Since 1915, the station next to the Bay Bridge has been home to the San Francisco Fire Department's boats and firefighters who respond to fire alarms near the water's edge and calls for water rescues.
Last week it's replacement showed up, a new fire station built on a barge and brought to town from Treasure Island by a couple of tug boats.The new station is permanently moored and will float up and down with the changing tides. The old station will be maintained and used for storage.
In a way this is the latest phase of a process that began with the Gold Rush in 1849. A long wharf was built to cross the mud flats that separated dry land from the deep water where ships could anchor. Over time oyster shells and other refuse were used to fill in the flats and create dry land between the shore and the ships. Today, about seven city blocks separates the sea wall from the former shoreline.
Even in recent decades there have been proposals to fill more of the Bay to create valuable real estate next to downtown. They have all been rejected. But occupying more of the Bay by building barges looks like it may have a future.