2521 - TANKER/PUMPER Tanker/Pumper 2521 was designed to be a backup unit to our first due engine unit 2511. Its main function is to supply water. However, it has the capabilities of being the first in engine. This unit's pump can flow 2000 gallons per minute and it has a 2500/gallon water tank. Unit 2521 is equipped with 2000 feet of 5 inch supply hose and a 3000 gallon portable dock tank, 3 pre-connect hand lines, 40 gallons of class A and B foam, self-contained breathing apparatus for five 5 fire fighters as well as ground ladders.