SOCOM's Dry Combat Submersible prompting safer US LIB Development

Lockheed Martin's S302 Dry Combat Submersible (DCS) intentionally dull locking to promote stealth (Artwork courtesy H I Sutton's Covert Shores)
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STOP PRESS

Since I wrote the article below (in June 2016)

-  See this August 10, 2016 Popular Mechanics article indicating that the latest Dry Combat Submersible (DCS) is less stealthy than older models because the DCS can only be lowered from a surface ship rather than attached to a submarine.  

-  StrategyPage, August 2, 2016, reports :

"SOCOM has ordered three of these [Dry Combat Submersibles] for $55.4 million each. Each DSC can carry a crew of two and six SEALs and their equipment. Max depth is 100 meters (320 feet) and max speed is nine kilometers an hour". 

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JUNE 2015 ARTICLE

I have re-written this article as the route I suggested of emulating the Russian all features Losos-Piranha diesel mini-sub took the debate far away from the battery only submersibles the US has been developing. The US seems determined to develop submarine Lithium-ion Batteries (LIBs).

The SOCOM Dry Combat Submersible (DCS) Program is seeking, new, efficient, safe LIBs with a low risk of catching fire. See General Atomics' updates at the end of this article.

Problem - SEALS (called Clearance Divers elsewhere) and other special forces (even, the odd, non-military, Agent) become tired in WET submersibles where they have to wear and breathe scuba gear. The water can also be freezing making them cold and even more exhausted before they hit the beach

A DRY submersible has occasionally been seen as a solution but having quiet, long enough range, propulsion has been a major technical obstacle. Also the occupants of a DRY submersible may still need to change into some WET gear to transition from submersible to beach. All this may leave DRY submersibles a comparatively low priority for the USN, with much likely riding on new, efficient and safe Lithium-ion Batteries. 

DRY submersible programs need to compete with the USNs already well developed WET swimmer delivery vehicles for divers/SEALS wearing scuba gear. See Submarine Matters article Navy SEAL and Submarine Capabilities of August 18, 2014.

Reading https://en.wikipedia.org/wiki/Advanced_SEAL_Delivery_System  a DRY submersible was developed from studies in 1984 until problems became too great by 2009

-  Along the way a "study issued in 2003 cited two major technical problems: noisy propellers and silver-zinc batteries that depleted more quickly than planned. A new propeller made of composite material [was] developed to rectify the noise problem. Development [was] under way on lithium-ion batteries to replace the silver-zinc batteries and enable the electrical system to meet the navy's requirements [by 2006] however, technical, reliability, and cost issues [proved practically] insurmountable."

-  Then a prototype was "damaged in a "serious fire" in November 2008 [which ended that DRY program] As of December 2008 the cause of the fire is yet to be determined."

Pete's Comment - It may well be that use of not yet fully developed LIBs was at the root of the fire.

A US Defense Department document of 2011 indicates the US requirement revived (or continued) in 2011 for a battery powered dry submersible - see http://www.dtic.mil/ndia/2011SOFIC/Wed1515Rms22_23Armstrong.pdf  

The requirement as at 2016 seems to have shifted from the USN main carriage to US Special Operations Command (SOCOM). There may be a two finalist runoff for a 10 meter long DRY submersible, called the SOCOM bland User Operational Evaluation System (UOES). Finalists may be General Dynamics Electric Boat vs Lockheed Martin, each working with a three-year, $44 million SOCOM firm-fixed price design, build and deliver contract. A requirement includes carriage of up to six people. 

- On June 10, 2016 Scout Warrior reported on the General Dynamics Electric Boat bid, GD-EB is working with Italy’s Giunio Santi Engineering (GSE) given Italy's lengthy record of building devastingly effective mini-subs and diver delivery vehicles. 

and

- on June 7, 2016 H I Sutton/Covert Shores, discusses the Lockheed Martin S302 Dry Combat Submersible (DCS) design

 Ideally DRY and WET submersibles can fit into dry deck shelter (DDS) that sits on a submarine back behind the sail/fin of large submarines. A large SSN may be required for DDS/decompression chamber assembly above. I wonder if Australia's future Shortfin would be large enough? (Diagram courtesy HI Sutton/Covert Shores)

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I've pieced together some details of the LIB specs likely to apply to the SOCOM Dry Combat Submersible. A 2005 reference indicated: For "Class 8" (2 pilots + 6 special forces) submersible "...it will apparently be eleven metres long, propelled by two eight-kW motors and powered by a lithium-ion battery. This will give a range of 50 nautical miles (93 km) at five knots, with a maximum speed of six knots."  

A September 3, 2013 report from Military Aerospace repeated similar specs to the 2005 reference, with "USSOCOM officials are interested in dry combat submersibles that can move at speeds of at least five knots, at depths to 200 feet, with provisions for two pilots. [earlier indicating] Officials of the Naval Surface Warfare Center in Crane, Ind., have awarded a $12.5 million contract to General Atomics for lithium ion batteries to be used on the Dry Combat Submersible program of…SOCOM at MacDill Air Force Base, Fla."

On April 13, 2016 GovConWire reported: "TYSONS CORNER, VA, April 13, 2016 - General Atomics‘Lithium-ion Fault Tolerant battery technology has been certified by Det Norske Veritas Germanischer Lloyd after it completed tests aboard an undersea vehicle of the U.S. Special Operations Command, ExecutiveBiz reported Tuesday."

Two days earlier, on April 11, 2016 General Atomics Electromagnetic Systems (GA-EMS)  reported:
""Unlike prior Lithium-ion battery technologies, GA-EMS' LiFT battery system offers a single cell fault tolerance to prevent uncontrolled cascading failure.  This means the battery is capable of surviving a catastrophic cell failure without propagating to neighboring cells, ensuring the safety of on-board personnel and equipment," stated Paul Clark, senior manager responsible for LiFT program at GA-EMS."

So the US is clearly developing LIBs for, at least, DRY delivery submersible use. Whether the US will have LIBs as backup batteries on its SSNs and new SSBNs is a mystery. 

There seems to be no pictures of GA's LiFT batteries available...

See a subsequent Business Insider article of July 27, 2016.

Pete