Braking with Empty, Full, Partial Loads Flashcards

A driver is hauling a tank that is only half full of liquid. What happens to the liquid when the driver brakes, and how should the driver brake?

Answer: The liquid surges forward, so the driver should brake early and gradually

Liquid in a partly filled tank moves forward when the truck brakes, and the surge pushes the truck ahead. The driver should brake early and gradually to keep it under control.

Compared with the same truck carrying a full load, an empty tank truck generally:

Answer: Needs a longer distance to stop because it has less traction

Empty trucks take longer to stop than loaded ones because a lighter vehicle has less traction. Brakes designed for heavy loads can lock up or skid more easily when the truck is empty.

Which tank design lets liquid surge forward and backward the most when the driver brakes?

Answer: A smooth bore tank

A smooth bore tank has no internal barriers, so the liquid can surge freely forward and back. This makes braking harder to control when it is partly full.

A driver in a partly filled tank truck brakes hard on a wet road. The liquid surges forward. What is the most likely result?

Answer: The surge pushes the truck forward and can carry it farther than the driver expects

On a slippery surface, forward liquid surge can push the truck even with the brakes applied. The stop takes longer than the driver expects.

Which technique is best for slowing a tank truck that is carrying a partial load?

Answer: Brake early and smoothly, and allow extra following distance

Braking early and smoothly, with extra following distance, keeps liquid surge to a minimum. It also gives the driver room to control the truck.

Which statement about stopping a tank truck is correct?

Answer: Stopping distance depends on how much liquid is loaded and how it can move in the tank

The amount of liquid and the freedom it has to move both change how the truck stops. Full, partial and empty loads each need different braking care.

Why does a tank that is completely full of liquid produce little surge when the truck brakes?

Answer: There is almost no empty space for the liquid to move into

Surge needs room to move. A full tank leaves almost no outage space, so the liquid cannot slosh.

A driver leaves a loading rack with a tank only one-third full of liquid. What is the best way to handle the first stop sign ahead?

Answer: Begin slowing well before the sign and brake gently throughout

A partly filled tank can surge, so the driver should start slowing early and brake gently. This keeps the liquid from pushing the truck.

Baffles in a tank help the driver during braking mainly by:

Answer: Reducing the forward and back movement of the liquid

Baffles are barriers with holes that slow the forward-and-back movement of the liquid. The liquid can still surge, though, so the driver must still brake with care.

Which load condition requires a tank driver to be MOST concerned about liquid surge during braking?

Answer: A tank that is partially filled

A partly filled tank has space for the liquid to surge. Full tanks and bulkheaded compartments have little room for it, and an empty tank has nothing to surge.