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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. [1]
On water craft, the superstructure consists of the parts of the ship or a boat, including sailboats, fishing boats, passenger ships, and submarines, that project above her main deck. This does not usually include its masts or any armament turrets. Note that, in modern times, turrets do not always carry naval artillery. They can also carry missile launchers and/or antisubmarine warfare weapons.
The size of a watercraft's superstructure can have many implications in the performance of ships and boats, since these structures can alter their structural rigidity, their displacements, and/or stability. These can be detrimental to any vessel's performance if they are taken into consideration incorrectly.
The height and the weight of superstructure on board a ship or a boat also affects the amount of freeboard that such a vessel requires along its sides, down to her waterline. In broad terms, the more and heavier superstructure that a ship possesses (as a fraction of her length), the less the freeboard that is needed.
The span of a bridge, the portion that directly receives the live load, is referred to as the superstructure. In contrast, the abutment, piers, and other support structures are called the 'substructure'. [2]
In order to improve the response during earthquakes of buildings and bridges, the superstructure may be separated from its foundation by various civil engineering mechanisms or machinery. All together, these implement the system of earthquake protection called base isolation.
Structural engineering is a sub-discipline of civil engineering in which structural engineers are trained to design the 'bones and joints' that create the form and shape of human-made structures. Structural engineers also must understand and calculate the stability, strength, rigidity and earthquake-susceptibility of built structures for buildings and nonbuilding structures. The structural designs are integrated with those of other designers such as architects and building services engineer and often supervise the construction of projects by contractors on site. They can also be involved in the design of machinery, medical equipment, and vehicles where structural integrity affects functioning and safety. See glossary of structural engineering.
A sailboat or sailing boat is a boat propelled partly or entirely by sails and is smaller than a sailing ship. Distinctions in what constitutes a sailing boat and ship vary by region and maritime culture.
A monitor is a relatively small warship that is neither fast nor strongly armored but carries disproportionately large guns. They were used by some navies from the 1860s, during the First World War and with limited use in the Second World War.
HMS Captain was a major warship built for the Royal Navy as a semi-private venture, following a dispute between the designer and the Admiralty. With wrought-iron armour, steam propulsion, and the main battery mounted in rotating armoured turrets, the ship was, at first appearance, quite innovative and formidable. However, poor design and design changes resulted in a vessel that was overweight and ultimately unstable. In terms of seaworthiness she was reported as closely comparable to the higher freeboard turret-ship HMS Monarch, but her reduced freeboard added a sense of "sluggishness". The Captain capsized in heavy seas, only five months after being commissioned, with the loss of nearly 500 lives.
The Kearsarge-class was a group of two pre-dreadnought battleships built for the United States Navy in the 1890s. The two ships—USS Kearsarge and USS Kentucky—represented a compromise between two preceding battleship designs, the low-freeboard Indiana class and the high-freeboard USS Iowa, though their design also incorporated several improvements. Their primary advances over earlier designs consisted of new quick-firing guns and improved armor protection, but their most novel feature was their two-story gun turrets that consisted of a secondary 8-inch (203 mm) gun turret fixed to the top of their primary 13-inch (330 mm) turrets. The ships suffered from a number of problems, however, including a tertiary battery mounted too low in the hull and poorly-designed turrets, though the latter were attempted again with the Virginia class in the early 1900s, also with negative results.
HMS Hood was a modified Royal Sovereign-class pre-dreadnought battleship built for the Royal Navy in the early 1890s. She differed from the other ships of the class in that she had cylindrical gun turrets instead of barbettes and a lower freeboard. She served most of her active career in the Mediterranean Sea, where her low freeboard was less of a disadvantage. The ship was placed in reserve in 1907 and later became the receiving ship at Queenstown, Ireland. Hood was used in the development of anti-torpedo bulges in 1913 and was scuttled in late 1914 to act as a blockship across the southern entrance of Portland Harbour after the start of World War I.
The County class was a class of heavy cruisers built for the Royal Navy in the years between the First and Second World Wars. They were the first 'post-war' cruisers constructed for the Royal Navy and were designed within the limits of the Washington Naval Treaty of 1922. Such ships, with a limit of 10,000 tons standard displacement and 8-inch calibre main guns may be referred to as "treaty cruisers".
A deck is a permanent covering over a compartment or a hull of a ship. On a boat or ship, the primary or upper deck is the horizontal structure that forms the "roof" of the hull, strengthening it and serving as the primary working surface. Vessels often have more than one level both within the hull and in the superstructure above the primary deck, similar to the floors of a multi-storey building, that are also referred to as decks, as are certain compartments and decks built over specific areas of the superstructure. Decks for some purposes have specific names.
Turret ships were a 19th-century type of warship, the earliest to have their guns mounted in a revolving gun turret, instead of a broadside arrangement.
This glossary of nautical terms is an alphabetical listing of terms and expressions connected with ships, shipping, seamanship and navigation on water. Some remain current, while many date from the 17th to 19th centuries. The word nautical derives from the Latin nauticus, from Greek nautikos, from nautēs: "sailor", from naus: "ship".
A gun turret is a mounting platform from which weapons can be fired that affords protection, visibility and ability to turn and aim. A modern gun turret is generally a rotatable weapon mount that houses the crew or mechanism of a projectile-firing weapon and at the same time lets the weapon be aimed and fired in some degree of azimuth and elevation.
The bow is the forward part of the hull of a ship or boat, the point that is usually most forward when the vessel is underway. The aft end of the boat is the stern.
Earthquake engineering is an interdisciplinary branch of engineering that designs and analyzes structures, such as buildings and bridges, with earthquakes in mind. Its overall goal is to make such structures more resistant to earthquakes. An earthquake engineer aims to construct structures that will not be damaged in minor shaking and will avoid serious damage or collapse in a major earthquake. A properly engineered structure does not necessarily have to be extremely strong or expensive. It has to be properly designed to withstand the seismic effects while sustaining an acceptable level of damage.
HMS Glatton was a breastwork monitor which served in the Victorian Royal Navy.
A trunk deck ship is a type of merchant ship with a hull that was stepped inward in order to obtain more favourable treatment under canal toll rules then in effect. As those tolls were set by net tonnage, a measure of volume, and as the tonnage rules did not account for all of the cargo space of such vessels, trunk deck ships incurred lower tolls than more conventional ships of equivalent capacity. When the measurement rules were changed, this ship type was no longer built.
Hoche was an ironclad battleship built as a hybrid barbette–turret ship for the French Navy in the 1880s. Originally designed in response to very large Italian ironclads along the lines of the French Amiral Baudin class, by the time work on Hoche began, changes in French design philosophy led to a radical re-design that provided the basis for a generation of French capital ships. Her armament was reduced in size compared to the Amiral Baudins, and was placed in the lozenge arrangement that would be used for most French capital ships into the 1890s. Hoche suffered from serious stability problems that resulted from her large superstructure and low freeboard, which required extensive work later in her career to correct. The ship incorporated new technologies for the French Navy, including gun turrets for some of her main battery guns and compound armor plate.
Ground–structure interaction (SSI) consists of the interaction between soil (ground) and a structure built upon it. It is primarily an exchange of mutual stress, whereby the movement of the ground-structure system is influenced by both the type of ground and the type of structure. This is especially applicable to areas of seismic activity. Various combinations of soil and structure can either amplify or diminish movement and subsequent damage. A building on stiff ground rather than deformable ground will tend to suffer greater damage. A second interaction effect, tied to mechanical properties of soil, is the sinking of foundations, worsened by a seismic event. This phenomenon is called soil liquefaction.
In the Eurocode series of European standards (EN) related to construction, Eurocode 8: Design of structures for earthquake resistance describes how to design structures in seismic zone, using the limit state design philosophy. It was approved by the European Committee for Standardization (CEN) on 23 April 2004. Its purpose is to ensure that in the event of earthquakes:
This glossary of nautical terms is an alphabetical listing of terms and expressions connected with ships, shipping, seamanship and navigation on water. Some remain current, while many date from the 17th to 19th centuries. The word nautical derives from the Latin nauticus, from Greek nautikos, from nautēs: "sailor", from naus: "ship".
