The icebreaking tanker S.S.Manhattan made an historic voyage to test the feasibility of using the Artic Northwest Passage as a year round trade route. Humble Oil & Refining Co., the sponsor of the project hoped to prove that the passage can be used by special ships to deliver Arctic oil to U.S. East Coast ports. The cost for this project reached $54-Million. Benefits of an open Polar sea route included increasing U.S. self-sufficiency in oil. The converted Manhattan was well equipped for the task. Even before the modifications, the Manhattan was stronger and more powerful than any ship of its type in the world. Built in 1962 in Bethlehem Steels’ shipyard in Quincy, Mass, the Manhattan is the largest merchant ship ever to fly the American flag and the largest commercial ship ever constructed in the U.S. It’s 43,000 shaft horsepower powerplant is nearly 1-1/2 times more powerful than those on ships twice her size. In addition to size, the Manhattan was highly maneuverable, due to twin five-bladed propellers and twin rudders.
In short, the Manhattan is a one-vessel breed of supertanker, more powerful, and more maneuverable than any similar ship on the seas.
To speed the conversion to a icebreaking tanker, the ship was drydocked at Sun Shipbuilding and Dry Dock Company and cut into four pieces.
The 65-foot forward bow was stored at Sun, to be replaced by a new 125-foot icebreaking bow which was built in two sections. The forward piece was built by Bath Iron Works and the after piece was built by Sun Shipbuilding & Dry Dock Co. The forward section, including the No.1 cargo tank, was towed to Newport News Shipbuilding and Dry Dock Company where it was fitted with a heavy 1-1/2″ thick ice belt to protect the sides of the ship from large floes of ice. The midship section, which included the bridge, was towed to Alabma Dry Dock and Shipbuilding Company where an ice belt, of steel was also fitted. The stern section remained at Sun to be strengthened internally. While the hull work was being carried on, Sun Ship workers were installing additional quaraters, laboratories and electronic gear.
When the hull sections were returned, Sun rejoined them, sealed off most of the cargo tanks (which were used for ballast) and then put the ship through river trials. As completed, the Manhattan has been lengthened from 940 feet to 1,005 feet, widened by 16 feet to 148 feet, and it weight increased by 9,000 tons.
Accompanying the Manhattan, the first commercial vessel to transit the “Top of the World” route, was the U.S. Coast Guard icebreaker Westwind and the Canadian icebreaker John A. McDonald.
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