Casing (submarine)
Encyclopedia
The casing of a submarine
is a light metal structure, usually incorporating a deck
, built-up and-over the upper surface of the vessel's pressure hull.
The pressure hull of a submarine is usually cylindrical
and possesses a low freeboard when in the water, which makes walking on the hull when on the surface dangerous in high seas or rough weather. The casing provides a flat, safer, platform for personnel to walk on.
The casing is outside of the pressure hull and free-flooding so is usually perforated with numerous holes, allowing water to enter and trapped air to escape easily, destroying any buoyancy
contributed by the casing and allowing the submarine to submerge with as little delay as possible.
Casings have become superfluous since the end of World War II
as the flow of water through the numerous flood-holes creates noise that may be detected by an enemy using passive sonar
, as well as causing hydrodynamic drag
.
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...
is a light metal structure, usually incorporating a deck
Deck (ship)
A deck is a permanent covering over a compartment or a hull of a ship. On a boat or ship, the primary deck is the horizontal structure which forms the 'roof' for the hull, which both strengthens the hull and serves as the primary working surface...
, built-up and-over the upper surface of the vessel's pressure hull.
The pressure hull of a submarine is usually cylindrical
Cylinder (geometry)
A cylinder is one of the most basic curvilinear geometric shapes, the surface formed by the points at a fixed distance from a given line segment, the axis of the cylinder. The solid enclosed by this surface and by two planes perpendicular to the axis is also called a cylinder...
and possesses a low freeboard when in the water, which makes walking on the hull when on the surface dangerous in high seas or rough weather. The casing provides a flat, safer, platform for personnel to walk on.
The casing is outside of the pressure hull and free-flooding so is usually perforated with numerous holes, allowing water to enter and trapped air to escape easily, destroying any buoyancy
Buoyancy
In physics, buoyancy is a force exerted by a fluid that opposes an object's weight. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus a column of fluid, or an object submerged in the fluid, experiences greater pressure at the bottom of the...
contributed by the casing and allowing the submarine to submerge with as little delay as possible.
Casings have become superfluous since the end of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
as the flow of water through the numerous flood-holes creates noise that may be detected by an enemy using passive sonar
Sonar
Sonar is a technique that uses sound propagation to navigate, communicate with or detect other vessels...
, as well as causing hydrodynamic drag
Drag (physics)
In fluid dynamics, drag refers to forces which act on a solid object in the direction of the relative fluid flow velocity...
.