Supplying an aerial with a 2.5in discharge from an Engine
I am new to this, so please help me out here. I have read a few previous posts and I have already received more information about this topic than I ever thought. My question has still only been partially answered.
My question is based on a previous incident at a fire. It is about GPMs supplied to the aerial. We used a single 2.5 in., 30 degree elbow discharge on a 1,250 GPM single stage pump. Connected to the 2.5in. discharge was an adapter (2.5in. to 5in., stortz) followed by 100 ft of 5in. LDH. This is what supplied the aerial. The water supply was 800ft. of 5in. LDH hooked up to the steamer cap of a hydrant capable of flowing 1,499 GPMs, as the color coding goes (green bonnet). There was no relay pump and the elevation increase was less than 10 feet.
I am in the belief, and maybe wrong, that greater gallonage to the aerial could have been accomplished using 2 discharges instead of one. Here is the difference though. I believe using 2 2.5in. discharges with 50 or 100ft. (negligable) of 2.5in hose into a Siamese (2.5in to 5in.) on the LDH intake of the pump of the aerial. the aeriel was close enough to the primary pumping engine to use 50ft. of hose. I recognize there is greater friction loss to overcome on the 2.5in hose. Both set ups have adapters that should cancel each other out.
The previous posts I have read were based on a hydrant to pump. This is pump to pump. I am not sure what the primary pump set the discharge supplying the aeriel to and the aerial was set to 150psi at its pump. No other hoses were flowing on either apparatus at the time. Can anyone help me out?