If Engine one supplies Engine two with a 2 1/2" hoseline 600 ft long, what is Engine one's pump discharge pressure if Engine two has two 150 ft long handlines?

To find the pump discharge pressure from Engine One when supplying Engine Two, we need to consider the pressure loss due to friction in the hose and the required pressure at the discharge end after accounting for the addition of the handlines.

In this scenario, Engine One supplies a 600 ft long 2 1/2" hoseline to Engine Two, which then splits into two handlines, each 150 ft long. The total length of the handlines will therefore be 150 ft each, meaning we have a total of 300 ft to account for in pressure calculations once Engine Two engages the handlines.

The pressure drop in the hose is influenced by factors such as hose diameter, length, and flow rate. A common method to calculate friction loss for a straight-length hose is the formula which uses a specific coefficient for 2 1/2" hose, typically around 2.0 psi per 100 ft of hose at a given flow rate (if the flow rate is around 250 gallons per minute, for example).

By calculating the total friction loss for the 600 ft hoseline leading to Engine Two and then for the 300 ft of handlines, you would attribute the necessary pressure to maintain effective flow at each nozzle.