1.
Dartmouth, Devon
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Dartmouth is a town and civil parish in the English county of Devon. It is a tourist destination set on the bank of the estuary of the River Dart. Their combined population at the census was 6,822. Dartmouth was of importance as a deep-water port for sailing vessels. The port was used as the point for the Crusades of 1147 and 1190. The narrow mouth of the Dart is protected by two fortified castles, Dartmouth Castle and Kingswear Castle, originally Dartmouths only wharf was Bayards Cove, a relatively small area protected by a fort at the southern end of the town. In 1373 Geoffrey Chaucer visited and among the pilgrims in his Canterbury Tales A schipman was ther, wonyng fer by weste, For ought I wost, notwithstanding Dartmouths connections with the crown and respectable society, it was a major base for privateering in medieval times. John Hawley or Hauley, a privateer and sometime mayor of Dartmouth is reputed to be a model for Chaucers schipman. The earliest street in Dartmouth to be recorded by name is Smith Street, several of the houses on the street are originally late 16th century or early 17th century and probably rebuilt on the site of earlier medieval dwellings. The street name derives from the smiths and shipwrights who built. Smith Street was also the site of the pillory in medieval times. St Saviours Church was constructed in 1335 and consecrated in 1372 and it contains a pre-Reformation oak rood screen built in 1480 and several monuments including the tomb of John Hawley and his two wives, covered with a large brass plate effigy of all three. A large medieval ironwork door is decorated with two leopards of the Plantagenets and is possibly the original portal, although it is dated 1631, this is thought to be the date of a subsequent refurbishment coincidental with major renovations of the church in the 17th century. In 1592 the Madre de Deus, a Portuguese treasure ship captured by the English in the Azores, still, ten freighters were needed to carry the treasure to London. Henry Hudson put in to Dartmouth on his return from North America, the Pilgrim Fathers put in to Dartmouths Bayards Cove, en route from Southampton to America. They rested a while before setting off on their journey in the Mayflower, about 300 miles west of Lands End, upon realising that the Speedwell was unseaworthy, it returned to Plymouth. The Mayflower departed alone to complete the crossing to Cape Cod, Dartmouths sister city is Dartmouth, Massachusetts. The town contains many medieval and Elizabethan streetscapes and is a patchwork of narrow lanes, a significant number of the historic buildings are listed
2.
BC Ferries
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British Columbia Ferry Services Inc. operating as BC Ferries, is a former provincial Crown corporation, now operating as an independently managed, publicly owned company. BC Ferries provides all passenger and vehicle ferry services for coastal. The inland ferries operating on British Columbias rivers and lakes are not run by BC Ferries, the responsibility for their provision rests with the British Columbia Ministry of Transportation, which contracts operation to various private sector companies. Minister of Highways Phil Gaglardi was tasked with overseeing the new Crown corporation, BC Ferries first route, commissioned in 1960, was between Swartz Bay, north of Sidney on Vancouver Island, and Tsawwassen, a part of the Corporation of Delta, using just two vessels. These ships were the now-retired MV Tsawwassen and the MV Sidney, the vast majority of the vessels in the fleet were built in B. C. waters, with only two foreign purchases and one domestic purchase. In the mid-1980s, BC Ferries took over the operations of the branch of the B. C. Ministry of Transportation and Highways, which ran services to very small coastal communities. This action dramatically increased the size of BC Ferries fleet and its service area. The distinctive dogwood on green flag that BC Ferries used between 1960 and 2003 gave the service its popular nickname the Dogwood Fleet, at its inception, BC Ferries was a division of the British Columbia Toll Highways and Bridges Authority, a provincial Crown corporation. Through successive reorganizations, it evolved into the British Columbia Ferry Authority and then the British Columbia Ferry Corporation, the single voting share of BC Ferries Corporation is held by the provincial governments BC Ferry Authority, which operates under the rules of the Act. During the 1990s, the NDP government commissioned a series of three fast ferries to improve service between the Mainland and Vancouver Island. The ships proved problematic when they suffered many technical issues and cost double what was expected, the fast ferries were eventually sold off for $19.4 million in 2003. The contract is estimated at $542 million for the three ships, which are designed to carry 370 vehicles and 1600 passengers. BC Ferries CEO David Hahn claimed that building the ferries in Germany would save almost $80 million, on September 17,2004, BC Ferries awarded the vessel construction contract to Germanys Flensburger shipyard. The contract protects BC Ferries from any delays through a fixed price, Coastal Renaissance entered service in March 2008, while Coastal Inspiration was delivered the same month and entered service in June. The third ship, Coastal Celebration, has delivered and is now in service as well. The new northern service vessel, Northern Expedition, has been delivered, in fiscal year 2011, BC Ferries reported a loss of $16.5 million due to declining ridership, with vehicle traffic dropping 3. 5% and passenger traffic dropping 2. 8%. Increased fares were to blame for the drop in ridership, and warnings came that there would likely be cutbacks in the service on a number of its routes in order to reduce costs
3.
Dock (maritime)
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The exact meaning varies among different variants of the English language. Dock may also refer to a dockyard or shipyard where the loading, unloading, building, the earliest known docks were those discovered in Wadi al-Jarf, an ancient Egyptian harbor dating from 2500 BCE located on the Red Sea coast. Archaeologists also discovered anchors and storage jars near the site, a dock from Lothal in India dates from 2400 BCE and was located away from the main current to avoid deposition of silt. This was the earliest known dock found in the world, equipped to berth and it is speculated that Lothal engineers studied tidal movements, and their effects on brick-built structures, since the walls are of kiln-burnt bricks. The engineers built a structure, with north-south arms of average 21.8 metres. In British English, a dock is an area of water used for loading, unloading, building or repairing ships. Such a dock may be created by building enclosing harbour walls into a natural water space. The level of water in the dock is maintained despite the raising and lowering of the tide and this makes transfer of cargo easier. It works like a lock which controls the level and allows passage of ships. The worlds first enclosed wet dock with lock gates to maintain a constant water level irrespective of tidal conditions was the Howland Great Dock on the River Thames, the dock was merely a haven surrounded by trees, with no unloading facilities. The worlds first commercial enclosed wet dock, with quays and unloading warehouses, was the Old Dock at Liverpool, built in 1715, the dock reduced ship waiting giving quick turn arounds, greatly improving the throughput of cargo. A drydock is another variant, also with dock gates, which can be emptied of water to allow investigation, where the water level is not controlled berths may be, Floating where there is always sufficient water to float the ship. NAABSA where ships settle on the bottom at low tide, ships using NAABSA facilities have to be designed for them. A dockyard consists of one or more docks, usually with other structures, in American English, a dock is technically synonymous with pier or wharf—any human-made structure in the water intended for people to be on. In American English, the term for the area between piers is slip. In the cottage country of Canada and the United States, a dock is a platform built over water. The platform is used for the boarding and offloading of small boats, R. Lothal, a Harappan Port Town. New Delhi, Archaeological Survey of India
4.
Ferry
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A ferry is a merchant vessel used to carry passengers, and sometimes vehicles and cargo as well, across a body of water. Most ferries operate regular return services, a passenger ferry with many stops, such as in Venice, Italy, is sometimes called a water bus or water taxi. Ferries form a part of the transport systems of many waterside cities and islands. However, ship connections of much larger distances may also be called ferry services, the profession of the ferryman is embodied in Greek mythology in Charon, the boatman who transported souls across the River Styx to the Underworld. Speculation that a pair of oxen propelled a ship having a wheel can be found in 4th century Roman literature Anonymus De Rebus Bellicis. Though impractical, there is no reason why it could not work and such a ferry, see When Horses Walked on Water, Horse-Powered Ferries in Nineteenth-Century America. The Marine Services Company of Tanzania offers passenger and cargo services in three of the African Great Lakes viz, Lake Victoria, Lake Tanganyika and Lake Nyasa. It also operates one of the oldest ferries in the region, Ferries from Great Britain also sail to Belgium, Denmark, the Netherlands, Norway, Spain and Ireland. Some ferries carry mainly tourist traffic, but most also carry freight, in Britain, car-carrying ferries are sometimes referred to as RORO for the ease by which vehicles can board and leave. The busiest single ferry route is across the part of Øresund. Before the Øresund bridge was opened in July 2000, car and car & train ferries departed up to seven times every hour, in 2013, this has been reduced, but a car ferry still departs from each harbor every 15 minutes during daytime. The route is around 2.2 nautical miles and the crossing takes 22 minutes, today, all ferries on this route are constructed so that they do not need to turn around in the harbors. This also means that the ferries lack natural stems and sterns, due to the same circumstances, starboard and port-side are dynamic and depending of in what direction the ferry sails. Despite the short crossing, the ferries are equipped with restaurants, cafeteria, kiosks, large cruiseferries sail in the Baltic Sea between Finland, Åland, Sweden, Estonia, Latvia and Saint Petersburg, Russia and from Italy to Sardinia, Corsica, Spain and Greece. In many ways, these ferries are like cruise ships, also many smaller ferries operate on domestic routes in Finland, Sweden and Estonia. The south-west and southern parts of the Baltic Sea has several routes mainly for heavy traffic, on the longer of these routes, simple cabins are available. In Istanbul, ferries connect the European and Asian shores of Bosphorus, as well as Princes Islands, in 2014 İDO transported 47 million passengers, the largest ferry system in the world. Due to the numbers of freshwater lakes and length of shoreline in Canada
5.
Train ferry
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A train ferry is a ship designed to carry railway vehicles. Typically, one level of the ship is fitted with tracks. In the United States, train ferries are sometimes referred to as car ferries, as distinguished from auto ferries used to transport automobiles. The wharf has a ramp, and a linkspan or apron, balanced by weights, a train ferry that is a barge is called a car float or rail barge. An early train ferry was established as early as 1833 by the Monkland, to extend the line over the Forth and Clyde Canal in Scotland, the company began operating a wagon ferry to transport the rolling stock over the canal. In April 1836, the first railroad car ferry in the U. S. Susquehanna, the first modern train ferry was Leviathan, built in 1849. The Edinburgh, Leith and Newhaven Railway was formed in 1842, the company hired the up-and-coming civil engineer Thomas Bouch who argued for a train ferry with an efficient roll-on roll-off mechanism to maximise the efficiency of the system. Custom-built ferries were to be built, with lines and matching harbour facilities at both ends to allow the rolling stock to easily drive on and off the boat. To compensate for the tides, adjustable ramps were positioned at the harbours. The wagons were loaded on and off with the use of steam engines. ”The company was persuaded to install this train ferry service for the transportation of goods wagons across the Firth of Forth from Burntisland in Fife to Granton. The ferry itself was built by Thomas Grainger, a partner of the firm Grainger and Miller, the service commenced on 3 February 1850. The Japanese train ferry, Toya Maru, sank during typhoon Marie on 26 September 1954, killing more than a thousand. Four other train ferries, Seikan maru No.11, Kitami Maru, Tokachi Maru and Hidaka Maru also sank on that day, the loss appeared to be of about 1,430 people. In those days, Japanese train ferries did not have a rear sea-gate, because engineers believed that water would simply flow out again quickly. After the accidents, all Japanese train ferries were retrofitted with rear sea-gates, one person subsequently died of injuries, and six freight cars and a number of automobiles sank to the bottom with the ship. The Canadian train ferry MV Patrick Morris sank on 20 April 1970, while assisting in a search, the ferry was trying to maintain position to retrieve a body when its stern gates were overpowered by 30-foot waves. It sank within 30 minutes taking several cars and 4 crew members, including the Captain. Train ferries rarely sank because of sea hazards, although they have some weaknesses linked to the nature of transporting trains on rail on a ship
6.
Barge
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A barge is a flat-bottomed boat, built mainly for river and canal transport of heavy goods. Some barges are not self-propelled and must be towed or pushed by towboats, Barge is attested from 1300, from Old French barge, from Vulgar Latin barga. The word originally could refer to any small boat, the modern meaning arose around 1480, bark small ship is attested from 1420, from Old French barque, from Vulgar Latin barca. The more precise meaning three-masted ship arose in the 17th century, both are probably derived from the Latin barica, from Greek, βάρις, translit. Egyptian boat, from Coptic, ⲃⲁⲁⲣⲉ bāri small boat, hieroglyphic Egyptian, by extension, the term embark literally means to board the kind of boat called a barque. The long pole used to maneuver or propel a barge has given rise to the saying I wouldnt touch that with a barge pole. On the British canal system, the barge is used to describe a boat wider than a narrowboat. In the United States, deckhands perform the labor and are supervised by a leadman or the mate, the captain and pilot steer the towboat, which pushes one or more barges held together with rigging, collectively called the tow. The crew live aboard the towboat as it travels along the river system or the intracoastal waterways. These towboats travel between ports and are also called line-haul boats, poles are used on barges to fend off the barge as it nears other vessels or a wharf. These are often called pike poles, barges are used today for low-value bulk items, as the cost of hauling goods by barge is very low. Barges are also used for heavy or bulky items, a typical American barge measures 195 by 35 feet. The most common European barge measures 76.5 by 11.4 metres, as an example, on June 26,2006, a 565-short-ton catalytic cracking unit reactor was shipped by barge from the Tulsa Port of Catoosa in Oklahoma to a refinery in Pascagoula, Mississippi. Extremely large objects are normally shipped in sections and assembled onsite, of the reactors 700-mile journey, only about 40 miles were traveled overland, from the final port to the refinery. Canal barges are made for the particular canal in which they will operate. Many barges, primarily Dutch barges, which were designed for carrying cargo along the canals of Europe, are no longer large enough to compete in this industry with larger newer vessels. Many of these barges have been renovated and are now used as hotel barges carrying holidaymakers along the same canals on which they once carried grain or coal. This holds true today, for areas of the world
7.
Car float
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A railroad car float or rail barge is an unpowered barge with rail tracks mounted on its deck. It is used to move railroad cars across water obstacles, or to locations they could not otherwise go, as such, the car float is a specialised form of the lighter, as opposed to a train ferry, which is self-powered. During the Civil War Herman Haupt used huge barges fitted with tracks to enable trains to cross the Rappahannock River in support of the Army of the Potomac. The ferry operation ended in 1906, the B&O operated a carfloat across the Baltimore Inner Harbor until the mid-1890s. It connected trains from Philadelphia to Washington, D. C. the operation was discontinued after the opening of the Baltimore Belt Line in 1895. Carfloat service was provided to many pier stations and waterfront warehouse facilities by the above-mentioned railroads. At their peak, the railroads had 3,400 employees operating small fleets totalling 323 car floats, plus 1,094 other barges, towed by 150 tugboats between New Jersey and New York City. A complete list can be here, Surviving Float Bridges of New York Harbor The only remaining carfloat service currently in operation in New York Harbor is operated by New York New Jersey Rail. This company, operated by the government agency Port Authority of New York & New Jersey is the successor to the New York Cross Harbor Railroad. Carfloat service operates between Bush Terminal in Brooklyn, New York and Greenville Yard in Jersey City and it has been proposed that carfloat service be transferred from Bush Terminal 50th float bridge to 65th Street / Bay Ridge Yard float bridges. Freight cars do not run in the East River Tunnels nor the North River Tunnels, between 1912–1936 the Erie Railroad operated a car float service on the Chicago River in Chicago, Illinois. Santa Fe Railroad, San Francisco Southern Pacific Railroad Union Pacific Railroad Western Pacific Railroad, San Francisco Chicago, Milwaukee, the rail ferries Pere Marquette 12 and Pere Marquette 10 were converted to barges and used until 1995 to carry dangerous cargoes and oversize cars. Windsor, Ontario – Detroit, Michigan BC Rail. until 1955 railcars were barged from North Vancouver to Squamish, a large number of isolated BC pulp mills had chemicals and freight moved by car floats. The Alaska Railroad provides the Alaska Rail Marine rail barge service from downtown Seattle, additionally, CN Rail provides the Aqua Train rail barge service from Prince Rupert, British Columbia to Whittier. The only remaining carfloat service currently in operation in the Port of New York and this company, operated by the bi-state government agency Port Authority of New York & New Jersey is the successor to the New York Cross Harbor Railroad. Car float service operates between Bush Terminal in Brooklyn, New York and Greenville Yard in Jersey City, New Jersey and it has been proposed that carfloat service be transferred from Bush Terminal 50th float bridge to 65th Street / Bay Ridge Yard float bridges. Bay Coast Railroad currently operates a 2-barge car float connecting Virginias Eastern Shore with the city of Norfolk, Prince Rupert – Whittier Delta – Nanaimo, British Columbia Matane, Quebec – Baie-Comeau, Quebec Railroad ferry, Hudson River, New York, Andreas Feininger,1940. Still Photograph Archive, George Eastman House, Rochester, NY, NYNJ Rail – official site Industrial & Offline Terminal Railroads of Brooklyn, Queens, Staten Island, Bronx & Manhattan
8.
Wheel
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A wheel is a circular component that is intended to rotate on an axle bearing. The wheel is one of the components of the wheel. Wheels, in conjunction with axles, allow heavy objects to be moved easily facilitating movement or transportation while supporting a load, wheels are also used for other purposes, such as a ships wheel, steering wheel, potters wheel and flywheel. Common examples are found in transport applications, a wheel greatly reduces friction by facilitating motion by rolling together with the use of axles. In order for wheels to rotate, a moment needs to be applied to the wheel about its axis, cognates within Indo-European include Icelandic hjól wheel, tyre, Greek κύκλος kúklos, and Sanskrit chakra, the latter both meaning circle or wheel. The invention of the falls into the late Neolithic. Note that this implies the passage of several wheel-less millennia even after the invention of agriculture and of pottery, precursors of wheels, known as tournettes or slow wheels, were known in the Middle East by the 5th millennium BCE. These were made of stone or clay and secured to the ground with a peg in the center, but required effort to turn. True potters wheels were apparently in use in Mesopotamia by 3500 BCE and possibly as early as 4000 BCE, and the oldest surviving example, which was found in Ur, dates to approximately 3100 BCE. The earliest well-dated depiction of a vehicle is on the Bronocice pot. The oldest securely dated real wheel-axle combination, that from Stare Gmajne near Ljubljana in Slovenia is now dated in 2σ-limits to 3340–3030 BCE, the axle to 3360–3045 BCE. Two types of early Neolithic European wheel and axle are known, a type of wagon construction. They both are dated to c, in China, the wheel was certainly present with the adoption of the chariot in c.1200 BCE, although Barbieri-Low argues for earlier Chinese wheeled vehicles, c.2000 BC. In Britain, a wooden wheel, measuring about 1 m in diameter, was uncovered at the Must Farm site in East Anglia in 2016. The specimen, dating from 1, 100–800 years BCE, represents the most complete, the wheels hub is also present. A horses spine found nearby suggests the wheel may have part of a horse-drawn cart. The wheel was found in a settlement built on stilts over wetland and it is thought that the primary obstacle to large-scale development of the wheel in the Americas was the absence of domesticated large animals which could be used to pull wheeled carriages. The only large animal that was domesticated in the Western hemisphere, Nubians from after about 400 BCE used wheels for spinning pottery and as water wheels
9.
Vehicle
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A vehicle is a mobile machine that transports people or cargo. Typical vehicles include wagons, bicycles, motor vehicles, railed vehicles, Land vehicles are classified broadly by what is used to apply steering and drive forces against the ground, wheeled, tracked, railed or skied. ISO 3833-1977 is the standard, also used in legislation, for road vehicles types, terms. Boats were used between 4000 BC-3000 BC in Sumer, ancient Egypt and in the Indian Ocean, there is evidence of camel pulled wheeled vehicles about 3000–4000 BC. Wheeled vehicles pulled by men and animals ran in grooves in limestone, in 200 CE, Ma Jun built a south-pointing chariot, a vehicle with an early form of guidance system. Railways began reappearing in Europe after the Dark Ages, the earliest known record of a railway in Europe from this period is a stained-glass window in the Minster of Freiburg im Breisgau dating from around 1350. In 1515, Cardinal Matthäus Lang wrote a description of the Reisszug, the line originally used wooden rails and a hemp haulage rope and was operated by human or animal power, through a treadwheel. 1769 Nicolas-Joseph Cugnot is often credited with building the first self-propelled mechanical vehicle or automobile in 1769. In Russia, in the 1780s, Ivan Kulibin developed a human-pedalled, three-wheeled carriage with modern features such as a flywheel, brake, gear box and bearings, however and it was introduced by Drais to the public in Mannheim in summer 1817. 1903 Wright brothers flew the first controlled, powered aircraft 1907 First helicopters Gyroplane no.1, there are over 1 billion bicycles in use worldwide. In 2002 there were an estimated 590 million cars and 205 million motorcycles in service in the world, at least 500 million Chinese Flying Pigeon bicycles have been made, more than an other single model of vehicle. The most-produced model of vehicle is the Honda Super Cub motorcycle. The most-produced car model is the Toyota Corolla, with at least 35 million made by 2010, by far, most vehicles use wheels which employ the principle of rolling to enable displacement with very little rolling friction. It is essential that a vehicle have a source of energy to drive it, energy can be extracted from the surrounding environment, as in the case of a sailboat, a solar-powered car or a streetcar. Energy can also be stored, in any form, provided it can be converted on demand, the most common type of energy source is fuel. Batteries also facilitate the use of motors, which have their own advantages. On the other hand, batteries have low densities, short service life, poor performance at extreme temperatures. Like fuel, batteries store energy and can cause burns
10.
Railroad car
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A railroad car or railcar, railway wagon or railway carriage, also called a train car or train wagon, is a vehicle used for the carrying of cargo or passengers on a rail transport system. Such cars, when coupled together and hauled by one or more locomotives, alternatively, some passenger cars are self-propelled in which case they may be either single railcars or make up multiple units. The term car is used by itself in American English when a rail context is implicit. Indian English sometimes uses bogie in the manner, though the term has other meanings in other variants of English. In American English, railcar is a term for a railway vehicle, in other countries railcar refers specifically to a self-propelled, powered. Tables may be provided between seats facing one another, alternatively, seats facing in the same direction may have access to a fold-down ledge on the back of the seat in front. If the aisle is located between seats, seat rows may face the direction, or be grouped, with twin rows facing each other. In some vehicles intended for services, seats are positioned with their backs to the side walls. This gives a wide accessway and allows room for standing passengers at peak times, if the aisle is at the side, the car is usually divided into small compartments. These usually contain six seats, although sometimes in second class they contain eight, modern cars usually have either air-conditioning or windows that can be opened, or sometimes both. Various types of onboard train toilet facilities may also be provided, other types of passenger car exist, especially for long journeys, such as the dining car, parlor car, disco car, and in rare cases theater and movie theater car. In some cases another type of car is converted to one of these for an event. Observation cars were built for the rear of many trains to allow the passengers to view the scenery. Sleeping cars outfitted with small bedrooms allow passengers to sleep through their night-time trips, long-distance trains often require baggage cars for the passengers luggage. In European practice it used to be common for day coaches to be formed of compartments seating 6 or 8 passengers, in the UK, Corridor coaches fell into disfavor in the 1960s and 1970s partially because open coaches are considered more secure by women traveling alone. Another distinction is between single- and double deck train cars, an example of a double decker is the Amtrak superliner. A trainset is a semi-permanently arranged formation of cars, rather than one created ad hoc out of cars are available. These are only broken up and reshuffled on shed, trains are then built of one or more of these sets coupled together as needed for the capacity of that train
11.
Tugboat
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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
12.
San Francisco Bay
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San Francisco Bay is a shallow estuary in the U. S. state of California. It is surrounded by a region known as the San Francisco Bay Area, dominated by the large cities San Francisco, Oakland. San Francisco Bay drains water from approximately 40 percent of California and it then connects to the Pacific Ocean via the Golden Gate strait. However, this group of interconnected bays is often called the San Francisco Bay. The bay was designated a Ramsar Wetland of International Importance on February 2,2013, the bay covers somewhere between 400 and 1,600 square miles, depending on which sub-bays, estuaries, wetlands, and so on are included in the measurement. The main part of the bay measures 3 to 12 miles wide east-to-west and it is the largest Pacific estuary in the Americas. Later, wetlands and inlets were filled in, reducing the Bays size since the mid-19th century by as much as one third. Recently, large areas of wetlands have been restored, further confusing the issue of the Bays size, despite its value as a waterway and harbor, many thousands of acres of marshy wetlands at the edges of the bay were, for many years, considered wasted space. As a result, soil excavated for building projects or dredged from channels was often dumped onto the wetlands, from the mid-19th century through the late 20th century, more than a third of the original bay was filled and often built on. The idea was, and remains, controversial, there are five large islands in San Francisco Bay. Alameda, the largest island, was created when a shipping lane was cut in 1901 and it is now predominantly a bedroom community. Angel Island was known as Ellis Island West because it served as the point for immigrants from East Asia. It is now a park accessible by ferry. Mountainous Yerba Buena Island is pierced by a tunnel linking the east and west spans of the San Francisco–Oakland Bay Bridge, attached to the north is the artificial and flat Treasure Island, site of the 1939 Golden Gate International Exposition. From the Second World War until the 1990s, both served as military bases and are now being redeveloped. Isolated in the center of the Bay is Alcatraz, the site of the federal penitentiary. The federal prison on Alcatraz Island no longer functions, but the complex is a popular tourist site, despite its name, Mare Island in the northern part of the bay is a peninsula rather than an island. During the last ice age, the now filled by the bay was a large linear valley with small hills
