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.
An early appearance was in 1782 at the Great Siege of Gibraltar, and
its invention and usage is attributed to Spanish Lieutenant General
A purpose-built floating battery was Flådebatteri No. 1, designed
by Chief Engineer Henrik Gerner in 1787; it was 47 m
(154 ft) long, 13 m (43 ft) wide and armed with 24
guns, and was used during the 1801 Battle of Copenhagen under the
command of Peter Willemoes. The British made limited use of floating
batteries during the French Revolutionary and Napoleonic Wars, with
the two-vessel Musquito and Firm-class floating batteries, and some
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.
Demologos, the first steam-propelled warship, was a floating battery
designed for the protection of
New York Harbor
New York Harbor 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. 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 on the Black
Sea, where they were effective against Russian shore defences. The
British planned to use theirs in the
Baltic Sea against Kronstadt, and
may have been influential in causing the Russians to sue for peace.
Kronstadt was widely regarded as the most heavily fortified
naval arsenal in the world throughout most of the 19th-century,
continually upgrading its combined defences to meet new changes in
technology. Even as the British armoured-batteries were readied
Kronstadt in early 1856, the Russians had already constructed
newer networks of outlying forts, mortar batteries of their own, and
submarine mines against which the British had no system for removing
Floating batteries were popularly implemented by both the Union and
the Confederacy during the American Civil War. The first was the
Confederate Floating Battery of Charleston Harbor, which took an
active part in the bombardment of Fort Sumter 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. Here too, Civil War batteries
and even ironclads such as the famed monitors, were acutely vulnerable
to mines protected in turn by forts. As a result, the combined
defences of Charleston, South Carolina, for example, were never
overwhelmed by the Union Navy.
United States floating battery Demologos
^ Orlogsbasen (JPEG), DK .
^ Lambert A., "Iron Hulls and Armour Plate"; Gardiner, Steam, Steel