The Satsuma class was a pair of semi-dreadnought battleships built for the Imperial Japanese Navy in the first decade of the 20th century. They were the first battleships to be built in Japan and marked a transitional stage between the pre-dreadnought and true dreadnought designs, they saw no combat during World War I, although Satsuma led a squadron that occupied several German colonies in the Pacific Ocean in 1914. Both ships were disarmed and expended as targets in 1922–1924 in accordance with the terms of the Washington Naval Treaty of 1922; the Satsuma class was ordered in late 1904 under the 1904 War Naval Supplementary Program during the Russo-Japanese War. Unlike the previous Katori-class pre-dreadnought battleships, they were the first battleships ordered from Japanese shipyards, although the first ship in the class, used many imported components, they were intended to mount a dozen 12-inch gun in four twin and four single-gun turrets, but the combination of a shortage of Japanese-built 12-inch guns and their additional expense caused the ships to be redesigned to carry four 12-inch and twelve 10-inch guns, all in twin-gun turrets.
The intended armament of these ships, laid down before HMS Dreadnought, would have made them the first "all big-gun" battleships in the world had they been completed to their original design. Reflecting extensive British technical assistance, the Satsuma-class ships resembled an enlarged version of the British Lord Nelson class with the single-gun amidships intermediate turrets replaced by twin-gun turrets. With their heavy intermediate armament, the ships were considered to be semi-dreadnoughts, a transitional stage between pre-dreadnoughts with their light intermediate armament and dreadnoughts equipped with large guns; the construction of Aki was delayed since she could not be laid down until the slipway occupied by the armored cruiser Tsukuba was freed by that ship's launching. The IJN took the opportunity provided by the delay to modify the ship to accommodate steam turbines and various other changes that increased her size; the changes were great enough that Aki is considered a half sister to Satsuma.
The crew enlisted men. Satsuma had an overall length of 482 feet, a beam of 83.5 feet, a normal draft of 27.5 feet. She displaced 19,372 long tons at normal load. Aki was 492 feet long overall, had a beam of 83.6 feet, the same draft as her half-sister. She displaced 20,100 long tons at normal load. Satsuma was powered by a pair of vertical triple-expansion steam engines, each driving one propeller shaft, using steam generated by 20 Miyabara water-tube boilers using a mixture of coal and fuel oil; the engines were rated at a total of 17,300 indicated horsepower and designed to reach a top speed of 18.25 knots. During the ship's sea trials she reached 18.95 knots from 18,507 ihp. Satsuma carried a maximum of 2,860 long tons of coal and 377 long tons of oil which allowed her to steam for 9,100 nautical miles at a speed of 10 knots. Unlike her half-sister, she only had two funnels. Aki was intended use the same type of engines as her sister, but the IJN decided fit her with a pair of Curtiss steam turbine sets after she was launched in 1907.
The turbines each powered one propeller shaft using steam from 15 Miyabara boilers. The turbines were rated at a total of 24,000 shaft horsepower for a design speed of 20 knots; the ship reached a top speed of 20.25 knots during her sea trials from 27,740 shp. She carried a maximum of 3,000 long tons of coal and 172 long tons of oil gave her the same range as her half sister; the ships were completed with four 45-caliber 12-inch 41st Year Type guns in two gun turrets, one each fore and aft of the superstructure. They fired 850-pound armor-piercing shells at a muzzle velocity of 2,800 ft/s; the intermediate armament was much more numerous than in the preceding Katori class, with six twin-gun turrets equipped with 45-caliber Type 41 10-inch guns, three turrets on each side of the superstructure. The guns had a muzzle velocity of 2,707 ft/s; the other major difference between the two ships was that Aki's secondary armament consisted of eight 45-caliber 6-inch 41st Year Type guns, mounted in casemates in the sides of the hull.
The gun fired a 100-pound AP shell at a muzzle velocity of 2,706 ft/s. Satsuma, in contrast, was equipped with a dozen 40-caliber 4.7-inch 41st Year Type quick-firing guns, mounted in casemates in the sides of the hull. The gun fired a 45-pound shell at a muzzle velocity of 2,150 ft/s; the ships were equipped with four or eight 40-caliber 12-pounder 12-cwt QF guns and four 28-caliber 12-pounder QF guns. Both of these guns fired 12.5-pound shells with muzzle velocities of 2,300 ft/s and 1,500 feet per second respectively. In addition, the battleships were fitted with five submerged 18-inch torpedo tubes, two on each broadside and one in the stern; the waterline main belt of the Satsuma-class vessels consisted of Krupp cemented armor that had a maximum thickness of 9 inches amidships and tapered to a thickness of 4 inches inches at the ends of the ship. A 6-inch strake of armor protected the casemates; the barbettes for the main guns were 7–9.5 inches thick. The armor of Satsuma's main gun turrets had a max
A broadside is the side of a ship, the battery of cannon on one side of a warship. From the 16th century until the early decades of the steamship, vessels had rows of guns set in each side of the hull. Firing all guns on one side of the ship became known as a "broadside"; the cannons of 18th-century men of war were accurate only at short range, their penetrating power mediocre, entailing that the thick hulls of wooden ships could only be pierced at short ranges. These wooden ships sailed closer towards each other until cannon fire would be effective; each tried to be the first to fire a broadside giving one party a decisive headstart in the battle when it crippled the other ship. Since ancient times, war at sea had been fought much like on land: with melee weapons and bows and arrows, but on floating wooden platforms rather than battlefields. Though the introduction of guns was a significant change, it only changed the dynamics of ship-to-ship combat; the first guns on ships were small wrought-iron pieces mounted on the open decks and in the fighting tops requiring only one or two men to handle them.
They were designed to injure, kill or stun and frighten the enemy prior to boarding. As guns were made more durable to withstand stronger gunpowder charges, they increased their potential to inflict critical damage to the vessel rather than just its crew. Since these guns were much heavier than the earlier anti-personnel weapons, they had to be placed lower in the ships, fire from gunports, to avoid ships becoming unstable. In Northern Europe the technique of building ships with clinker planking made it difficult to cut ports in the hull; the solution was the gradual adoption of carvel-built ships that relied on an internal skeleton structure to bear the weight of the ship. The development of propulsion during the 15th century from single-masted, square-rigged cogs to three-masted carracks with a mix of square and lateen sails made ships nimbler and easier to maneuver. Gunports cut in the hull of ships had been introduced as early as 1501. According to tradition the inventor was a Breton shipwright called Descharges, but it is just as to have been a gradual adaptation of loading ports in the stern of merchant vessels, in use for centuries.
The gunports were used to mount heavy so-called stern chasers pointing aft, but soon gun ports migrated to the sides of ships. This made possible coordinated volleys from all the guns on one side of a ship for the first time in history, at least in theory. Guns in the 16th century were considered to be in fixed positions and were intended to be fired independently rather than in concerted volleys, it was not until the 1590s that the word "broadside" in English was used to refer to gunfire from the side of a ship rather than the ship's side itself. The main batteries in 20th century battleships tended to be powered gun turrets which could swivel 180 degrees or more to establish wider firing arcs around the entire vessel. Although this could allow at least some of the main guns to be focused directly forward or aft, most or all battleships still relied on broadsides for maximum firepower. Structures such as the bridge tower in the middle of a battleship would prevent guns in the aft portion of the ship from firing forward, vice versa.
Additionally, directing the guns to the port or starboard projected the massive muzzle blast out over the ocean, while firing the guns too close to the deck could cause damage to the ship. Additionally, the term broadside is a measurement of a vessel's maximum simultaneous firepower which can be delivered upon a single target, because this concentration is obtained by firing a broadside; this is calculated by multiplying the shell weight of the ship's main armament shells times the number of barrels that can be brought to bear. If some turrets are incapable of firing to either side of the vessel, only the maximum number of barrels which can fire to one side or the other are counted. For example, the American Iowa-class battleships carried a main armament of nine 16-inch main guns in turrets which could all be trained to a single broadside; each 16-inch shell weighed 2,700 pounds, which when multiplied by nine equals a total of 24,300 pounds. Thus, an Iowa-class battleship had a broadside of 12 short tons, the weight of shells that she could theoretically land on a target in a single firing.
See list of broadsides of major World War II ships for a comparison. Barrage Salvo Fusillade Volley fire Sailing ship tactics#Early history Marsden, Sealed by Time: The Loss and Recovery of the Mary Rose; the Archaeology of the Mary Rose, Volume 1. The Mary Rose Trust, Portsmouth. 2003. ISBN 0-9544029-0-1 Platt, Richard,Man-of-war. Dorling Kindersley, New York. 1993. ISBN 978-1-56458-321-5. Rodger, Nicholas A. M; the Safeguard of the Sea: A Naval History of Britain 660–1649. W. W. Norton & Company, New York. 1997. ISBN 0-393-04579-X Rodger, N. A. M.. The Command of the Ocean: a naval history of Great Britain 1649 - 1815. Penguin History. ISBN 0-14-102690-1. George Dorsey, "When a U. S. Battleship Fires a Broadside," The New York Times Magazine, 30 December 1917
The waterline is the line where the hull of a ship meets the surface of the water. It is the name of a special marking known as an international load line, Plimsoll line and water line, that indicates the draft of the ship and the legal limit to which a ship may be loaded for specific water types and temperatures in order to safely maintain buoyancy with regard to the hazard of waves that may arise. Varying water temperatures will affect a ship's draft. In the same way, fresh water is less dense than salinated or seawater with the same lessening effect upon buoyancy. For vessels with displacement hulls, the hull speed is determined by, among other things, the waterline length. In a sailing boat, the waterline length can change as the boat heels, can dynamically affect the speed of the boat; the waterline can refer to any line on a ship's hull, parallel to the water's surface when the ship is afloat in a normal position. Hence, all waterlines are one class of "ships lines" used to denote the shape of a hull in naval architecture plans.
In aircraft design, the term "waterline" refers to the vertical location of items on the aircraft. This is the "Z" axis of an XYZ coordinate system, the other two axes being the fuselage station and buttock line; the purpose of a load line is to ensure that a ship has sufficient freeboard and thus sufficient reserve buoyancy. The freeboard of commercial vessels is measured between the lowest point of the uppermost continuous deck at side and the waterline and this must not be less than the freeboard marked on the load line certificate issued to that ship. All commercial ships, other than in exceptional circumstances, have a load line symbol painted amidships on each side of the ship; this symbol is permanently marked, so that if the paint wears off it remains visible. The load line makes it easy for anyone to determine; the exact location of the load line is calculated and verified by a classification society and that society issues the relevant certificates. This marking was invented in 1876 by Samuel Plimsoll.
The first official loading regulations are thought to date back to maritime legislation originating with the Kingdom of Crete in 2500 BC when vessels were required to pass loading and maintenance inspections. Roman sea regulations contained similar regulations. In the Middle Ages the Venetian Republic, the city of Genoa and the Hanseatic League required ships to show a load line. In the case of Venice this was a cross marked on the side of the ship, of Genoa three horizontal lines; the first 19th-century loading recommendations were introduced by Lloyd's Register of British and Foreign Shipping in 1835, following discussions among shipowners and underwriters. Lloyds recommended freeboards as a function of the depth of the hold; these recommendations, used extensively until 1880, became known as "Lloyd's Rule". In the 1860s, after increased loss of ships due to overloading, a British MP, Samuel Plimsoll, took up the load line cause. A Royal Commission on unseaworthy ships was established in 1872, in 1876 the United Kingdom Merchant Shipping Act made the load line mark compulsory, although the positioning of the mark was not fixed by law until 1894.
In 1906, laws were passed requiring foreign ships visiting British ports to be marked with a load line. It was not until 1930 that there was international agreement for universal application of load line regulations. In 1966 the International Convention on Load Lines was concluded in London which re-examined and amended the 1930 rules; the 1966 convention has since seen amendments in 1971, 1975, 1979, 1983, 1995 and 2003, none of which have entered into force. The original "Plimsoll mark" was a circle with a horizontal line through it to show the maximum draft of a ship. Additional marks have been added over the years, allowing for different water densities and expected sea conditions. Letters may appear to the sides of the mark indicating the classification society that has surveyed the vessel's load line; the initials used include AB for the American Bureau of Shipping, BV for Bureau Veritas, CN for Conarina, GL for Germanischer Lloyd, IR for the Indian Register of Shipping, KI for Biro Klasifikasi Indonesia, LR for Lloyd's Register, NK for Nippon Kaiji Kyokai, NV for Det Norske Veritas and RI for the Registro Italiano Navale.
These letters are 115 millimetres in height and 75 millimetres in width. The load line length is referred to during; the letters on the load line marks have the following meanings: TF – tropical fresh water F – fresh water T – tropical seawater S – summer temperate seawater W – winter temperate seawater WNA – winter North AtlanticFor the purposes of loadline marks, fresh water is considered to have a density of 1,000 kg/m3 and typical sea water 1,025 kg/m3. Fresh water marks make allowance for the fact that the ship will float deeper in fresh water than salt water. A ship loaded to her fresh water mark in fresh water will float at her summer mark once she has passed into seawater at the same displacement. If loaded to her tropical fresh water mark she will float at her tropical seawater mark once she passes into seawater; the summer load line is the primary load line and it is from this mark that all other marks are derived. The position of the summer load line is calculated from the load line rules and depends on many factors such as length of ship, type of ship and number of superstructures, amount of sheer, bow height.
Glossary of nautical terms
This is a partial glossary of nautical terms. See Wiktionary's nautical terms, Category:Nautical terms, Nautical metaphors in English. See the Further reading section for additional words and references. AbackA foresail. AbaftToward the stern, relative to some object. Abaft the beamFurther aft than the beam: a relative bearing of greater than 90 degrees from the bow: "two points abaft the beam, starboard side"; that would describe "an object lying 22.5 degrees toward the rear of the ship, as measured clockwise from a perpendicular line from the right side, center, of the ship, toward the horizon." Abandon ship! An imperative to leave the vessel usually in the face of some imminent overwhelming danger, it is an order issued by the Master or a delegated person in command.. It is the last resort after all other mitigating actions have failed or become impossible, destruction or loss of the ship is imminent. AbeamOn the beam, a relative bearing at right angles to the ship's keel. Able seaman. A merchant seaman qualified to perform a junior rank in some navies.
AboardOn or in a vessel. Synonymous with "on board." AboutTo go. "Ready about" is the order to prepare for tacking." Above boardOn or above the deck, in plain view, not hiding anything. Pirates would hide their crews below decks, thereby creating the false impression that an encounter with another ship was a casual matter of chance. Above-water hullThe hull section of a vessel above the visible part of a ship. Topsides. Absentee pennantSpecial pennant flown to indicate absence of commanding officer, his chief of staff, or officer whose flag is flying. Absolute bearingThe bearing of an object in relation to north. Either true bearing, using the geographical or true north, or magnetic bearing, using magnetic north. See bearing and relative bearing. Accommodation ladderA portable flight of steps down a ship's side. Accommodation ship A ship or hulk used as housing when there is a lack of quarters available ashore. An operational ship can be used, but more a hulk modified for accommodation is used. Act of Pardon or Act of Grace A letter from a state or power authorising action by a privateer.
See Letter of marque. Action StationsSee Battle stations. AdmiralSenior naval officer of Flag rank. In ascending order of seniority, Rear Admiral, Vice Admiral and Admiral of the Fleet. Derivation Arabic, from Amir al-Bahr. Admiralty1. A high naval authority in charge of a state's a major territorial component. In the Royal Navy the Board of Admiralty, executing the office of the Lord High Admiral, promulgates Naval law in the form of Queen's Regulations and Admiralty Instructions.2. Admiralty law Admiralty lawBody of law that deals with maritime cases. In the UK, administered by the Admiralty court a special court within the Queen's Bench Division of the High Court of Justice; the Admiralty Court is now in the Rolls Building. Adrift 1. Afloat and unattached in any way to the shore or seabed, but not under way; when referring to a vessel, it implies that the vessel is not under control and therefore goes where the wind and current take her. 2. Any gear not fastened down or put away properly. 3. Any person or thing, misplaced or missing.
When applied to a member of the navy or marine corps, such a person is "absent without leave" or, in US Navy and US Marine Corps terminology, is guilty of an "unauthorized absence". Advance noteA note. AdvisoSee aviso. AfloatOf a vessel, floating freely. More of vessels in service. Afore 1. In, on, or toward the front of a vessel. 2. In front of a vessel. Aft 1; the portion of the vessel behind the middle area of the vessel. 2. Towards the stern. Afterbrow 1. On larger ships, a secondary gangway rigged in the area aft of midship. On some military vessels, such as US Naval vessels, enlisted personnel below E-7 board the ship at the afterbrow. Afternoon watchThe 1200–1600 watch. AgroundResting on or touching the ground or bottom. AheadForward of the bow. AhoyA cry to draw attention. Term used to hail a boat or a ship, as "Boat ahoy!" Ahull 1. Lying broadside to the sea. 2. To ride out a storm with no sails and helm held to leeward. Aid to Navigation 1. Any device external to a vessel or aircraft intended to assist navigators in determining their position or safe course, or to warn them of dangers or obstructions to navigation.
2. Any sort of marker which aids the traveler in navigation. Common types of such aids include lighthouses, fog signals, day beacons. Aircraft carrierA warship designed with a primary mission of deploying and recovering aircraft, acting as a seagoing airbase. Shortened to carrier. Since 1918, the term has been limited to a warship with an extensive flight deck designed to operate conventional fixed-wing aircraft. In United States Navy slang called a flat top or a bird farm. Alee 1. On t
A steam turbine is a device that extracts thermal energy from pressurized steam and uses it to do mechanical work on a rotating output shaft. Its modern manifestation was invented by Sir Charles Parsons in 1884; because the turbine generates rotary motion, it is suited to be used to drive an electrical generator—about 85% of all electricity generation in the United States in the year 2014 was by use of steam turbines. The steam turbine is a form of heat engine that derives much of its improvement in thermodynamic efficiency from the use of multiple stages in the expansion of the steam, which results in a closer approach to the ideal reversible expansion process; the first device that may be classified as a reaction steam turbine was little more than a toy, the classic Aeolipile, described in the 1st century by Hero of Alexandria in Roman Egypt. In 1551, Taqi al-Din in Ottoman Egypt described a steam turbine with the practical application of rotating a spit. Steam turbines were described by the Italian Giovanni Branca and John Wilkins in England.
The devices described by Taqi al-Din and Wilkins are today known as steam jacks. In 1672 an impulse steam turbine driven car was designed by Ferdinand Verbiest. A more modern version of this car was produced some time in the late 18th century by an unknown German mechanic. In 1775 at Soho James Watt designed a reaction turbine, put to work there. In 1827 the Frenchmen Real and Pichon constructed a compound impulse turbine; the modern steam turbine was invented in 1884 by Sir Charles Parsons, whose first model was connected to a dynamo that generated 7.5 kW of electricity. The invention of Parsons' steam turbine made cheap and plentiful electricity possible and revolutionized marine transport and naval warfare. Parsons' design was a reaction type, his patent was the turbine scaled-up shortly after by an American, George Westinghouse. The Parsons turbine turned out to be easy to scale up. Parsons had the satisfaction of seeing his invention adopted for all major world power stations, the size of generators had increased from his first 7.5 kW set up to units of 50,000 kW capacity.
Within Parson's lifetime, the generating capacity of a unit was scaled up by about 10,000 times, the total output from turbo-generators constructed by his firm C. A. Parsons and Company and by their licensees, for land purposes alone, had exceeded thirty million horse-power. A number of other variations of turbines have been developed that work with steam; the de Laval turbine accelerated the steam to full speed before running it against a turbine blade. De Laval's impulse turbine does not need to be pressure-proof, it can operate with any pressure of steam, but is less efficient. Auguste Rateau developed a pressure compounded impulse turbine using the de Laval principle as early as 1896, obtained a US patent in 1903, applied the turbine to a French torpedo boat in 1904, he taught at the École des mines de Saint-Étienne for a decade until 1897, founded a successful company, incorporated into the Alstom firm after his death. One of the founders of the modern theory of steam and gas turbines was Aurel Stodola, a Slovak physicist and engineer and professor at the Swiss Polytechnical Institute in Zurich.
His work Die Dampfturbinen und ihre Aussichten als Wärmekraftmaschinen was published in Berlin in 1903. A further book Dampf und Gas-Turbinen was published in 1922; the Brown-Curtis turbine, an impulse type, developed and patented by the U. S. company International Curtis Marine Turbine Company, was developed in the 1900s in conjunction with John Brown & Company. It was used in John Brown-engined merchant ships and warships, including liners and Royal Navy warships; the present-day manufacturing industry for steam turbines is dominated by Chinese power equipment makers. Harbin Electric, Shanghai Electric, Dongfang Electric, the top three power equipment makers in China, collectively hold a majority stake in the worldwide market share for steam turbines in 2009-10 according to Platts. Other manufacturers with minor market share include Bharat Heavy Electricals Limited, Alstom, General Electric, Doosan Škoda Power, Mitsubishi Heavy Industries, Toshiba; the consulting firm Frost & Sullivan projects that manufacturing of steam turbines will become more consolidated by 2020 as Chinese power manufacturers win increasing business outside of China.
Steam turbines are made in a variety of sizes ranging from small <0.75 kW units used as mechanical drives for pumps and other shaft driven equipment, to 1.5 GW turbines used to generate electricity. There are several classifications for modern steam turbines. Turbine blades are of two basic types and nozzles. Blades move due to the impact of steam on them and their profiles do not converge; this results in a steam velocity drop and no pressure drop as steam moves through the blades. A turbine composed of blades alternating with fixed nozzles is called an impulse turbine, Curtis turbine, Rateau turbine, or Brown-Curtis turbine. Nozzles appear similar to blades; this results in a steam pressure velocity increase as steam moves through the nozzles. Nozzles move due to both the impact of steam on them and the reaction due to the high-velocity steam at the exit. A turbine composed of moving nozzles alternating with fixed nozzles is called a reaction turbine or Parsons turbine. Except for low-power applications, turbine blades are arranged in multiple stages in series, called c
On boats and ships, the keel is either of two parts: a structural element that sometimes resembles a fin and protrudes below a boat along the central line, or a hydrodynamic element. These parts overlap; as the laying down of the keel is the initial step in the construction of a ship, in British and American shipbuilding traditions the construction is dated from this event. Only the ship's launching is considered more significant in its creation; the word can be used as a synecdoche to refer to a complete boat, such as a keelboat. The adjustable centerboard keel traces its roots to the medieval Chinese Song dynasty. Many Song Chinese junk ships had a ballasted and bilge keel that consisted of wooden beams bound together with iron hoops. Maritime technology and the technological know-how allowed Song dynasty ships to be used in naval warfare between the Southern Song Dynasty, the Jin dynasty, the Mongols. A structural keel is the bottom-most structural member; the keel runs from the bow to the stern.
The keel is the first part of a ship's hull to be constructed, laying the keel, or placing the keel in the cradle in which the ship will be built may mark the start time of its construction. Large, modern ships are now built in a series of pre-fabricated, complete hull sections rather than being built around a single keel, so shipbuilding process commences with cutting the first sheet of steel; the most common type of keel is the "flat plate keel", this is fitted in the majority of ocean-going ships and other vessels. A form of keel found on smaller vessels is the "bar keel", which may be fitted in trawlers and smaller ferries. Where grounding is possible, this type of keel is suitable with its massive scantlings, but there is always a problem of the increased draft with no additional cargo capacity. If a double bottom is fitted, the keel is inevitably of the flat plate type, bar keels being associated with open floors, where the plate keel may be fitted. Duct keels are provided in the bottom of some vessels.
These run from the forward engine room bulkhead to the collision bulkhead and are utilized to carry the double bottom piping. The piping is accessible when cargo is loaded; the keel surface on the bottom of the hull gives the ship greater directional stability. In non-sailing hulls, the keel helps the hull to move forward, rather than slipping to the side. In traditional boat building, this is provided by the structural keel, which projects from the bottom of the hull along most or all of its length. In modern construction, the bar keel or flat-plate keel performs the same function. There are many types of fixed keels, including full keels, long keels, fin keels, winged keels, bulb keels, bilge keels among other designs. Deep-draft ships will have a flat bottom and employ only bilge keels, both to aid directional control and to damp rolling motions In sailboats, keels use the forward motion of the boat to generate lift to counteract the leeward force of the wind; the rudimentary purpose of the keel is to convert the sideways motion of the wind when it is abeam into forward motion.
A secondary purpose of the keel is to provide ballast. Keels are different from centreboards and other types of foils in that keels are made of heavy materials to provide ballast to stabilize the boat. Keels may be fixed, or non-movable. Retracting keels may pivot or slide upwards to retract, are retracted with a winch due to the weight of the ballast. Since the keel provides far more stability when lowered than when retracted, the amount of sail carried is reduced when sailing with the keel retracted. Types of non-fixed keels include canting keels. Canting keels can be found on racing yachts, such as those competing in the Volvo Ocean Race, they provide more righting moment as the keel moves out to the windward-side of the boat while using less weight. The horizontal distance from the weight to the pivot is increased, which generates a larger righting moment; the word "keel" comes from Old English cēol, Old Norse kjóll, = "ship" or "keel". It has the distinction of being regarded by some scholars as the first word in the English language recorded in writing, having been recorded by Gildas in his 6th century Latin work De Excidio et Conquestu Britanniae, under the spelling cyulae.
Carina is the origin of the term careen. An example of this use is Careening Cove, a suburb of Sydney, where careening was carried out in early colonial days. Coin ceremony Kelson False keel Daggerboard Leeboard Bilgeboard Bruce foil Keelhauling – an archaic maritime punishment Rousmaniere, The Annapolis Book of Seamanship, Simon & Schuster, 1999 Chapman Book of Piloting, Hearst Corporation, 1999 Herreshoff, The Sailor’s Handbook, Little Brown and Company Seidman, The Complete Sailor, International Marine, 1995 Jobson, Sailing Fundamentals, Simon & Schuster, 1987
Battleship secondary armament
The secondary armament of a battleship is composed of smaller, faster-firing weapons that are effective at a shorter range than the main weapons. The nature, disposition and purpose of secondary weapons changed as the threat changed from torpedo boats, to torpedo-carrying destroyers, to aircraft, to anti-ship missiles. Pre-dreadnoughts, from the period 1890 to 1905, were fitted with 3 or 4 different calibres of weapon; the main guns were approximately 12-inch caliber, secondary weapons 6-inch but in the range 5-inch to 7.5-inch. Guns smaller than 4.7-inch are considered "tertiary". Secondary guns were "quick firers", could fire 5 to 10 rounds per minute, it was this attribute, rather than their destructive power or accuracy, that provided the military value. Secondary guns were universally carried in "casemates", or a long armoured wall through which the battery of guns projected; such weapons were designed to fire at both capital ship targets and smaller targets such as torpedo craft and destroyers.
Small targets were of course vulnerable to 6-inch projectiles, a high rate of fire was necessary to be able to hit a small and evasive target. In this era, secondary weapons were expected to engage capital ships. Heavily-armoured areas of battleships would not be vulnerable to 6-inch fire, but there were large areas that could not be protected; these armoured and unarmoured areas would be "riddled" at the expected ranges of 3000 yards. This would knock out the enemy's secondary armament, punch holes in the armoured bow and stern knock down funnels and spotting tops, destroy the bridge and command positions. Secondary guns were a important factor in battleship combat. Dreadnoughts were characterized by an "all-big-gun" armament. Broadly, this era spans from 1906, through the super-dreadnought era, to the end of World War I. During this period, there was some variation in the selection of secondary weapon. British practice, at first, was to mount small guns that were considered a tertiary battery.
These guns were mounted unarmoured in the open, or in a casemate battery. The guns grew to 6-inch size. In other navies, the 6-inch size was mounted throughout the era as a casemate battery. British doctrine at first held. Other navies, with a larger secondary battery, held that they should be used against capital ships. For instance, German doctrine, for fighting in the North Sea, held that poor visibility provided a good opportunity for the shorter ranges at which smaller guns would be effective. Britain came around to this point of view, although the primary justification for mounting a 6-inch battery remained fighting against the large torpedo boats and destroyers. Naval historians covering this period disagree on the value of the secondary battery. Arguing for, it provided protection against surface torpedo craft without needing a flotilla of supporting craft that smoked up the range and burdened the admiral with additional command and signalling. Arguing against, it consumed considerable displacement, were holes in the side close to the waterline that increased the risk of capsizing, could not be armoured yet were connected to magazines that threatened the destruction of the ship.
There were considerable difficulties in bringing secondary weapons into action with the main guns. Battle experience showed that capital ships were always accompanied by their flotillas, secondary batteries were ineffective against capital ships, but that German battleship secondary batteries were effective in the Jutland night action against British destroyers. With the emergence of the threat from air-delivered weapons, the nature of the secondary guns changed once more. Now they needed to be multi-purpose weapons, with a high-angle fire capability to engage aircraft, as well as the traditional use against destroyers. Although they were used against capital ships, the extreme range of capital ship engagements, meant they were not expected to achieve much. High angle weapons could not be mounted in casemates. Thus, they migrated to small turrets mounted on the upper deck. In order to hit a fast-moving air target, a high rate of fire was required, thus secondary guns reverted to the 5-inch from 6-inch size although 6 inch guns were still used by several navies including France, Germany and Japan in new built battleships.
Main battery Point defence Close-in weapon system