The National Iron & Steel Heritage Museum
SS Manhattan
Length: 1,005 feet
Beam: 148 feet
Displacement: 115,000 tons
Speed: 17 knots (20mph)
Ice Capacity: 15 feet

History: The SS Manhattan was built as an oil tanker in 1962 and was converted into an icebreaker in 1968-1969.  It was the largest tanker in America and was converted into an icebreaker to sail through the Northwest Passage to Alaska, where an estimated 40 billion barrels of crude oil was discovered under the frozen tundra of the state’s northern slope.  

Lukens Steel Company in Coatesville, PA supplied almost 5,000 tons of steel for the Manhattan’s conversion project.  More than 1,100 tons of Lukens ABS Hull Structural Steel was used to strengthen the ship’s forward section and 286 tons of plate for the bow section.  The new bow featured design techniques that increased the Manhattan’s icebreaking abilities up to 60%.  It lifted the ship up onto the ice, allowing the weight of the ship to break through it.  Lukens plates were also used in the “ice belts” that were placed around the hull for the protection from ice floes.

The SS Manhattan successfully became the first commercial vessel in history to fully navigate the Northwest Passage to Alaska in 1969.  Her success was due to the converted icebreaker bow and added ice belt reinforcements, all made with Lukens steel.  During the passage, the Manhattan was able to break through ice as thick as 15 feet.  The ship returned home with two holes in its side, a part that was not modified for ice.  Lukens then supplied additional steel to repair those holes.  The Manhattan remined in service until 1987 and then was scrapped.

Photograph: SS Manhattan during a Northwest Passage transit, date unknown.  (Source: United States Government)