KM/Hr, 5.8 MPH). Maximum speed: Classified
o Endurance: greater than 24 hours (Classified range with aluminum-saltwater batteries (USSOCOM specific))
▪ Triple the range of SEAL Delivery Vehicle and twice that of Shallow Water Combat Submersible (potential of up to ten times the range with aluminum-saltwater batteries)
• Sensors:
o Inertial navigation and Doppler Velocity Log
o Sonar and fathometer
o Underwater telephone and UHF radio
o Two sensor masts
o Terrain-Following/Terrain-Avoidance sonar (USSOCOM specific)
o Radio Frequencies Countermeasures sensor and library (USSOCOM specific)
According to officials at vSOFIC, additional USSOCOM-specific sensors include Terrain-following, Terrain-avoidance sonar capability (useful for hugging coastal cliffs, islands, and continental shelfs), low acoustic and thermal signature, and “Radio Frequency countermeasures” which officials defined as an onboard computer possessing a library of threat radar signatures that the DCS can identify and track according to radar band, position, and type. Such RF countermeasures would be very helpful when penetrating a coastline undetected and for avoiding surface water search radars.
Located behind an asterisk tailfin controls at the stern, the DCS uses a shrouded propeller with pinwheel curved fins (similar to the current large submarine propellers) to avoid cavitation while pop-out thrusters provide pinpoint navigation and hovering on station. Graphic renderings show two extendable masts, one probably a zoom electro-optical digital camera periscope and the other a communications antenna and electronic sensor. The bow sonar appears to be arc-shaped for as close to 180 or even 270-degree sonar coverage and appears to be accessible from the front for servicing and future upgrades. Crew entry is through a retractable accordion tower over two roof hatches and a diver’s lockout door at the side.
Mr. Smith also stated that USSOCOM is in the process of exploring the next-generation of future Dry Combat Submersibles besides the S351 “Nemesis” Dry Combat Submersible. S351 “Nemesis” is just one of the mini submersible models offered by the MSubs Ltd. company with the other model versions larger and capable of carrying more passengers.
A Cheaper, Safer, and Lighter Form of DCS Battery Power
The first DCS with LiFT (Lithium-ion Fault Tolerant) battery system was accepted by USSOCOM on April 21, 2020. General Atomics Electromagnetic Systems is providing LiFT long-lifecycle batteries to power the propulsion and internal support systems of DCS. Nonetheless, Lithium-ion batteries are inherently dangerous and are known to catch fire and explode, thus preventing their transportation via air freight. Lithium-ion batteries are also considered heavy and expensive.
At vSOFIC, Mr. James Smith added that USSOCOM worked with Massachusetts Institute of Technology’s (M.I.T.) Open Water Power™ startup on aluminum-seawater batteries that are exposed to the ocean and corrode during transit. In theory, MIT’s batteries are capable of powering submersibles up to ten times the range of normal Lithium-ion batteries. (Open Water Power has since been purchased by L3 Harris Technologies Corporation around 2017 although USSOCOM still keeps in contact with M.I.T.).
“The power system consists of an alloyed aluminum anode, an alloyed cathode, and an alkaline electrolyte positioned between the electrodes. Components are only activated when flooded with water. Once the aluminum anode corrodes, it can be replaced at low cost.”
The aluminum-seawater battery can, in theory, change the range for an Unmanned Underwater Vehicle (UUV) from hundreds to even a thousand miles by just feeding off seawater as the fuel oxidizer. The aluminum batteries split the pulled seawater into aluminum hydroxide where it interacts with an aluminum anode to create electrons, powering the DCS. Both the aluminum hydroxide and hydrogen gas are jettisoned to the waters as harmless waste. Thus, an SOCOM DCS outfitted with aluminum-seawater batteries can travel safely from shore without having to be maintained at sea by submarine tenders or support ships. This is important because the United Kingdom-manufactured DCS was engineered and designed to be lowered from a crane aboard a surface ship. With a battery range of around 60 miles, a surface ship could easily be spotted off an enemy’s coastline, not particularly clandestine. With aluminum-seawater batteries using the open ocean as “fuel,” the DCS’s range could be extended to hundreds to even a thousand miles offshore until SOCOM can perfect delivering and launching the new DCSs from a stealthy U.S Navy submarine.
“Lithium-ion batteries are huge for us and we’re working hard to get them approved for use,” said Captain Kate Dolloff, PEO Maritime at vSOFIC 2020. PEO Maritime is working with various government and U.S. Defense agencies to get them aboard SOCOM vessels from submersibles to surface combat boats. Mr. Smith, USSOCOM PEO Acquisitions, revealed that SOCOM has spent $4.4 million to improve special forces’ battery technology in efforts to drive SOCOM’s focus on improving signature reduction, survivability, and sustainability.
