The concrete reinforced with steel bars attracted a considerable attention from shipbuilders at the beginning of its invention. The first reinforced concrete boat was tested 163 years ago in France.

The gardener’s invention

The first reinforced concrete was invented not by a builder or a shipbuilder but by a simple gardener in Paris Joseph Monier (1823-1906). He looked for stable substances to create better pots for palms and accidentally created what today is called reinforced concrete. He patented the invention, but later sold the copyrights at the first opportunity and lost the chance to make huge profits.

Another French engineer, Joseph Lambo (1814-1887), remembering Archimedes’s principle, lowered the gardener’s invented pot into the water. Convinced that it is sailing, the inventor made a small boat out of concrete and in 1848 demonstrated his invention to the audience of French seaside town of Toulon. Under the recommendation of the town’s prefect, Lambo’s boat was demonstrated at the World Exhibition of Paris in 1855 and received an interest of industry.

The boat has remained until our days and is kept at the inventor’s hometown, Brinjol Museum. At the end of nineteenth century, one might say, that the building of concrete ships began. Before the First World War, they were massively built in England, Germany, the Netherlands, Norway and California, U.S.

The novelty was attracting because of its economy. Concrete was relatively inexpensive, while steel consumption in such a ship’s construction process was significantly lower than of the full constructed steel-hulled vessel. Using the same molds, cheaper costs were achieved. However, such ships did not have maneuverability and were used only in the inland waters.

The ships which did not make it to the war

The first maritime self-propelled concrete vessel was created by Norwegian Nicholas Frougner. In 1917, 2 August, he lowered into the water, 30 meter long steamer Namsenfjord. His body was made of three inch (7.62 cm) thick concrete, reinforced with wire mesh. Soon, the Norwegian fjords saw five of these vessels.

During the years of the First World War, the reduced metal stocks and rise in their prices, forced the President of the United States, Thomas Woodrow Wilson to approve the program, whereby 24 war ships of reinforced concrete had to be built. Only 12 of these vessels were lowered into the water, after the war in Europe ended.

In March, 1918, the first American concrete steamer Faith started to be used. Nearly 100 meter long ship could accommodate more than six thousand tons of cargo and two steam engines could reach the speed up to 17 knots. A year later, the biggest American concrete tanker Selma was lowered into the water, its length being 129 meters. Both of these vessels were built in California and successfully sailed on long voyages, reaching Honolulu, Hawaii islands, South American ports of Callao, Valparaiso, via Panama Canal and returned safe to the Eastern Coast of the U.S.

After the war, when the prices of metal dropped, all twelve concrete warships were sold out to private companies. They were used in place of warehouse, piers and breakwaters. Some of the debris of these ships is still visible in some of the U.S. shores.

Again to war

At the beginning of the Second World War, due to the scarcity of metal, reinforced concrete was remembered again. The U.S. started building concrete ships in 1943 in Philadelphia. Reinforced concrete technology has been visibly improved. New concrete ships were lighter and stronger than their predecessors in the First World War.

The construction took place at a rapid rate. Six thousand workers were working for Philadelphia shipyard and were able to lower into the water one such ship per month. It was landing party and cargo ships, barges and floating marina. They were used in the Pacific and Atlantic oceans for military munitions and troops. The soldiers called them flying gravestones. Prone to mine or torpedoed such ship would sink instantly like a stone.

Concrete barges played a decisive role in the Allied Landing in Normandy. They transported munitions and troops; they were also used for marina and barrier against German ships. Concrete ships were also used by Nazi Germany. In Third Reich in 1942, the special committee for the concrete shipbuilding was created in order to oversee the shipbuilding in Riugenvalde (now the Polish city of Darlowo). Here, the reinforced concrete tankers were built.

After the war, the remaining concrete ships were used. Large, thick-boarded ships required powerful engines and a huge amount of fuel and lacked agility. Some of them became hotels, restaurants and other marinas, jetties or breakwaters.

A treat for enthusiasts

Today, large concrete ships are not built. One research institute still considers such an opportunity. Small concrete barges can be seen in the Dutch canals and in other European countries.

There are many enthusiasts around the world, who make concrete boat and yacht hulls. It is cheaper and easier to produce a stable boat. Miami based Hartley & Brooks Association produces and sells concrete boats and yachts. The American Society of Civil Engineers organizes annual concrete canoe competition since 1960. The participants, mostly university students, launch their designed boats and race them. It is said that a few decades ago, a sports enthusiast in Klaipeda has tried or even built a small concrete boat.