A floating battery is a kind of armed watercraft, often improvised or experimental, which carries a heavy armament but has few other qualities as a warship

Warship

A warship is a ship that is built and primarily intended for combat. Warships are usually built in a completely different way from merchant ships. As well as being armed, warships are designed to withstand damage and are usually faster and more maneuvrable than merchant ships...

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An early appearance was during the Great Siege of Gibraltar

Great Siege of Gibraltar

The Great Siege of Gibraltar was an unsuccessful attempt by Spain and France to capture Gibraltar from the British during the American War of Independence. This was the largest action fought during the war in terms of numbers, particularly the Grand Assault of 18 September 1782...

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A purpose-built floating battery was Flådebatteri No. 1, designed by Chief Engineer Henrik Gerner in 1787; it was 47 m long, 13 m wide and armed with 24 guns and used during the 1801 battle of Copenhagen under command of Peter Willemoes

Peter Willemoes

-Biography:Willemoes was born on 11 May 1783 in Assens on the island of Funen, where his father was a public servant. At the age of twelve he was sent to the Naval Academy in Copenhagen, where he was a mediocre student who chafed under and rebelled against the harsh discipline. He became a cadet in...

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The most notable floating batteries were built or designed in the 19th century, and are related to the development of the first steam warship and the ironclad warship

Ironclad warship

An ironclad was a steam-propelled warship in the early part of the second half of the 19th century, protected by iron or steel armor plates. The ironclad was developed as a result of the vulnerability of wooden warships to explosive or incendiary shells. The first ironclad battleship, La Gloire,...

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Demologos

Demologos

Demologos was the first warship to be propelled by a steam engine. She was a wooden floating battery built to defend New York Harbor from the Royal Navy during the War of 1812. The vessel was designed to a unique pattern by Robert Fulton, and was renamed Fulton after his death...

, the first steam-propelled warship, was a floating battery designed for the protection of New York Harbor

New York Harbor

New York Harbor refers to the waterways of the estuary near the mouth of the Hudson River that empty into New York Bay. It is one of the largest natural harbors in the world. Although the U.S. Board of Geographic Names does not use the term, New York Harbor has important historical, governmental,...

 in the War of 1812.

In the 1850s, the British and French navies deployed iron-armoured floating batteries as a supplement to the wooden steam battlefleet in the Crimean War

Crimean War

The Crimean War was a conflict fought between the Russian Empire and an alliance of the French Empire, the British Empire, the Ottoman Empire, and the Kingdom of Sardinia. The war was part of a long-running contest between the major European powers for influence over territories of the declining...

. The role of the battery was to assist unarmoured mortar and gunboats bombarding shore fortifications. The French used their batteries in 1855 against the defenses at Kinburn

Battle of Kinburn (1855)

The Battle of Kinburn/Kil-Bouroun was a naval engagement during the final stage of the Crimean War. It took place on the tip of the Kinburn Peninsula on 17 October 1855...

 on the Black Sea

Black Sea

The Black Sea is bounded by Europe, Anatolia and the Caucasus and is ultimately connected to the Atlantic Ocean via the Mediterranean and the Aegean seas and various straits. The Bosphorus strait connects it to the Sea of Marmara, and the strait of the Dardanelles connects that sea to the Aegean...

, where they were effective against Russian shore defences. The British planned to use theirs in the Baltic Sea

Baltic Sea

The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...

 against Kronstadt

Kronstadt

Kronstadt , also spelled Kronshtadt, Cronstadt |crown]]" and Stadt for "city"); is a municipal town in Kronshtadtsky District of the federal city of St. Petersburg, Russia, located on Kotlin Island, west of Saint Petersburg proper near the head of the Gulf of Finland. Population: It is also...

, and were influential in causing the Russians to sue for peace.

Floating batteries were popularly implemented by both the Union

Union (American Civil War)

During the American Civil War, the Union was a name used to refer to the federal government of the United States, which was supported by the twenty free states and five border slave states. It was opposed by 11 southern slave states that had declared a secession to join together to form the...

 and the Confederacy

Confederate States of America

The Confederate States of America was a government set up from 1861 to 1865 by 11 Southern slave states of the United States of America that had declared their secession from the U.S...

 during the American Civil War

American Civil War

The American Civil War was a civil war fought in the United States of America. In response to the election of Abraham Lincoln as President of the United States, 11 southern slave states declared their secession from the United States and formed the Confederate States of America ; the other 25...

. The first was the Confederate Floating Battery of Charleston Harbor

Floating Battery of Charleston Harbor

The Floating Battery of Charleston Harbor was an ironclad vessel that was constructed by the Confederacy in early 1861, a few months before the American Civil War ignited...

, which took an active part in the bombardment of Fort Sumter

Battle of Fort Sumter

The Battle of Fort Sumter was the bombardment and surrender of Fort Sumter, near Charleston, South Carolina, that started the American Civil War. Following declarations of secession by seven Southern states, South Carolina demanded that the U.S. Army abandon its facilities in Charleston Harbor. On...

in April 1861. Experimental ironclad vessels that proved too cumbersome or were underpowered were often converted into floating batteries and posted for river and coastal waterway control.