New Hampshire CDL: Tanker Vehicles Practice Test

Not quite. The answer is Rear

Shut-off valves are used in the service and supply air lines at the rear of trailers used to tow other trailers. These valves permit closing off the air lines when another trailer is not being towed. You must check that all shut-off valves are in the open position except the ones at the rear of the last trailer, which must be closed.

Not quite. The answer is both of the above are true.

Some liquids expand significantly when they warm up. To fill a tank with such a liquid, you must leave some room in the tank (called "outage") to take the expansion. Also, some liquids are so dense that a full load may exceed the legal weight limit. For these reasons, you may not be able to fill your tanks completely.

Not quite. The answer is surging.

When a tank is not completely filled, the liquid has room to move around. It can slosh back and forth or side to side. This is called surging.

Not quite. The answer is Watch gauges and mirrors and use your senses to check for problems.

During your trip, you should be watching a number of things, such as your mirrors, gauges, instruments, lights, tires, and cargo. Use several of your senses – sight, hearing, smell, and feel – to detect possible trouble.

Not quite. The answer is There will be less front-to-back surge than in a smooth bore tank.

Bulkheads divide a tank into several smaller tanks. This will reduce forward-and-backward surge, making it less likely that surge will push your vehicle forward when you try to stop. However, when loading and unloading the smaller tanks, be sure to pay attention to weight distribution.

Not quite. The answer is closed before you drive the vehicle.

To help prevent leaks, close all manhole covers before you drive the vehicle.

Not quite. The answer is There will be less front-to-back surge than in a tank without baffles.

A baffled tank has bulkheads with holes through which the liquid can flow forward or backward but with less force than if there were no baffles. This will reduce forward-and-backward surge, making it less likely that surge will push your vehicle forward when you try to stop.

Not quite. The answer is 9,000 gallons.

The average capacity of a DOT-406 or MC-306 fuel delivery truck (often called a "gasoline truck") is 9,000 gallons.

Not quite. The answer is an unbaffled tank.

A smooth bore tank is another name for an unbaffled tank. Without baffles, there is likely to be strong forward-and-backward surge. Nevertheless, certain cargoes such as milk and other liquid food products must be transported in smooth bore, unbaffled tanks. Sanitation regulations forbid the use of baffles because they are hard to keep sufficiently clean.

Not quite. The answer is can have strong forward-and-backward surge.

Baffles are often used in tanks to reduce forward-and-backward surge. Nevertheless, certain cargoes, such as milk and other liquid food products, must be transported in smooth bore, unbaffled tanks. (Sanitation regulations forbid the use of baffles because they are hard to keep sufficiently clean.) These tanks are liable to have very strong forward-and-backward surge. Be very careful when driving vehicles with such tanks.

Not quite. The answer is You should avoid traveling alongside other vehicles whenever possible.

Whenever another vehicle is traveling alongside yours, there's always a chance that the vehicle might try to move into your lane and accidentally hit your vehicle. Also, the vehicle is blocking you from changing lanes. It's safer to find an open spot where there are no vehicles on either side of you. (Of course, that may not be possible in heavy, congested traffic.)

Not quite. The answer is you have to press the brake pedal harder than usual to control your speed.

If your brakes begin to fade, you'll notice that you have to depress the brake pedal harder to achieve the same braking effect as before. If your vehicle is so equipped, check the application pressure gauge to see just how much pedal effort you are employing. If the brakes continue to fade, you may not be able to slow down or stop at all.

Not quite. The answer is S-cam drum brake.

Foundation brakes are present on each wheel. In North America as of this writing, S-cam drum brakes are much more common than wedge or disc brakes.

Not quite. The answer is Before loading it, driving it, or unloading it

You should inspect a tank vehicle before loading it, driving it, or unloading it. This is to ensure that it is safe to carry out these activities and the vehicle can safely hold its liquid or gas contents.

Not quite. The answer is Slow down gradually.

Braking on a slippery surface can lock the wheels and cause a skid. Brake gently and slow down very gradually.

Not quite. The answer is 250 feet.

You should always be able to stop within the distance you can see ahead. Fog, rain, or other conditions may require that you slow down to be able to stop in the distance you can see. If your headlights let you see only 250 feet ahead, adjust your speed so that you can stop within that distance. Otherwise, by the time you notice a hazard ahead, you may not be able to stop in time to avoid it.

Not quite. The answer is Surge can move the truck in the direction the liquid waves move.

One of the reasons you must drive a tanker vehicle carefully is that liquid surge can push the vehicle in the same direction as the surge. This can be especially hazardous on icy roads, where a truck may be pushed forward a dangerous amount, maybe past a red light into an intersection.

Not quite. The answer is Set the parking brake and pull forward gently.

The parking brake is meant to keep your vehicle from moving. The best way to test it is to apply the parking brake and then try to pull forward gently. The parking brake should hold your vehicle in place. If you're pulling one or more trailers, test each trailer's parking brakes in the same way.

Not quite. The answer is Unstable loads such as hanging meat or livestock can require extra caution on curves.

Hanging meat can sway on curves, and livestock can move around. These motions can affect the handling of your vehicle. One reason that you must drive a tanker vehicle carefully is that liquid surge can push the vehicle in the same direction as the surge. This can be especially hazardous on icy roads, where your truck may be pushed forward a dangerous amount, maybe past a red light into an intersection. Another concern is that liquid expands when it warms. Outage is the space in the tank that must be allocated to handle the expansion. Different types of liquids expand by different amounts. Therefore, the amount of outage you will need depends on the type of liquid.

Not quite. The answer is both of the above.

When deciding how much liquid you can load on your tank vehicle, you must consider the weight of the liquid, the amount of space to allocate for the liquid to expand as it heats up (called outage), and all legal weight limits on your vehicle. A full tank of a dense liquid may exceed the legal weight limits, so you can only fill the tanks partially with such a liquid.