Sutro Tower

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The Sutro Tower as viewed from the east

Sutro Tower is a three-pronged antenna tower on Mount Sutro in the western part of San Francisco, California at 37°45'19.0" N and 122°27'10.0" W. It is a dominant part of the city skyline, but is relatively unknown to tourists as it is often airbrushed out of travel brochures. It is less picturesque than other landmarks and is considerably west of the main downtown tourist area. San Francisco writer Herb Caen once said, “I keep waiting for it to stalk down the hill and attack the Golden Gate Bridge.”

On a clear day, the tower can be seen from the East Bay peak of Mount Diablo and is sometimes the only part of San Francisco seen above the coastal fog when it is blown inland—typically on summer mornings and evenings.

Construction began in 1971, by Kline Tower of Columbia, SC, and was completed in 1972, with the first transmissions from Sutro Tower on July 4, 1973. Named after Adolph Sutro, a businessman and former mayor of San Francisco, the tower stands 977 feet (298 metres) from the ground and 1,800 ft (549 m) from sea level. It is the tallest structure in the city, surpassing the 853 ft (260 m) Transamerica Pyramid by more than 100 ft (30 m). In addition, it is built on one of the highest peaks in the city, the old site of the Sutro Mansion owned by Adolph Sutro's descendents. The original site of the mansion was in the north west corner of the city near the Sutro Baths and the Cliff House The facility is surrounded by a fence and the site offers no panoramic viewpoints of San Francisco. Good views, however, can be found at the adjacent Twin Peaks. A unique view comes from the top platform of the tower, 762 ft (232 m) above ground. Access for authorized maintenance workers is by a tiny two-person elevator that runs inside one of the tower's enclosed legs. The elevator ride ends at a catwalk and a breathtaking open-air span allowing engineers to walk along the horizontal platform. The circular outline of the original Sutro Mansion is visible from this height. Fog often rolls in below the level of the platform, giving the impression of standing on a cloud.

About 15 million pound (6,800 tonnes) of concrete were used to make the foundation of the 3.7 million pound (1,700 tonnes) tower. Earthquake proofing includes ballasting two thirds of the weight of the structure below ground, with resulting center of gravity sixteen at feet below ground level. It is used to transmit ten analog, eleven digital TV stations and four FM radio stations to the San Francisco Bay area. The tower is owned by Sutro Tower, Inc., which in turn is owned by the four main television stations KTVU, KRON, KPIX and KGO with usage leased to other Bay Area TV and radio stations.

Sutro Tower is restricted to authorized personnel and stands on private property. The tower may be viewed up close from La Avanzada Drive.

Before its construction, television reception in San Francisco was quite spotty as the many hills of the city would block the line-of-site radio waves - this was before the rise in popularity of cable television but is the main source of free over the air television in the Bay Area. Before Sutro Tower, transmitters were scattered throughout the Bay Area including at San Bruno Mountain, Mt. Allison, Monument Peak, and Mt. Diablo. Reception outside of San Francisco was incrementally improved by the tower. By having all the main Bay Area television stations in one location reception was improved by allowing all receiving antennas to be pointed at one tower instead of many. However, local NBC affiliate KNTV, which originally broadcast from Loma Prieta Peak in Santa Clara County, currently broadcasts from San Bruno Mountain. Most residents in San Mateo County, the East Bay, and Marin County can aim their antennas in the general direction on Sutro Tower and get all stations, including KNTV. Some residents in San Francisco need to rotate their antenna as San Bruno Mountain is approximately five miles south of Sutro Tower.

Sutro Tower at sunset

In function, Sutro Tower is a unique structure in the world of transmitting towers by allowing Bay Area television stations to share resources.

[edit] In popular culture

The video game Grand Theft Auto: San Andreas contains a radio tower that bears a striking resemblance to Sutro Tower. The tower is also an important presence in the classic 1977 San Francisco horror novel 'Our Lady of Darkness' by Fritz Leiber.

It is also seen in Midway's 1997 game San Francisco Rush.