SHANGHAI'S Waigaoqiao shipyard started construction of China's first self-made deepwater oil drilling platform yesterday.

The so-called sixth generation semi-submersible drilling rig, used in waters up to a depth of over 3,000 meters, is co-designed and constructed by the 708 Research Institute and Shanghai Waigaoqiao Shipbuilding Co, both under the China State Shipbuilding Corp.

The construction of the platform is seen as a key progress for the nation's marine equipment manufacturing industry, experts said.

At a time when similar imported equipment is expensive, the platform plays a key role in supporting China's effort to venture into deep sea to tap increasing oil and gas demand and fast rising prices, a Waigaoqiao Shipbuilding statement said.

"It not only fills the blank in building deepwater drilling platform for China but it also improves our capability in deep sea operations and ocean equipment manufacturing, and uphold our national interests," it added.

The oil rig, classified by American Bureau of Shipping and China Classification Society, is due to be delivered to China National Offshore Oil Corp, at the end of 2010.

The rig, weighing 30,670 tons, has a maximum operating depth of 3,050 meters and a maximum drilling depth of 12,000 meters, it said.

With a designed lifespan of 30 years, the offshore oil production platform can operate normally under wind speed of 45 nautical miles per hour, or 23.15 meters per second, and can still survive winds of 109 nautical mile/hour.