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Beam (nautical)
The beam of a ship is its width at its widest point. The maximum beam (BMAX) is the distance between planes passing through the outer extremities of the ship, beam of the hull (BH) only includes permanently fixed parts of the hull, and beam at waterline (BWL) is the maximum width where the hull intersects the surface of the water. Generally speaking, the wider the beam of a ship (or boat), the more initial stability it has, at the expense of secondary stability in the event of a capsize, where more energy is required to right the vessel from its inverted position. A ship that heels on her ''beam ends'' has her deck beams nearly vertical. Typical values Typical length-to-beam ratios ( aspect ratios) for small sailboats are from 2:1 (dinghies to trailerable sailboats around ) to 5:1 (racing sailboats over ). Large ships have widely varying beam ratios, some as large as 20:1. Rowing shells designed for flatwater racing may have length to beam ratios as high as 30:1, while a cor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ship Length Measurements
A ship is a large watercraft that travels the world's oceans and other sufficiently deep waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research, and fishing. Ships are generally distinguished from boats, based on size, shape, load capacity, and purpose. Ships have supported exploration, trade, warfare, migration, colonization, and science. After the 15th century, new crops that had come from and to the Americas via the European seafarers significantly contributed to world population growth. Ship transport is responsible for the largest portion of world commerce. The word ''ship'' has meant, depending on the era and the context, either just a large vessel or specifically a ship-rigged sailing ship with three or more masts, each of which is square-rigged. As of 2016, there were more than 49,000 merchant ships, totaling almost 1.8 billion dead weight tons. Of these 28% were oil tankers, 43% were bulk carriers, and 13% were con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hull (watercraft)
A hull is the watertight body of a ship, boat, or flying boat. The hull may open at the top (such as a dinghy), 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. General features There is a wide variety of hull types that are chosen for suitability for different usages, the hull shape being dependent upon the needs of the design. Shapes range from a nearly perfect box in the case of scow barges to a needle-sharp surface of revolution in the case of a racing multihull sailboat. The shape is chosen to strike a balance between cost, hydrostatic considerations (accommodation, load carrying, and stability), hydrodynamics (speed, power requirements, and motion and behavior in a seaway) and special considerations for the ship's role, such as the rounded bow of an icebreaker or the flat bottom of a landing craft. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Initial Stability
Initial stability or primary stability is the resistance of a boat to small changes in the difference between the vertical forces applied on its two sides. The study of initial stability and secondary stability are part of naval architecture as applied to small watercraft (as distinct from the study of ship stability concerning large ships). Determination Initial stability is determined by the angle of tilting on each side of the boat as its center of gravity (CG) moves sideways as a result of the passengers or cargo moving laterally, or as a response to an external force (e.g. wave). The wider the boat and the further its volume is distributed away from its center line (CL), the greater the initial stability. Examples Wide mono-hull small boats such as the jon boat have a great deal of initial stability and allow the occupants to stand upright to engage in fishing activities, and so do narrower small boats such as W-kayaks that feature a twin hull. Very narrow mono-hull b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Stability
Secondary stability, also known as reserve stability, is a boat or ship's ability to right itself at large angles of heel (lateral tilt), as opposed to primary or initial stability, the boat's tendency to stay laterally upright when tilted to low ( The study of initial and secondary stability are part of naval architecture as applied to small watercraft (as distinct from the study of ship stability concerning large ships). A greater lateral width (beam) and more initial stability decrease the secondary stability- once tilted more than a certain angle the boat is conversely harder to restore to its stable upright position. Other types of ship stability * Primary stability * Tertiary stability (also called inverse stability): Tertiary stability is undesirable as it causes a vessel to remain upside-down. Self-righting watercraft have negative tertiary stability, and no limit of positive stability. For kayak rolling, the stability of an upside-down kayak is also important; lower ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capsizing
Capsizing or keeling over occurs when a boat or ship is rolled on its side or further by wave action, instability or wind force beyond the angle of positive static stability or it is upside down in the water. The act of recovering a vessel from a capsize is called righting. Capsize may result from broaching, , loss of stability due to cargo shifting or flooding, or in high speed boats, from turning too fast. If a capsized vessel has enough flotation to prevent sinking, it may recover on its own in changing conditions or through mechanical work if it is not stable inverted. Vessels of this design are called self-righting. Small vessels In dinghy sailing, a practical distinction can be made between being knocked down (to 90 degrees; on its beam-ends, figuratively) which is called a capsize, and being inverted, which is called being turtled. Small dinghies frequently capsize in the normal course of use and can usually be recovered by the crew. Some types of dinghy are occasi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heeling (sailing)
Sailing employs the wind—acting on sails, wingsails or kites—to propel a craft on the surface of the ''water'' (sailing ship, sailboat, raft, windsurfer, or kitesurfer), on ''ice'' (iceboat) or on ''land'' (land yacht) over a chosen course, which is often part of a larger plan of navigation. From prehistory until the second half of the 19th century, sailing craft were the primary means of maritime trade and transportation; exploration across the seas and oceans was reliant on sail for anything other than the shortest distances. Naval power in this period used sail to varying degrees depending on the current technology, culminating in the gun-armed sailing warships of the Age of Sail. Sail was slowly replaced by steam as the method of propulsion for ships over the latter part of the 19th century – seeing a gradual improvement in the technology of steam through a number of stepwise developments. Steam allowed scheduled services that ran at higher average speeds than sail ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Racing Shell
In watercraft, a racing shell (also referred to as just a ''fine boat'' (UK) or just ''shell'') is an extremely narrow, and often comparatively long, rowing boat specifically designed for racing or exercise. It is outfitted with long oars, outriggers to hold the oarlocks away from the boat, and sliding seats. The boat's long length and semicircular cross-section reduce drag to a minimum. This makes the boat both fast and unstable. It must be balanced by the rowers to avoid tipping. Being able to balance – or "set" – the boat while putting maximum effort into the oars is therefore an essential skill of sport rowing. History The racing shell evolved from the simple working rowboat. Boats with longer hulls and narrower in beam were developed in the early 19th century specifically for team racing. These dedicated boats were the first boats that could be called racing shells, and they evolved into the highly specialized forms used today. Riggers A narrower boat provides a sharper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coracle
A coracle is a small, rounded, lightweight boat of the sort traditionally used in Wales, and also in parts of the West Country and in Ireland, particularly the River Boyne, and in Scotland, particularly the River Spey. The word is also used of similar boats found in India, Vietnam, Iraq, and Tibet. The word ''coracle'' is an English spelling of the original Welsh , cognate with Irish and Scottish Gaelic , and is recorded in English text as early as the sixteenth century. Other historical English spellings include ''corougle'', ''corracle'', ''curricle'' and ''coricle''. Structure The structure is made of a framework of split and interwoven willow rods, tied with willow bark. The outer layer was originally an animal skin such as horse or bullock hide (corium), with a thin layer of tar to waterproof it – today replaced by tarred calico, canvas, or fibreglass. The Vietnamese/Asian version of the coracle is made of interwoven bamboo and made water proof by using resin and coconu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volvo Open 70
The Volvo Open 70 (sometimes referred to as a Volvo Ocean 70) is the former class of racing yachts designed for the Volvo Ocean Race. It was first used in the 2005–06 race (replacing the Volvo Ocean 60 yachts which were first used in 1993). According to the VO70 rule, the yachts can be made from glass fibres, aramid fibres, or carbon fibres (which were not allowed for VO60s). It uses a canting keel which is capable of canting transversely up to an angle of 40 degrees. The Volvo Open 70 is not a singular yacht design or boat but rather a set of design rules to which competing boats must adhere. This is similar to the concept to the design and construction rules that define a racing car. Competing teams design and build boats within the scope of this rule to try and come up with the fastest boat for the expected conditions of the race. Version 2 of the VO70 rule which ''“has been further developed to apply the lessons learned on the last event and ensure the continuing evol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seawaymax
The term Seawaymax refers to vessels which are the maximum size that can fit through the canal locks of the St. Lawrence Seaway, linking the inland Great Lakes of North America with the Atlantic Ocean. Seawaymax vessels are in length, wide, and have a draft of and a height above the waterline of . A number of lake freighters larger than this size cruise the Great Lakes and cannot pass through to the Atlantic Ocean. The size of the locks limits the size of the ships which can pass and so limits the size of the cargoes they can carry. The record tonnage for one vessel on the Seaway is 28,502 tons of iron ore while the record through the larger locks of the Great Lakes Waterway is 72,351 tons. Most new lake vessels, however, are constructed to the Seawaymax limit to enhance versatility by allowing the possibility of off-Lakes use. See also * Canso Canal The Canso Canal is a short canal located in Nova Scotia, Canada. Canal location The Canso Canal is in the Strait of Ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nautical Terminology
This glossary of nautical terms is an alphabetical listing of terms and expressions connected with ships, shipping, seamanship and navigation on water (mostly though not necessarily on the sea). 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". Further information on nautical terminology may also be found at Nautical metaphors in English, and additional military terms are listed in the Multiservice tactical brevity code article. Terms used in other fields associated with bodies of water can be found at Glossary of fishery terms, Glossary of underwater diving terminology, Glossary of rowing terms, and Glossary of meteorology. This glossary is split into two articles: * terms starting with the letters A to L are at Glossary of nautical terms (A-L) * terms starting with the letters M to Z are at Glossary of nautical terms (M-Z). __ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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