The legendary ocean liner S.S. United States was in the news today when it was announced that the preservationist group S.S. United States Conservatory will officially become the owner of the ship, buying it for $3 million from cruise-line operator NCL Group. The ship, which hasn’t sailed since 1969, has bounced from from owner to owner during that 40 year period with suggested uses ranging from making her into a floating hotel, a dormitory for Alaskan oil-field workers, a tourist attraction, and casino. NCL most recently bought the ship in 2003 with plans to refurbish her for cruises around Hawaii thinking that the 9-11 terror attacks would increase demand for cruises close to U.S. waters. After almost six years of study and delays, the company finally abandoned plans and recently looked to sell the ship for scrap.
But for those who aren’t aware of the United States’ rich lineage, it was considered an engineering marvel and truly innovative in design at the time of its launch. On its maiden voyage on July 4, 1952, United States demolished the transatlantic speed record previously held for the the past 14 years by Queen Mary – averaging over 40 mph for the passage. It then broke the westbound crossing record on her return trip back to America.
While United States four massive steam turbine engines played a key role in breaking the speed record, it was the ship’s use of materials was the real innovation. According to Edward R. Crews of American Heritage, the use of aluminum was the key:
To keep the ship’s weight down, the builders used a great deal of aluminum, about twenty-two hundred tons, the most in any structure on earth or sea at the time. Most of this lightweight metal went into the superstructure, but it also found its way into furniture, lifeboats, handrails, and even the lifeboat oars. Aluminum wasn’t always easy to work with. Where it made contact with steel, which was used in the hull, electrolysis could occur and eat away at the aluminum. Engineers insulated the two metals with neoprene, a synthetic rubber, using strips of neoprene tape to separate plates and tubes of the substance in rivet holes. Aluminum not only made the ship lighter but also increased its stability, by reducing its top-heaviness, making the ship both safer and more comfortable in rough waters.
The strongest available steel was used also to save weight. And Gibbs prohibited the use of a heavy deck covering. Teak is a traditional material; Gibbs considered it not only a fire hazard but also too heavy, at ten pounds per square foot once installed.
The United States’s combination of lightness and powerful engines gave her an exceptionally high power-to-displacement ratio, far greater than that of any of her contemporaries.
Here’s the takeaway: While most experts attribute United States‘ superior speed to its massive steam turbines, it was the innovative use of weight-saving aluminum that made the ship significantly lighter with increased stability. These two factors differentiated it from the rest of the competition and paved the way for future ship design – two necessary factors for it to be considered truly innovative.
