Water Sources
Nurse Tanker
A nurse tanker is a large water-hauling apparatus parked at the fire that the attack engine draws from directly, acting as a mobile reservoir. It lets smaller tankers dump into one big tank rather than coordinating with the pumper one at a time.
Instead of every tanker connecting to the attack engine in turn, a nurse tanker sits at the scene as a single large source. The pumper draws from it continuously while shuttling tankers top it up, smoothing the supply the same way a drop tank does.
The nurse tanker's own capacity buffers the gap between deliveries, so the attack does not stall between loads. It is one common way to run a rural shuttle when a large-capacity apparatus is available to anchor the dump site.
Where this shows up
Calculator
Tanker Shuttle