After the earthquake in April of 1906, San Francisco suffered huge losses from that famous fire that spread quickly due to a lack of water supply. The City fathers decided to think ahead and developed an auxiliary water system fed from 3 large tanks throughout the City. At an incident, the different tanks can be added to the system and a large amount of high pressure water diverted to the hydrants nearby.
If the nearly 10,000,000 gallons of water run out or are not available for whatever reason, the system can be augmented by pumping salt water into the system in one of three ways. Either from lines fed from the fire boat, by the pump house in the basement of Headquarters or this non-descript building in my first due area.
Inside the house, built in the 19teens, are the large coal fired furnaces that created the steam to push the water into the hundreds of miles of large diameter hydrant pipe. Here’s a pic of me and my fireman Joe in front of one of the three 3 story tall furnaces. They are no longer fired, diesel engines have long replaced them, but they are so large and built into the structure, removing them would be cost ineffective and likely damage the entire building. I can only imagine what it must have been like to be in this pump house when a greater alarm fire was working and water was needed. Coal fire smoke, heat and exhaustion must have been all in the day’s work for the men assigned here.
We were stopping by to drop off a few fire prevention items and ended up staying for almost an hour looking around and asking the pumpman (yes, there is still a pumpman there) all about what we were seeing.
The valves and gauges are still the originals and are kept in good working order and polished clean. After all, there is still the possibility of firing these big guys up should we ever need to.
Many of the components here were installed between 1912 and 1925 and while my East Coast readers may think this quite recent in comparison to their own services, out here on the west coast this kind of history is unheard of. The building sure, the valves on display maybe, but a still operational unit kept in this kind of condition blew me away.
In addition to powering the water system, this building served as a large electrical generator for the nearby Army Depot. On the other side of the room, right out of Dr Frankenstien’s laboratory is the electrical panel and breaker switches. Around every corner was another confusing tangled maze of pipes and valves, coal doors and pressure gauges.
It made me more appreciative of where the water comes from, not unlike I felt the first time I had to repair a hot water heater and appreciated where that water came from all that much more.
This system can produce up to 300psi at 10,000 gpm and can operate for almost 2 days solid without refueling. Which is good since each high pressure hydrant can move up to 12,000 gpm. Of course the folks back then had to develop a way to handle such pressures, which occur naturally when opening the progressively higher altitude supply tanks. the lower zone may rate at 60psi static, 150 with the first tank open, then 225 and 300 when the others are opened.
A special hydrant device was patented in 1926, the Gleason Valve, for this single purpose. Made of spun brass and weighing almost 90 lbs, this special hydrant valve device attaches to the high pressure hydrants and can lead 2 3″ lines from a pressure reducing valve. In the old days these were used as fire pumps without putting the supply through a steamer. Nowadays we can either tie it into a pumper or use it as a stand alone supply for a master stream or to charge our above ground backup hydrant system. You can spot the high pressure hydrants not only because they have a 10″ diameter supply, but have 3 3 1/2″ caps and a colored bonnett.. This allows the crews to see which reservoir feeds that particular hydrant.
More on the hydrants in another post, including the significance of our ball top hydrants.