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Severn-class Lifeboat
The Severn class is the largest lifeboat operated by the Royal National Lifeboat Institution (RNLI). The class, which is long, was introduced in to service in 1996. It is named after the River Severn, the longest river in Great Britain. The lifeboats are stationed at 35 locations around the coasts of the United Kingdom and Ireland and can provide coverage up to out to sea. History In the 1980s the RNLI's fast Arun and Waveney all-weather lifeboats provided coverage out to sea, operating at up to to cover the distance in two hours in good weather. However, the RNLI felt that they needed the capability to extend their coverage to radius, which would require lifeboats with a top speed of . This resulted in the Severn and Trent lifeboats. The prototype Severn was launched in 1991 (ON1179) and was named ''Maurice and Joyce Hardy''. Trials started the following year and lasted until 1998. In 1995, the boat was de-named. Problems were encountered during the trials with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flag Of The Royal National Lifeboat Institution
A flag is a piece of fabric (most often rectangular or quadrilateral) with a distinctive design and colours. It is used as a symbol, a signalling device, or for decoration. The term ''flag'' is also used to refer to the graphic design employed, and flags have evolved into a general tool for rudimentary signalling and identification, especially in environments where communication is challenging (such as the maritime environment, where semaphore is used). Many flags fall into groups of similar designs called flag families. The study of flags is known as "vexillology" from the Latin , meaning "flag" or "banner". National flags are patriotic symbols with widely varied interpretations that often include strong military associations because of their original and ongoing use for that purpose. Flags are also used in messaging, advertising, or for decorative purposes. Some military units are called "flags" after their use of flags. A ''flag'' (Arabic: ) is equivalent to a briga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chine (boating)
A chine in boat design is a sharp change in angle in the cross section of a hull. The chine typically arises from the use of sheet materials (such as sheet metal or marine ply) as the mode of construction. Rationale of chines Using sheet materials in boat construction is cheap and simple, but whereas these sheet materials are flexible longitudinally, they tend to be rigid vertically. Examples of steel vessels with hard chines include narrowboats and widebeams; examples of plywood vessels with hard chines include sailing dinghies such as the single-chined Graduate and the double-chined Enterprise. Although a hull made from sheet materials might be unattractively "slab-sided", most chined hulls are designed to be pleasing to the eye and hydrodynamically efficient. Hulls without chines (such as clinker-built or carvel-built vessels) usually have a gradually curving cross section. A hard chine is an angle with little rounding, where a soft chine would be more rounded, but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rathlin Island
Rathlin Island ( ga, Reachlainn, ; Local Irish dialect: ''Reachraidh'', ; Scots: ''Racherie'') is an island and civil parish off the coast of County Antrim (of which it is part) in Northern Ireland. It is Northern Ireland's northernmost point. Geography Rathlin is the only inhabited offshore island of Northern Ireland, with a steadily growing population of approximately 150 people, and is the most northerly inhabited island off the coast of the island of Ireland. The reverse-L-shaped Rathlin Island is from east to west, and from north to south. The highest point on the island is Slieveard, above sea level. Rathlin is from the Mull of Kintyre, the southern tip of Scotland's Kintyre peninsula. It is part of the Causeway Coast and Glens council area, and is represented by the Rathlin Development & Community Association. Townland Rathlin is part of the traditional barony of Cary (around the town of Ballycastle), and of current district Moyle. The island constitutes a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MMSI
A Maritime Mobile Service Identity (MMSI) is effectively a maritime object's international ''maritime telephone number'', a temporarily assigned UID, issued by that object's current flag state, (unlike an IMO, which is a global forever UID). An MMSI comprises a series of nine digits, consisting Maritime Identification Digits(country-codes), concatenated with a specific identifier. Whenever an object is re-flagged, a new MMSI must be assigned. A 'maritime object' could be anything which requests an MMSI identifier. e.g. a vessel, fixed offshore installation, mobile unit, maritime aircraft, coast station, etc. Communications may be routed to 'individual objects', or to 'groups of objects'. A group call to objects can be based on an object's - locale, owner/operator/fleet, type, etc. or combinations thereof. MMSI are formed in such a way that the identity or part thereof can be used by telephone and telex subscribers connected to the general telecommunications network to call a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflatable Boat
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 is often flexible, while for boats longer than , 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. Some inflatable boats can be disassembled and packed into a small volume, so that they can be easily stored and transported. The boat, when inflated, is kept rigid cross-ways by a foldable removable thwart. This feature makes these boats suitable for liferafts for larger boats or aircraft, and for travel or recreational purposes. History Early attempts There are ancient carved images of animal skins filled with air being used as one-man floats to cross rivers. These floats were inflated by mouth. The discovery of the process to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diesel Engine
The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-called compression-ignition engine (CI engine). This contrasts with engines using spark plug-ignition of the air-fuel mixture, such as a petrol engine ( gasoline engine) or a gas engine (using a gaseous fuel like natural gas or liquefied petroleum gas). Diesel engines work by compressing only air, or air plus residual combustion gases from the exhaust (known as exhaust gas recirculation (EGR)). Air is inducted into the chamber during the intake stroke, and compressed during the compression stroke. This increases the air temperature inside the cylinder to such a high degree that atomised diesel fuel injected into the combustion chamber ignites. With the fuel being injected into the air just before combustion, the dispersion of the fuel i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caterpillar Inc
Caterpillar Inc. (stock symbol CAT) is an American ''Fortune'' 500 corporation and the world's largest construction-equipment manufacturer. In 2018, Caterpillar was ranked number 65 on the ''Fortune'' 500 list and number 238 on the Global ''Fortune'' 500 list. Caterpillar stock is a component of the Dow Jones Industrial Average. Caterpillar Inc. traces its origins to the 1925 merger of the Holt Manufacturing Company and the C. L. Best Tractor Company, creating a new entity, California-based Caterpillar Tractor Company. In 1986, the company reorganized itself as a Delaware corporation under the current name, Caterpillar Inc. It announced in January 2017 that over the course of that year, it would relocate its headquarters from Peoria, Illinois, to Deerfield, Illinois, scrapping plans from 2015 of building an $800 million new headquarters complex in downtown Peoria. Its headquarters are located in Irving, Texas, since 2022. The company also licenses and markets a line of clo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrous Oxide And Oxygen
Nitrous oxide, is an inhaled gas used as a pain medication and together with other medications for anesthesia. Common uses include during childbirth, following trauma, and as part of end-of-life care. Onset of effect is typically within half a minute, and the effect lasts for about a minute. There are few side effects, other than vomiting, with short-term use. With long-term use anemia or numbness may occur. It should always be given with at least 21% oxygen. It is not recommended in people with a bowel obstruction or pneumothorax. Use in the early part of pregnancy is not recommended. It is possible to continue breastfeeding following use. Nitrous oxide was discovered between 1772 and 1793 and used for anesthesia in 1844. It is on the World Health Organization's List of Essential Medicines. It often comes as a 50/50 mixture with oxygen. Devices with a demand valve are available for self-administration. The setup and maintenance is relatively expensive for developing coun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radar
Radar is a detection system that uses radio waves to determine the distance ('' ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the objects. Radio waves (pulsed or continuous) from the transmitter reflect off the objects and return to the receiver, giving information about the objects' locations and speeds. Radar was developed secretly for military use by several countries in the period before and during World War II. A key development was the cavity magnetron in the United Kingdom, which allowed the creation of relatively small systems with sub-meter resolution. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Direction Finder
Direction finding (DF), or radio direction finding (RDF), isin accordance with International Telecommunication Union (ITU)defined as radio location that uses the reception of radio waves to determine the direction in which a radio station or an object is located. This can refer to radio or other forms of wireless communication, including radar signals detection and monitoring (ELINT/ESM). By combining the direction information from two or more suitably spaced receivers (or a single mobile receiver), the source of a transmission may be located via triangulation. Radio direction finding is used in the navigation of ships and aircraft, to locate emergency transmitters for search and rescue, for tracking wildlife, and to locate illegal or interfering transmitters. RDF was important in combating German threats during both the World War II Battle of Britain and the long running Battle of the Atlantic. In the former, the Air Ministry also used RDF to locate its own fighter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Differential GPS
Differential Global Positioning Systems (DGPSs) supplement and enhance the positional data available from global navigation satellite systems (GNSSs). A DGPS for GPS can increase accuracy by about a thousandfold, from approximately to . DGPSs consist of networks of fixed position, ground-based reference stations. Each reference station calculates the difference between its highly accurate known position and its less accurate satellite-derived position. The stations broadcast this data locally—typically using ground-based transmitters of shorter range. Non-fixed (mobile) receivers use it to correct their position by the same amount, thereby improving their accuracy. The United States Coast Guard (USCG) and the Canadian Coast Guard (CCG) each run DGPSs in the United States and Canada on longwave radio frequencies between and near major waterways and harbors. The USCG's DGPS was named NDGPS (Nationwide DGPS) and was jointly administered by the Coast Guard and the U.S. Departmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Selective Calling
Digital selective calling or DSC is a standard for transmitting predefined digital messages via the medium-frequency (MF), high-frequency (HF) and very-high-frequency (VHF) maritime radio systems. It is a core part of the Global Maritime Distress Safety System (GMDSS).Bréhaut (2009): 35 Workings DSC was developed to replace a voice call in older procedures. Because a DSC signal uses a stable signal with a narrow bandwidth and the receiver has no squelch, it has a slightly longer range than analog signals, with up to twenty-five percent longer range and significantly faster. DSC senders are programmed with the ship's Maritime Mobile Service Identity (MMSI) and may be connected to the ship's Global Positioning System (GPS), which allows the apparatus to know who it is, what time it is and where it is. This allows a distress signal to be sent very quickly. Often, ships use separate VHF DSC and MF/HF DSC controllers. For VHF, DSC has its own dedicated receiver for monitoring Ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
