Sutro Tower

Sutro Tower
Sutro Tower viewed from Grandview Park in San Francisco
General information
Status	Complete
Type	Radio mast
Location	San Francisco, California
Address	1 La Avanzada Drive Clarendon Heights
Coordinates
Elevation	254.2 m (834 ft)
Completed	4 July 1973 (4 July 1973)
Owner	Sutro Tower, Inc.
Height
Antenna spire	297.8 m (977 ft)
Observatory	on Level 6, 228.8 m (751 ft) above base
Dimensions
Other dimensions	base triangle legs spaced 45.7 m (150 ft) on a side waist triangle legs spaced 18.3 m (60 ft) on a side antenna triangle spaced 30.5 m (100 ft) on a side
Technical details
Structural system	Truss tower
Design and construction
Architect	Furman L. Anderson, Jr.
Architecture firm	Kline Iron & Steel Albert C. Martin and Associates
Renovating team
Engineer	Simpson Gumpertz & Heger
Website
sutrotower.com
References

Sutro Tower is a 977 ft (298 m) three-pronged TV and radio antenna tower in San Francisco, CA. Rising from a hill between Twin Peaks and Mount Sutro near Clarendon Heights, it is a prominent feature of the city skyline and a landmark for city residents and visitors.

History

Before the construction of Sutro Tower in 1973, television reception in San Francisco was spotty because the many hills of the city blocked the line-of-sight television signal. The great height of the new tower helped to resolve that problem. Transmitters had been scattered throughout the Bay Area, including at San Bruno Mountain, Mt. Allison, Monument Peak, and Mt. Diablo. By having all the main Bay Area television station transmitters in one location, reception was improved by allowing a receiving antenna pointed in a single direction to receive all those stations rather than a subset.

Local residents opposed the tower even before it was completed, including criticism of the aesthetic effect the tower would have on the rest of San Francisco. San Francisco writer Herb Caen once wrote, "I keep waiting for it to stalk down the hill and attack the Golden Gate Bridge." Acknowledging both displeasure and affection for its undeniable prominence on the city's skyline, it is sometimes referred to light-heartedly as the Sutro Monster or Space Claw.

When first built, the long legs of the tower were illuminated at night with long tubes of white light that looked like long fluorescent tubes. However, public outcry resulted in the lights being removed soon after they were turned on.

Despite the initial revulsion of some residents, Sutro Tower is now recognized by many as a Bay Area icon, it appears in local art, television shows, and movies as one of the architectural symbols of the city. The tower is featured in video games, business logos, on clothing, as furniture and even tattoos. The U.S. band Information Society used it on the cover of their album 'Don't Be Afraid'. A local entertainment guide, SF Station, uses it as a logo, as do the collaborative art game SFZero and the Expose SF art competition.

Construction

Tower, including base

Construction commenced in 1971 by Kline Towers of Columbia, South Carolina, and the tower was completed in 1973, with the first transmissions on July 4, 1973. Approximately 3,750 m³ (132,000 cu ft) of concrete were used to make the foundation of the 3.7 million pound (1,700 ton) tower. Earthquake proofing includes ballasting two thirds of the weight of the structure below ground, resulting in a center of gravity at sixteen feet below ground level. It is used to transmit the signals of eleven television stations and four FM radio stations and for various other communications services.

The tower is owned by Sutro Tower Inc., which in turn is owned by a consortium of the four major television broadcasters in San Francisco at the time of its construction: KTVU (previously owned by Cox Enterprises, now owned by Fox Television Stations); KRON-TV (owned by the San Francisco Chronicle at the time of the tower's completion, now owned by Media General); KPIX (a former Westinghouse Broadcasting property, now owned by CBS); and KGO-TV (an ABC-owned station). Sutro Tower also leases space to other Bay Area radio and television stations, including PBS outlet KQED; independent station KOFY-TV; and KBCW, a sister station to KPIX.

Three other major Bay Area TV stations are unable to be located at Sutro Tower—the NBC-owned duopoly of KNTV and KSTS; and KTVU's duopoly partner KICU-TV. KNTV, which assumed the area's NBC affiliation from KRON-TV in 2002, relocated its transmitter from Loma Prieta Peak to San Bruno Mountain, five miles south of Sutro Tower; KSTS and KICU-TV transmit from east of Fremont. Those locations allow these stations to maintain primary coverage over San Jose and the South Bay—San Jose is the city of license for all three stations.

Named after Adolph Sutro, a businessman and former mayor of San Francisco who had a mansion located about 100 feet away from where the tower is now located, it is built on one of the highest peaks in the city. The tower stands 297.8 m (977 ft) above ground and 552 m (1,811 ft) above sea level. It is the tallest structure in the city, surpassing the 258.4 m (848 ft) Transamerica Pyramid by more than 39 m (128 ft). The old site of the Sutro Mansion, and thus the land on which the tower stands, is owned by Adolph Sutro's descendants.

Access

File:SutroTower.JPG

Night view

Seen above the coastal fog

The facility is accessible only by authorized vehicles. The area near the site offers beautiful panoramic viewpoints of San Francisco. There is a platform near the top of the tower, 232 m (761 ft) above ground and 486.2 m (1,595 ft) above sea level. Only authorized maintenance workers can access the tower via a small two-person elevator that runs inside the west tower enclosed leg. There is no public access within the Sutro Tower property lines.

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.

Stations

Television

TV stations that transmit from Sutro Tower include the following. As most of these stations carry additional subchannels on their frequencies, only their main affiliations on the .1 subchannel are listed here. Subchannel affiliations are shown via the Digital channels link.

Callsign	Virtual Channel	Physical Channel	Affiliation	Digital channels
KTVU	2	44	Fox	2.1-2.4
KRON	4	38	MyNetworkTV	4.1-4.3
KPIX	5	29	CBS	5.1-5.2
KGO	7	7	ABC	7.1-7.3
KQED	9	30	PBS	9.1-9.3
KOFY	20	19	Ind.	20.1-20.4
KMTP	32	33	Multilingual Ind.	32.1-32.6
KCNS	38	39	MundoMax	38.1-38.6
KBCW	44	45	The CW	44.1
KCSM	60	43	Public Ind.	60.1-60.3
KFSF	66	34	UniMás	66.1-66.4

Radio

FM stations that transmit from Sutro Tower include the following:

Callsign	Frequency	Format	Owner
KOIT-FM	96.5	Lite Rock	Entercom
KSOL-FM	98.9	Regional Mexican	Univision
KOSF-FM	103.7	Classic Hits	Clear Channel
KFOG-FM	104.5	Triple-A	Cumulus Media

In popular culture

The tower is an important presence in the 1977 San Francisco horror novel Our Lady of Darkness by Fritz Leiber.

The video game Grand Theft Auto: San Andreas, set in a fictionalized San Francisco, contains a radio tower that bears a striking resemblance to Sutro Tower. Versions of the tower are also seen in Midway's 1997 game San Francisco Rush and Need for Speed Underground 2.

The MMORPG Defiance includes Sutro Tower as the location of the mission Turret Turnabout.

External links

• Official Site of Sutro Tower, Inc
• Listing 1001289 in the U.S. Federal Communications Commission (FCC) Antenna Structure Registration database
• Flickr: Photos tagged with "sutrotower"

• Sutrotower.org, "a comprehensive guide to Sutro Tower and Mount Sutro"
• User page with information about Sutro Tower
• Sutro Tower Community Perspectives
• RCA Broadcast Magazine from 1973 detailing engineering
• Fybush.com Tower Site of the Week September 23, 2011