Every Tuesday at noon in San Francisco, the outdoor public warning system rings out across the city. There are 109 speakers in total as part of the OPWS, though these days only 108 of them are functioning. That’s because the one at the intersection of Taraval and Great Highway has, reports Rick Prelinger, been turned off. The Taraval siren isn’t broken. None of the sirens are broken. The whole point of the weekly siren test is to check and quickly repair any siren — any one of the four speakers that make up each of the 109 sirens — that isn’t functioning. The Taraval siren is silent because it has become a shelter for a family of Red-Tailed Hawk.
Prelinger, who gave me permission to post the photo shown up top, wrote on his Facebook page:
When I toured the San Francisco Department of Emergency Management on June 16 prior to my communications infrastructure talk that evening at Long Now’s Interval, I was told they’d turned off the emergency siren and speakers at Taraval and Great Highway so as not to disturb a nesting Red-Tailed Hawk. Of course I had to go and see what was going on.
(Update: He also clarified this morning that the nest may be empty by now.)
If you’ve never heard it, here’s a recording:
Here’s a shot of the tower at Taraval and Great Highway via Google Street view. This is facing north. A very short walk to the left and you hit the Pacific Ocean:
Residents near Taraval and Geary needn’t worry too much for their safety. There are three other sirens within blocks. For reference, Taraval and Geary is number 78 in this chart, available as a PDF at the San Francisco Department of Emergency Management’s website, sfdem.org. The actual number of sirens is a little unclear. The main site states 109, but there are 114 listed in that PDF and 111 in an accompanying list. Note that some, like the one at Taraval and Great Highway, double for tsunami warnings.
Thanks to Rick Prelinger — associate professor at the University of California, Santa Cruz, and founder of the Prelinger Archives (prelingerlibrary.org) — for sharing the photo, and to Paul Socolow for alerting me to it. More on the sirens at sfdem.org. For additional reading, last month the duo 52-Blue (Nick Sowers and Bryan Finoki) in their designobserver.com series ran a piece on the tainted, wartime history of the siren. My audio recording of the siren is at soundcloud.com/disquiet. And for a recent shot of siren number 102, the one closest to my office, visit instagram.com/dsqt.