Lockheed Shipbuilding and Construction Company (a.k.a. Lockheed Shipbuilding), was a shipyard in Seattle, Washington on Harbor Island at the mouth of the Duwamish River. Founded in 1898 as the Puget Sound Bridge and Dredging Company, the company that built Harbor Island, it was purchased by Lockheed in 1959. The shipyard was permanently closed in 1988. Between 1971 and 1977, Lockheed built two Polar-class icebreakers for the US Coast Guard.