Contibutor Mode The following was posted on a discusion site concerning AIP Boats in 2005. (Link Below). It appears that an effective defence or solution has yet to be found by Surface or SSN units to this threat. A Google search on "Independent Submarine Propulsion" throws up loads of interesting sites. For an Island State set on a continental shelf we need this type of weapon. Quote USN countering AIP -------------------------------------------------------------------------------- Navy US Navy Trains To Operate Against AIP Submarines Posted by vkthakur on Friday, March 25, 2005 (EST) The introduction of Air Independent Propulsion (AIP) in conventional submarines has dramatically altered the equation in submarine warfare. The introduction of Air Independent Propulsion (AIP) in conventional submarines has dramatically altered the equation in submarine warfare. AIP equipped submarines can operate submerged for several weeks, not just days, allowing them to pose challenges that were earlier associated only with nuclear powered submarines. Before the advent of AIP it was easy for the US to track pinpoint and target conventional submarines. Radar and Ocean Surviellance satellites could provide the general location since these vessels had to periodically surface in order to recharge their batteries by running their diesel engines. Once the general location of a conventional submarine is known, pinpointing and targetting it is relatively easy - send in an ASW aircraft like the P-3 Orion. AIP works by allowing submarines to run their diesel engines submerged using stored oxygen in a closed cycle. An alternate form of AIP permits the submarine to operate its electric motors on energy produced by fuel cells. AIP equipped submarines can operate submerged for several weeks. The use of AIP in combination with advances in weaponry and propulsion allows an increasing number of nations to threaten US shipping in littoral environment. Control of littoral environments is essential to ensuring prompt access for joint forces moving ashore from the sea. US Navy Hones Its ASW Skills The US Navy, preoccupied by strike tasks and no more challenged by the over 300 submarines that the erstwhile Soviet Union used to field, has in the recent past been lax in ASW training. According to JINSA, in 2002 during the biennial RIMPAC, exercises involving the navies of the U.S., South Korea, Canada, Japan, Chile, Peru, and Australia, an Australian Collins-class diesel-electric submarine was able to score multiple kills against two U.S. Los Angeles-class nuclear-powered attack submarines. The Los Angeles-class attack submarine USS Alexandria (SSN 757) pulls into Goa, India, during Exercise Malabar 04. The U.S. Navy and the Swedish navy signed a Memorandum of Understanding March 21 that will begin a bilateral training effort, providing a Swedish advanced diesel submarine and crew for U.S. Navy fleet anti-submarine warfare (ASW) training. The Swedish navy will provide a Gotland-class air independent propulsion (AIP) submarine, for the U.S. Navyâ€™s long-term use. ASW training will be conducted from San Diego and attached to Submarine Squadron 11. The Swedish submarine will be Swedish-flagged, commanded, manned and operated. U.S. Navy personnel will be aboard the Swedish submarine as riders and observers for training purposes. The U.S.-Swedish effort will focus on acoustic analysis performance of fleet operators aboard all ASW platforms; theater, carrier/expeditionary strike group, unit-level ship, aviation squadron and submarine levels ASW performance assessments against standardized, common metrics; individual student ASW training and qualifications; and overall theater undersea warfare capability. Gotland Class Submarines Gotland Class Submarine The Stirling engines fitted on the Gotland Class Submarines burn pure oxygen and diesel fuel in a pressurized combustion chamber. The combustion pressure is higher than the surrounding seawater pressure, thereby allowing the exhaust products, dissolved in seawater, to be discharged overboard without using a compressor. Oxygen is stored in liquid form (LOX) in cryogenic tanks. Submerged endurance is primarily determined by the amount of stored LOX. The Stirling AIP system is an add-on system. When the LOX supply is exhausted, the submarine remains a powerful conventional submarine. The Stirling AIP system is equally well suited for modernization of existing submarines and for integration into new submarine designs. Â©Vijainder K Thakur AIP.