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Monday, March 26, 2007

Bill Cereske - SFFD Gear Wizard


Bill Cereske is known to most of the San Francisco Fire Department and to memebers of the SFFD NERT (Neighborhood Emergency Response Team). Bill is known affectionately as Bill, the Gear Wizard. Bill sells SFFD hats, T shorts and other items.

Once a weel Bill sends out an email to his subscribers (I'm one of them) and this week he talked about San Francisco's unique emergency water supply system. I thought sonme of you might find this interesting and I've reproduced it here ...

San Francisco has an Auxiliary Water Supply System (AWSS), which is actually three separate supplies. Squat, color topped hydrants are connected to various tanks in The City, and are used in case of large fires, or in case normal water is unavailable. Larger than the normal hydrants, these have the appearance of being ready for serious business, and they are. Had this system been in place in 1906, my opinion is that the Great Fire of 1906 never would have happened. Remember, almost NO water was stored in The City at that time.

The color of the top tells the source: Blue indicates the Jones St. Tank, which is located near Clay. This 500,000 gallon tank supplies hydrants in the “lower zone” which is generally 150 feet above sea level or less. Red means the Ashbury Hill tank, at Clayton, which is a 750,000 gallon store of firefighting water. It supplies the "upper zone" which has an elevation about 150 feet above sea level and above. A Black topped hydrant is fed from the King of them all: a 10.5 million gallon reservoir carved into the bedrock atop Twin Peaks. Perhaps you've seen it - it looks like a lake with a wall down the middle. The wall isn't there by accident: it turns the mighty tank into two tanks. If a catastrophie damages one section and the water leaks out, the other section is still ready to supply over FIVE MILLION GALLONS of Firefighting water!

Cleverly, the Ashbury tank can send it’s water to the Jones St. system, and Twin Peaks can send water to the Ashbury Tank. This means that every drop of water in the Twin Peaks tank(s) can be delivered to any auxiliary hydrant by the turn of a valve or control at the system control point, or out in the streets of San Francisco, at various locations.

Pressure at these hydrants can get so high (Over 300 p.s.i.)! when all the tanks are connected, that a special pressure reducing valve, called a "Gleeson" must be used before a fire engine can draw water. The volume is also incredible: Any one block of the downtown district can be filled to a minimum depth of one foot within an hour – without pumping! (Source: AWSS construction specifications). The threads on these hydrants are deliberately different than any in California - and perhaps the Country. Only a Gleeson valve fits them. If a mutual aid engine were to connect to a High Pressure (Auxiliary) hydrant without the protection of a Gleeson valve, the engine (the pump, anyway) could explode!

You can subscribe to Bill's weekly e-letter by sending him an email to:

If you want to browse Bill's SFFD Gear web site, go to: http://www.sffdgear.com/

For more information on the SFFD NERT, click here.
on Monday, March 26, 2007

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