Vehicle Stability, Rollover Prevention, and Safe Speeds on Curves
Rollover is the tanker hazard that leaves the least room for recovery. This domain asks you to connect high center of gravity, liquid movement, centrifugal force, and curve speed to a practical driving speed.
Why tankers roll
A loaded tank puts much of its weight high. Liquid movement raises the effective center of gravity and can shift weight to the outside of a turn. Centrifugal force increases with speed and with a tighter curve, so a small speed increase can sharply increase the overturning push. Baffles help with surge but do not lower the tank's center of gravity or increase its rollover threshold.
Managing curves and stability
Reduce speed before the curve, while the vehicle is still straight. Select a lower gear before entering, then use gentle, steady steering. Do not brake hard in the curve; if you are already too fast, ease off smoothly and avoid a sharp steering correction. Watch ramps, off-ramps, crowned roads, crosswinds, and soft shoulders. Load compartments evenly and keep axle loads within limits; an off-center load makes one side more likely to lift. Maintain tire pressure and inspect suspension and shocks, because poor tires or worn shocks make rollover more likely.
Worked example
A tanker approaches a 45 mph off-ramp. The posted speed is for cars, not for a high-center-of-gravity tank with liquid. The driver slows well below the posted speed before the ramp, downshifts, and steers a smooth arc. If the truck begins to lean, the driver does not jerk the wheel or slam the brakes; those inputs can transfer more weight and cause a rollover. The reasoning is that rollover prevention happens before the curve, not during it.
Traps that cost marks
Treating the posted speed as a tanker target; braking late; oversteering to correct a small error; assuming a full tank is automatically stable; and ignoring side-to-side load balance. Smooth speed control and a low, balanced load are the marks of a safe tanker driver.