Sponsons are projections extending from the sides of land vehicles, aircraft or watercraft to provide protection, stability, storage locations, mounting points for weapons or other devices, or equipment housing.
Sponsons are projections extending from the sides of land vehicles, aircraft or watercraft to provide protection, stability, storage locations, mounting points for weapons or other devices, or equipment housing.
On watercraft, a sponson is a projection that extends outward (usually from the hull, but sometimes other parts of the vessel) to improve stability while floating, or to act as a securing point for other equipment. Vessels with unstable body shapes or unevenly distributed weight are likely to feature sponsons to help prevent capsizing or other instabilities. On many vessels, these projections from the main body of the vessel can be attached and removed quickly and fairly easily. [1]
Canoes and kayaks sometimes feature sponson attachments as well, for stability in rough waters. These differ from outriggers, which extend a significant distance away from the body of the craft, and are employed on craft designed for open waters. A sponson's terminus is close to the craft, thereby allowing the boat to maneuver through narrower spaces, and so is more likely to be used on smaller craft that still require maneuverability through narrow passages. [1]
In the mid-1990s, advances in sponson design made sponsons a tool for better handling at high speeds, and they began being added to racing boats. [2]
There are essentially three types of sponsons for watercraft available on the market today—the basic block type, the hooked or winged type, and the paddle or rudder type. [2]
The block type is the simplest type. The leading end is usually rounded or pointed for reduced drag. "Its main function is to provide additional lift on the back of the hull, mostly during acceleration. It can also help provide better side-to-side stability at speed and reduce porpoising by providing a bit more hull surface at the rear of the craft." [2]
Winged or hooked sponsons are the most common type. In addition to added lift during acceleration, better side-to-side stability, and reduced porpoising, they provide improved handling. "The outside edge provides grip in turns, allowing you to turn sharper and faster without fear of the back end sliding out. They can also provide a pivot point for the hull in turns." One of the most overlooked benefits of this type of sponson is that riders can lean into turns more, making watercraft easier to push to their limits. [2]
Paddle or rudder-type sponsons, which use a flat paddle-shaped rudder attached vertically to a block-type sponson, do essentially the same thing, but the effect can be even more dramatic, because the flat paddle or rudder portion of the sponson provides a sharper and more pronounced edge to catch the water. [2]
On flying boats—as first patented by Claudius Dornier and first used on the Kaiserliche Marine 's German World War I flying boat, the Zeppelin-Lindau Rs.IV [3] [4] —a sponson can help extend the hull higher in the water, reducing drag and providing additional lift when the plane is taking off.
Helicopters may also feature one or more sponsons, and though most helicopters are not designed to land in or take off from water, these safety features are important should the aircraft crash land in water. Sponsons on a helicopter can also store fuel or landing gear, [1] e.g., the Sikorsky S-92 and the Bell 222. When mounted on aircraft, they must be adjusted properly for aerodynamics when the aircraft is in flight; if they are not adjusted properly, the aircraft might become unstable or damage to the aircraft might occur. [1]
On land vessels, such as tanks or other military vehicles, and on naval warships, a sponson may refer to a mounting or enclosure projecting from the side or top of the structure/hull that is not used for buoyancy, but for armaments such as machine guns, or for purposes of visibility. In the case of warships of the late 19th to early 20th centuries, the sponson could be enclosed and combined with a casemate, similar to those of early British heavy tanks. Alternatively, a sponson could be open-topped for a pivoting gun (which could be fitted with a backless blast shield or unshielded). Often a collapsing bulwark would be mounted around the edge of an sponson to improve seaworthiness. Later examples of open-topped sponsons on warships were even used to mount fully-enclosed turrets upon and were sometimes combined with an embrasure of the hull. It can be used for storage as well as a transport platform for people entering or leaving the vehicle. [1] It may also provide layers of bulletproof protection and storage space, as found over the tracks of the Bradley Fighting Vehicle.
A hull is the watertight body of a ship, boat, submarine, or flying boat. The hull may open at the top, or it may be fully or partially covered with a deck. Atop the deck may be a deckhouse and other superstructures, such as a funnel, derrick, or mast. The line where the hull meets the water surface is called the waterline.
A kayak is a small, narrow human-powered watercraft typically propelled by means of a long, double-bladed paddle. The word kayak originates from the Greenlandic word qajaq.
A propeller is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon a working fluid such as water or air. Propellers are used to pump fluid through a pipe or duct, or to create thrust to propel a boat through water or an aircraft through air. The blades are shaped so that their rotational motion through the fluid causes a pressure difference between the two surfaces of the blade by Bernoulli's principle which exerts force on the fluid. Most marine propellers are screw propellers with helical blades rotating on a propeller shaft with an approximately horizontal axis.
Naval architecture, or naval engineering, is an engineering discipline incorporating elements of mechanical, electrical, electronic, software and safety engineering as applied to the engineering design process, shipbuilding, maintenance, and operation of marine vessels and structures. Naval architecture involves basic and applied research, design, development, design evaluation (classification) and calculations during all stages of the life of a marine vehicle. Preliminary design of the vessel, its detailed design, construction, trials, operation and maintenance, launching and dry-docking are the main activities involved. Ship design calculations are also required for ships being modified. Naval architecture also involves formulation of safety regulations and damage-control rules and the approval and certification of ship designs to meet statutory and non-statutory requirements.
A skeg is a sternward extension of the keel of boats and ships which have a rudder mounted on the centre line. The term also applies to the lowest point on an outboard motor or the outdrive of an inboard/outboard. In more recent years, the name has been used for a fin on a surfboard which improves directional stability and to a movable fin on a kayak which adjusts the boat's centre of lateral resistance. The term is also often used for the fin on water skis in the U.S. It has been used for the vertical fin on seaplane hulls and floats. The wear-bar on the bottom of snowmobile ski may also be called a skeg.
A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, airship, or other vehicle that moves through a fluid medium. On an airplane, the rudder is used primarily to counter adverse yaw and p-factor and is not the primary control used to turn the airplane. A rudder operates by redirecting the fluid past the hull or fuselage, thus imparting a turning or yawing motion to the craft. In basic form, a rudder is a flat plane or sheet of material attached with hinges to the craft's stern, tail, or after end. Often rudders are shaped so as to minimize hydrodynamic or aerodynamic drag. On simple watercraft, a tiller—essentially, a stick or pole acting as a lever arm—may be attached to the top of the rudder to allow it to be turned by a helmsman. In larger vessels, cables, pushrods, or hydraulics may be used to link rudders to steering wheels. In typical aircraft, the rudder is operated by pedals via mechanical linkages or hydraulics.
A runabout is any small motorboat holding between four and eight people, well suited to moving about on the water. Characteristically between 20' and 35' in length, runabouts are used for pleasure activities like boating, fishing, and water skiing, as a ship's tender for larger vessels, or in racing. Some common runabout types are bow rider, center console, cuddy boat and walkaround. The world's largest runabout, Pardon Me, is 48 feet long and owned by the Antique Boat Museum in Clayton, New York.
A warship or combatant ship is a ship that is built and primarily intended for naval warfare. Usually they belong to the armed forces of a nation. As well as being armed, warships are designed to withstand damage and are typically faster and more maneuverable than merchant ships. Unlike a merchant ship, which carries cargo, a warship typically carries only weapons, ammunition and supplies for its crew. Warships usually belong to a navy, though they have also been operated by individuals, cooperatives and corporations.
A watercraft or waterborne vessel is any vehicle designed for travel across or through water bodies, such as a boat, ship, hovercraft, submersible or submarine.
Landing gear is the undercarriage of an aircraft or spacecraft that is used for taxiing, takeoff or landing. For aircraft it is generally needed for both. It was also formerly called alighting gear by some manufacturers, such as the Glenn L. Martin Company. For aircraft, Stinton makes the terminology distinction undercarriage (British) = landing gear (US).
An inflatable boat is a lightweight boat constructed with its sides and bow made of flexible tubes containing pressurised gas. For smaller boats, the floor and hull are often flexible, while for boats longer than 3 metres (9.8 ft), the floor typically consists of three to five rigid plywood or aluminium sheets fixed between the tubes, but not joined rigidly together. Often the transom is rigid, providing a location and structure for mounting an outboard motor.
The Zodiac Milpro Futura Commando 470 or in short FC470 Combat Rubber Raiding Craft (CRRC), also known as the "Combat Rubber Reconnaissance Craft," is a specially fabricated rubber inflatable boat often used by the U.S. Navy, U.S. Marine Corps, the U.S. Army, and others. The CRRC is typically called "Zodiac," referring to the boat's manufacturer, Zodiac Milpro.
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.
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".
Outrigger boats are various watercraft featuring one or more lateral support floats known as outriggers, which are fastened to one or both sides of the main hull. They can range from small dugout canoes to large plank-built vessels. Outrigger boats can also vary in their configuration, from the ancestral double-hull configuration (catamarans), to single-outrigger vessels prevalent in the Pacific Islands and Madagascar, to the double-outrigger vessels (trimarans) prevalent in Island Southeast Asia. They are traditionally fitted with Austronesian sails, like the crab claw sails and tanja sails, but in modern times are often fitted with petrol engines.
Ship stability is an area of naval architecture and ship design that deals with how a ship behaves at sea, both in still water and in waves, whether intact or damaged. Stability calculations focus on centers of gravity, centers of buoyancy, the metacenters of vessels, and on how these interact.
The Zeppelin-Lindau Rs.II was a biplane flying boat, designed by Claudius Dornier as a follow-on to his Zeppelin-Lindau Rs.I and built during 1914–1915 on the German side of Lake Constance. Initially this aircraft was powered by three engines mounted inside the hull driving three pusher propellers via gearboxes and shafts. The later version was powered by four engines in two push-pull nacelles mounted between the wings.
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".
This glossary defines the various types of ships and accessory watercraft that have been used in service of the United States. Such service is mainly defined as military vessels used in the United States Navy and United States Coast Guard, as well as the defunct, incorporated, or renamed institutions such as the United States Revenue Cutter Service. Service of the United States can also be defined in this context as special government missions in the form of expeditions, such as the Wilkes Expedition or the North Pacific Exploring and Surveying Expedition. The scope of the glossary encompasses both the "Old Navy" of the United States, from its beginnings as the "Continental Navy", through the "New Navy" and up to modern day. The watercraft included in the glossary are derived from United States ships with logbooks published by the National Archives and Records Administration.