1.
Research vessel
–
A research vessel is a ship or boat designed, modified, and/or equipped to carry out research at sea. Research vessels carry out a number of roles, some of these roles can be combined into a single vessel but others require a dedicated vessel. Due to the nature of the work, research vessels are often constructed around an icebreaker hull. The research ship had origins in the voyages of exploration. By the time of James Cooks Endeavour, the essentials of what today we would call a ship are clearly apparent. In 1766, the Royal Society hired Cook to travel to the Pacific Ocean to observe, the Endeavour was a sturdy boat, well designed and equipped for the ordeals she would face, and fitted out with facilities for her research personnel, Joseph Banks. And, as is common with contemporary research vessels, Endeavour carried out more than one kind of research, some other notable early research vessels were HMS Beagle, RV Calypso, HMS Challenger, USFC Albatross, and the Endurance and Terra Nova. The names of early research vessels have been used to later research vessels. A hydrographic survey ship is a designed to conduct hydrographic research. Nautical charts are produced from this information to ensure safe navigation by military, hydrographic survey vessels also conduct seismic surveys of the seabed and the underlying geology. Apart from producing the charts, this information is useful for detecting geological features which are likely to bear oil or gas, in practice, hydrographic survey vessels are often equipped to perform multiple roles. Some function also as oceanographic research ships, naval hydrographic survey vessels often do naval research, for example, on submarine detection. An example of a survey vessel is CCGS Frederick G. Creed. For an example of the employment of a survey ship see HMS Hydra and these vessels often also carry scientific divers and unmanned underwater vehicles. Since the requirements of both oceanographic and hydrographic research are very different from those of fisheries research, these boats often fulfill dual roles, examples of an oceanographic research vessel include the NOAAS Ronald H. Brown and the Chilean Navy Cabo de Hornos. An example of a research vessel is FRV Scotia. Naval research vessels investigate naval concerns, such as submarine and mine detection, sonar, an example of a naval research vessel is the Planet of the German Navy. Polar research vessels are constructed around a hull, allowing them to operate in polar waters
2.
Ketchikan, Alaska
–
Ketchikan is a city in the Ketchikan Gateway Borough, Alaska, United States, the southeasternmost city in Alaska. With a population at the 2010 census of 8,050, it is the fifth-most populous city in the state, estimates put the 2014 population at 13,787 people. Ketchikan is located on Revillagigedo Island, so named in 1793 by Captain George Vancouver, Ketchikan is named after Ketchikan Creek, which flows through the town, emptying into the Tongass Narrows a short distance southeast of its downtown. Ketchikan comes from the Tlingit name for the creek, Kitschk-hin and it may mean the river belonging to Kitschk, other accounts claim it means Thundering Wings of an Eagle. In modern Tlingit this name is rendered as Kichx̱áan, Ketchikan Creek served as a summer fish camp for Tlingit natives for untold years before the town was established by Mike Martin in 1885. According to the U. S. Postal Service, one of Ketchikans two zip codes,99950, is the highest-numbered in the United States, Ketchikans economy is based upon government services, tourism and commercial fishing. Civic boosters have dubbed the community the Salmon Capital of the World, the Misty Fiords National Monument is one of the areas major attractions, and the Tongass National Forest has long been headquartered in Ketchikan, mostly in the citys historic Federal Building. For most of the half of the 20th century, a large portion of Ketchikans economy. The mill closed in 1997 in the wake of the passage of the Tongass Timber Reform Act of 1990, which reduced timber harvest targets in the national forest. Most of the totems at Saxman Totem Park and Totem Bight State Park are recarvings of older poles, the Totem Heritage Center displays preserved 19th-century poles rescued from abandoned village sites near Ketchikan. Ketchikan is located on Revillagigedo Island,700 miles north of Seattle, Washington and it is surrounded by the Tongass National Forest, which is managed by the United States Forest Service from headquarters in the Ketchikan Federal Building downtown. According to the United States Census Bureau, the city has an area of 5.9 square miles. 4.4 square miles of it is land and 1.5 square miles of it is water, the ½-mile wide channel called the Tongass Narrows separates Ketchikan from Gravina Island, where Ketchikan International Airport is located. Deer Mountain, a 3, 001-foot peak, rises immediately east of the downtown area. Ketchikan has a greatly modified and moderated by its maritime location. Winters are cool but far milder than its latitude alone may suggest, summers are mild, as August’s high averages 64.4 °F. Another feature of the climate is the high amount of rainfall, with an equivalent average of 153 inches per year, falling more heavily in autumn. Further east in North America, winters on these parallels are extremely cold, the record high temperature in Ketchikan was 89 °F on June 20,1958, and August 14,1977
3.
Ship
–
Historically, a ship was a sailing vessel with at least three square-rigged masts and a full bowsprit. Ships are generally distinguished from boats, based on size, shape, Ships have been important contributors to human migration and commerce. They have supported the spread of colonization and the trade, but have also served scientific, cultural. After the 16th century, new crops that had come from, Ship transport is responsible for the largest portion of world commerce. As of 2016, there were more than 49,000 merchant ships, of these 28% were oil tankers, 43% were bulk carriers, and 13% were container ships. Military forces operate vessels for naval warfare and to transport and support forces ashore, the top 50 navies had a median fleet of 88 surface vessels each, according to various sources. There is no definition of what distinguishes a ship from a boat. Ships can usually be distinguished from boats based on size and the ability to operate independently for extended periods. A legal definition of ship from Indian case law is a vessel that carries goods by sea, a common notion is that a ship can carry a boat, but not vice versa. American and British 19th Century maritime law distinguished vessels from other craft, ships and boats fall in one legal category, a number of large vessels are usually referred to as boats. Other types of vessel which are traditionally called boats are Great Lakes freighters, riverboats. Though large enough to carry their own boats and heavy cargoes, in most maritime traditions ships have individual names, and modern ships may belong to a ship class often named after its first ship. The first known vessels date back about 10,000 years ago, the first navigators began to use animal skins or woven fabrics as sails. Affixed to the top of a pole set upright in a boat and this allowed men to explore widely, allowing for the settlement of Oceania for example. By around 3000 BC, Ancient Egyptians knew how to assemble wooden planks into a hull and they used woven straps to lash the planks together, and reeds or grass stuffed between the planks helped to seal the seams. Sneferus ancient cedar wood ship Praise of the Two Lands is the first reference recorded to a ship being referred to by name, the ancient Egyptians were perfectly at ease building sailboats. A remarkable example of their skills was the Khufu ship. Aksum was known by the Greeks for having seaports for ships from Greece, a panel found at Mohenjodaro depicted a sailing craft
4.
Able seaman
–
An able seaman is a Naval rating of the deck department of a merchant ship with more than two years experience at sea and considered well acquainted with his duty. An AB may work as a watchstander, a day worker, once a sufficient amount of sea time is acquired, then the AB can apply to take a series of courses/examinations to become certified as an officer. At sea an AB watchstanders duties include standing watch as helmsman, a helmsman is required to maintain a steady course, properly execute all rudder orders and communicate utilizing navigational terms relating to heading and steering. A watchstander may be called upon to stand security-related watches, such as a watch or anchor watch while the ship is not underway. An AB day worker performs general maintenance, repair, sanitation and upkeep of material, equipment and this can include maintenance of the ships metal structures such as chipping, scraping, cleaning, priming, and painting. Areas frequently in need of such include the hull, decks, superstructure, cargo gear. Day workers also perform maintenance on lifeboats, rescue boats and liferafts. For many vessels, being a dayworker is a position granted to senior ABs, since it allows more time for rest. An AB may be called on to use emergency, lifesaving, damage control, Able seamen perform all operations connected with the launching of lifesaving equipment. An AB is expected to be able to operate machinery, such as the windlass or winches while mooring or unmooring. Able seamen require advanced training, including lifeboatman certification, the ships boatswain, if carried, is typically a senior AB. The boatswain is in charge of the seamen and ordinary seaman that comprise the unlicensed deck crew. The Code of Federal Regulations establishes in 46 CFR12.05 five categories of able seaman for the United States Merchant Marine, Able Seaman—Any Waters, requires three years service on deck on vessels operating on the oceans or the Great Lakes. Requires 18 months service on deck in vessels of 100 gross tons or more which operate in a service not exclusively confined to the rivers, requires 12 months service on deck on vessels operating on the oceans, or the navigable waters of the United States including the Great Lakes. Requires six months service on deck on vessels operating on the oceans, requires six months service on deck on sail or auxiliary sail vessels operating on the oceans or the navigable waters of the United States including the Great Lakes. Time served in training programs and school ships may be substituted for the time of service listed above. For the United States Merchant Marine, the Code of Federal Regulations establishes in 46 CFR12, the AB shall demonstrate ability to row by pulling an oar in the boat. The applicant shall also demonstrate knowledge of the knots, bends, splices
5.
Maritime pilot
–
A pilot, also referred to as a marine pilot, maritime pilot, or harbor pilot is a mariner who manoeuvres ships through dangerous or congested waters, such as harbors or river mouths. Since the pilot is on board the ship, he controls the tugs and linesmen through a radio, the ships captain ensures his crew carry out the pilots orders. Even if a ship Captain is a visitor to a certain Port, he can not match the expertise. In an unfortunate case of an accident, high pollution is a risk as the ships carry thousands of tonnes of fuel for her own consumption. Also if a ship is wrecked in the channel, the channel, legally, the master has full responsibility for safe navigation of his vessel, even if a pilot is on board. Only in transit of the Panama Canal and in Canada does the pilot have the responsibility for the navigation of the vessel. In English law, Section 742 of the Merchant Shipping Act 1894 defines a pilot as any person not belonging to a ship who has the conduct thereof. In other words, someone other than a member of the crew who has control over the speed, direction, the current United Kingdom legislation governing pilotage is the Pilotage Act 1987. Pilotage is one of the oldest professions, as old as sea travel, the oldest recorded history dates back to about the 7th century BC. The economic and environmental risk from large cargo ships makes the role of the pilot essential. Eventually, because the act of pilotage needed to be regulated and to ensure pilots had adequate insurance. The California Board of Pilot Commissioners was the first government agency created by Californias legislature, before harbour boards were established, pilots known as hobblers would compete with one another. The first to reach a ship would navigate it to the docks. In Dún Laoghaire, Ireland, there is a monument to the hobblers who lost their lives, in Kent they were known as hovellers and worked alongside and in competition with the licensed pilots, but were sometimes blamed as wreckers. George Byng Gattie defends the hovellers or hobilers as lifesavers in his 1890 book about the Goodwin Sands, although licensed by the harbour to operate within their jurisdiction, pilots were generally self-employed, and so had to have quick transport to get from the port to the incoming ships. As pilots were often still dual-employed, they used their own fishing boats to reach the incoming vessels, but fishing boats were heavy working boats, and filled with fishing equipment, hence a new type of boat was required. Early boats were developed from single-masted cutters and twin-masted yawls, and these were effectively light-weight and over-powered single masted boats with large steeply angled keels, making them deep draft under power and shallow draft in lighter sail. Joseph Henderson was an early American harbor pilot and he is well known for being a Sandy Hook Pilot for the New York harbor and along the Atlantic Coast during the Civil War
6.
Tugboat
–
A tug is a boat or ship that maneuvers vessels by pushing or towing them. Tugboats are powerful for their size and strongly built, and some are ocean-going, some tugboats serve as icebreakers or salvage boats. Early tugboats had steam engines, but today most have diesel engines, many tugboats have firefighting monitors, allowing them to assist in firefighting, especially in harbors. Seagoing tugs fall into four categories, The standard seagoing tug with model bow that tows its payload on a hawser. The notch tug which can be secured in a notch at the stern of a specially designed barge and this configuration is dangerous to use with a barge which is in ballast or in a head- or following sea. Therefore, notch tugs are usually built with a towing winch and these units stay combined under virtually any sea conditions and the tugs usually have poor sea-keeping designs for navigation without their barges attached. Vessels in this category are considered to be ships rather than tugboats. These vessels must show navigation lights compliant with those required of ships rather than required of tugboats. Articulated tug and barge units also utilize mechanical means to connect to their barges, the tug slips into a notch in the stern and is attached by a hinged connection. ATBs generally utilize Intercon and Bludworth connecting systems, aTBs are generally staffed as a large tugboat, with between seven and nine crew members. The typical American ATB operating on the east coast customarily displays navigational lights of a towing vessel pushing ahead, compared to seagoing tugboats, harbour tugboats are generally smaller and their width-to-length ratio is often higher, due to the need for a lower draught. In smaller harbours these are also termed lunch bucket boats, because they are only manned when needed and only at a minimum. The number of tugboats in a harbour varies with the harbour infrastructure, things to take into consideration includes ships with/without bow thrusters and forces like wind, current and waves and types of ship. River tugs are also referred to as towboats or pushboats and their hull designs would make open ocean operation dangerous. River tugs usually do not have any significant hawser or winch and their hulls feature a flat front or bow to line up with the rectangular stern of the barge, often with large pushing knees. Tugboat engines typically produce 500 to 2,500 kW, for safety, tugboats engines often feature two of each critical part for redundancy. A tugboats power is stated by its engines horsepower and its overall bollard pull. The largest commercial harbour tugboats in the 2000s-2010s, used for towing container ships or similar, had around 60-65 tons of bollard pull, Tugboats are highly maneuverable, and various propulsion systems have been developed to increase maneuverability and increase safety
7.
Battle of the Atlantic
–
The Battle of the Atlantic was the longest continuous military campaign in World War II, running from 1939 to the defeat of Germany in 1945. At its core was the Allied naval blockade of Germany, announced the day after the declaration of war and it was at its height from mid-1940 through to the end of 1943. The convoys, coming mainly from North America and predominantly going to the United Kingdom and these forces were aided by ships and aircraft of the United States from September 13,1941. The Germans were joined by submarines of the Italian Royal Navy after their Axis ally Italy entered the war on June 10,1940, as an island nation, the United Kingdom was highly dependent on imported goods. Britain required more than a million tons of imported material per week in order to be able to survive and fight. In essence, the Battle of the Atlantic was a war, the Allied struggle to supply Britain. From 1942 onwards, the Axis also sought to prevent the build-up of Allied supplies, the defeat of the U-boat threat was a pre-requisite for pushing back the Axis. The outcome of the battle was a victory for the Allies—the German blockade failed—but at great cost,3,500 merchant ships and 175 warships were sunk for the loss of 783 U-boats. The name Battle of the Atlantic was coined by Winston Churchill in February 1941 and it has been called the longest, largest, and most complex naval battle in history. The campaign started immediately after the European war began, during the so-called Phoney War and it involved thousands of ships in more than 100 convoy battles and perhaps 1,000 single-ship encounters, in a theatre covering millions of square miles of ocean. The Allies gradually gained the hand, overcoming German surface raiders by the end of 1942 and defeating the U-boats by mid-1943. The first meeting of the Cabinets Battle of the Atlantic Committee was on March 19, Churchill claimed to have coined the phrase Battle of the Atlantic shortly before Alexanders speech, but there are several examples of earlier usage. Following the use of unrestricted submarine warfare by Germany in the First World War, countries tried to limit, even abolish, the effort failed. or active resistance to visit or search. This made restrictions on submarines effectively moot, in 1939, the Kriegsmarine lacked the strength to challenge the combined British Royal Navy and French Navy for command of the sea. Instead, German naval strategy relied on commerce raiding using capital ships, armed merchant cruisers, submarines and these ships immediately attacked British and French shipping. U-30 sank the ocean liner SS Athenia within hours of the declaration of war—in breach of her orders not to sink passenger ships, much of the early German anti-shipping activity involved minelaying by destroyers, aircraft and U-boats off British ports. With the outbreak of war, the British and French immediately began a blockade of Germany, the Royal Navy quickly introduced a convoy system for the protection of trade that gradually extended out from the British Isles, eventually reaching as far as Panama, Bombay and Singapore. Convoys allowed the Royal Navy to concentrate its escorts near the one place the U-boats were guaranteed to be found, each convoy consisted of between 30 and 70 mostly unarmed merchant ships
8.
Sailing ship
–
A modern sailing ship or sailship is any large wind-powered vessel. Traditionally a sailing ship is a vessel that carries three or more masts with square sails on each. Large sailing vessels that are not ship-rigged may be more referred to by their sail rig, such as schooner, barque, brig. There are many different types of sailing ships, but they all have certain basic things in common, every sailing ship has a hull, rigging and at least one mast to hold up the sails that use the wind to power the ship. The crew who sail a ship are called sailors or hands and they take turns to take the watch, the active managers of the ship and her performance for a period. Watches are traditionally four hours long, some sailing ships use traditional ships bells to tell the time and regulate the watch system, with the bell being rung once for every half hour into the watch and rung eight times at watch end. A severe storm could lead to shipwreck, and the loss of all hands, Sailing ships are limited in their maximum size compared to ships with heat engines, so economies of scale are also limited. The heaviest sailing ships never exceeded 14,000 tons displacement, there are many types of sailing ships, mostly distinguished by their rigging, hull, keel, or number and configuration of masts. There are also types of smaller sailboats not listed here. The steam power was used to drive the winches, hoists, a similar ship Kruzenshtern, a very large sailing vessel without mechanical assists, had a crew of 257 men, compared to the Preussen, which required only 48 men. In 2006, automated control had been taken to the point where sails could be operated by one using a central control unit. The DynaRig technology was first developed in the 1960s in Germany by W. Prolls as an alternative for commercial ships to prepare for a possible future energy crisis. The technology is a version of the same type of sail used by the Preussen. The main difference is that the yards do not swing around a fixed mast but are attached to a rotating mast. DynaRig along with extensive computerization was used in the proof-of-concept Maltese Falcon to enable it to be sailed with no crew aloft, as of 2013, with increasing restrictions on use of bunker fuel, attempts were underway to develop hybrid sailing ships using automated sail and alternative fuels. Tall ship Rigging Sail-plan List of large sailing vessels Cruising Shipbuilding, the History of a Ship from Her Cradle to Her Grave, With a Short Account of Modern Steamships and Torpedoes. The sailing-ship, six years of history. Media related to Sailing ships at Wikimedia Commons
9.
Quarterdeck
–
The quarterdeck is a raised deck behind the main mast of a sailing ship. Traditionally it was where the captain commanded his vessel and where the colours were kept. This led to it being used as the ceremonial and reception area on board. Many such facilities have areas decorated like shipboard quarterdecks, in the 20th century the word came to be applied to the area at the stern of the ship, often used for secondary weapons and seaplane catapults. There are ancient traditions of offering special deference to the quarterdeck, greek, Roman, and Carthaginian warships all carried shrines which were given special respect. This continued into Christian times, and in medieval British warships, all hands were required to salute it by taking off their hats or caps. This led to the habit of saluting whenever one entered the quarterdeck, today, quarterdeck refers not to a specific deck, but to a ceremonial area designated as such by the captain, often used as the ships reception area while in harbour. As in the days of sail, it is a place where the captain has special control, in port, the quarterdeck is the most important place on the ship, and is the central control point for all its major activities. Underway, its importance diminishes as control of the ship is transferred to the bridge, the quarterdeck is normally on the main deck, but may be elsewhere in some types of ship. It is usually marked off by lines, deck markings, decorative cartridge cases. Special attention is paid to the cleanliness and physical appearance. Those standing watch on the quarterdeck must be in the uniform of the day, personnel not in the uniform of the day generally avoid crossing the quarterdeck unless their work requires it. On ships with a well-defined quarterdeck area, uniformed personnel should salute when they enter it, smoking and recreational activities are prohibited on the quarterdeck unless specially authorised by the commanding officer. The starboard gangway to the quarterdeck is used by officers and their visitors. In bad weather, all use the lee gangway. On smaller ships with only one gangway, it may be rigged to either side and is used by everyone, flagships sometimes have an additional starboard gangway for the flag officer and officers of his staff. In Medieval times, warships had a deck, with raised structures at each end. Later the halfdeck was extended the length of the ship, becoming the main deck
10.
Ship's wheel
–
A ships wheel or boats wheel is a device used aboard a water vessel to change that vessels course. Together with the rest of the mechanism, it forms part of the helm. It is connected to a mechanical, electric servo, or hydraulic system which alters the angle of the vessels rudder relative to its hull. A typical ships wheel is composed of eight wooden spokes shaped like balusters. The outer rim is composed of each made up of stacks of three felloes, the facing felloe, the middle felloe, and the after felloe. Because each group of three felloes at one time made up a quarter of the distance around the rim, the outer wooden wheel was sometimes called the quadrant. Each spoke ran through the middle felloe creating a series of handles beyond the wheels rim, the completed ships wheel and associated axle and pedestal might even be taller than the person using it. The steering gear of earlier shipss wheels sometimes consisted of a wheel where each wheel was connected to the other with a wooden spindle that ran through a barrel or drum. The spindle was held up by two pedestals that rested on a platform, often no more than a grate. Movement of the wheels caused the rope to wind in one of two directions and angled the tiller left or right. Having two wheels connected by an axle allowed two people to take the helm in severe weather when one person alone might not have had enough strength to control the ships movements
11.
Rudder
–
A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other conveyance that moves through a fluid medium. On an aircraft the rudder is used primarily to counter adverse yaw, a rudder operates by redirecting the fluid past the hull or fuselage, thus imparting a turning or yawing motion to the craft. In basic form, a rudder is a plane or sheet of material attached with hinges to the crafts stern, tail. Often rudders are shaped so as to minimize hydrodynamic or aerodynamic drag, on simple watercraft, a tiller—essentially, a stick or pole acting as a lever arm—may be attached to the top of the rudder to allow it to be turned by a helmsman. In larger vessels, cables, pushrods, or hydraulics may be used to link rudders to steering wheels, in typical aircraft, the rudder is operated by pedals via mechanical linkages or hydraulics. Generally, a rudder is part of the apparatus of a boat or ship that is fastened outside the hull, that is denoting all different types of oars, paddles. More specifically, the gear of ancient vessels can be classified into side-rudders and stern-mounted rudders. A third term, steering oar, can denote both types, in a Mediterranean context, side-rudders are more specifically called quarter-rudders as the later term designates more exactly the place where the rudder was mounted. Stern-mounted rudders are uniformly suspended at the back of the ship in a central position. S, a steering oar was used at this time because the rudder had not yet been invented. With a single sail, a frequent movement of the oar was required to steer a straight course. The steering oar or steering board is an oar or board to control the direction of a ship or other watercraft prior to the invention of the rudder. It is normally attached to the side in larger vessels, though in smaller ones it is rarely, if ever. Rowing oars set aside for steering appeared on large Egyptian vessels long before the time of Menes, in the Old Kingdom as much as five steering oars are found on each side of passenger boats. The tiller, at first a small pin run through the stock of the steering oar, both the tiller and the introduction of an upright steering post abaft reduced the usual number of necessary steering oars to one each side. In Iran, oars mounted on the side of ships for steering are documented from the 3rd millennium BCE in artwork, wooden models, the strength of the steering oar lay in its combination of effectiveness, adaptability and simpleness. Roman quarter steering oar mounting systems survived mostly intact through the medieval period, by the first half of the 1st century AD, steering gear mounted on the stern were also quite common in Roman river and harbour craft as proved from reliefs and archaeological finds. A tomb plaque of Hadrianic age shows a harbour tug boat in Ostia with a long stern-mounted oar for better leverage, interestingly, the boat already featured a spritsail, adding to the mobility of the harbour vessel. Further attested Roman uses of stern-mounted steering oars includes barges under tow, transport ships for wine casks, also, the well-known Zwammerdam find, a large river barge at the mouth of the Rhine, featured a large steering gear mounted on the stern
12.
Paddle steamer
–
A paddle steamer is a steamship or riverboat powered by a steam engine that drives paddle wheels to propel the craft through the water. In antiquity, paddle wheelers followed the development of poles, oars and sails, modern paddle wheelers may be powered by diesel engines. The paddle wheel is a steel framework wheel. The outer edge of the wheel is fitted with numerous, regularly-spaced paddle blades, the bottom quarter or so of the wheel travels underwater. An engine rotates the wheel in the water to produce thrust. More advanced paddle wheel designs feature feathering methods that keep each paddle blade closer to vertical while in the water to increase efficiency, the upper part of a paddle wheel is normally enclosed in a paddlebox to minimise splashing. There are two ways to mount paddle wheels on a ship, either a single wheel on the rear, known as a sternwheeler, or a paddle wheel on each side. Both sternwheelers and sidewheelers were used as riverboats in the United States, some still operate for tourists, for example on the Mississippi River. Sidewheelers are used as riverboats and as coastal craft and this extra maneuverability makes sidewheelers popular on the narrower, winding rivers of the Murray-Darling system in Australia, where a number still operate. European sidewheelers, such as the PS Waverley, connect the wheels with solid drive shafts that limit maneuverability, some were built with paddle clutches that disengage one or both paddles so they can turn independently. However, wisdom gained from experience with sidewheelers deemed that they be operated with clutches out. Crews noticed that as ships approached the dock, passengers moved to the side of the ready to disembark. The shift in weight, added to independent movements of the paddles, could lead to imbalance, in a simple paddle wheel, where the paddles are fixed around the periphery, power is lost due to churning of the water as the paddles enter and leave the water surface. Ideally, the paddles should remain vertical while under water and this ideal can be approximated by use of levers and linkages connected to a fixed eccentric. The eccentric is fixed slightly forward of the wheel centre. It is coupled to each paddle via a rod and lever, the geometry is designed such that the paddles are kept almost vertical for the short duration that they are in the water. One of the drawings of the Anonymous Author of the Hussite Wars shows a boat with a pair of paddle-wheels at each end turned by men operating compound cranks. In 1704, the French physicist Denis Papin constructed the first ship powered by his steam engine and this made him the first to construct a steam-powered boat
.jpg)
