Driving Tank Vehicles and Vehicle Stability
Domain 2: Driving Tank Vehicles and Vehicle Stability
Tanker driving is stability management. A cargo tank carries a high center of gravity and a moving load, so the test expects you to adjust speed, steering, and braking before the liquid moves, not after.
Core rules
- Slow down before curves and ramps. Centrifugal force rises with speed; a posted ramp speed that is safe for a car may be too fast for a tank.
- Steer smoothly. One abrupt correction can start a side-to-side surge that compounds.
- Brake early and gently. Liquid moving forward adds force and lengthens stopping distance.
- Keep a longer following distance and avoid quick lane changes.
- Use a lower gear on downgrades and avoid riding the brakes; brake fade is more dangerous with a heavy, high-center-of-gravity vehicle.
- Secure the load: hatches closed, valves positioned correctly, and no unsecured equipment.
- Remember that a partially loaded tank can be less stable than a full one because the liquid has room to move.
Worked example
A tanker enters a 25 mph off-ramp at 40 mph with a half-full compartment. The liquid surges to the outside of the curve as the truck leans, shifting weight to the outer wheels. The driver feels the lean and brakes mid-curve, which adds forward surge. The correct response is to slow to the posted speed before entering, hold a steady line, and avoid braking in the curve.
Traps
Treating the tank like a van; braking hard in a curve; oversteering to correct a small drift; assuming an empty tank is automatically stable, since residual liquid can still move; ignoring tire and brake condition.