Driving Tank Vehicles
Surge and stability
Liquid cargo moves. When you accelerate, liquid shifts rearward; when you brake, it surges forward; in a curve, it moves to the outside. Baffles reduce surge but do not eliminate it, and a partly filled smooth-bore tank can be harder to control than a full one. The tank's high center of gravity raises rollover risk, especially in curves, ramps, and sudden lane changes.
Smooth control
Start, steer, and stop gently. Look far ahead and adjust speed before hazards, not after. Enter curves below the posted speed, stay off the brakes in the curve if possible, and accelerate only when the tank is straight. Increase following distance because stopping distance grows with weight and surge. Make lane changes slowly and avoid sharp steering. Watch for off-tracking: the rear wheels of a long tanker cut inside the front wheels.
Traps
A common trap is believing baffles make a tank behave like a dry van. Another is using the posted curve speed as a target; it is a maximum for cars, not a safe speed for a loaded tanker. Drivers also forget that a partial load can surge more than a full load.
Worked example
A tanker enters a 45 mph curve at 45 mph. The liquid shifts outward, the high center of gravity leans, and the driver brakes mid-curve. Correct approach: slow to a safe speed before the curve, hold steady throttle, and let the tank settle. Rule of thumb: finish braking before the curve and keep both hands on the wheel.