What is the purpose of wheel chocks during pump operation near traffic?

• A. To improve engine performance.
• B. To regulate water source.
• C. To provide a visual warning.
• D. To prevent vehicle movement on a slope or ramp, especially when parked near traffic or on uneven ground.

Answer: (D)

Wheel chocks are used to keep a parked pump apparatus from rolling when you’re operating near traffic or on uneven ground. On slopes, ramps, or unstable surfaces, movements from hose tension, engine vibrations, or wind can push the vehicle. Placing chocks against the wheels physically prevents that motion, giving you a stable platform to deploy hoses, operate the pump, and manage the scene safely. It’s an extra layer of protection beyond the parking brake, ensuring the apparatus stays put while you work. The other options don’t address preventing movement: they’re not about engine performance, water source regulation, or serving primarily as a warning.