page_title: Alcatraz Island Lighthouse
section_title: Structural details
hierarchical_section_title: Alcatraz Island Lighthouse / Structural details
caption_attribution_description: English: The second Alcatraz Light
context_page_description: 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, and 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 which was 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 easily looks the tallest structure on Alcatraz, it is actually shorter than the Alcatraz Water Tower, but as it lies on higher ground it looks much taller.
context_section_description: The first lighthouse was 50 feet (15 m) in height, and was based on a design that was typical of early "Cape Cod style" lighthouses, in which the light tower was an integral part of the keeper's house, and was centered atop the dwelling's roof. Construction of the foundation started in 1852, and 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 eventually demolished between 1912 and 1913.
  The existing lighthouse is built to a height of 84 feet (26 m), 214 feet (65 m) above sea level, to the south of the original lighthouse. Its foundation is made of masonry while the octagonal pyramidal shaped tower is made of concrete. Initially, a third order Fresnel reflector was installed in 1854, and 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 also 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 also on the Southeast Farallon Island about 30 miles (48 km) west of the San Francisco Strait. 
  There was also a telephone installed, in the 1930, in the keepers quarters (moved to the hall later) 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 the keepers whose responsibility included operation of fog signals found located on the northern and southern tips of the island. The prison guards facilitated the keepers to blow the fog horns as they were in advantageous position stationed on the elevated watch towers; the guards who were in position to see "a bank of fog started to roll through the Golden Gate", would inform  notify the keepers so that the fog horns could be activated.
caption: Coastguard building blueprint
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