Lighthouse

Lighthouse

Overview
A lighthouse is a tower, building, or other type of structure designed to emit light from a system of lamps and lenses or, in older times, from a fire, and used as an aid to navigation for maritime pilot
Maritime pilot
A pilot is a mariner who guides ships through dangerous or congested waters, such as harbours or river mouths. With the exception of the Panama Canal, the pilot is only an advisor, as the captain remains in legal, overriding command of the vessel....

s at sea or on inland waterways.

Lighthouses mark dangerous coastlines, hazardous shoal
Shoal
Shoal, shoals or shoaling may mean:* Shoal, a sandbank or reef creating shallow water, especially where it forms a hazard to shipping* Shoal draught , of a boat with shallow draught which can pass over some shoals: see Draft...

s, reef
Reef
In nautical terminology, a reef is a rock, sandbar, or other feature lying beneath the surface of the water ....

s, safe entries to harbors, and can also assist in aerial navigation. Once widely used, the number of operational lighthouses has declined due to the expense of maintenance and replacement by modern electronic navigational devices.

In a lighthouse, the source of light is called the "lamp" (whether electric or fueled by oil) and the concentration of the light is by the "lens" or "optic".
Originally lit by open fires and later candles, the Argand hollow wick lamp
Argand lamp
The Argand lamp is home lighting oil lamp producing a light output of 6 to 10 candlepower which was invented and patented in 1780 by Aimé Argand...

 and parabolic reflector was developed around 1781 in Europe.
Discussion
Ask a question about 'Lighthouse'
Start a new discussion about 'Lighthouse'
Answer questions from other users
Full Discussion Forum
 
Recent Discussions
Encyclopedia
A lighthouse is a tower, building, or other type of structure designed to emit light from a system of lamps and lenses or, in older times, from a fire, and used as an aid to navigation for maritime pilot
Maritime pilot
A pilot is a mariner who guides ships through dangerous or congested waters, such as harbours or river mouths. With the exception of the Panama Canal, the pilot is only an advisor, as the captain remains in legal, overriding command of the vessel....

s at sea or on inland waterways.

Lighthouses mark dangerous coastlines, hazardous shoal
Shoal
Shoal, shoals or shoaling may mean:* Shoal, a sandbank or reef creating shallow water, especially where it forms a hazard to shipping* Shoal draught , of a boat with shallow draught which can pass over some shoals: see Draft...

s, reef
Reef
In nautical terminology, a reef is a rock, sandbar, or other feature lying beneath the surface of the water ....

s, safe entries to harbors, and can also assist in aerial navigation. Once widely used, the number of operational lighthouses has declined due to the expense of maintenance and replacement by modern electronic navigational devices.

Lighthouse technology


In a lighthouse, the source of light is called the "lamp" (whether electric or fueled by oil) and the concentration of the light is by the "lens" or "optic".
Originally lit by open fires and later candles, the Argand hollow wick lamp
Argand lamp
The Argand lamp is home lighting oil lamp producing a light output of 6 to 10 candlepower which was invented and patented in 1780 by Aimé Argand...

 and parabolic reflector was developed around 1781 in Europe. In the U.S., whale oil
Whale oil
Whale oil is the oil obtained from the blubber of various species of whales, particularly the three species of right whale and the bowhead whale prior to the modern era, as well as several other species of baleen whale...

 was used with solid wicks as the source of light until the Argand parabolic reflector system was introduced around 1810 by Winslow Lewis
Winslow Lewis
Winslow Lewis was a sea captain, engineer, inventor and contractor active in the construction of many American lighthouses during the first half of the nineteenth century....

.
Colza oil
Colza oil
Colza oil is a nondrying oil obtained from the seeds of Brassica rapa, var. oleifera, a variety of the plant that produces turnips. Colza is extensively cultivated in France, Belgium, the United States, the Netherlands and Germany and Poland. In France, especially, the extraction of the oil is an...

 replaced whale oil in the early 1850s, but U.S. farmers' lack of interest in growing this caused the service to switch to lard oil in the mid 1850s. Kerosene started replacing lard oil in the 1870s and the lighthouse service was finally converted by the late 1880s. Electricity and carbide (acetylene gas) began replacing kerosene around the turn of the 20th century. It was promoted by the Dalén light
Dalén light
The Dalén light was the predominant form of light source in lighthouses from the 1900s through the 1960s, when electric lighting had become dominant. The system was invented by Gustaf Dalén and marketed by his company AGA. Dalén later invented the AGA cooker in 1922. The Dalén light is notable...

, which automatically lit the lamp at nightfall and extinguished it at dawn.

Lens technology



Prior to modern strobe lights, lenses
Lens (optics)
A lens is an optical device with perfect or approximate axial symmetry which transmits and refracts light, converging or diverging the beam. A simple lens consists of a single optical element...

 were used to concentrate the light from a continuous source. Two tasks were involved:
  • vertical light rays of the lamp are redirected into a horizontal plane
  • horizontally the light is focused into one or a few directions at a time, with the light beam
    Light beam
    A light beam or beam of light is a narrow projection of light energy radiating from a source into a beam. Sunlight is a natural example of a light beam when filtered through various mediums...

     sweeping around; as a result, in addition to seeing the side of the light beam, the light is directly visible from further away.

Fresnel lens



This concentration of light is accomplished with a rotating lens assembly. In classical period lighthouses, the light source was a kerosene lamp
Kerosene lamp
The kerosene lamp is a type of lighting device that uses kerosene as a fuel. This article refers to kerosene lamps that have a wick and a tall glass chimney. Kerosene lanterns that have a wick and a glass globe are related to kerosene lamps and are included here as well...

 or, earlier, an animal or vegetable oil Argand lamp, and the lenses rotated by a weight driven clockwork assembly wound by lighthouse keeper
Lighthouse keeper
A lighthouse keeper is the person responsible for tending and caring for a lighthouse, particularly the light and lens in the days when oil lamps and clockwork mechanisms were used. Keepers were needed to trim the wicks, replenish fuel, wind clockworks and perform maintenance tasks such as cleaning...

s, sometimes as often as every two hours. The lens assembly sometimes floated in liquid mercury
Mercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...

 to reduce friction. In more modern lighthouses, electric lights and motor drives were used, generally powered by diesel electric generators. These also supplied electricity for the lighthouse keepers.

Efficiently concentrating the light from a large omnidirectional light source requires a very large diameter lens. This would require a very thick and heavy lens if a conventional lens were used. The invention of the Fresnel lens
Fresnel lens
A Fresnel lens is a type of lens originally developed by French physicist Augustin-Jean Fresnel for lighthouses.The design allows the construction of lenses of large aperture and short focal length without the mass and volume of material that would be required by a lens of conventional design...

 in 1822 by French physicist Augustin-Jean Fresnel
Augustin-Jean Fresnel
Augustin-Jean Fresnel , was a French engineer who contributed significantly to the establishment of the theory of wave optics. Fresnel studied the behaviour of light both theoretically and experimentally....

 revolutionized lighthouses in the 19th century, focusing 85% of a lamp's light versus the 20% focused with the parabolic reflectors of the time. Its design enabled construction of lenses of large size and short focal length without the weight and volume of material in conventional lens designs. Although the Fresnel lens was invented in 1822, it was not used in the U.S. until the 1850s due to the parsimonious administrator of the United States lighthouse establishment, Stephen Pleasonton. With the creation of the United States Lighthouse Board
United States Lighthouse Board
The United States Lighthouse Board was the agency of the US Federal Government that was responsible for the upkeep and maintenance of all lighthouses in the United States...

 in 1852, all U.S. lighthouses received Fresnel lenses by 1860.



Fresnel lenses are ranked by order, a measure of refracting power, with a first order lens being the largest, most powerful and expensive; and a sixth order lens being the smallest. The order is based on the focal length of the lens. A first order lens has the longest focal length, with the sixth being the shortest. Coastal lighthouses generally use first, second, or third order lenses, while harbor lights and beacons use fourth, fifth, or sixth order lenses.

Some lighthouses, such as those at Cape Race
Cape Race
Cape Race is a point of land located at the southeastern tip of the Avalon Peninsula on the island of Newfoundland, Canada. Its name is thought to come from the original Portuguese name for this cape, "Raso", or "bare"...

, Newfoundland, and Makapuu Point
Makapuu Point Light
The Makapuu Point Light on the island of Oahu has the largest lens of any lighthouse in the United States. It was listed on the National Register of Historic Places in 1977.-History:...

, Hawaii, used a more powerful hyperradiant Fresnel lens
Hyperradiant Fresnel lens
Hyper-radial or hyperradiant Fresnel lenses are Fresnel lenses larger than "first order" lenses. They have a focal length of 1330 mm. The idea was mentioned by Thomas Stevenson in 1869 and first proposed by John Richardson Wigham in 1872, and again proposed by Thomas Stevenson in 1885.The...

 manufactured by the firm of Chance Brothers
Chance Brothers
Chance Brothers and Company was a glassworks originally based in Spon Lane, Smethwick, West Midlands , in England. It was a leading glass manufacturer and a pioneer of British glassmaking technology....

.

In recent times, many Fresnel lenses have been replaced by rotating aerodrome beacon
Aerodrome beacon
An aerodrome beacon or rotating beacon is a beacon installed at an airport or aerodrome to indicate its location to aircraft pilots at night....

s which require less maintenance. In modern automated lighthouses, this system of rotating lenses is often replaced by a high intensity light that emits brief omnidirectional flashes (concentrating the light in time rather than direction). These lights are similar to obstruction lights used to warn aircraft of tall structures. Recent innovations are "Vega Lights", and initial experiments with Light-emitting diode
Light-emitting diode
A light-emitting diode is a semiconductor light source. LEDs are used as indicator lamps in many devices and are increasingly used for other lighting...

 (LED) panels.

Light characteristics



In any of these designs an observer, rather than seeing a continuous weak light, sees a brighter light during short time intervals. These instants of bright light are arranged to create a light characteristic or, pattern specific to a lighthouse. For example, the Scheveningen Lighthouse
Scheveningen Lighthouse
De Scheveningen Lighthouse is a lighthouse in Scheveningen, Netherlands. It was designed by Quirinus Harder and activated finished in 1875.-History:...

 flashes are alternately 2.5 and 7.5 seconds. Some lights have sectors of a particular color (usually formed by colored panes in the lantern) to distinguish safe water areas from dangerous shoals. Modern lighthouses often have unique reflectors or Racon transponders
Racon
A racon is a radar transponder commonly used to mark maritime navigational hazards. The word is a portmanteau of RAdar and beaCON.When a racon receives a radar pulse, it responds with a signal on the same frequency which puts an image on the radar display...

 so the radar signature of the light is also unique.

Design


To be effective the lamp must be high enough to be seen before the danger is reached by a mariner. The minimum height is calculated according to trigonometry by taking the square root of the height of the light above the water in feet and multiplying it by 1.17 to yield the distance to the horizon in nautical miles.

Where dangerous shoals are located far off a flat sandy beach, the prototypical tall masonry coastal lighthouse is constructed to assist the navigator making a landfall after an ocean crossing. Often these are cylindrical to reduce the effect of wind on a tall structure, such as Cape May Light. Smaller versions of this design are often used as harbor lights to mark the entrance into a harbor, such as New London Harbor Light
New London Harbor Light
New London Harbor Light is a lighthouse in Connecticut,United States, on the west side of the New London harbor entrance, Connecticut. It is the nation's fifth oldest light station and the seventh oldest U.S...

.

Where a tall cliff exists, a smaller structure may be placed on top such as at Horton Point Light
Horton Point Light
Horton Point Light is a lighthouse on the north side of Eastern Long Island, New York near Southold.-History:The current lighthouse was established and the tower was first lit in 1857. The site is on a bluff above Long Island Sound. The tower was automated in 1933 and is now operational. The...

. Sometimes, such a location can be too high–as along the west coast of the United States. In these cases, lighthouses are placed below clifftop to ensure that they can still be seen at the surface during periods of fog or low clouds, as at Point Reyes Lighthouse. Another victim of fog was former Point Loma Light which was replaced with a lower lighthouse, Point Loma
Point Loma Light (new)
New Point Loma Lighthouse is a lighthouse on Point Loma in California,United States, near San Diego, California. It was built in 1891 to replace the Old Point Loma Lighthouse, that was ineffective due to elevation .thumb|left|Undated [[USCG]] photo...

.

As technology advanced, prefabricated skeletal iron or steel structures tended to be used for lighthouses constructed in the 20th century. These often have a narrow cylindrical core surrounded by an open lattice work bracing, such as Finns Point Range Light
Finns Point Range Light
The Finns Point Range Rear Light, located just east of the Delaware River was part of Range light pair that guided ships into the Delaware River. It is deactivated and its lamp has been removed, but the lighthouse is open to the public as part of a National Wildlife Refuge...

.

Sometimes a lighthouse needs to be constructed in the water itself. Wave-washed lighthouses are masonry structures constructed to withstand water impact, such as Eddystone Lighthouse
Eddystone Lighthouse
Eddystone Lighthouse is on the treacherous Eddystone Rocks, south west of Rame Head, United Kingdom. While Rame Head is in Cornwall, the rocks are in Devon and composed of Precambrian Gneiss....

 in Britain and the St. George Reef Light off California. In shallower bays, Screw-pile lighthouse
Screw-pile lighthouse
A screw-pile lighthouse is a lighthouse which stands on piles that are screwed into sandy or muddy sea or river bottoms. The first screw-pile lighthouse was built by blind Irish engineer Alexander Mitchell...

 ironwork structures are screwed into the seabed and a low wooden structure is placed above the open framework, such as Thomas Point Shoal Lighthouse. As screw piles can be disrupted by ice, steel caisson lighthouses such as Orient Point Light
Orient Point Light
Orient Point Light is a sparkplug lighthouse off Orient Point, New York.It was listed on the National Register of Historic Places in 2007.In June 2011, the General Services Administration made the Orient Point Light available at no cost to public organizations willing to preserve them...

 are used in cold climates. Orient Long Beach Bar Light
Orient Long Beach Bar Light
Orient Long Beach Bar Light is a lighthouse off Orient, New York. It is interesting because it was originally a screwpile lighthouse that was later converted to concrete caisson foundation. Its early appearance as a screwpile lighhouse gave it the nickname "Bug Light" as there were no other such...

 (Bug Light) is a blend of a screw pile light that was converted to a caisson light because of the threat of ice damage.

In waters too deep for a conventional structure, a lightship
Lightship
Lightship may refer to:* Lightvessel, a permanently moored ship that has light beacons mounted as navigational aids* Light displacement, a displacement figure that measures a ship complete in all respects, but without consumables, stores, cargo, crew, and effects*Lightship, a type of blimp operated...

 might be used instead of a lighthouse, such as the former lightship Columbia. Most of these have now been replaced by fixed light platforms (such as Ambrose Light
Ambrose Light
Ambrose Light, often called Ambrose Tower, was a light station at the convergence of several major shipping lanes in Lower New York Bay, including Ambrose Channel, the primary passage for ships entering and departing the Port of New York and New Jersey....

) similar to those used for offshore oil exploration.

Components


While lighthouse buildings differ depending on the location and purpose, they tend to have common components.

A light station comprises the lighthouse tower and all outbuildings, such as the keeper's living quarters, fuel house, boathouse, and fog-signaling building. The Lighthouse itself consists of a tower structure supporting the lantern room where the light operates.

The lantern room is the glassed-in housing at the top of a lighthouse tower containing the lamp and lens. Its glass storm panes are supported by metal Astragal
Astragal
An astragal is a moulding profile composed of a half-round surface surrounded by two flat planes . An astragal is sometimes referred to as a miniature torus...

bars running vertically or diagonally. At the top of the lantern room is a stormproof ventilator designed to remove the smoke of the lamps and the heat that builds in the glass enclosure. A lightning rod
Lightning rod
A lightning rod or lightning conductor is a metal rod or conductor mounted on top of a building and electrically connected to the ground through a wire, to protect the building in the event of lightning...

 and grounding system connected to the metal cupola roof provides a safe conduit for any lightning strikes.

Immediately beneath the lantern room is usually a Watch Room or Service Room where fuel and other supplies were kept and where the keeper prepared the lanterns for the night and often stood watch. The clockworks (for rotating the lenses) were also located there. On a lighthouse tower, an open platform called the gallery is often located outside the watch room (called the Main Gallery) or Lantern Room (Lantern Gallery). This was mainly used for cleaning the outside of the windows of the Lantern Room.

Lighthouses near to each other that are similar in shape are often painted in a unique pattern so they can easily be recognized during daylight, a marking known as a daymark
Daymark
A daymark or a day marker is a structure such as a tower constructed on land as an aid to navigation by sailors. While similar in concept to a lighthouse, a daymark does not have a light and so is usually only visible during daylight hours...

. The black and white barber pole spiral pattern of Cape Hatteras Lighthouse is one example. Race Rocks Light in western Canada is painted in horizontal black and white bands to stand out against the horizon.

Range lights




Aligning two fixed points on land provides a navigator with a line of position called a range in the U.S. and a transit in Britain. Ranges can be used to precisely align a vessel within a narrow channel such as in a river. With landmarks of a range illuminated with a set of fixed lighthouses, nighttime navigation is possible.

Such paired lighthouses are called range lights in the U.S. and leading lights in the United Kingdom. The closer light is referred to as the beacon or front range; the furthest away is called the rear range. The rear range light is almost always taller than the front.

When the vessel is on the correct course, the two lights line up vertically. But when the observer is out of position, the difference in alignment indicates the proper direction of travel to correct the course.

History




Ancient


Perhaps the most famous lighthouse in history is the Lighthouse of Alexandria
Lighthouse of Alexandria
The Lighthouse of Alexandria, also known as the Pharos of Alexandria , was a tower built between 280 and 247 BC on the island of Pharos at Alexandria, Egypt...

, built on the island of Pharos
Alexandria
Alexandria is the second-largest city of Egypt, with a population of 4.1 million, extending about along the coast of the Mediterranean Sea in the north central part of the country; it is also the largest city lying directly on the Mediterranean coast. It is Egypt's largest seaport, serving...

 in Hellenistic Egypt.
The name Pharos is still used as the noun for "lighthouse" in some languages, for example: Albanian, Catalan, and Romanian (far), French (phare), Italian, Galician, and Spanish (faro), Portuguese (farol), Danish, Norwegian, and Swedish (fyr), Bulgarian (фар), and Greek (φάρος). The term pharology
Pharology
Pharology is the scientific study of lighthouses and signal lights, their construction and illumination. The variation pharonology is occasionally attested. Those who study or are enthused by lighthouses are known as pharologists...

(study of lighthouses) also derives from the island's name.

The Lighthouse of Alexandria was built in 280 BC to serve as the port's landmark. With a height variously estimated between 115 and 135 m (377.3 and 442.9 ft) it was among the tallest man made structures on Earth for many centuries, and was identified as one of the Seven Wonders of the World by classical writers. Two lighthouses, each called the Pharos, were built at Dover soon after the Roman conquest of Britain. They were sited on the two heights (Eastern Heights and Western Heights
Dover Western Heights
The Western Heights of Dover are one of the most impressive fortifications in Britain. They comprise a series of forts, strong points and ditches, designed to protect the country from invasion...

) and modeled on the one built for Caligula's aborted invasion at Boulogne.

Tang Dynasty Chinese writer Jia Dan wrote in his book (written between 785 - 805) that in the sea route forming the opening mouth of the Persian Gulf, the medieval Iranians had erected large minaret towers that served as lighthouses. Confirming the Chinese reports, a century later, Arab writers al-Mas'udi and al-Muqaddasi wrote of the same lighthouses.

In China, the medieval mosque at Canton had a minaret that served as a lighthouse. The later Song Dynasty Chinese pagoda tower built in medieval Hangzhou, known as the Liuhe Pagoda
Liuhe Pagoda
Liuhe Pagoda , literally Six Harmonies Pagoda or Six Harmonies Tower, is a multi-story Chinese pagoda in southern Hangzhou, Zhejiang province, China. It is located at the foot of Yuelun Hill, facing the Qiantang River...

 (erected in 1165), also served as a lighthouse for sailors along the Qiantang River.

During the Dark Ages, Roman lighthouses fell into disuse, but some remained functional, such as the Farum Brigantium, now known as the Tower of Hercules
Tower of Hercules
The Tower of Hercules is an ancient Roman lighthouse on a peninsula about from the centre of A Coruña, Galicia, in north-western Spain. Until the 20th century, the tower itself was known as the "Farum Brigantium". The Latin word farum is derived from the Greek pharos for the Lighthouse of...

, in A Coruña, Spain, and others in the Mediterranean Sea. As navigation improved, lighthouses gradually expanded into Western and Northern Europe. One of the oldest working lighthouses in Europe is Hook Lighthouse
Hook Lighthouse
The Hook Lighthouse is a building situated at the tip of the Hook Peninsula in County Wexford, in Ireland. It is one of the oldest lighthouses in the world, and the oldest operating lighthouse in the British Isles...

 located at Hook Head in County Wexford, Ireland. It was built during the medieval period, in a sturdy circular design.
A century later, in the Late Middle Ages, a 40 feet (12.2 m) tower was built by Edward the Black Prince at Cordouan near Gironde, France. One hundred years later, in 1581, Henri III asked architect Louis de Foix to survey it and estimate the cost of repair. The high cost led to de Foix being contracted three years later to build a new one.

Building the lighthouse took twenty-seven years; finally completed in 1611, the tiered Cordouan symbolized French maritime power and prestige. The interior had sumptuous king's apartments, decorated pillars and murals. Its upper level was rebuilt in 1788, and the lighthouse has remained active since. The tower later became the first to use the revolutionary Fresnel lens, in the early 1820s. While visiting at this time, Briton Robert Stevenson
Robert Stevenson (civil engineer)
Robert Stevenson FRSE MInstCE FSAS MWS FGS FRAS FSA was a Scottish civil engineer and famed designer and builder of lighthouses.One of his finest achievements was the construction of the Bell Rock Lighthouse.-Early life:...

 was deeply impressed by the work being done with the new light. He sought to expand its use across Scotland as, fueled by the demands of the Age of Sail, lighthouse development began to gain pace.

Classic period


Lighthouse development accelerated in the 17th century with Britain's Trinity House
Trinity House
The Corporation of Trinity House of Deptford Strond is the official General Lighthouse Authority for England, Wales and other British territorial waters...

 constructing its first in 1609, and a national lighthouse services established in Denmark (1650). In the UK, the first Eddystone Lighthouse was lit in 1698, though its third incarnation was the most enduring, designed by John Smeaton
John Smeaton
John Smeaton, FRS, was an English civil engineer responsible for the design of bridges, canals, harbours and lighthouses. He was also a capable mechanical engineer and an eminent physicist...

 and finished in 1759. As Britain became the dominant sea power, lighthouses constructed by the Stevenson family for the Northern Lighthouse Board
Northern Lighthouse Board
The Northern Lighthouse Board is the General Lighthouse Authority for Scotland and the Isle of Man. It is a non-departmental public body responsible for marine navigation aids around coastal areas.-History:...

 began to appear in Scotland.

The earliest light in North America was in St. Augustine, Florida, depicted on the map of Boazio, printed in London in 1791. Menendez built the tower after his landing in 1586. Boazio interviewed the Drake's crew upon their return from the sack of St. Augustine.

The next lighthouse in America was Boston Light
Boston Light
Boston Light is a lighthouse located on Little Brewster Island in outer Boston Harbor, Massachusetts. The first lighthouse to be built on the site dates back to 1716, and was the first lighthouse to be built in what is now the United States...

 on Little Brewster Island (1716). The first keeper was George Worthylake who drowned, along with his wife and daughter, when returning to the island in 1718. The original tower was destroyed by the British during the evacuation of Boston in 1775 and eventually reconstructed in 1784. The oldest existing lighthouse in the United States is the Sandy Hook Lighthouse
Sandy Hook Lighthouse
__notoc__The Sandy Hook Lighthouse, located about one and a half statute miles inland from the tip of Sandy Hook, New Jersey, is the oldest working lighthouse in the United States. It was designed and built in 1764 by Isaac Conro...

 in New Jersey (1764), which is still in operation. By the end of the 19th century, the United States, with its long coastlines had the most lighthouses of any nation.
The US Bureau of Lighthouses was created in 1789 by the 9th Act of the first Congress which placed lighthouses under federal control. Over the years, lighthouses were placed under the direction of U.S. Department of Revenue (disbanded in 1820), U.S. Department of Treasury (until 1903), then the U.S. Department of Commerce. The Lighthouse Board (of the U.S. Lighthouse Establishment) held sway from 1852 to July 1, 1910, when the Lighthouse Service was established. The United States Coast Guard
United States Coast Guard
The United States Coast Guard is a branch of the United States Armed Forces and one of the seven U.S. uniformed services. The Coast Guard is a maritime, military, multi-mission service unique among the military branches for having a maritime law enforcement mission and a federal regulatory agency...

 took over on July 7, 1939.

After 1852, the U.S. was divided into lighthouse districts; originally eight, then eventually numbered 19. Each district was run by a naval officer appointed by the Lighthouse Board as the District Inspector. He ran the district in tandem with an Army Corps of Engineers' officer who was in charge of engineering projects. In 1910, civilians started replacing the military officers.

Canada's first lighthouse was the Louisbourg Light
Louisbourg Light
Louisbourg Lighthouse is a historic Canadian lighthouse at Louisbourg, Nova Scotia, and is the site of the first lighthouse in Canada.-The first light:...

 built by the French in Nova Scotia in 1734. It was destroyed during the Siege of Louisbourg in 1758. The British built the Sambro Island Light at Halifax, Nova Scotia in the same year which has survived to the present day, making it the oldest surviving lighthouse in North America. The network of lighthouses built by the colonies of British North America were united in 1867 by the Canadian government which greatly expanded the Canadian lighthouse system through the Canadian Department of Marine, largely through economical wooden lighthouses staffed by families.

Lighthouses were extremely labour intensive in the classic era of lighthouse operation. Lighthouse keeper
Lighthouse keeper
A lighthouse keeper is the person responsible for tending and caring for a lighthouse, particularly the light and lens in the days when oil lamps and clockwork mechanisms were used. Keepers were needed to trim the wicks, replenish fuel, wind clockworks and perform maintenance tasks such as cleaning...

s were needed to trim the wicks, replenish fuel, wind clockworks, and perform maintenance tasks such as cleaning lenses and windows. In 1907, Nils Gustaf Dalén produced the sun valve
Sun valve
A sun valve is a form of flow control valve, notable because it earned its inventor Gustaf Dalén the Nobel prize in physics....

 which turned the beacon on and off using daylight. The first one was erected on Furuholmen Lighthouse lighthouse between Stockholm and Vaxholm. In 1912 Dalén was awarded the Nobel Prize in Physics for his invention of 'automatic valves designed to be used in combination with gas accumulators in lighthouses'.

Dalén's inventions, electrification, and automatic lamp changers began to make lighthouse keepers obsolete. For many years, lighthouses still had keepers, partly because lighthouse keepers could serve as a rescue service if necessary. Improvements in maritime navigation and safety such as the Global Positioning System
Global Positioning System
The Global Positioning System is a space-based global navigation satellite system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites...

 (GPS) have led to the phasing out of non-automated lighthouses in the United States, with the last keepers removed in the 1990s. In Canada, this trend has been stopped and there are still 50 staffed light stations, with 27 on the west coast alone.

Modern


Often in inaccessible locations, modern lighthouses are more functional and less picturesque; usually they use solar-charged batteries and have a single stationary flashing light sitting on a steel skeleton tower. The last manned lighthouse built in the U.S. was the Charleston Light
Charleston Light
Charleston Light on Sullivan's Island, South Carolina, which is the northern entrance to Charleston Harbor, was built to replace the defunct Morris Island Light on Morris Island. Construction was started in 1960, and it was first lit on June 15, 1962....

 constructed in 1962. Resembling an air traffic control tower, it features a modern triangular shape, aluminum alloy skin, air conditioning, and an elevator.

Famous lighthouse builders


John Smeaton
John Smeaton
John Smeaton, FRS, was an English civil engineer responsible for the design of bridges, canals, harbours and lighthouses. He was also a capable mechanical engineer and an eminent physicist...

 is noteworthy for having designed the third and most famous Eddystone Lighthouse
Eddystone Lighthouse
Eddystone Lighthouse is on the treacherous Eddystone Rocks, south west of Rame Head, United Kingdom. While Rame Head is in Cornwall, the rocks are in Devon and composed of Precambrian Gneiss....

 but some builders are well known for their work in building multiple lighthouses. The Stevenson family (Robert
Robert Stevenson (civil engineer)
Robert Stevenson FRSE MInstCE FSAS MWS FGS FRAS FSA was a Scottish civil engineer and famed designer and builder of lighthouses.One of his finest achievements was the construction of the Bell Rock Lighthouse.-Early life:...

, Alan
Alan Stevenson
Alan Stevenson FRSE MInstCE was a Scottish lighthouse engineer who was Engineer to the Board of Northern Lighthouses...

, David
David Stevenson (engineer)
David Stevenson FRSE FRSSA was a Scottish lighthouse designer, who designed over thirty lighthouses in and around Scotland, and helped found a great dynasty of lighthouse engineering.-Background:...

, Thomas
Thomas Stevenson
Thomas Stevenson PRSE MInstCE FRSSA FSAScot was a pioneering Scottish lighthouse designer and meteorologist, who designed over thirty lighthouses in and around Scotland, as well as the Stevenson screen used in meteorology...

, David Alan
David Alan Stevenson
David Alan Stevenson was a lighthouse engineer who built twenty six lighthouses in and around Scotland.Born into the famous Stevenson family of lighthouse engineers, son of David Stevenson, brother of Charles Stevenson, and nephew of Thomas Stevenson, he was educated at Edinburgh University...

, and Charles
Charles Alexander Stevenson
Charles Alexander Stevenson was a Scottish lighthouse engineer who built twenty three lighthouses in and around Scotland....

) made lighthouse building a three generation profession in Scotland. Irishman Alexander Mitchell
Alexander Mitchell (engineer)
Alexander Mitchell, was an Irish engineer who from 1802 was blind. He is known as the inventor of the screw-pile lighthouse...

 invented and built a number of screwpile lighthouses despite his blindness.

United States Army Corps of Engineers
United States Army Corps of Engineers
The United States Army Corps of Engineers is a federal agency and a major Army command made up of some 38,000 civilian and military personnel, making it the world's largest public engineering, design and construction management agency...

 Lieutenant George Meade
George Meade
George Gordon Meade was a career United States Army officer and civil engineer involved in coastal construction, including several lighthouses. He fought with distinction in the Second Seminole War and Mexican-American War. During the American Civil War he served as a Union general, rising from...

 built numerous lighthouses along the Atlantic and Gulf coasts before gaining wider fame as the winning general at the Battle of Gettysburg
Battle of Gettysburg
The Battle of Gettysburg , was fought July 1–3, 1863, in and around the town of Gettysburg, Pennsylvania. The battle with the largest number of casualties in the American Civil War, it is often described as the war's turning point. Union Maj. Gen. George Gordon Meade's Army of the Potomac...

. Colonel Orlando M. Poe, engineer to General William Tecumseh Sherman in the Siege of Atlanta, designed and built some of the most exotic lighthouses in the most difficult locations on the U.S. Great Lakes. Alexander Ballantyne built two of the most challenging wave-washed lighthouses on barren rock in the Pacific, Tillamook Rock Light
Tillamook Rock Light
Tillamook Rock Light is a deactivated lighthouse on the Oregon Coast of the United States. It is located approximately offshore from Tillamook Head, and south of the Columbia River, situated on less than acre of basalt rock in the Pacific Ocean. The construction of the lighthouse was commissioned...

 and St. George Reef Light. Englishman James Douglass
James Nicholas Douglass
Sir James Nicholas Douglass, FRS, , was an English civil engineer, a prolific lighthouse builder and designer, most famous for the design and construction of the fourth Eddystone Lighthouse, for which he was knighted....

 was knighted for his work on lighthouses.

French merchant navy officer Marius Michel Pasha
Marius Michel Pasha
Blaise-Jean-Marius Michel, Comte de Pierredon , also known as Michel Pasha or Michel Pacha in French, was a French architect and lighthouse builder.-Early life:He was born in Sanary, near Toulon, Provence, in 1819...

 built almost a hundred lighthouses along the coasts of the Ottoman Empire in a period of twenty years after the Crimean War (1853–1856).

Maintenance


In the United States, lighthouses are maintained by the United States Coast Guard (USCG).
Those in England and Wales are looked after by Trinity House
Trinity House
The Corporation of Trinity House of Deptford Strond is the official General Lighthouse Authority for England, Wales and other British territorial waters...

; in Scotland, by the Northern Lighthouse Board
Northern Lighthouse Board
The Northern Lighthouse Board is the General Lighthouse Authority for Scotland and the Isle of Man. It is a non-departmental public body responsible for marine navigation aids around coastal areas.-History:...

; and in Ireland by the Commissioners of Irish Lights
Commissioners of Irish Lights
The Commissioners of Irish Lights is the body that serves as the lighthouse authority for Ireland plus its adjacent seas and islands...

. In Canada, they are managed by the Canadian Coast Guard
Canadian Coast Guard
The Canadian Coast Guard is the coast guard of Canada. It is a federal agency responsible for providing maritime search and rescue , aids to navigation, marine pollution response, marine radio, and icebreaking...

. In Australia, lighthouses are conducted by the Australian Maritime Safety Authority
Australian Maritime Safety Authority
Australian Maritime Safety Authority is responsible, on behalf of the Commonwealth Government of Australia, for the regulation and safety oversight of Australia's shipping fleet and management of Australia's international maritime obligations...

.

The Soviet Union built a number of automated lighthouses powered by radioisotope thermoelectric generator
Radioisotope thermoelectric generator
A radioisotope thermoelectric generator is an electrical generator that obtains its power from radioactive decay. In such a device, the heat released by the decay of a suitable radioactive material is converted into electricity by the Seebeck effect using an array of thermocouples.RTGs can be...

s in remote locations. They operated for long periods without external support with great reliability. However numerous installations deteriorated, were stolen, or vandalized. Some cannot be found due to poor record keeping.

Preservation


As lighthouses became less essential to navigation, many of their historic structures faced demolition or neglect. In the United States, the National Historic Lighthouse Preservation Act
National Historic Lighthouse Preservation Act
The National Historic Lighthouse Preservation Act of 2000 is American legislation creating a process for the transfer of federally-owned lighthouses into private hands...

 of 2000 provides for the transfer of lighthouse structures to local governments and private non-profit groups, while the USCG continues to maintain the lamps and lenses. In Canada, the Nova Scotia Lighthouse Preservation Society
Nova Scotia Lighthouse Preservation Society
The Nova Scotia Lighthouse Preservation Society is a non profit charitable organization that works to save lighthouses in the province of Nova Scotia, Canada. It is the largest and oldest lighthouse heritage organization in Canada...

 won heritage status for Sambro Island Lighthouse
Sambro Island Lighthouse
Sambro Island Lighthouse is a landfall lighthouse located at the entrance to Halifax Harbour, Nova Scotia, on an island near the community of Sambro in the Halifax Regional Municipality...

, and sponsored the Heritage Lighthouse Protection Act to change Canadian federal laws to protect lighthouses.

Many groups formed to restore and save lighthouses around the world. They include the World Lighthouse Society and the United States Lighthouse Society
United States Lighthouse Society
The United States Lighthouse Society is a non-profit organization dedicated to aiding in the restoration of American lighthouses and educating the public about their history. There are currently five chapters of the Society around the United States. Among other activities, it publishes The...

. A further international group is the Amateur Radio Lighthouse Society, which sends amateur radio operators to publicize the preservation of remote lighthouses throughout the world.

Popular culture and symbolism



Visiting and photographing lighthouses are popular hobbies as is collecting ceramic replicas. Some lighthouses are popular travel destinations in their own right, and the buildings maintained as tourist attractions. In the U.S., National Lighthouse and Lightship Weekend is celebrated on the first weekend of August, and International Lighthouse and Lightship Weekend
International Lighthouse and Lightship Weekend
The International Lighthouse and Lightship Weekend is an amateur radio event held on the third full weekend of August. The event started in 1995, and now more than 470 lighthouses in over 55 countries participate.- Objective :...

 on the third weekend. Many lighthouses are open to the public and amateur radio operators communicate between them on these days.

Lighthouses are popular icons on vehicle license plates. Barnegat Lighthouse
Barnegat Lighthouse
Barnegat Lighthouse or Barnegat Light, colloquially known as "Old Barney", is a historic lighthouse located in Barnegat Lighthouse State Park on the northern tip of Long Beach Island, in the borough of Barnegat Light, New Jersey, on the south side of Barnegat Inlet.-19th century:The development of...

, Tuckerton Island Lighthouse, Thomas Point Shoal Light
Thomas Point Shoal Light
The Thomas Point Shoal Light, also known as Thomas Point Shoal Light Station, is a historic lighthouse in the Chesapeake Bay on the east coast of the United States, and the most recognized lighthouse in Maryland. It is the only screw-pile lighthouse in the bay which stands at its original site...

, Saybrook Breakwater Light
Saybrook Breakwater Light
Saybrook Breakwater Lighthouse is a sparkplug lighthouse in Connecticut,United States, at Fenwick Point at the mouth of the Connecticut River near Old Saybrook, Connecticut...

, White Shoal Light
White Shoal Light (Michigan)
The White Shoal Light is a lighthouse located 20 miles west of the Mackinac Bridge in Lake Michigan. It is an active aid to navigation.-Overview:...

, and Biloxi Light
Biloxi Light
Biloxi Light is a lighthouse in Biloxi, Mississippi, adjacent to the Mississippi Sound of the Gulf of Mexico. The lighthouse has been kept by female keepers for more years than any other lighthouse in the United States...

 are so depicted.

The Disney film Pete's Dragon
Pete's Dragon
Pete's Dragon is a 1977 live-action/animated musical film from Walt Disney Productions and the first Disney film to be recorded in the Dolby Stereo sound system...

featured a lighthouse and the resulting Helen Reddy song Candle on the Water
Candle on the Water
"Candle on the Water" is a song written by Al Kasha and Joel Hirschhorn from Walt Disney Picture's live action/animation film Pete's Dragon...

alludes to it. The Australian television series Round the Twist also involved a family living at Split Point Lighthouse
Split Point Lighthouse
Split Point Lighthouse is a lighthouse located in Aireys Inlet, a small town on the Great Ocean Road, Victoria, Australia.-History:Originally called Eagles Nest Point, the lighthouse was originally built in 1891. It was converted to automatic operation in 1919.The original British-made first order...

. The long-running American soap opera Guiding Light
Guiding Light
Guiding Light is an American daytime television drama that is credited by the Guinness Book of World Records as the longest running drama in television and radio history, running from 1937 until 2009...

has featured a lighthouse in many of its opening title segments, and the fictional Springfield, Illinois
Springfield (Guiding Light)
Springfield, Illinois is the setting of the television soap opera Guiding Light. It is generally portrayed as a small city or large town in the midwest, and circa 2008 is more specifically named as Springfield Township in the show's opening sequence. The township is also next to a lake large enough...

 has a lighthouse situated near the town.

To recognize the role of lighthouse keepers in maritime safety, the U.S. Coast Guard named a class of 175 feet (53 m) coastal buoy tenders
USCG Coastal Buoy Tender
The United States Coast Guard commissioned a new Keeper-class of coastal buoy tenders in the 1990s that are 175 feet in length and named after Lighthouse keepers.Keeper Class cutters serve the Coast Guard in a variety of missions...

 after famous U.S. lighthouse keepers. Fourteen ships in the class were built between 1996 and 2000.

Due to their function as beacons of safety, organizations choose lighthouses as a symbol. The lighthouse is the symbol of Lighthouse International, a U.S. organization for the blind. Lighthouses are often interpreted in dreams as beacons of truth or as male fertility and influence.

Lighthouses were once regarded as an archetypal public good
Public good
In economics, a public good is a good that is non-rival and non-excludable. Non-rivalry means that consumption of the good by one individual does not reduce availability of the good for consumption by others; and non-excludability means that no one can be effectively excluded from using the good...

, because ships could benefit from the light without being forced to pay. One reason the Confederacy broke off from the United States was the former's opposition to most taxpayer-funded internal improvements; yet even the Confederate States Constitution explicitly allowed public funds to be spent on lighthouses.

A widely-disseminated urban legend tells of a radio conversation between a U.S. or British naval vessel and what is believed to be another ship on a collision course. The naval vessel insists the other ship change course, but the other ship continues to insist the naval vessel do so. After the captain of the naval vessel identifies himself and demands a course change, the other party responds with, "I'm a lighthouse. It's your call"
Lighthouse and naval vessel urban legend
The lighthouse and naval vessel urban legend describes an encounter between a large naval ship and what at first appears to be another vessel, with which the ship is on a collision course. The naval vessel, usually identified as of the United States Navy and generally described as a battleship or...

.

Their isolated and mysterious nature makes lighthouses a frequent setting of horror and suspense films, as well as adventure video games. Recently, a lighthouse played a pivotal role in Martin Scorsese's Shutter Island, and was featured in the final shot of the film.

St. Anthony's Lighthouse
St. Anthony's Lighthouse
St Anthony's Lighthouse is a lighthouse on St Anthony Head on the eastern coast of the entrance to the harbour of Falmouth, Cornwall.The lighthouse was built in 1835 by Olver of Falmouth. The light originally came from eight Argand oil lamps. The light source was changed to pressure vapour and...

 at St. Anthony's Head near Falmouth, Cornwall was featured in the title sequence of the children's live action puppet television program series Fraggle Rock created by Jim Henson.

See also

  • List of lighthouses and lightvessels
  • Day beacon
    Day beacon
    A day beacon is an unlighted nautical sea mark. Typically, day beacons mark channels whose key points are marked by lighted buoys. Day beacons may also mark smaller navigable routes in their entirety. They are the most common aid to nautical navigation in shallow water as they are relatively...

  • Lens lantern
    Lens lantern
    A lens lantern is a small, self-contained lamp structure which may sometimes be used to serve as a lighthouse. Unlike a regular Fresnel lens, the lantern requires no housing to protect it from the weather; its glass sides would refract and magnify the light in the same fashion as would the lens...

  • Pintsch gas
    Pintsch gas
    Pintsch gas was a compressed gas derived from distilled naphtha for illumination purposes during the 19th and early 20th centuries.It was invented in 1851 by German inventor and manufacturer Julius Pintsch . Its primary use in the latter half of the 19th century was for illumination of railroad cars...


External links