Tanker Vehicle Inspection and Driving
Domain 1 tests the pre-trip items unique to a tank vehicle and the driving habits that keep a moving load upright. The exam expects you to know tank hardware by name and to explain why a tanker cannot be driven like a dry van.
Inspection items the test asks about
- Tank shell, baffles and mounts: cracks, dents, loose or missing bolts.
- Dome/manhole cover and gasket: seat clean, gasket intact, cover secured.
- Vents and pressure/vacuum relief: clear and undamaged.
- Internal (emergency) shutoff valve: closes fully and the remote actuator works.
- Hoses, couplings, pump: cuts, bulges, soft spots, leaks.
- Grounding/bonding cable: clamp teeth and continuity.
- Placards and tank markings match the shipping papers.
Driving rules
- Slow down before curves and ramps; rollover is the leading tanker crash.
- Brake and accelerate smoothly; a hard stop throws the liquid forward.
- Allow a longer following distance and stopping distance.
- Watch mirrors through turns; the rear of the tank swings wide.
- Use engine braking on grades; never coast in neutral.
Worked example
You enter a 25 mph off-ramp at 40 mph with a half-full 6,500-gallon tank. The right answer is to brake to 25 mph or a little under before the ramp and hold steady throttle through it. Reason: a half-full tank has a free surface, so the load surges as you turn; combined with the high center of gravity, the posted speed may already be too fast for a tanker.
Traps that cost marks
- Believing baffles stop surge; they only reduce it.
- Thinking a heavy vehicle stops shorter.
- Skipping the internal valve and dome gasket checks on pre-trip.