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2 May 2024 — “Floating Bathtubs”?—When the US Government Turned to Concrete Ships

In the Department of Concrete Construction of the Emergency Fleet Corporation… no doubts are held up as to the practicability of the concrete ship. The men there believe thoroughly in the proposition; they are filled with enthusiasm at the thought that, at a dramatic and crucial time in the history of the world, they are to make a revolutionary contribution to the cause of democracy—one that may be an important factor in the turning of the scales against autocracy.

—The New York Times, 21 April 1918

Concrete ships? The idea of concrete vessels wasn’t new, of course. As far back as 1848, Frenchman Joseph-Louis Lambot built two concrete dinghies, one of which he later presented at the 1855 World’s Fair. He submitted his patent application for ferciment (ferrocement) in 1852, describing it as the result of a process where “a metal net of wire or sticks which are connected or formed like a flexible woven mat” is covered with “hydraulic cement or similar bitumen tar or mix, to fill up the joints." Sporadic experiments with the technology followed, such as the Dutch concrete sloop Zeemeuw (“Seagull”) of 1877, and a handful of other vessels around Europe as well as the Panama Canal. In the US the concept of a concrete ship took hold when the country entered the First World War and it suddenly needed new ships to serve and supply its armed forces, but that same need had driven up the demand for skilled manpower and materials such as steel. 

“Just a year ago the first concrete ship of commercial size was launched here and was christened the ‘Faith.’ Shipping men, and particularly structural engineers say that perhaps no ship ever was the subject of so many skeptical forecasts while being built and previous to operation than this. Yet these men declare the name was a happy one and that the faith of her builders has been justified.” 

—The Billings Gazette, 23 March 1919 SS Faith. PD

Rudolph J. Wig of the Government Bureau of Standards, who was charged with investigating the viability of concrete ships when the US entered the war, told the New York Times about the selling points of the “crockery ships”: ”Concrete ships can be built in much larger numbers than ships of steel or wood, mainly because the concrete vessels do not require a large plant installation and because the material is readily available. Even a small steel plant costs $500,000. On the other hand, a cement ship plant can be built for $15,000. It may be made so as to be portable. The principal machinery required is a mixer, a hoist, and a derrick.” The labor skills required to build the ships—carpentry to build the wooden molds, and concrete mixing/pouring—were different from those in demand in a steel shipyard, so the concrete plants were able to draw from a less-scarce workforce. A concrete ship, while incorporating a steel reinforcement mesh, still used about 35 percent less steel than a ship of traditional construction. 

President Woodrow Wilson’s Emergency Fleet program commissioned the construction of 24 concrete ships, which would serve as cargo ships or oil tankers. The program also ordered barges, water tankers, car floats, river boats and a few other miscellaneous craft using the concrete process. The steamer SS Faith was launched in March of 1918, but none of her sisters would be completed before the war’s end. Eventually, however a dozen of them were completed and were sold into private ownership. Some served as cargo carriers and oil tankers, and over the years some individual ships were converted to a rum-runner’s floating liquor warehouse, a hotel, and a dance club. Many were eventually scrapped as breakwaters or piers. When the Armistice led to a renewed abundance of steel for ship construction, the concrete option was pretty much forgotten. 

Concrete barges produced by Barrett and Hilp shipyard. PD

That is, of course, until the US entered into World War II, and the cycle began again—the country needed a lot of new ships in a hurry, and steel production and skilled labor were again an issue. The David O. Saylor was the first self-propelled concrete ship built in the US during the war, and its captain reported that she was maneuverable, experienced less pitching and rolling in a high sea, and could generally hold her own against her steel cousins. The Saylor and SS Vitruvius took part in the Normandy invasion, as part of a fleet of aging and/or damaged vessels that would be sunk to form a breakwater and landing piers in support of the operation. The US government contracted for a total of 24 self-propelled ships as well as concrete barges, which were often used as supply vessels. After the war, however, the US saw no need to keep its “bathtub fleet,” and again many of them were sunk as breakwaters. 

The river boat General D. H. Rucker served the US Army until a fire in 1937 destroyed her superstructure; the final report on the craft found that the cost for her hull maintenance and repair for her 18 years of service had been a total of $35. Even when you convert that today’s dollars, for a cost of $760, that is still a bargain! Image: PD

While we probably won’t see mass production of concrete ships again, it remains an interesting project for hobbyists. The American Society of Civil Engineers, for example, holds an annual concrete canoe competition, which they like to call the “America’s Cup of Civil Engineering.” We’d like to think that the competitors in that contest today are carrying on the tradition of the “crockery ships” of the last century.

Extra Credit

“100 Years and Counting: The SS Palo Alto”

Sea History Today is written by Shelley Reid, NMHS senior staff writer. Past issues can be read online by clicking here.