Advanced SEAL Delivery System

The Advanced SEAL Delivery System (ASDS) was a midget submarine operated by the United States Navy and United States Special Operations Command. It provided stealthy submerged transportation for United States Navy SEALs from the decks of nuclear submarines for use as an insertion platform for covert and clandestine special operations missions. The ASDS was canceled in 2009 due to cost overruns and reliability issues, after the prototype was destroyed in a fire in 2008. The Navy replaced the ASDS with the Dry Combat Submersible (DCS) from Lockheed Martin, which is roughly half the size and became operational in 2023.

ASDS was conceived to address the need for stealthy long-range insertion of special operations forces on covert or clandestine missions. It was designed to replace the wet SEAL Delivery Vehicle (SDV), which exposed combat swimmers to long, cold waits during transit that impeded combat readiness on arrival, limited operational range, and hindered underwater navigational capability. The primary limitation on the SDV's range is not fuel or batteries but water temperature, as Navy SEALs can only stay in cold water for so long, even with wetsuits.

The first study to define the ASDS was performed in 1983. Competitive conceptual designs were developed in the late 1980s, the Request for proposal was issued in 1993, and the first contract for design and construction of the ASDS was awarded in 1994.

The Navy stated a requirement for six boats, but that was established before it decided to convert four Ohio-class ballistic missile submarines to guided-missile submarines (SSGNs) with the additional mission of support of special operations forces. Each SSGN is capable of carrying two ASDS vehicles.

Detailed design of the first ASDS was started in 1994, and hull construction began in 1996, at a cost of $160 million, to a low bid for the delivery of $69 million for the first ASDS (to include non-recurring design costs, fabrication, and testing), and subsequent copies for $25 million each. It was delivered for testing and evaluation in 2000 and cost $300 million, including vendor and program office costs. Subsequent submarines were estimated to cost $125 million each, based on a 2001 estimate. Five more were planned.

The first ASDS became operational (completed testing and evaluation) at Naval Station Pearl Harbor, Hawaii, in 2003, six years behind schedule. From there, it was deployed to the Indian Ocean and Persian Gulf on board Los Angeles-class nuclear attack submarine USS Greeneville, as a unit of Expeditionary Strike Group One. The first ASDS was never joined by other units, as the program was derailed by escalating costs and technical problems. A Congressional Budget Office (CBO) 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 is under way on lithium-ion batteries to replace the silver-zinc batteries and enable the electrical system to meet the Navy's requirements. Yardney Technical Products of Pawcatuck, Connecticut, was awarded a $44 million contract modification to provide four lithium-ion batteries for the ASDS program by May 2009.

In the end, cost, technical, and reliability issues proved insurmountable, and the ASDS was cancelled in 2009.

According to the Government Accountability Office (GAO), the initial $70 million cost-plus contract ended up costing the government $885 million by 2007. Instead of entering service in 2000, as was initially planned, testing continued and the first boat was not delivered until July 2003. Global Security adds that the program was initially projected to cost $527 million over its lifetime, including delivery of all six subs, but by 2003 total program cost was predicted to rise to more than $2 billion—significantly more than the $1.4 billion SSGN Tactical Trident conversion program to which it is related. An independent GAO audit of the program published in 2007 placed the blame for the cost overruns on Northrop Grumman, the prime contractor, for failing to meet their time and cost estimates and on the Navy for accepting the ASDS "as is" and failing to hold Northrop Grumman accountable for cost overruns and delays. After 2000, most of the cost overruns were for cost- and incentives . The Department of Defense endorsed GAO's findings.