District of Columbia CDL: Tanker Vehicles Practice Test

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 bulkheads with holes that let the liquid flow through.

Baffled tanks have bulkheads with holes through which the liquid can flow but with less force than in a tank without such bulkheads.

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 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 At the start of each trip and each time you stop

If you have a placarded trailer with dual tires, you should check the tires at the start of each trip and each time that you stop for any reason, whether to rest or to refuel. Use a tire pressure gauge to get an accurate reading.

Not quite. The answer is Within 500 feet behind the vehicle

If you park on the side of the road and the view of your vehicle is obscured by a hill or curve, place a reflective triangle far enough (up to 500 feet) behind your vehicle so it can be seen by other drivers.

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 there is an even distribution of weight.

Some liquid tanks are divided into several smaller tanks by bulkheads. When loading and unloading the smaller tanks, pay attention to weight distribution. Don’t put too much weight on the front or rear of the trailer.

Not quite. The answer is driving too fast.

Over-braking and over-steering can cause skids. Both over-braking and over-steering are more likely when you're driving too fast for the current road conditions.

Not quite. The answer is roll over.

Baffled tanks can control back-and-forth surge but not side-to-side surge. During sudden steering changes, side-to-side surge can cause your tanker to roll over. Avoid such sudden moves when possible.

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.

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 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 your vehicle may jackknife.

If your drive wheels are skidding, it's likely because you applied the brakes too hard and locked the drive wheels. A drive-wheel skid can let the trailer push the tractor sideways, causing a sudden jackknife. To recover from this type of skid, the first thing to do is stop braking. The drive wheels will unlock and start to roll again.

Not quite. The answer is the front or the rear

Bulkheads help separate the load. When loading such tanks, distribute the weight evenly. Avoid putting too much weight on the front or the rear of the vehicle.

Not quite. The answer is receive a citation and be prevented from further driving.

It is illegal to knowingly carry liquids or gases in a leaking tank. If you do, you may receive a citation and be prevented from driving further.

Not quite. The answer is baffles.

Baffles are devices that regulate the flow of liquid. In a tank vehicle, baffles are a type of bulkhead with holes through which liquid may flow but with reduced force.

Not quite. The answer is use controlled or stab braking.

Sudden or hard braking can cause the liquid in the tank to surge forward, pushing your vehicle forward. If you must stop quickly, use controlled or stab braking instead. (However, don't use stab braking if your vehicle is equipped with antilock brakes.)

Not quite. The answer is are bulk containers that are not permanently attached to a vehicle.

A portable tank is bulk packaging that is not permanently attached to a vehicle. The tank is loaded or unloaded while it is off the vehicle. Then the tank is put on the vehicle for transportation. Hence, the portable tank must show the owner or lessee's name. "Bulk packaging" means that the tank's capacity is more than 450 L (119 gallons) of liquid, or more than 454 kg (1,000 pounds) of gas. Some portable tanks have a capacity of 25,000 L (6,600 gallons).

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.