Achieving Maximum Flow from Hydrants
© 2001 Capt. Willis Lamm, Water Supply Officer, Moraga-Orinda (CA) Fire District

The following procedures are examples of low water pressure evolutions based on the procedures of the Moraga-Orinda Fire District, presented for illustrative purposes.

Most of the mercantile areas are protected by high volume hydrants. These "blue tops" are sufficient to supply two independent pumping operations.

Utilizing nearby hydrants effectively eliminates the need for extended hose lays from distant hydrants which often result in blocked access for other emergency vehicles and blocked egress for citizens who need to remove their vehicles from the fire area. There is also some strategic value when supply engines aren't spread over a wide area.

Some sample scenarios where 2-pumper hookups may be useful include:

  • One engine supplies tactical lines while another supplies a sprinkler or standpipe FDC.

  • One engine supplies tactical lines while another supplies an elevated stream.

  • Deployment of multiple large defensive lines

  • Defensive / offensive operations which result in a radical difference in operating pressures between smaller diameter interior lines and large defensive or exposure lines.

These are but a few of the tactical possibilities where it would be convenient to connect multiple engines to a single hydrant.


We tested these operations using a 2450 GPM hydrant located in the west parking lot at Miramonte High School. Our objectives were to pump 1000 GPM simultaneously from two engines (2000 GPM total) and maintain a residual pressure of not less than 10 p.s.i. during the operation. The methods tested included a two pumper hookup (two engines on one hydrant) and dual pumping (shared suction.) Both are discussed on the following pages.


Two Pumper Hookup

Dual Pumping

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