November 21, 2007: China has been importing the German MTU 396 SE85 diesel engines for nearly a decade. These engines are used to power submarines, specifically the 039A ("Song") class. These 2,000 ton boats are similar to the Russian Kilo class, and are the first modern diesel-electric boats designed and built in China. Nine have been launched and a tenth is under construction. But that only accounts for 30 of the 396 SE85 engines. China has at least a dozen more of those engines, and it's unclear what they are using them for. They might be backup engines for nuclear subs, or for a new class of diesel electric boats. The 039A class had a lot of teething problems, but the Chinese are acquiring lots of valuable experience. And there's a lot of curiosity what the Chinese are doing with all the expensive experience.