Located at the front end of the superstructure, the conning tower was a heavily armored cylinder, with tiny slit windows on three sides providing a reasonable field of view.
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.
[4] The RN's analysis of World War I combat revealed that command personnel were unlikely to use an armoured conning tower, preferring the superior visibility of unarmoured bridge positions.
Beginning in the late 1930s, as radar surpassed visual sighting as the primary method of detecting other ships, battleships began reducing or eliminating the conning tower.
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.
To clarify: 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.