Beijing’s state television shows off a Russian-made attack submarine.

A news report on Chinese state television provided a rare look inside one of the submarines of the Chinese Navy. The Kilo-class submarine was purchased from Russia during the 1990s and is the tip of Beijing’s spear in its disputes with neighbors.

The People’s Republic of China bought twelve 636-class submarines in the 1990s and early 2000s. The submarines, known as the “Kilo” class to NATO, were originally designed by the Soviet Union to operate in Cold War European coastal waters. After the fall of the USSR and the end of the Warsaw Pact, the 636 class became a useful means for Russia to earn hard currency, and the submarines were exported to China, Algeria, India, Iran, and Vietnam.

The 636 class is fairly small by modern standards, just 238 feet long by 32 feet wide. They displace 3,076 tons submerged, less than half that of an American nuclear attack submarine. The subs are powered by diesel engines that allow them to move at speeds of up to 10 knots on the surface and 17 knots underwater. They have a maximum operating depth of 984 feet, but normally dive to a maximum of 787 feet.

The 636 class excels in two areas: silence and shallow water operations. Nicknamed “Black Holes” by the U.S. Navy, their teardrop hulls reduce water resistance and offer a huge leap over China’s older Ming class diesel electric subs. The 636’s propulsion plant is isolated on a rubber base to prevent vibrations from being picked up by enemy submarine hunters. Each ship is covered from bow to stern with rows of rubber tiles that deaden sound. A pair of ducted props powered by low-speed motoring motors allow it to operate closer to the sea floor, a useful feature when operating in shallow water.

http://www.popularmechanics.com/military/navy-ships/a24068/china-submarine-636/