Home » City Guide » , , , ,

SF’s “Sutro Tower” is 50 Years Old Today (July 4)

The 977-ft tall San Francisco skyline icon celebrates 50 years in service in 2023
By - posted 7/1/2023 No Comment

Sutro Tower, the famed 977-foot-tall beacon of communication, celebrates a half-century of standing tall above SF’s skyline on July 4, 2023

From its lofty perch atop Mount Sutro, the tri-pronged steel leviathan has been piercing the clouds and delivering clear signals throughout the San Francisco Bay Area since 1973.

Dubbed “Sutro Tower”, this unmistakable landmark takes its name from the hill it’s anchored in, which itself pays homage to the former mayor of San Francisco and Gold Rush engineer, Adolph Sutro. His grandson, Adolph G. Sutro, once presided over a mansion on the same spot until it was sold to ABC to be used as a transmission site for the new KGO-TV station in 1948.

Sutro Tower Stats

  • Sutro Tower stands at a colossal height of 977 feet
  • Construction was completed in 1973. The first stations went on-air on July 4, 1973. In 2009, the tower converted to all-digital transmissions.
  • The structure of Sutro Tower incorporates 3.5 million pounds of steel.
  • The three legs of the tower are embedded in 15 million pounds of cement.
  • The project to construct Sutro Tower in 1971 cost a total of $4 million – taking into account inflation, that’s the equivalent of $30 million in 2023.

Decades ago, the Bay Area’s television landscape was vastly different, with stations initially operating out of the grand Sutro Mansion and broadcasting from a more modest 508-foot tower. But as the technology advanced and viewers demanded better reception, the call for a more formidable structure was inevitable.

After an exhaustive search and following some legal wrangling, the Sutro site was chosen over Mount San Bruno for the future of Bay Area broadcasting. The project, valued at $4 million, commenced in 1971. Designed by Albert C. Martin & Associates, the new tower boasted a 68% height increase from the original, setting the stage for its commanding presence in San Francisco’s skyline.

Sutro Tower FAQ

Q. What does Sutro Tower do?
Ten television stations, three FM radio stations, and 20 wireless and mobile communications users (i.e. law enforcement agencies, taxi cabs, school buses, wireless internet, etc.) rely on Sutro Tower antennas to transmit signals over the air to the entire Bay Area.

Q. Why is Sutro Tower Necessary?
Over the air television reception is still used by more than 1 million people in the Bay Area who do not pay to subscribe to cable or satellite television. Over the air television and radio also provide critical local news sources during emergencies even if cable lines are down. New wireless and mobile technologies also are supported by Sutro Tower.

Q. Can Sutro Tower antennas be located elsewhere?
No. In the recently completed Environmental Impact Report, other locations were studied and found to be inadequate to serve the needs of the entire area population.

Q. Is the tower safe during a major earthquake?
Yes. Exhaustive structural studies have determined that the tower will withstand an earthquake at least as severe as the 1906 event. In fact, it will withstand what engineers believe is the maximum energy able to be caused by any event in the San Andreas Fault. One-third of the tower undergoes a detailed inspection each year by an independent testing laboratory approved by the City, including plates, bolts, welds, trusses, concrete and all other components. Remediation of instances of wear or rust result in like-new condition every three years. Sutro Tower has undergone several structural reinforcing projects over the years to maintain its structural integrity as engineers learn more and more about seismic events.

Learn more at sutrotower.com – the official site of Sutro Tower

In a fascinating display of engineering prowess, the colossal structure was fabricated and erected by Kline Towers. Its three legs are firmly rooted in 15 million pounds of cement, while the tower itself is a steel marvel, crafted from 3.5 million pounds of the stuff.

After the completion of this gargantuan project , the first broadcast transmissions lit up Bay Area televisions on July 4, 2023, cementing Sutro Tower’s crucial role in local media. By 2009, the tower had fully embraced the digital age, converting to all-digital transmissions.

So, on this notable anniversary, let’s tip our hats to this steadfast sentinel of the sky, Sutro Tower. Here’s to another 50 years of standing tall, connecting us all, and keeping our selfies interesting with its iconic backdrop. Happy birthday, Sutro Tower!