South Korea's top three shipyards won stronger-than-expected shipbuilding orders worth over US$30 billion in the first 11 months of the year on strong contracts, industry sources said Sunday.The three -- Hyundai Heavy Industries Co., Daewoo Shipbuilding & Marine Engineering Co. and Samsung Heavy Industries Co. -- clinched orders worth a combined $35.6 billion for ships and marine oil-drilling facilities by the end of November, the sources said.