(Ferrocement ships require thick hulls, which results in either a larger cross-sectional area that hurts hydrodynamics, or leaves less space for cargo.)
[9][10] The Fougner Concrete Shipbuilding Company, Flushing Bay, New York, reported calculated cost was of $290 per deadweight ton for the Cape Fear (List of shipwrecks in 1920 "10.21 30 October") and the Sapona which they presumably built.
[5] On April 12, 1918, President Woodrow Wilson approved the Emergency Fleet Corporation program which oversaw the construction of 24 ferrocement ships for the war.
[5] Other countries that looked into ferrocement ship construction during this period included Canada, Denmark, Italy, Spain, Sweden[7] and the United Kingdom.
In Europe, ferrocement barges (FCBs) played a crucial role in World War II operations, particularly in the D-Day Normandy landings, where they were used as part of the Mulberry harbour defenses, for fuel and munitions transportation, as blockships,[14] and as floating pontoons.
Some of these vessels survive as abandoned wrecks or sea defenses (against storm surges) in the Thames Estuary including near Rainham Marshes.
One notable wartime FCB, previously beached at Canvey Island, was partially removed in 2003 by the local sailing club, whose land it was on, for fear it was a "danger to children".
[18] From the Charleroi, Pennsylvania, Mail, February 5, 1945: Largest unit of the Army's fleet is a BRL, (Barge, Refrigerated, Large) which is going to the South Pacific to serve fresh frozen foods – even ice cream – to troops weary of dry rations.
[20] Modern hobbyists also build ferrocement boats (ferroboats),[21] as their construction methods do not require special tools, and the materials are comparatively cheap.
The largest collection is at Powell River, British Columbia, 49°51′55″N 124°33′21″W / 49.865238°N 124.555821°W / 49.865238; -124.555821, where a lumber mill uses ten floating ferrocement ships as a breakwater,[24] known as The Hulks.
The Kiptopeke Breakwater in Chesapeake Bay, Virginia, 37°09′51″N 75°59′29″W / 37.164267°N 75.991402°W / 37.164267; -75.991402, is formed by nine sunken concrete ships built in World War II.
[25] SS San Pasqual, a former oil tanker, lies off the coast of Cayo Las Brujas, Cuba, 22°37′24″N 79°13′24″W / 22.623439°N 79.22327°W / 22.623439; -79.22327, where it served as a hotel, then as a base for divers.
The ship was launched the same day Germany signed the Treaty of Versailles, ending the war, so it never saw wartime duty and instead was used as an oil tanker in the Gulf of Mexico.
[2] The SS Palo Alto, a concrete tanker launched on May 29, 1919, was purchased and turned into an amusement pier, and is still visible at Seacliff State Beach, near Aptos, California, 36°58′11″N 121°54′50″W / 36.969704°N 121.913947°W / 36.969704; -121.913947.
[28] The vessel aground in the surf at Shipwreck Beach on the north shore of Lanai, Hawaii is the wreck of YOG-42, 20°55′17″N 156°54′37″W / 20.921299°N 156.910139°W / 20.921299; -156.910139, a concrete gasoline barge built for the US Navy in 1942 and placed in service in 1943.
One of the few concrete ships built for but not completed in time to be used in World War I, the SS Crete Boom, lies abandoned in the River Moy, 54°08′08″N 9°08′18″W / 54.135515°N 9.138452°W / 54.135515; -9.138452 just outside the town of Ballina, County Mayo, Ireland, and is considered of much interest to the area's many tourists.
In the late 1950s Polish authorities decided to lift it and tow it to another location to be converted into swimming pools, but during that operation it began sinking again, so it was abandoned in shallow water, where it has remained since.
Due to the need to deliver necessary raw materials (such as oil, weapons, ammunition, food and drugs) through mined river currents, Adolf Hitler ordered the production of 50 concrete ships for different purposes.