A conning tower is a raised platform on a
ship
A ship is a large watercraft, vessel that travels the world's oceans and other Waterway, navigable waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research and fishing. Ships are generally disti ...
or
submarine
A submarine (often shortened to sub) is a watercraft capable of independent operation underwater. (It differs from a submersible, which has more limited underwater capability.) The term "submarine" is also sometimes used historically or infor ...
, often armoured, from which an officer in charge can
conn (conduct or control) the vessel, controlling movements of the ship by giving orders to those responsible for the ship's engine, rudder, lines, and ground tackle. It is usually located as high on the ship as is practical, to give the conning team good visibility of the entirety of the ship, ocean conditions, and other vessels.
The naval term "conn" may derive from the Middle English ''conne'' (study, become acquainted with) or French ''conduire'' from Latin ''conducere'' (conduct).
Surface ships
On surface ships, the conning tower was a feature of all
battleship
A battleship is a large, heavily naval armour, armored warship with a main battery consisting of large naval gun, guns, designed to serve as a capital ship. From their advent in the late 1880s, battleships were among the largest and most form ...
s and
armoured cruiser
The armored cruiser was a type of warship of the late 19th and early 20th centuries. It was designed like other types of cruisers to operate as a long-range, independent warship, capable of defeating any ship apart from a pre-dreadnought battles ...
s from about 1860 to the early years of
World War II
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
. Located at the front end of the
superstructure
A superstructure is an upward extension of an existing structure above a baseline. This term is applied to various kinds of physical structures such as buildings, bridges, or ships.
Aboard ships and large boats
On water craft, the superstruct ...
, the conning tower was a heavily armored cylinder, with tiny slit windows on three sides providing a reasonable
field of view
The field of view (FOV) is the angle, angular extent of the observable world that is visual perception, seen at any given moment. In the case of optical instruments or sensors, it is a solid angle through which a detector is sensitive to elec ...
. Designed to shield just enough personnel and devices for navigation during battles, its interior was cramped and basic, with little more than
engine order telegraphs, speaking tubes or telephones, and perhaps a steering wheel. At all other times than during battles, the ship would be commanded and helmed from the
bridge
A bridge is a structure built to Span (engineering), span a physical obstacle (such as a body of water, valley, road, or railway) without blocking the path underneath. It is constructed for the purpose of providing passage over the obstacle, whi ...
.
Conning towers were used by the French on their
floating batteries at the
Battle of Kinburn.
They were then fitted to the first ironclad .
The first
Royal Navy
The Royal Navy (RN) is the naval warfare force of the United Kingdom. It is a component of His Majesty's Naval Service, and its officers hold their commissions from the King of the United Kingdom, King. Although warships were used by Kingdom ...
(RN) conning tower appeared on which had 3 inches of armour.
In the Royal Navy, the conning tower became a massive structure reaching weights of hundreds of tons on the s (such as ), and formed part of a massive armoured citadel (
superstructure
A superstructure is an upward extension of an existing structure above a baseline. This term is applied to various kinds of physical structures such as buildings, bridges, or ships.
Aboard ships and large boats
On water craft, the superstruct ...
) on the mid-1920s s, which had armour over a foot thick. The , in contrast to the ''Nelson'' class, had comparatively light conning tower protection with sides, front and rear, and roof and deck. The RN's analysis of
World War I
World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...
combat revealed that command personnel were unlikely to use an armoured conning tower, preferring the superior visibility of unarmoured bridge positions. Older RN battleships that were reconstructed with new superstructures had their heavily armoured conning towers removed and replaced with much lighter structures. These new conning towers were also placed much higher in the ship, for superior visibility. There is no evidence that RN captains and admirals used the armoured conning towers on those ships that did have them during World War II, with, for example,
Vice-Admiral Holland and
Captain Kerr commanding ''Hood'' during the
Battle of the Denmark Strait
The Battle of the Denmark Strait was a naval engagement in the Second World War, which took place on 24 May 1941 between ships of the Royal Navy and the ''Kriegsmarine''. The British battleship and the battlecruiser fought the German battlesh ...
from her unarmoured bridge. Even in the
United States Navy
The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 millio ...
(USN), battleship captains and admirals preferred to use the unarmoured bridge positions during combat.
The USN had mixed opinions of the conning tower, pointing out that its weight, high above the ship's center of gravity, did not contribute directly to fighting ability. Beginning in the late 1930s, as
radar
Radar is a system that uses radio waves to determine the distance ('' ranging''), direction ( azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track ...
surpassed visual sighting as the primary method of detecting other ships, battleships began reducing or eliminating the conning tower. The
Naval Battle of Guadalcanal
The Naval Battle of Guadalcanal took place from 12 to 15 November 1942 and was the decisive engagement in a series of naval battles between Allies of World War II, Allied (primarily American) and Imperial Japanese Armed Forces, Imperial Japan ...
during World War II briefly slowed this trend: when the hit on the superstructure, many exposed crewmen were killed or wounded; yet Admiral Lee and Captain Davis of declined to use the armoured conning tower during the battle.
[Musicant, ''Battleship at war'', p118. Captain Davis of and Admiral Lee fought 2nd Guadalcanal from the unarmoured bridges of their battleships. Musicant makes reference to ''South Dakota'' Bridge personnel observing the battle but remains silent on their use of the armoured conning tower.] Soon the heavy battleship conning towers were removed from , , , and during their post-
Pearl Harbor attack
The attack on Pearl HarborAlso known as the Battle of Pearl Harbor was a surprise military strike by the Empire of Japan on the United States Pacific Fleet at its naval base at Pearl Harbor on Oahu, Hawaii, on December 7, 1941. At the ti ...
reconstructions and replaced with much lighter
cruiser
A cruiser is a type of warship. Modern cruisers are generally the largest ships in a fleet after aircraft carriers and amphibious assault ships, and can usually perform several operational roles from search-and-destroy to ocean escort to sea ...
-style conning towers.
By the end of World War II, US ships were designed with expanded weather bridges enclosing the armoured conning towers. On
s, the conning tower is a thick vertical armour-plated cylinder with slit windows located in the middle of the bridge, climbing from the
03 level all the way up to the
flying bridge on the 05 level.
With the demise of battleships after World War II, along with the advent of missiles and nuclear weapons during the
Cold War
The Cold War was a period of global Geopolitics, geopolitical rivalry between the United States (US) and the Soviet Union (USSR) and their respective allies, the capitalist Western Bloc and communist Eastern Bloc, which lasted from 1947 unt ...
, modern warships no longer feature conning towers.
Submarines

Early naval submarines were typically fitted with a small watertight protrusion on top of their hulls, from which the boat's crew could observe their surroundings through a number of viewports.
As larger and larger submarines were made, and eventually fitted with periscopes, this protrusion grew into a small
pressure-hull of its own, typically connected to the control room inside the boat's main pressure-hull via a watertight hatch to mitigate the risk of flooding if the viewports or periscopes were damaged. Thus, the conning tower effectively became the boat's dedicated attack center, from which the commanding officer would command the boat whilst submerged. Some late 1930s designs even located their
hydrophone
A hydrophone () is a microphone designed for underwater use, for recording or listening to underwater sound. Most hydrophones contains a piezoelectric transducer that generates an electric potential when subjected to a pressure change, such as a ...
and
RADAR
Radar is a system that uses radio waves to determine the distance ('' ranging''), direction ( azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track ...
operators' stations inside this compartment to maximize the commander's situational awareness.
In addition to their primary purpose, conning towers also served as elevated attachment points for air intakes,
magnetic compasses, and even collapsible
open air bridges. As conning towers were eventually built large enough that crewmen could comfortably stand on top of them, the collapsible bridges gave way to fixed structures, leading to the development of the so-called "bridge fairwater". To clarify:
* The conning tower is the small watertight compartment above the control room, from which the boat's commanding officer would command the boat during submerged attacks.
* The bridge was built on top of—but not considered part of—the conning tower, and was used for surfaced navigation and signalling.
* The fairwater is a streamlined casing around the conning tower and/or around the bridge. The tapering aft end of this casing also provided a sheltered location for the boat's air intakes, as well as an elevated base for various
AA gun (anti-aircraft) platforms.
In the post-1950s era, an increased focus on deep submerged operation, together with improvements in technology that allowed periscopes to be made longer, removed the need for a raised conning station. (laid down 1956) was the last US submarine to have a conning tower, after which the conning tower's function as an attack center was integrated into the
control rooms of subsequent designs.
References
External links
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Watercraft components
Submarine design