Visiting an SF Landmark. Sutro Tower.
Not many people get inside Sutro Tower, so I consider myself pretty fortunate. My current employer doesn’t have transmit facilities or other interests at Sutro, so I was escorted through the gate and into the facility by a contract engineer, John Buckham, that our SF station has who also maintains a radio station there for another employer of his.
This was a unique opportunity for a few reasons; since I don’t work there, getting access is impossible unless you know someone and can get something arranged. This is a historically interesting site and it is a unique tower engineering design that has currently weathered 25 years of use.
As is typical, especially in these days of greater cable and satellite television penetration in the market place, Sutro Tower comes under attack from local residents who don’t want it because they feel they don’t benefit from its presence or they feel their health is in danger or they think the tower will fall on them when the next earthquake comes.
These arguments are classic, unfounded and used by others elsewhere in the country when they want to git rid of a tower in their immediate view in an effort to increase their property values. The tower supports several dozen antennae for multiple services (television, radio, cellular telephone, paging, land mobile, etc.), there is negligible downward radiation (because the viewers that the antennas are meant for are out on the horizon) and the tower has been upgraded in 2003 to withstand an earthquake greater than 8.0 – which was well after it survived the 7.1 magnitude earthquake of 1989.
The tower is 977 feet tall and once you get up close to it you get a feel for just how massive the 3.7 million pound structure really is.
Once you are past the gate guard and inside the compound which sits beneath the tower you have access to to the entrance to the three-level, concrete structure that is home to the multitudes of TV and radio transmitter rooms, each with their own concrete suite.
Of course, transmitters require a lot of power so there are redundant electrical services inside the facility along with several back-up generators.
Because of the importance of the facility’s operation for the major Bay Area broadcasters, there is an on-site facility manager to deal with the day-to-day issues in addition to the manned guard shack by the gate. During periods of antenna, tower or transmitter maintenance many of the broadcasters have an auxiliary antenna they can utilize. The current antenna in use by a broadcaster is monitored at a central point in a common area of the building. This will allow for tower workers (and anyone else) to see at a glance which antennae are radiating energy and can take appropriate precautions when working on the tower.
For those working on this tower they will likely make use of this elevator which is built into one leg of the structure:
Well, this about sums up my nickel tour of the site. There is a lot more to the site to see in the way of the nuts-and-bolts elements that make all the transmitters play nice with each other, but this wraps up the more superficial and outwardly interesting elements.
Be sure to visit the links I’ve provided to learn more about the site from those that have worked really hard to collect a lot of information about Sutro’s history and technical details.