India Looks to Modify Scorpene Subs With MESMA AIP Propulsion

Chilean Scorpene cutaway(click to view full) Back on September 19, 2005, DID offered in-depth coverage of India’s $3.5 billion local-build deal for 6 SSK Scorpene Class ultra-quiet diesel-electric submarines between 2012-1017, as well as the present status and future plans of the rival Chinese and Pakistani submarine programs. Now the Times of India reports that India’s Navy wants the last 3 submarines to include DCN’s MESMA air-independent propulsion (AIP) systems, changing them from CM-2000 to AM-2000 Scorpene designation. What’s MESMA, why does it matter, who else builds AIPs, and how does MESMA compare? The MESMA anaerobic system will change the Scorpene’s ability to operate underwater for sustained periods without having to surface. An AM-2000 is still not in the same league as SSN nuclear subs which can do this indefinitely, but it is a substantial improvement that reduces “indiscretion time” on the surface where the sub can be spotted by radar, and also heard more easily by underwater sensors. A CM-2000 Scorpene can operate underwater for 4-6 days without surfacing or snorkelling to get oxygen to recharge its batteries. An AM-2000 Scorpene, in contrast, will be able to operate for up to 18 days, depending on variables like speed, etc. […]