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91-426: In wartime, the distinction between warships and merchant ships is often blurred. Until the 17th century it was common for merchant ships to be pressed into naval service, and not unusual for more than half of a fleet to be composed of merchant ships—there was not a large difference in construction, unlike the difference between a heavily armoured battleship and an ocean liner. Until the threat of piracy subsided in

182-480: A line of battle . The man-of-war now evolved into the ship of the line . In the 18th century, the frigate and sloop-of-war  – too small to stand in the line of battle – evolved to escort convoy trade, scout for enemy ships and blockade enemy coasts. During the 19th century a revolution took place in the means of marine propulsion , naval armament and construction of warships . Marine steam engines were introduced, at first as an auxiliary force, in

273-651: A vertical beam or overhead beam , and sometimes simply referred as a "beam", was another early adaptation of the beam engine, but its use was confined almost entirely to the United States. After its introduction, the walking beam quickly became the most popular engine type in American waters for inland waterway and coastal service, eventually making its way into American transoceanic steamships as well. The type proved to have remarkable longevity, with walking beam engines still being occasionally manufactured as late as

364-417: A beam (i.e. walking beam, side-lever or grasshopper) engine. The later definition only uses the term for engines that apply power directly to the crankshaft via the piston rod and/or connecting rod. Unless otherwise noted, this article uses the later definition. Unlike the side-lever or beam engine, a direct-acting engine could be readily adapted to power either paddlewheels or a propeller. As well as offering

455-464: A centrally located crankshaft. Back-acting engines were another type of engine popular in both warships and commercial vessels in the mid-19th century, but like many other engine types in this era of rapidly changing technology, they were eventually abandoned for other solutions. There is only one known surviving back-acting engine—that of the TV Emery Rice (formerly USS  Ranger ), now

546-536: A century after Newcomen, when Scottish engineer William Symington built the world's "first practical steamboat ", the Charlotte Dundas , in 1802. Rivaling inventors James Rumsey and John Fitch were the first to build steamboats in the United States. Rumsey exhibited his steamboat design in 1787 on the Potomac River; however, Fitch won the rivalry in 1790 after his successful test resulted in

637-492: A common, T-shaped crosshead. The vertical arm of the crosshead extended down between the two cylinders and was attached at the bottom to both the crankshaft connecting rod and to a guide block that slid between the vertical sides of the cylinders, enabling the assembly to maintain the correct path as it moved. The Siamese engine was invented by British engineer Joseph Maudslay (son of Henry ), but although he invented it after his oscillating engine (see below), it failed to achieve

728-553: A compound engine gave a significant increase in fuel efficiency, so allowing steamships to out-compete sail on the route from the UK to China, even before the opening of the Suez Canal in 1869. A triple-expansion engine is a compound engine that expands the steam in three stages, e.g. an engine with three cylinders at three different pressures. A quadruple-expansion engine expands the steam in four stages. However, as explained above,

819-468: A compound walking beam type, compound being the cylinder technology, and walking beam being the connection method. Over time, as most engines became direct-acting but cylinder technologies grew more complex, engines began to be classified solely according to cylinder technology. More commonly encountered marine steam engine types are listed in the following sections. Note that not all these terms are exclusive to marine applications. The side-lever engine

910-407: A deck like a helicopter carrier for helicopters and V/STOL aircraft. Naval fleet A fleet or naval fleet is a large formation of warships – the largest formation in any navy – controlled by one leader. A fleet at sea is the direct equivalent of an army on land. In the modern sense, fleets are usually, but not necessarily, permanent formations and are generally assigned to

1001-430: A different design operating at only 90 psi (620 kPa). This was insufficient to fully realise the economic benefits of triple expansion. Aberdeen was fitted with two double ended Scotch type steel boilers, running at 125 psi (860 kPa). These boilers had patent corrugated furnaces that overcame the competing problems of heat transfer and sufficient strength to deal with the boiler pressure. This provided

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1092-472: A displacement hierarchy, and the size of all vessel types has grown beyond the definitions used earlier in the 20th century. Another key difference between older and modern vessels is that all modern warships are "soft", without the thick armor and bulging anti-torpedo protection of World War II and older designs. Most navies also include many types of support and auxiliary vessels , such as minesweepers , patrol boats and offshore patrol vessels . By 1982

1183-474: A lower profile, direct-acting engines had the advantage of being smaller and weighing considerably less than beam or side-lever engines. The Royal Navy found that on average a direct-acting engine (early definition) weighed 40% less and required an engine room only two thirds the size of that for a side-lever of equivalent power. One disadvantage of such engines is that they were more prone to wear and tear and thus required more maintenance. An oscillating engine

1274-535: A particular ocean or sea . Most fleets are named after that ocean or sea, but the convention in the United States Navy is to use numbers. A fleet is typically commanded by an admiral , who is often also a commander in chief . Still, many fleets have been or are commanded by vice admirals or rear admirals . Most fleets are divided into several squadrons , each under a subordinate admiral. Those squadrons, in turn, are often divided into divisions. In

1365-809: A passenger service on the Delaware River. In 1807, the American Robert Fulton built the world's first commercially successful steamboat, simply known as the North River Steamboat , and powered by a Watt engine. Following Fulton's success, steamboat technology developed rapidly on both sides of the Atlantic . Steamboats initially had a short range and were not particularly seaworthy due to their weight, low power, and tendency to break down, but they were employed successfully along rivers and canals, and for short journeys along

1456-445: A pioneer of modern-day amphibious assault ships . During some of her operations, she was known to have used at least four cover names, R1, GL, MT, and Ryujo Maru. An amphibious warfare ship is an amphibious vehicle warship employed to land and support ground forces, such as marines , on enemy territory during an amphibious assault. Specialized shipping can be divided into two types, most crudely described as ships and craft. In general,

1547-416: A ship class without redefinition. The destroyer is generally regarded as the dominant surface-combat vessel of most modern blue-water navies. However, the once distinct roles and appearances of cruisers , destroyers , frigates , and corvettes have blurred. Most vessels have come to be armed with a mix of anti-surface, anti-submarine and anti-aircraft weapons. Class designations no longer reliably indicate

1638-729: A ship's economy or its speed. Broadly speaking, a compound engine can refer to a steam engine with any number of different-pressure cylinders—however, the term usually refers to engines that expand steam through only two stages, i.e., those that operate cylinders at only two different pressures (or "double-expansion" engines). Note that a compound engine (including multiple-expansion engines, see below) can have more than one set of variable-pressure cylinders. For example, an engine might have two cylinders operating at pressure x and two operating at pressure y, or one cylinder operating at pressure x and three operating at pressure y. What makes it compound (or double-expansion) as opposed to multiple-expansion

1729-407: A side-rod, extended down each side of the cylinder to connect to the end of the side-lever on the same side. The far ends of the two side-levers were connected to one another by a horizontal crosstail, from which extended a single, common connecting rod which operated the crankshaft as the levers rocked up and down around the central pin. The main disadvantage of the side-lever engine was that it

1820-511: A small, low-profile engine like the trunk engine to power the U.S. Federal government's monitors , a type of warship developed during the American Civil War that had very little space for a conventional powerplant. The trunk engine itself was, however, unsuitable for this purpose, because the preponderance of weight was on the side of the engine that contained the cylinder and trunk—a problem that designers could not compensate for on

1911-459: A smaller number of larger guns to be carried. The final innovation during the 19th century was the development of the torpedo and development of the torpedo boat . Small, fast torpedo boats seemed to offer an alternative to building expensive fleets of battleships. Pre-dreadnought battleships were sea-going battleships built between the mid- to late- 1880s and 1905, before the launch of HMS Dreadnought in 1906. The pre-dreadnought ships replaced

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2002-415: A smaller, lighter, more efficient design. In a steeple engine, the vertical oscillation of the piston is not converted to a horizontal rocking motion as in a beam engine, but is instead used to move an assembly, composed of a crosshead and two rods, through a vertical guide at the top of the engine, which in turn rotates the crankshaft connecting rod below. In early examples of the type, the crosshead assembly

2093-462: Is also an alternative name for the steeple engine (below). Many sources thus prefer to refer to it by its informal name of "square" engine to avoid confusion. Additionally, the marine crosshead or square engine described in this section should not be confused with the term " square engine " as applied to internal combustion engines , which in the latter case refers to an engine whose bore is equal to its stroke . The walking beam, technically known as

2184-401: Is that the engine could be easily started from any crank position. Like the conventional side-lever engine however, grasshopper engines were disadvantaged by their weight and size. They were mainly used in small watercraft such as riverboats and tugs . The crosshead engine, also known as a square , sawmill or A-frame engine, was a type of paddlewheel engine used in the United States. It

2275-438: Is that there are only two pressures , x and y. The first compound engine believed to have been installed in a ship was that fitted to Henry Eckford by the American engineer James P. Allaire in 1824. However, many sources attribute the "invention" of the marine compound engine to Glasgow 's John Elder in the 1850s. Elder made improvements to the compound engine that made it safe and economical for ocean-crossing voyages for

2366-540: The Age of Sail , fleets were divided into van, center, and rear squadrons, named after each squadron's place in the line of battle . In more modern times, the squadrons are typically composed of homogeneous groups of the same class of warship , such as battleships or cruisers . Since many smaller navies contain a single fleet, the term the fleet is often synonymous with the navy . Multinational fleets are not uncommon in naval history. For example, several nations made up

2457-533: The First World War and the armed merchant cruisers of the Second World War . The main types of warships today are, in order of decreasing size: aircraft carriers – amphibious assault ships – cruisers – destroyers – frigates – corvettes – fast attack boats . A more extensive list follows: The first evidence of ships being used for warfare comes from Ancient Egypt , specifically

2548-639: The Holy League fleet at the Battle of Lepanto in 1571, and a Franco-Spanish fleet faced the British Royal Navy at the Battle of Trafalgar in 1805. In modern times, NATO has formed standing combined fleets and operations from several national navies such as Operation Active Endeavour . Modern fleets combine surface warships , submarines , support ships, and ship-based aircraft to conduct naval operations at sea. Generally understood to be

2639-541: The Second World War Nazi Germany's fleet of U-boats (submarines) almost starved Britain into submission and inflicted huge losses on US coastal shipping. The success of submarines led to the development of new anti-submarine convoy escorts during the First and Second World Wars, such as the destroyer escort . Confusingly, many of these new types adopted the names of the smaller warships from

2730-587: The United Nations Convention on the Law of the Sea (UNCLOS) treaty negotiations had produced a legal definition of what was then generally accepted as a late-twentieth century warship. The UNCLOS definition was : "A warship means a ship belonging to the armed forces of a State bearing the external marks distinguishing such ships of its nationality, under the command of an officer duly commissioned by

2821-443: The age of sail , such as corvette , sloop and frigate . A seaplane tender is a ship that supports the operation of seaplanes . Some of these vessels, known as seaplane carriers, could not only carry seaplanes but also provided all the facilities needed for their operation; these ships are regarded by some as the first aircraft carriers and appeared just before the First World War . A major shift in naval warfare occurred with

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2912-417: The beam engine . The typical side-lever engine had a pair of heavy horizontal iron beams, known as side-levers, each secured in the centre by a pin near the base of the engine, allowing the levers to pivot through a limited arc. The engine cylinder stood vertically between this pair of levers at one end, with the piston rod attached to a horizontal crosshead above, from each end of which a vertical rod, known as

3003-465: The blue water , or oceanic, green water or littoral versus the brown water or coastal/riverine forces. The fleets of larger navies are usually divided into smaller numbered or named fleets based on geographic operating areas or administrative groupings of the same type of ships. Modern fleets are usually administrative units. Individual task forces are formed to conduct specific operations. In fictional literary works and/or media, most notably in

3094-512: The capital ships from the menace of the torpedo boat. At this time, Britain also introduced the use of fuel oil to power steam warships, instead of coal. Oil produced twice as much power per unit weight as coal, and was much easier to handle. Tests were conducted by the Royal Navy in 1904 involving the torpedo-boat destroyer Spiteful , the first warship powered solely by fuel oil. These proved its superiority, and all warships procured for

3185-420: The dreadnoughts on an even larger hull , battlecruisers sacrificed armour protection for speed. Battlecruisers were faster and more powerful than all existing cruisers, but much more vulnerable to shellfire than contemporary battleships. The torpedo-boat destroyer was developed at the same time as the dreadnoughts. Bigger, faster and more heavily gunned than the torpedo boat , the destroyer evolved to protect

3276-471: The screw propeller , and the introduction of iron and later steel hulls to replace the traditional wooden hull allowed ships to grow ever larger, necessitating steam power plants that were increasingly complex and powerful. A wide variety of reciprocating marine steam engines were developed over the course of the 19th century. The two main methods of classifying such engines are by connection mechanism and cylinder technology . Most early marine engines had

3367-524: The 1830s and the type was perfected in the early 1840s by the Scottish shipbuilder David Napier . The steeple engine was gradually superseded by the various types of direct-acting engine. The Siamese engine, also referred to as the "double cylinder" or "twin cylinder" engine, was another early alternative to the beam or side-lever engine. This type of engine had two identical, vertical engine cylinders arranged side-by-side, whose piston rods were attached to

3458-504: The 1940s. In marine applications, the beam itself was generally reinforced with iron struts that gave it a characteristic diamond shape, although the supports on which the beam rested were often built of wood. The adjective "walking" is believed to have originated from a corruption of the technical term "working beam". Walking beam engines were a type of paddlewheel engine and were rarely used for powering propellers. They were used primarily for ships and boats working in rivers, lakes and along

3549-655: The 19th century, it was normal practice to arm larger merchant ships such as galleons . Warships have also often been used as troop carriers or supply ships, such as by the French Navy in the 18th century or the Imperial Japanese Navy during the Second World War. In war since the early 20th century, merchant ships were often armed and used as auxiliary warships , such as the Q-ships of

3640-504: The 20th century by steam turbines and marine diesel engines . The first commercially successful steam engine was developed by Thomas Newcomen in 1712. The steam engine improvements brought forth by James Watt in the later half of the 18th century greatly improved steam engine efficiency and allowed more compact engine arrangements. Successful adaptation of the steam engine to marine applications in England would have to wait until almost

3731-554: The 4th century BC and the subsequent refinement of this technology enabled the first fleets of siege engine - equipped warships by the Hellenistic age . During late antiquity , ramming fell out of use and the galley tactics against other ships used during the Middle Ages until the late 16th century focused on boarding. Naval artillery was redeveloped in the 14th century, but cannon did not become common at sea until

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3822-739: The Royal Navy from 1912 were designed to burn fuel oil. During the lead-up to the Second World War , Germany and the United Kingdom once again emerged as the two dominant Atlantic sea powers. The German navy, under the Treaty of Versailles , was limited to only a few minor surface ships. But the clever use of deceptive terminology, such as Panzerschiffe deceived the British and French commands. They were surprised when ships such as Admiral Graf Spee , Scharnhorst , and Gneisenau raided Allied supply lines. The greatest threat however,

3913-514: The United States and in Ericsson's native country of Sweden, and as they had few advantages over more conventional engines, were soon supplanted by other types. The back-acting engine, also known as the return connecting rod engine , was another engine designed to have a very low profile. The back-acting engine was in effect a modified steeple engine, laid horizontally across the keel of a ship rather than standing vertically above it. Instead of

4004-412: The assembly maintained the correct path as it moved. The engine's alternative name—"A-frame"—presumably derived from the shape of the frames that supported these guides. Some crosshead engines had more than one cylinder, in which case the piston rods were usually all connected to the same crosshead. Because the cylinder was above the crankshaft in this type of engine, it had a high center of gravity, and

4095-553: The attacks, as in the Battle of the Coral Sea . Modern warships are generally divided into seven main categories, which are: aircraft carriers , cruisers , destroyers , frigates , corvettes , submarines , and amphibious warfare ships . Battleships comprise an eighth category, but are not in current service with any navy in the world. Only the deactivated American Iowa -class battleships still exist as potential combatants, and battleships in general are unlikely to re-emerge as

4186-488: The centerpiece of a display at the American Merchant Marine Museum . As steamships grew steadily in size and tonnage through the course of the 19th century, the need for low profile, low centre-of-gravity engines correspondingly declined. Freed increasingly from these design constraints, engineers were able to revert to simpler, more efficient and more easily maintained designs. The result was

4277-457: The close of the 19th century. Because they became so common, vertical engines are not usually referred to as such, but are instead referred to based upon their cylinder technology, i.e. as compound, triple-expansion, quadruple-expansion etc. The term "vertical" for this type of engine is imprecise, since technically any type of steam engine is "vertical" if the cylinder is vertically oriented. An engine someone describes as "vertical" might not be of

4368-431: The coast. The first successful transatlantic crossing by a steamship occurred in 1819 when Savannah sailed from Savannah, Georgia to Liverpool, England . The first steamship to make regular transatlantic crossings was the sidewheel steamer Great Western in 1838. As the 19th century progressed, marine steam engines and steamship technology developed alongside each other. Paddle propulsion gradually gave way to

4459-640: The coastline, but were a less popular choice for seagoing vessels because the great height of the engine made the vessel less stable in heavy seas. They were also of limited use militarily, because the engine was exposed to enemy fire and could thus be easily disabled. Their popularity in the United States was due primarily to the fact that the walking beam engine was well suited for the shallow- draft boats that operated in America's shallow coastal and inland waterways. Walking beam engines remained popular with American shipping lines and excursion operations right into

4550-435: The conservatism of American domestic shipbuilders and shipping line owners, who doggedly clung to outdated technologies like the walking beam and its associated paddlewheel long after they had been abandoned in other parts of the world. The steeple engine, sometimes referred to as a "crosshead" engine, was an early attempt to break away from the beam concept common to both the walking beam and side-lever types, and come up with

4641-424: The crankshaft rotated—hence the term, oscillating . Steam was supplied and exhausted through the trunnions. The oscillating motion of the cylinder was usually used to line up ports in the trunnions to direct the steam feed and exhaust to the cylinder at the correct times. However, separate valves were often provided, controlled by the oscillating motion. This let the timing be varied to enable expansive working (as in

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4732-410: The early 20th century. Although the walking beam engine was technically obsolete in the later 19th century, it remained popular with excursion steamer passengers who expected to see the "walking beam" in motion. There were also technical reasons for retaining the walking beam engine in America, as it was easier to build, requiring less precision in its construction. Wood could be used for the main frame of

4823-412: The engine in the paddle ship PD Krippen ). This provides simplicity but still retains the advantages of compactness. The first patented oscillating engine was built by Joseph Maudslay in 1827, but the type is considered to have been perfected by John Penn . Oscillating engines remained a popular type of marine engine for much of the 19th century. The trunk engine, another type of direct-acting engine,

4914-471: The engine, at a much lower cost than typical practice of using iron castings for more modern engine designs. Fuel was also much cheaper in America than in Europe, so the lower efficiency of the walking beam engine was less of a consideration. The Philadelphia shipbuilder Charles H. Cramp blamed America's general lack of competitiveness with the British shipbuilding industry in the mid-to-late 19th century upon

5005-404: The first Royal Navy steam vessel in 1820 until 1840, 70 steam vessels entered service, the majority with side-lever engines, using boilers set to 4psi maximum pressure. The low steam pressures dictated the large cylinder sizes for the side-lever engines, though the effective pressure on the piston was the difference between the boiler pressure and the vacuum in the condenser. The side-lever engine

5096-403: The first time, the aircraft carrier became the clear choice to serve as the main capital ship within a naval task force. World War II was the only war in history in which battles occurred between groups of carriers. World War II saw the first use of radar in combat. It brought the first naval battle in which the ships of both sides never engaged in direct combat, instead sending aircraft to make

5187-550: The first time. To fully realise their benefits, marine compound engines required boiler pressures higher than the limit imposed by the United Kingdom 's Board of Trade , who would only allow 25 pounds per square inch (170 kPa). The shipowner and engineer Alfred Holt was able to persuade the authorisation of higher boiler pressures, launching SS  Agamemnon in 1865, with boilers running at 60 psi (410 kPa). The combination of higher boiler pressures and

5278-493: The government of the State and whose name appears in the appropriate service list or its equivalent, and manned by a crew which is under regular armed forces discipline." The first practical submarines were developed in the late 19th century, but it was only after the development of the torpedo that submarines became truly dangerous (and hence useful). By the end of the First World War submarines had proved their potential. During

5369-424: The growing dominance of the so-called "vertical" engine (more correctly known as the vertical inverted direct acting engine). In this type of engine, the cylinders are located directly above the crankshaft, with the piston rod/connecting rod assemblies forming a more or less straight line between the two. The configuration is similar to that of a modern internal combustion engine (one notable difference being that

5460-716: The gunboat type exists in the Western Australian Museum in Fremantle . After sinking in 1872, it was raised in 1985 from the SS ; Xantho and can now be turned over by hand. The engine's mode of operation, illustrating its compact nature, could be viewed on the Xantho project's website. The vibrating lever, or half-trunk engine, was a development of the conventional trunk engine conceived by Swedish - American engineer John Ericsson . Ericsson needed

5551-468: The guns were capable of being reloaded quickly enough to be reused in the same battle. The size of a ship required to carry a large number of cannons made oar-based propulsion impossible, and warships came to rely primarily on sails. The sailing man-of-war emerged during the 16th century. By the middle of the 17th century, warships were carrying increasing numbers of cannons on their broadsides and tactics evolved to bring each ship's firepower to bear in

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5642-499: The higher boiler pressures that became prevalent in the latter half of the 19th century due to the difficulty of maintaining a steam seal around the trunk, and builders abandoned them for other solutions. Trunk engines were normally large, but a small, mass-produced, high-revolution, high-pressure version was produced for the Crimean War. In being quite effective, the type persisted in later gunboats. An original trunk engine of

5733-527: The introduction of the aircraft carrier . First at Taranto and then at Pearl Harbor , the aircraft carrier demonstrated its ability to strike decisively at enemy ships out of sight and range of surface vessels. By the end of the Second World War, the carrier had become the dominant warship. Shinshū Maru was a ship of the Imperial Japanese Army during World War II. She was the world's first purpose-built landing craft carrier ship, and

5824-551: The ironclad battleships of the 1870s and 1880s. Built from steel, protected by case-hardened steel armour, and powered by coal-fired triple-expansion steam engines, pre-dreadnought battleships carried a main battery of very heavy guns in fully-enclosed rotating turrets supported by one or more secondary batteries of lighter weapons. The role of corvettes , sloops and frigates were taken by new types of ships like destroyers , protected cruisers and armoured cruisers . Another revolution in capital warship design began shortly after

5915-500: The literature of the early period then, an engine can generally be assumed to be simple-expansion unless otherwise stated. Compound engines were a method of improving efficiency. Until the development of compound engines, steam engines used the steam only once before it was recycled back to the boiler. A compound engine first recycles the steam into one or more larger, lower-pressure secondary cylinders, to use more of its heat energy. Compound engines could be configured to increase either

6006-459: The location of the lever pivot and connecting rod are more or less reversed, with the pivot located at one end of the lever instead of the centre, while the connecting rod is attached to the lever between the cylinder at one end and the pivot at the other. Chief advantages of the grasshopper engine were cheapness of construction and robustness, with the type said to require less maintenance than any other type of marine steam engine. Another advantage

6097-399: The main material for warship construction. From the 1850s, the sailing ships of the line were replaced by steam-powered battleships , while the sailing frigates were replaced by steam-powered cruisers . The armament of warships also changed with the invention of the rotating barbettes and turrets , which allowed the guns to be aimed independently of the direction of the ship and allowed

6188-754: The northern Nile River most likely to defend against Mediterranean peoples. The galley warship most likely originated in Crete an idea which was soon copied and popularized by the Phoenicians . In the time of Mesopotamia , Ancient Persia , Phoenicia , Ancient Greece and the Ancient Rome , warships were always galleys (such as biremes , triremes and quinqueremes ): long, narrow vessels powered by banks of oarsmen and designed to ram and sink enemy vessels, or to engage them bow -first and follow up with boarding parties. The development of catapults in

6279-673: The number of expansion stages defines the engine, not the number of cylinders, e.g. the RMS Titanic had four-cylinder, triple-expansion engines. The first successful commercial use was an engine built at Govan in Scotland by Alexander C. Kirk for the SS  Aberdeen in 1881. An earlier experiment with an almost identical engine in SS Propontis in 1874 had had problems with the boilers. The initial installation, running at 150 psi (1,000 kPa) had to be replaced with

6370-567: The realm of science fiction , the term 'fleet' has also been used for a group of space-faring vessels used for interstellar travel. Marine steam engine A marine steam engine is a steam engine that is used to power a ship or boat . This article deals mainly with marine steam engines of the reciprocating type, which were in use from the inception of the steamboat in the early 19th century to their last years of large-scale manufacture during World War II . Reciprocating steam engines were progressively replaced in marine applications during

6461-595: The same cylinder technology (simple expansion, see below) but a number of different methods of supplying power to the crankshaft (i.e. connection mechanism) were in use. Thus, early marine engines are classified mostly according to their connection mechanism. Some common connection mechanisms were side-lever, steeple, walking beam and direct-acting (see following sections). However, steam engines can also be classified according to cylinder technology (simple-expansion, compound, annular etc.). One can therefore find examples of engines classified under both methods. An engine can be

6552-455: The same widespread acceptance, as it was only marginally smaller and lighter than the side-lever engines it was designed to replace. It was however used on a number of mid-century warships, including the first warship fitted with a screw propeller, HMS  Rattler . There are two definitions of a direct-acting engine encountered in 19th-century literature. The earlier definition applies the term "direct-acting" to any type of engine other than

6643-472: The second quarter of the 19th century. The Crimean War gave a great stimulus to the development of guns. The introduction of explosive shells soon led to the introduction of iron , and later steel , naval armour for the sides and decks of larger warships. The first ironclad warships, the French Gloire and British Warrior , made wooden vessels obsolete. Metal soon entirely replaced wood as

6734-470: The ships carry the troops from the port of embarkation to the drop point for the assault and the craft carry the troops from the ship to the shore. Amphibious assaults taking place over short distances can also involve the shore-to-shore technique, where landing craft go directly from the port of embarkation to the assault point. Amphibious assault ships have a well deck with landing craft which can carry tanks and other armoured fighting vehicles and also have

6825-475: The side-to-side motion of the connecting rod, which links a gudgeon pin at the piston head to an outside crankshaft. The walls of the trunk were either bolted to the piston or cast as one piece with it, and moved back and forth with it. The working portion of the cylinder is annular or ring-shaped, with the trunk passing through the centre of the cylinder itself. Early examples of trunk engines had vertical cylinders. However, ship builders quickly realized that

6916-406: The small monitor warships. Ericsson resolved this problem by placing two horizontal cylinders back-to-back in the middle of the engine, working two "vibrating levers", one on each side, which by means of shafts and additional levers rotated a centrally located crankshaft. Vibrating lever engines were later used in some other warships and merchant vessels, but their use was confined to ships built in

7007-478: The start of the 20th century, when Britain launched the Royal Navy 's all-big-gun battleship Dreadnought in 1906. Powered by steam turbines , it was bigger, faster and more heavily gunned than any existing battleships , which it immediately rendered obsolete. It was rapidly followed by similar ships in other countries. The Royal Navy also developed the first battlecruisers . Mounting the same heavy guns as

7098-436: The steam engine is double acting, see below, whereas almost all internal combustion engines generate power only in the downward stroke). Vertical engines are sometimes referred to as "hammer", "forge hammer" or "steam hammer" engines, due to their roughly similar appearance to another common 19th-century steam technology, the steam hammer . Vertical engines came to supersede almost every other type of marine steam engine toward

7189-404: The technical solution that ensured that virtually all newly built ocean-going steamships were fitted with triple expansion engines within a few years of Aberdeen coming into service. Multiple-expansion engine manufacture continued well into the 20th century. All 2,700 Liberty ships built by the United States during World War II were powered by triple-expansion engines, because the capacity of

7280-411: The triangular crosshead assembly found in a typical steeple engine however, the back-acting engine generally used a set of two or more elongated, parallel piston rods terminating in a crosshead to perform the same function. The term "back-acting" or "return connecting rod" derives from the fact that the connecting rod "returns" or comes back from the side of the engine opposite the engine cylinder to rotate

7371-543: The type was compact enough to lay horizontally across the keel . In this configuration, it was very useful to navies, as it had a profile low enough to fit entirely below a ship's waterline , as safe as possible from enemy fire. The type was generally produced for military service by John Penn. Trunk engines were common on mid-19th century warships. They also powered commercial vessels, where—though valued for their compact size and low centre of gravity—they were expensive to operate. Trunk engines, however, did not work well with

7462-420: The vertical inverted direct-acting type, unless they use the term "vertical" without qualification. A simple-expansion engine is a steam engine that expands the steam through only one stage, which is to say, all its cylinders are operated at the same pressure. Since this was by far the most common type of engine in the early period of marine engine development, the term "simple expansion" is rarely encountered. In

7553-491: Was a paddlewheel engine and was not suitable for driving screw propellers . The last ship built for transatlantic service that had a side-lever engine was the Cunard Line 's paddle steamer RMS  Scotia , considered an anachronism when it entered service in 1862. The grasshopper or 'half-lever' engine was a variant of the side-lever engine. The grasshopper engine differs from the conventional side-lever in that

7644-406: Was a type of direct-acting engine that was designed to achieve further reductions in engine size and weight. Oscillating engines had the piston rods connected directly to the crankshaft, dispensing with the need for connecting rods. To achieve this, the engine cylinders were not immobile as in most engines, but secured in the middle by trunnions that let the cylinders themselves pivot back and forth as

7735-464: Was large and heavy. For inland waterway and coastal service, lighter and more efficient designs soon replaced it. It remained the dominant engine type for oceangoing service through much of the first half of the 19th century however, due to its relatively low centre of gravity , which gave ships more stability in heavy seas. It was also a common early engine type for warships, since its relatively low height made it less susceptible to battle damage. From

7826-404: Was originally developed as a means of reducing an engine's height while retaining a long stroke . (A long stroke was considered important at this time because it reduced the strain on components.) A trunk engine locates the connecting rod within a large-diameter hollow piston. This "trunk" carries almost no load. The interior of the trunk is open to outside air, and is wide enough to accommodate

7917-619: Was rectangular in shape, but over time it was refined into an elongated triangle. The triangular assembly above the engine cylinder gives the engine its characteristic "steeple" shape, hence the name. Steeple engines were tall like walking beam engines, but much narrower laterally, saving both space and weight. Because of their height and high centre of gravity, they were, like walking beams, considered less appropriate for oceangoing service, but they remained highly popular for several decades, especially in Europe, for inland waterway and coastal vessels. Steeple engines began to appear in steamships in

8008-474: Was the first type of steam engine widely adopted for marine use in Europe . In the early years of steam navigation (from c1815), the side-lever was the most common type of marine engine for inland waterway and coastal service in Europe, and it remained for many years the preferred engine for oceangoing service on both sides of the Atlantic . The side-lever was an adaptation of the earliest form of steam engine,

8099-624: Was the introduction of the Kriegsmarine 's largest vessels, Bismarck and Tirpitz . Bismarck was heavily damaged and sunk/scuttled after a series of sea battles in the north Atlantic in 1941, while Tirpitz was destroyed by the Royal Air Force in 1944. The British Royal Navy gained dominance of the European theatre by 1943. The Second World War brought massive changes in the design and role of several types of warships. For

8190-406: Was the most common type of engine in the early years of American steam navigation. The crosshead engine is described as having a vertical cylinder above the crankshaft, with the piston rod secured to a horizontal crosshead, from each end of which, on opposite sides of the cylinder, extended a connecting rod that rotated its own separate crankshaft. The crosshead moved within vertical guides so that

8281-433: Was therefore deemed unsuitable for oceangoing service. This largely confined it to vessels built for inland waterways. As marine engines grew steadily larger and heavier through the 19th century, the high center of gravity of square crosshead engines became increasingly impractical, and by the 1840s, ship builders abandoned them in favor of the walking beam engine. The name of this engine can cause confusion, as "crosshead"

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