A marine construction company is working to remove its 250-foot-long, 6,000-ton barge that ran aground on the breakwater near Sachem’s Head last week. The barge, owned by Weeks Marine based in New Jersey, was en route from Electric Boat in Groton, carrying salvage steel from a job there, to its yard in Jersey City when it broke off from a tugboat moving through Long Island Sound during a storm March 31 and crashed into the breakwater near a local yacht club. Weeks was building a pier at Electric Boat for a nuclear submarine, according to the spokesperson. Before the vessel is removed, workers must make sure it won’t sink. When the barge is ready to be moved, two large ocean-going tugs will push the barge off the rocks during high tide, he said.