Mile Rocks Lighthouse is located on a rock about southwest of the
Golden Gate Bridge
The Golden Gate Bridge is a suspension bridge spanning the Golden Gate, the strait connecting San Francisco Bay and the Pacific Ocean in California, United States. The structure links San Francisco—the northern tip of the San Francisco Peni ...
, off of
Lands End in
San Francisco, California
San Francisco, officially the City and County of San Francisco, is a commercial, Financial District, San Francisco, financial, and Culture of San Francisco, cultural center of Northern California. With a population of 827,526 residents as of ...
. It was completed in 1906, replacing a nearby bell
buoy
A buoy (; ) is a buoyancy, floating device that can have many purposes. It can be anchored (stationary) or allowed to drift with ocean currents.
History
The ultimate origin of buoys is unknown, but by 1295 a seaman's manual referred to navig ...
. In 1966, the light was automated, and the original tower of the
lighthouse
A lighthouse is a tower, building, or other type of physical structure designed to emit light from a system of lamps and lens (optics), lenses and to serve as a beacon for navigational aid for maritime pilots at sea or on inland waterways.
Ligh ...
was demolished and replaced by a
helipad
A helipad is the landing area of a heliport, in use by helicopters, powered lift, and vertical lift aircraft to land on surface.
While helicopters and powered lift aircraft are able to operate on a variety of relatively flat surfaces, a fa ...
. The lighthouse was at one time painted with alternating red and white rings, but , the lighthouse is painted plain white.
History
In 1889, the
United States Lighthouse Service
The United States Lighthouse Service, also known as the Bureau of Lighthouses, was the agency of the United States Government and the general lighthouse authority for the United States from the time of its creation in 1910 as the successor of th ...
placed a bell
buoy
A buoy (; ) is a buoyancy, floating device that can have many purposes. It can be anchored (stationary) or allowed to drift with ocean currents.
History
The ultimate origin of buoys is unknown, but by 1295 a seaman's manual referred to navig ...
near the rocks. However, strong currents in the area would pull the buoy beneath the surface of the water and set it adrift.
On February 22, 1901, the
SS ''City of Rio de Janeiro'' wrecked on the rocks, which prompted the lighthouse to be built.
One hundred and twenty-eight persons, of 209 aboard, lost their lives when the ship sank.
The lighthouse was constructed by contractor James McMahon who hired sailors from San Francisco after his original crew refused to work in the dangerous conditions. Mile Rocks Lighthouse was finished in 1906 after considerable difficulty caused by the heavy seas and strong currents near the site.
The rock upon which the lighthouse is built measures only at high water. The base of the tower is a large block of concrete protected by steel plating. Steel and concrete in the foundation weigh . The superstructure is made of steel and houses the fog signal apparatus and the quarters for the former
keepers.
In 1966, the light was automated and the tower was removed, leaving only the foundation and first story. The top of the first story was modified to support a helipad for the US Coast Guard. The original third order
Fresnel lens
A Fresnel lens ( ; ; or ) is a type of composite compact lens (optics), lens which reduces the amount of material required compared to a conventional lens by dividing the lens into a set of concentric annular sections.
The simpler Dioptrics, d ...
was transferred to the
Old Point Loma Lighthouse in
San Diego
San Diego ( , ) is a city on the Pacific coast of Southern California, adjacent to the Mexico–United States border. With a population of over 1.4 million, it is the List of United States cities by population, eighth-most populous city in t ...
.
Gallery
USCGmilerocksBefore.JPG, Mile Rocks Lighthouse in 1962, showing the original configuration.
Mile Rocks Lighthouse crop.jpg, Mile Rocks lighthouse, with Point Bonita and Marin headlands in distance
Mile Rocks Light with Container ship Sealand Balboa outside the Golden Gate.jpg, Mile Rocks Light with Container ship ''Sealand Balboa'' in December 2019
USCGmilerocksAfter.JPG, The lighthouse after modifications
See also
*
List of lighthouses in the United States
This is a list of lighthouses in the United States. The United States has had approximately a thousand lights as well as light towers, range lights, and pier head lights. Michigan has the most lights of any state with over 150 past and present ...
References
External links
*
*
{{authority control
Lighthouses completed in 1906
Lighthouses in San Francisco
1906 establishments in California
Islands of San Francisco