Бетоннан салынған кемелер тарихы

Ship whose hull is primarily made of concrete
Concrete ships are built primarily with ferrocement (reinforced concrete) hulls, reinforced with steel bars. This contrasts against more traditional materials, such as pure steel or wood. The advantage of ferrocement construction is that materials are cheap and readily available, while the disadvantages are that construction labor costs are high, as are operating costs. (Ferrocement ships require thick hulls, which results in either a larger cross sectional area that hurts hydrodynamics, or leaves less space for cargo.) During the late 19th century, there were concrete river barges in Europe, and during both World War I and World War II, steel shortages led the US military to order the construction of small fleets of ocean going concrete ships, the largest of which was the SS Selma. United States Maritime Administration (MARAD) designation for concrete ships barges was Type B ship. Few concrete ships were completed in time to see wartime service during World War I, but during 1944 and 1945, concrete ships and barges were used to support U. S. and British invasions in Europe and the Pacific. Since the late 1930s, there have also been ferrocement pleasure boats.

The oldest known ferrocement watercraft was a dinghy built by Joseph Louis Lambot in Southern France in 1848. Lambot's boat was featured in the Exposition Universelle held in Paris in 1855. Beginning in the 1860s, ferrocement barges were built in Europe for use on canals, and around 1896, an Italian engineer, Carlo Gabellini, began building small ships out of ferrocement. The most famous of his ships was the Liguria. Between 1908 and 1914, larger ferrocement barges began to be made in Germany, United Kingdom, the Netherlands, Norway and United States. The remains of a British ship of this type, the auxiliary coaster Violette (built 1919), can be seen at Hoo, Kent, England. On August 2, 1917, Nicolay Fougner of Norway launched the first self propelled ferrocement ship intended for ocean travel. This was an vessel of 400 tons named Namsenfjord. With the success of this ship, additional ferrocement vessels were ordered, and in October 1917, the U. S. government invited Fougner to head a study into the feasibility of building ferrocement ships in the United States. 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. Between the world wars, there was little commercial or military interest in concrete ship construction. The reason was that other shipbuilding methods were cheaper and less labor intensive, and other kinds of ships were cheaper to operate. However, in 1942, after the U. S. entered World War II, the U. S. military found that its contractors had steel shortages. Consequently, the U. S. government contracted McCloskey & Company of Philadelphia, Pennsylvania to build 24 self propelled concrete ships. Construction started in July 1943. The shipyard was at Hookers Point in Tampa, Florida, and at its peak, it employed 6,000 workers. The U. S. government also contracted with two companies in California for the construction of concrete barge ships. and as floating pontoons. In 1940, 200 were commissioned to serve as petrol carrying barges. The barges weighed 160 tons and were constructed on the London dockside before being craned into the water by a giant crane.) Two remain in civil use as moorings at Westminster. 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". Local historians disagreed with the club and were displeased with their actions. In 1944 a concrete firm in California proposed a submarine shaped freighter which they claimed could achieve speeds of 75 knots. The war ended any more research into the project. In retrospect many believe the claims were greatly overstated. Concrete barges also served in the Pacific during 1944 and 1945. From the Charleroi, Pennsylvania, Mail, February 5, 1945:

One concrete barge under tow by Jicarilla (ATF 104) was lost off Saipan during a typhoon, and another barge damaged the Moreton Bay Pile Light in Brisbane, but the rest served admirably.

Modern hobbyists also build ferrocement boats , as their construction methods do not require special tools, and the materials are comparatively cheap. Since the 1960s, the American Society of Civil Engineers has sponsored the National Concrete Canoe Competition. In Europe, especially the Netherlands, concrete is still used to build some of the barges on which houseboats are built.

Surviving wartime concrete ships are no longer in use as ships. Several continue in use in various forms, mostly as museums or breakwaters.

The largest collection is at Powell River, British Columbia, , where a lumber mill uses ten floating ferrocement ships as a breakwater, known as The Hulks. The Kiptopeke Breakwater in Chesapeake Bay, Virginia, , is formed by nine sunken concrete ships built in World War II. , a former oil tanker, lies off the coast of Cayo Las Brujas, Cuba, , where it served as a hotel, then as a base for divers. Currently, the San Pasqual is abandoned. The wreckage of (commissioned in 1919, sunk in 1926) is visible off Sunset Beach near Cape May, New Jersey,
The SS McKittrick, launched in 1921 in Wilmington, North Carolina, later became the , a gaming ship off Coronado, California, that ran aground on December 31, 1936. The wreck is periodically exposed by strong storm tides. The vessel aground in the surf at Shipwreck Beach on the north shore of Lanai, Hawaii is the wreck of YOG 42, , a concrete gasoline barge built for the US Navy in 1942 and placed in service in 1943. The wreck is often misidentified as a Liberty ship. The remains of the Col. J. E. Sawyer can be seen near the Yorktown in Charleston Harbor, , South Carolina. The wreckage of the is visible slightly south of Bimini Island in the Bahamas, It is a popular snorkeling site and boating landmark in the area.

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, just outside the town of Ballina, County Mayo, Ireland, and is considered of much interest to the area's many tourists. A concrete barge, the Cretetree, is beached in the harbour of the Isle of Scalpay near Tarbert, Harris, Scotland, It was built by Aberdeen Concrete Ships, and completed in 1919. The Purton Hulks, a collection of vessels intentionally beached at Purton during the first half of the twentieth century as a method to prevent coastal erosion, includes eight ferro concrete barges. A large collection of abandoned concrete barges are seen at River Thames in Rainham, London. During the German occupation of Greece (1942–1944) during World War II, the German Army built 24 concrete cargo vessels for transporting goods to various Greek islands, including Crete. These were constructed in the Perama shipbuilding area of Piraeus. After the war, many of the vessels were used as piers (e. g., in Rafina, ) and breakwaters (e. g., in Agios Georgios, Methana, ). 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. Most were concrete barges made for oil transportation from Romania, and needed raw materials that were driven to the Baltic front. A smaller number of ships was intended for transporting food (specializing in cold storages). The most valuable ships were the specialized ship hospitals, which evacuated seriously wounded and "important" soldiers to German hospitals along rivers.

Several concrete ships were aground on the west beach of Iwo To (Iwo Jima) in Japan, , to make a breakwater by the US forces in 1945. Most of them were broken by typhoons but one was used as a pier. Japan built four concrete ships named Takechi Maru No. 1 to 4 (武智丸) during World War II. After the war, two of them turned into a breakwater in Kure, Hiroshima, .