In firefighting hydraulics, how do attack lines differ from supply lines?

In firefighting hydraulics, how do attack lines differ from supply lines?

• A. Attack lines are used for priming, supply lines are used for pressure testing
• B. Attack lines deliver water to the fire, while supply lines carry water from the pump toward attack lines or from hydrants to the pump
• C. Attack lines supply water from hydrants, while supply lines deliver water to the fire
• D. Attack lines and supply lines have identical roles

Answer: (B)

The main idea is how water moves on the fireground: one type of hose is used to deliver water to the fire, the other to bring water to the pump from the water source. Attack lines are the hoses you bring to the fire and use at the nozzle to apply water directly to the flames. Supply lines are the hoses that feed the pump from a water source—like a hydrant or another source—so the pump can pressurize the water and send it out through the attack lines. In practice, water typically travels hydrant or source → supply line → pump → discharge → attack line → nozzle. This setup keeps the pump fed with water while the crew at the nozzle focuses on applying it to extinguish the fire.

The main idea is how water moves on the fireground: one type of hose is used to deliver water to the fire, the other to bring water to the pump from the water source. Attack lines are the hoses you bring to the fire and use at the nozzle to apply water directly to the flames. Supply lines are the hoses that feed the pump from a water source—like a hydrant or another source—so the pump can pressurize the water and send it out through the attack lines. In practice, water typically travels hydrant or source → supply line → pump → discharge → attack line → nozzle. This setup keeps the pump fed with water while the crew at the nozzle focuses on applying it to extinguish the fire.