A tank shell looks intact, but liquid is seeping around a discharge-valve connection. Is the vehicle ready to haul the load?
Correct answer: No; valve, pipe, hose, and connection leaks are part of the tank inspection too.
Tank inspection includes the shell, valves, pipes, hoses, covers, and vents. Do not transport a load in a leaking tank system.
Source: South Dakota Commercial Driver License Manual, Revised 07/2025, 8.1.1 Leaks; physical PDF page 123. ↗
A partially filled liquid tanker has just stopped on ice. Why can the vehicle still be pushed forward?
Correct answer: Liquid continuing to surge inside the tank can push against its end.
Liquid in a partly filled tank can continue moving after the vehicle slows or stops. On a slick surface, that surge can move the vehicle.
Source: South Dakota Commercial Driver License Manual, Revised 07/2025, 8.2.2 Danger of Surge, physical PDF pages 123-124; physical PDF page 124. ↗
Your tanker has separate compartments divided by solid bulkheads. What must you consider when deciding which compartments to fill or empty?
Correct answer: How the resulting load distributes weight over the vehicle and its axles.
Bulkheads divide the load into smaller tanks, but uneven filling or unloading can still overload the front or rear. Plan weight distribution throughout the operation.
Source: South Dakota Commercial Driver License Manual, Revised 07/2025, 8.2.3 Bulkheads; physical PDF page 124. ↗
A driver says that tank baffles make abrupt lane changes safe because they control liquid movement. What is wrong with that reasoning?
Correct answer: Baffles reduce forward-and-back surge, but sideways surge can still contribute to rollover.
Openings in baffles allow flow between areas of the tank. They limit longitudinal surge, not all lateral movement or rollover risk.
Source: South Dakota Commercial Driver License Manual, Revised 07/2025, 8.2.4 Baffled Tanks; physical PDF page 124. ↗
You change from a baffled tanker to a smooth-bore tanker. What handling change should you particularly anticipate?
Correct answer: Stronger forward-and-back surge, requiring especially smooth starts and stops.
A smooth-bore tank has no baffles to slow longitudinal liquid flow. Anticipate stops and make gradual control changes.
Source: South Dakota Commercial Driver License Manual, Revised 07/2025, 8.2.5 Un-baffled Tanks and 8.3.1 Drive Smoothly; physical PDF page 124. ↗
A dispatcher asks you to fill every available gallon of a cargo tank with liquid. What must determine the actual loading amount?
Correct answer: Required expansion space, the liquid’s weight, and applicable vehicle weight limits.
Liquids can expand in transit, so loading must allow the appropriate outage. Dense liquids can also reach weight limits before filling the tank’s volume.
Source: South Dakota Commercial Driver License Manual, Revised 07/2025, 8.2.6 Outage and 8.2.7 How Much to Load; physical PDF page 124. ↗
