Water Sources
Booster Tank
The booster tank is the water carried on the apparatus itself, used to flow the first line before an external supply is set. It is a countdown, not a supply — a working line empties it in a couple of minutes.
Tank water makes the engine self-sufficient for the opening moments of an attack. Open tank-to-pump and the first line flows immediately, buying time to establish a hydrant or a draft.
Its limit is duration. The tank's gallons divided by the flow you are moving gives the minutes until it runs dry, and a bigger nozzle or a second line shortens that clock fast. Committing to tank water means committing to a stopwatch.
Where this shows up
Calculator
Tank DurationLesson
Tank-to-Pump & First Line