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A circle is a simple closed shape. It is the set of all points in a plane that are at a given distance from a given point, the centre; equivalently it is the curve traced out by a point that moves so that its distance from a given point is constant. The distance between any of the points and the centre is called the radius. This article is about circles in Euclidean geometry, and, in particular, the Euclidean plane, except where otherwise noted.
HMS Ocelot (S17) was an Oberon-class diesel-electric submarine operated by the Royal Navy.
The angular diameter, angular size, apparent diameter, or apparent size is an angular measurement describing how large a sphere or circle appears from a given point of view. In the vision sciences, it is called the visual angle, and in optics, it is the angular aperture. The angular diameter can alternatively be thought of as the angle through which an eye or camera must rotate to look from one side of an apparent circle to the opposite side. Angular radius equals half the angular diameter.
HMS Onslaught was a British Oberon-class submarine operated by the Royal Navy.
HMS Odin was a British Oberon-class submarine operated by the Royal Navy.
HMS Opportune (S20) was an Oberon-class submarine of the Royal Navy.
The beam of a ship is its width at the widest point as measured at the ship's nominal waterline. The beam is a bearing projected at right-angles from the fore and aft line, outwards from the widest part of ship. Beam may also be used to define the maximum width of a ship's hull, or maximum width including superstructure overhangs.
A rotor ship is a type of ship designed to use the Magnus effect for propulsion. The ship is propelled, at least in part, by large vertical rotors, sometimes known as rotor sails. German engineer Anton Flettner was the first to build a ship which attempted to tap this force for propulsion, and ships using his type of rotor are sometimes known as Flettner ships.
Length between perpendiculars is the length of a ship along the waterline from the forward surface of the stem, or main bow perpendicular member, to the after surface of the sternpost, or main stern perpendicular member. When there is no sternpost, the centerline axis of the rudder stock is used as the aft end of the length between perpendiculars.
HMS Osiris (S13) was an Oberon-class submarine that served in the Royal Navy.
The draft or draught of a ship's hull is the vertical distance between the waterline and the bottom of the hull (keel), with the thickness of the hull included; in the case of not being included the draft outline would be obtained. Draft determines the minimum depth of water a ship or boat can safely navigate. The draft can also be used to determine the weight of the cargo on board by calculating the total displacement of water and then using Archimedes' principle. A table made by the shipyard shows the water displacement for each draft. The density of the water and the content of the ship's bunkers has to be taken into account. The closely related term "trim" is defined as the difference between the forward and aft drafts.
HMS Otter (S15) was an Oberon-class submarine of the Royal Navy.
The stem is the most forward part of a boat or ship's bow and is an extension of the keel itself. It is often found on wooden boats or ships, but not exclusively.
An equator of a rotating spheroid is its zeroth circle of latitude (parallel). It is the imaginary line on the spheroid's surface, equidistant from its poles, dividing it into northern and southern hemispheres. In other words, it is the intersection of the spheroid's surface with the plane perpendicular to its axis of rotation and midway between its geographical poles.
Bulgaria was a 4,191 GRT cargo ship that was built as Empire Flamborough in 1945 by William Pickersgill & Sons Ltd, Sunderland, County Durham, United Kingdom for the Ministry of Transport (MoT). She was sold to Norway in 1946 and renamed Vindeggen. A further sale to Bulgaria in 1948 saw her renamed Bulgaria. She served until 1976 when she was scrapped.
Type 991 cable layer is a family of Chinese cable layers first saw service in Chinese navy, and later on, additional units also entered service with Chinese civilian authorities.
Empire Florizel was a 7,056 GRT cargo ship that was built in 1943 by Lithgows, Greenock, Renfrewshire, United Kingdom for the Ministry of War Transport (MoWT). She had a short career, being bombed and sunk during the Allied invasion of Sicily exactly three months after her launch.
M O P 223-C was a 2,588 GRT suction hopper dredger that was built in 1946 by William Simons & Co Ltd, Renfrew, United Kingdom as Empire Forager for the Ministry of War Transport (MoWT). She was sold in 1949 to the Argentinian Government and renamed M O P 229-C. She was renamed La Descanisada later that year and then renamed M O P 223-C in 1958, serving until she was scrapped in 1976.
