East Brother Island Light
East Brother Island Lighthouse is a lighthouse located on East Brother Island in San Rafael Bay, near the tip of Point San Pablo in Richmond, California. It marks the entrance to San Pablo Bay from San Francisco Bay. Built in 1874 and automated in 1969, the lighthouse was designed in the American Stick style by Paul J. Pelz, who designed East Brother Island's sister stations, Point Fermin Light in San Pedro CA, Mare Island Light, in Carquinez Strait, Point Hueneme Light in California, Hereford Inlet Light in North Wildwood, New Jersey, Point Adams Light in Washington State, all in the same style; the former keeper's house began operating as a bed and breakfast in 1980. Although the U. S. government recognized the need for a light to mark the area, mainland property was not available at a reasonable price. Instead the government turned its attention to the island, which it owned. Large-scale blasting leveled the island off, the two-story keeper's house was built with the attached tower and a fog signal building.
The lamp was first lit on March 1, 1874. The light tower is attached to keeper's house, a two-story Victorian placed on a blasted away 1-acre rock. There was an assistant keeper's house, equipment building and water tank; the water cistern was blasted to a depth of 30 feet and is capable of holding 50,000 US gallons of rain water. Two of the most notable lighthouse keepers were John Stenmark and Willard Miller, each of whom logged twenty years of service, more than any other keepers. From Sweden, Stenmark joined the lighthouse service at age twenty and distinguished himself for bravery during a boating accident, he was appointed keeper at East Brother in 1894, he lived at the station with his wife and four children. Miller began his tenure at East Brother in 1922. During his service the light was upgraded to a fixed, fifth-order Fresnel lens, powered by a 500-watt bulb; the steam fog signal was converted to a compressor-driven diaphone. A serious accident on March 4, 1940 resulted in a fire that destroyed the island's wharf and boathouse along with four boats.
The United States Lighthouse Service ran the lighthouse operation until 1939, when the Lighthouse Service merged with the United States Coast Guard. Large families occupied the lighthouse, they had to keep it filled with whale oil. On many foggy nights, they would have to fire up the steam boilers to drive the foghorns, hauling coal up the long ramp from the boat. After the lighthouse was automated, the government wanted to tear down the keeper's house and other buildings, but protests from local residents prevented the demolition; the lighthouse was listed on the National Register of Historic Places in 1971. After several years of neglect, a non-profit group, East Brother Light Station, Inc. was formed in 1979 to restore the landmark. Government grants, private donations, volunteer labor restored the structures on the island, which are now used for the bed-and-breakfast. F. Moran James Rankin William McCarthy List of lighthouses in the United States The Brothers United States Coast Guard East Brother Light Station "Historic Light Station Information and Photography: California".
United States Coast Guard Historian's Office. East Brother, CA at LighthouseFriends.com East Brother Light Station at www.us-lighthouses.com East Brother Island Light at the National Register of Historic Places
A Fresnel lens is a type of compact lens 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. A Fresnel lens can be made much thinner than a comparable conventional lens, in some cases taking the form of a flat sheet. A Fresnel lens can capture more oblique light from a light source, thus allowing the light from a lighthouse equipped with one to be visible over greater distances; the idea of creating a thinner, lighter lens in the form of a series of annular steps is attributed to Georges-Louis Leclerc, Comte de Buffon. Whereas Buffon proposed grinding such a lens from a single piece of glass, the Marquis de Condorcet proposed making it with separate sections mounted in a frame. French physicist and engineer Augustin-Jean Fresnel is most given credit for the development of the multi-part lens for use in lighthouses.
According to Smithsonian magazine, the first Fresnel lens was used in 1823 in the Cordouan lighthouse at the mouth of the Gironde estuary. Scottish physicist Sir David Brewster is credited with convincing the United Kingdom to adopt these lenses in their lighthouses; the Fresnel lens reduces the amount of material required compared to a conventional lens by dividing the lens into a set of concentric annular sections. An ideal Fresnel lens would have an infinite number of sections. In each section, the overall thickness is decreased compared to an equivalent simple lens; this divides the continuous surface of a standard lens into a set of surfaces of the same curvature, with stepwise discontinuities between them. In some lenses, the curved surfaces are replaced with flat surfaces, with a different angle in each section; such a lens can be regarded as an array of prisms arranged in a circular fashion, with steeper prisms on the edges, a flat or convex center. In the first Fresnel lenses, each section was a separate prism.'Single-piece' Fresnel lenses were produced, being used for automobile headlamps, brake and turn signal lenses, so on.
In modern times, computer-controlled milling equipment might be used to manufacture more complex lenses. Fresnel lens design allows a substantial reduction in thickness, at the expense of reducing the imaging quality of the lens, why precise imaging applications such as photography still use larger conventional lenses. Fresnel lenses are made of glass or plastic. In many cases they are thin and flat flexible, with thicknesses in the 1 to 5 mm range. Modern Fresnel lenses consist of all refractive elements; however many of the lighthouses have both refracting and reflecting elements, as shown in the photographs and diagram. That is, the outer elements are sections of reflectors while the inner elements are sections of refractive lenses. Total internal reflection was used to avoid the light loss in reflection from a silvered mirror. Fresnel produced six sizes of lighthouse lenses, divided into four orders based on their size and focal length. In modern use, these are classified as first through sixth order.
An intermediate size between third and fourth order was added as well as sizes above first order and below sixth. A first-order lens has a focal length of a maximum diameter 2590 mm high; the complete assembly is 1.8 m wide. The smallest has a focal length of an optical diameter 433 mm high; the largest Fresnel lenses are called hyperradiant Fresnel lenses. One such lens was on hand when it was decided to outfit the Makapuu Point Light in Hawaii. Rather than order a new lens, the huge optic construction, 3.7 metres tall and with over a thousand prisms, was used there. There are two main types of Fresnel lens: non-imaging. Imaging Fresnel lenses use segments with curved cross-sections and produce sharp images, while non-imaging lenses have segments with flat cross-sections, do not produce sharp images; as the number of segments increases, the two types of lens become more similar to each other. In the abstract case of an infinite number of segments, the difference between curved and flat segments disappears.
Spherical A spherical Fresnel lens is equivalent to a simple spherical lens, using ring-shaped segments that are each a portion of a sphere, that all focus light on a single point. This type of lens produces a sharp image, although not quite as clear as the equivalent simple spherical lens due to diffraction at the edges of the ridges. Cylindrical A cylindrical Fresnel lens is equivalent to a simple cylindrical lens, using straight segments with circular cross-section, focusing light on a single line; this type produces a sharp image, although not quite as clear as the equivalent simple cylindrical lens due to diffraction at the edges of the ridges. Spot A non-imaging spot Fresnel lens uses ring-shaped segments with cross sections that are straight lines rather than circular arcs; such a lens does not produce a sharp image. These lenses have application such as focusing sunlight on a solar panel. Fresnel lenses may be used as components of Köhler illumination optics resulting in effective nonimaging optics Fresnel-Köhler solar concentrators.
Linear A non-imagin
Point Blunt Light
Point Blunt Light is a lighthouse on Angel Island in San Francisco Bay, California. Point Blunt Lighthouse was established in 1915; the lighthouse was automated in 1976. From Coast Guard web site in 1970, before the lighthouse was automated: Point Blunt Light was maintained by personnel at Angel Island Light Station at Point Knox until 1960. In 1960 a new watch room was constructed at Point Blunt which afforded a view of the entire San Francisco Bay. With the new watch room and new quarters completed in 1961 at Point Blunt, the Coast Guard moved the personnel from Angel Island Light Station. Personnel at Point Blunt operate their own fog signals; the station provides special direction finder calibration services as requested. Four family units, 3 bedrooms each, are at Point Blunt. Two units are Coast Guard owned, two are leased from the State of California. One unit is occupied by the Officer in his family; the other units are presently being utilized by their families. One small boat is assigned to the station.
A pickup truck is assigned. Point Blunt Light Station rates a BM1 as Officer in Charge, plus one EN2, one FN, one SN. California Government Code section 23138, added in 1947, describes the northern boundary of San Francisco County as "Thence, through Point Bonita and Point Calvaljo, to the most southeastern point of Angel Island, all on the line of Marin." In 1960, to add the watchroom, the Bay was filled in between the southeastern point of Angel Island and the Point Blunt Rock - an Island. Point Blunt is an exclave of San Francisco County; the area below the mean high tide of the Federal Enclave, however, is not a Federal Enclave because California assumed sovereignty over the waters when it became a State in 1850. As a port facility, the lighthouse served the Port of San Francisco, transferred from State to San Francisco control in 1969. In 1976, the People of the State of California adopted the Coastal act, making the area below the mean high tide a condominium of the County and the California Coastal Commission, the Coastal Act required beach access for all California beaches, meaning there is a constitutionally-guaranteed right of way through the State Park property to the beach of the Federal Enclave.
Because the beach above the mean high tide is a Federal enclave and not part of Angel Island State Park, like Baker Beach in the Presidio of San Francisco, it is not subject to local ordinances. There is no statewide law prohibiting nudity. Moreover, because it is part of a Port of call, any vessel flying a friendly flag may anchor and its inhabitants may disembark and disrobe as long as they stay below the mean high tide. If they cross above it, they must proceed directly to customs. Immunity from local law applies to individuals in transit to customs as long as they do not tarry, so they will have transit immunity while they walk through Angel Island State Park to the ferry, over the Golden Gate Bridge, to the Federal Customs House near Fishermans' Wharf. Angel Island-Tiburon Ferry
Lime Point Light
Lime Point Lighthouse is a lighthouse in California, on northern side of narrowest part of Golden Gate strait. The lighthouse sits at the base of a steep cliff near the North anchorage of the Golden Gate Bridge, it is built on a 100 ft long rock spur named Lime Point. The brick structure for the Lime Point Lighthouse was built in 1883 as a fog-bell signaling station, it was fitted with coal powered 12-inch steam whistles. During operation, the facility included the fog signal building, a coal shed, water tank, a two-story keeper's quarters; the keepers building upgraded to include a third floor. In 1900, a lens lantern was hung on the south-east corner of the fog signal building, at a height of 20 feet above the water. In 1902, the coal-powered steam horn was modified to use crude oil to reduce operating costs and smoke pollution. Lime Point Lighthouse continued to operate after the completion of the Golden Gate Bridge since it remained an effective position for a light and fog horn though Fort Point Light, at the South end of the bridge was decommissioned.
Lime Point was automated by the United States Coast Guard in 1961, the three-story dwelling and other buildings were torn down, leaving only the fog signal building. List of lighthouses in the United States United States Coast Guard Lime Point Lighthouse Page at www.us-lighthouses.com U. S. Geological Survey Geographic Names Information System: Lime Point Lighthouse
Alcatraz Island Lighthouse
Alcatraz Island Lighthouse is a lighthouse – the first one built on the U. S. West Coast – located on Alcatraz Island in California's San Francisco Bay, it is located at the southern end of the island near the entrance to the prison. The first light house on the island was completed in 1854, served the bay during its time as a Citadel and military prison, it was replaced by a taller concrete tower built in 1909 to the south of the original one, demolished after it was damaged due to earthquake in 1906. The automation of the lighthouse with a modern beacon took place in 1963, the year Alcatraz closed as the Alcatraz Federal Penitentiary, it is the oldest light station on the island with a modern beacon and is part of the museum on the island. Although when viewed from afar it looks the tallest structure on Alcatraz, it is shorter than the Alcatraz Water Tower, but as it lies on higher ground it looks much taller. Though the Native Indians of the San Francisco area are stated to be the original settlers on the island, Alcatraz got its name in 1775 only when Juan de Ayala, a Spaniard was engaged to survey the harbor and the San Francisco Bay.
Since he observed pelicans in large numbers on the island he named the island as "Isla de los Alcatraces" meaning the "Island of Pelicans". The island is separated from the main land by more than 1 mile; the gold rush and the inherent risk of the choppy waters of the west coast prompted the urgent need for establishing lighthouses. Congress recognized the need and passed suitable acts in the years 1851 and 1852 to build seven lighthouses on the West Coast to guide navigation; the Baltimore firm of Gibbons and Kelly was awarded the contract to build seven lighthouses in California, at Alcatraz Island, Fort Point, Point Pinos, Point Loma, Farallon Island, Humboldt Bay, one at Cape Disappointment in Washington State. Equipment were shipped on Oriole, reached San Francisco on January 29, 1853; the Alcatraz Lighthouse was the first to be completed in July 1853, making it the oldest major navigational light on the West Coast. However, the foundation for building the light house had begun much before the equipment reached San Francisco.
In the original order placed for supply of the equipment Argand lamps and parabolic reflectors had been specified as the Fresnel lens, created by Augustin Fresnel of France in 1822 was considered costly at that time. However, the Lighthouse Board which replaced the Fifth Auditor of the Treasury's control, decided to install Fresnel lenses in all lighthouses considering its established better performance though the cost was high; the Baltimore firm was informed of this change. The shipping involved a long sea voyage of 12,000 miles from the East Coast going round the cape of South America, it was lit on June 1854, from a fixed, third-order Fresnel lens. In 1902, it was transferred to the Cape St. Elias Lighthouse in Alaska and replaced by a revolving fourth-order Fresnel lens, producing a white flash every five seconds. In 1909–12, the present cell house of Alcatraz was built. Since the new structure would interfere with the operation of the lighthouse, a taller 25.6 metres, concrete tower was built south of the original lighthouse.
The original lighthouse had been damaged during the great San Francisco earthquake of 1906 and was torn down. In 1963, the Alcatraz Lighthouse was automated by the United States Coast Guard. In 1970 a fire destroyed the warden's house, the keepers' quarters and other buildings on the island; the only remaining building is the tall cement tower equipped with a modern beacon. The lighthouse can be visited. In over 50 years, the lighthouse has not been damaged despite many prison escapes, the Battle of Alcatraz and fires; the first lighthouse was 50 feet in height, was based on a design, typical of early "Cape Cod style" lighthouses, in which the light tower was an integral part of the keeper's house, was centered atop the dwelling's roof. Construction of the foundation started in 1852, the one-and-a-half-storied keeper's house and light were completed in 1853; the lens arrived in October 1853 and Michael Cassin lit it on June 1, 1854, thus setting a "milestone" of sorts for this lighthouse, as the first lighthouse on the Pacific Coast.
The old lighthouse was damaged in the earthquake which occurred on Wednesday the April 18, 1906. A new lighthouse was built to the south east of the old one; the old lighthouse existed alongside the new structure for a while and used as a storehouse, but was demolished between 1912 and 1913. The existing lighthouse is built to a height of 84 feet, 214 feet above sea level, to the south of the original lighthouse, its foundation is made of masonry. A third order Fresnel reflector was installed in 1854, was replaced by a fourth order reflector in 1903; the foghorn bell was replaced by electronic Klaxon. Near the base of the tower was family accommodation built to house three keepers and their families. Similar "Cape-cod style" lighthouses, encircling the thick light brick tower, were built at Point Loma in San Diego, Point Pinos near Monterey and on the Southeast Farallon Island about 30 miles west of the San Francisco Strait. There was a telephone installed, in the 1930, in the keepers quarters known to and accessed only by the keepers.
When the Federal Penitentiary was established on the island more telephones were installed and was made accessible to others also. The lighthouse was operated and maintained by th
Anacapa Island Light
Anacapa Island Lighthouse is a lighthouse in California, United States, on the entrance to Santa Barbara Channel, California. Constructed in 1912, it was the last major light station built on the west coast. Anacapa and several other islands were collectively designated as Channel Islands National Monument in 1938, though the Coast Guard retained responsibility for the Anacapa lighthouse. Now automated and unmanned, the light house still operates, but the National Park Service is responsible for Channel Islands National Park. Anacapa Island is noted now for an environmental restoration program devised by the NPS to exterminate the large population of non-native rats which infested the island and was making significant inroads on native species; the program, which began in 2003, selectively killed off the invaders with few adverse effects on the non-targeted native wildlife species. By 2014, after careful examination of the island, NPS could declare it "rat-free". Positioned at the eastern entrance to the Santa Barbara Channel, Anacapa was a natural choice for a lighthouse.
The Lighthouse Board decided to place a light on the island, but to limit the expense of building an offshore beacon, an unmanned acetylene lens lantern on a tower was erected in 1912. In 1932, the current permanent light station was built on the island, was the last major light station to be built on the west coast; the 39-foot tower and fog signal were built on the highest point of the island. In 1938, under the direction of Franklin D. Roosevelt, Santa Barbara and Anacapa Islands became Channel Islands National Monument; the United States Coast Guard automated the station in 1966. In 1980, Congress designated five of the eight Channel Islands, Santa Cruz, Santa Rosa, San Miguel, Santa Barbara Islands, 125,000 acres of submerged lands as Channel Islands National Park; the lighthouse is still an active aid to navigation. Historical Information from Coast Guard web site: Anacapa, a native-American word meaning "ever changing", was first discovered by Juan Rodríguez Cabrillo in 1542; the islands were called Las Mesitas or the Little Tables by De Portola in 1769.
Captain George Vancouver renamed them Anacapa from the Canalino Indian name of Enecapah. Anacapa Island is a chain of three small islets extending four and a half miles from east to west; the easternmost island is one mile long, a quarter of a mile wide, rises 250 feet above the water. Middle Island is one and a half miles long, a quarter of a mile wide and 325 feet at its highest point; the western, largest island of this group, is two miles long by six tenths of a mile wide, rises to a peak of 930 feet. Anacapa’s 40-foot lighthouse tower and adjacent foghorn building are located on East Anacapa, her radiant 1.1 million candlepower light beacon, her bellowing foghorn and beeping radio signal have guided ships safely through the coastal channel since 1932, the date of construction. Prior to that an unattended light placed on the island in 1912 served as a guiding beacon for sailing vessels. A one tenth second of white light, 11-9/10 second of darkness, one-tenth second of light, 11-9/10 second of darkness, one tenth second of light, 35.9 seconds of darkness.
This is the visual voice of Anacapa Island Light Station. The foghorn, a diaphragm-type horn, groans one two second blast is silent for two seconds, blasts again for two seconds and completes the cycle with 14 seconds of silence during low visibility. Electronic equipment sends out a continual radio beacon signal with a range of 12 miles; the Coast Guardsmen and their families of the light station resided in the four large Spanish style white stucco houses with red tile roofs before the light station was automated in December, 1968. The buildings other than the lighthouse are now being utilized by the National Park Service. Anacapa is the nearest of the Channel Islands to the mainland, it is 9 miles across the Santa Barbara Channel from the nearest point on the mainland. It lies southwest of the city of Ventura. List of lighthouses in the United States National Register of Historic Places listings in Ventura County, California United States Coast Guard
Cape Mendocino Light
Cape Mendocino Light was a navigation light at Cape Mendocino, California. The former lighthouse was relocated to Shelter Cove near Point Delgada, California in 1998, the historic Fresnel lens to Ferndale, California, in 1948. An automated beacon operated for a number of years but was removed in May 2013. After many ships, including the SS Northerner and a lighthouse tender with supplies to build the facility, were lost to the jagged rocks surrounding the 326-foot sea stack "Sugar Loaf" and Blunt's Reef offshore of Cape Mendocino, the lighthouse with attendant buildings including a carpenter shop, an oil house, a barn and a two-story residence were built on 171 acres of remote rangeland. On December 1, 1868, the light began sending a signal of one white flash every thirty seconds; the United States Coast Guard took control of the Cape Mendocino Lighthouse in 1939 when the United States Lighthouse Service merged with the Coast Guard. The lighthouse was a 43-foot iron tower, sixteen-sided and double balconied, a twin to the lighthouse at Point Reyes but for the roof shape.
At 422 feet, the height of the light exceeded the 420 feet Makapuu Point Light, making it the highest focal plane of any lighthouse in the United States. The lens had been shipped in through Eureka and overland to the remote location as it was too risky to ship it directly to the lighthouse. Due to the remote location, lighthouse tenders serviced the facility. In 1881, three men being sent to the lighthouse were killed while attempting to land in a small boat from the tender Manzanita. New dwellings were built in 1908 for the keepers, some of whom raised cows or ponies for the Ferndale to Petrolia stage coach line. At least ten keepers served this lighthouse from 1869 to 1926. In 1905, the continuing danger from Blunt's Reef led to the installation of a lightship, which saved over 150 passengers of the steamer Bear after it ran aground in 1916. After five people were killed while trying to land lifeboats on the rocky shore, it was decided that the others would make for the Blunt's Reef lightship.
The survivors clustered on the lightship. On 6 August 1921 the Alaska, built in 1889 by the Alaska Steamship Company and sank at Blunt's Reef off the California coast, showing that the shore-mounted light and the lightship were not enough to save passing ships. In 1926, a keeper at the light was credited with saving the lives of all on board the Everett a steam schooner which he saw had caught on fire; the keeper called for a rescue via telephone. When the ship arrived to help, they discovered the crew was unconscious from the fire fumes and saved them. In 1941, the Blunt's Reef lightship saved the surviving crew of the SS Emidio, the first casualty of the Imperial Japanese Navy's submarine force action on California's Pacific Coast. After World War II, the original first order Fresnel lens was replaced by an automated rotating aerobeacon. On 24 December 24, 1948 the Coast Guard loaned the lens to the City of Ferndale who dismantled it in 1949, moved it to town, built a replica lighthouse at the entrance to the Humboldt County Fairgrounds and reinstalled the lens there.
In 2008, a Coast Guard inspection of the lens resulted in negotiations for the continued housing of the lens in Ferndale. The "Save Our Lens" group of local citizens raised $100,000 to store the lens. By agreement with the Coast Guard in early September 2012, the lens was disassembled and put in temporary storage while the Ferndale Museum is remodeled to display it; the actual lighthouse building continued to deteriorate after being abandoned by the Coast Guard and in 1998 a group of volunteers dismantled the 1868 lighthouse, removed the lantern by Army National Guard helicopter and the remainder of the building by truck. Restored, fitted with new glass and painted by the Cape Mendocino Lighthouse Preservation Society, it was installed at Point Delgada in Mal Coombs Park in Shelter Cove, California. In 1951, the Coast Guard installed a dual aerobeacon, but this light was replaced by a simpler light with a focal plane of 515 feet, which flashed white every 15 seconds; the new light was located on a cliff about 350 yards northwest and 93 feet higher than the old light.
The light was turned off on May 29, 2013. Aerial photos show. While the original lighthouse was moved to Shelter Cove, the keeper's residence demolished, the oil house is still at the site. List of lighthouses in the United States United States Coast Guard "Historic Light Station Information and Photography: California". United States Coast Guard Historian's Office