Oregon CDL: Tanker Vehicles Practice Test

Not quite. The answer is Upshift.

If your hydraulic brakes fail while you're driving, try pumping the brake pedal to build up enough hydraulic pressure to stop your vehicle. If this fails, downshift to use engine braking and apply the parking brake. Release the parking brake before you lock the wheels. If all else fails, look for an escape route. Head for an escape ramp or an open field and let your vehicle slow to a stop.

Not quite. The answer is may exceed legal weight limits.

A full tank of dense liquid (such as some acids) may exceed legal weight limits. For this reason, you may not be able to completely fill the tank with a dense liquid.

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 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 liquids or gases.

According to federal regulations, you need a tank endorsement to drive a tank vehicle that requires you to have a CDL. A tank vehicle is defined as a commercial motor vehicle that transports a bulk cargo of liquid or gas within one or more tanks that are either permanently or temporarily attached to the vehicle. [49 CFR 383.5],

Source: 49 CFR 383.93

Not quite. The answer is Spring brakes (or wheel chocks)

When parking a tank trailer, you should always apply the parking brake. On a modern trailer equipped with air brakes, applying the parking brake control will exhaust air from the brake chambers and cause the spring brakes to come on. However, an old trailer may lack spring brakes and instead use compressed air to set the parking brakes. In this case, you must chock the wheels to prevent the trailer from moving. A leak somewhere in the air braking system may cause the parking brakes to fail eventually.

Not quite. The answer is with holes that let liquid flow through.

Tank baffles are bulkheads with holes through which the liquid can flow, but with less force than in tanks without such baffles. These baffles significantly reduce forward-and-backward surge but not side-to-side surge, so the risk of surge causing a rollover remains.

Not quite. The answer is MC-331

MC-331 cargo tanks carry gases that are liquefied under relatively high pressure (maximum allowable pressure of 100–500 psi). The cargo tank has a circular cross section and rounded ends. These tanks are commonly used to carry such gases as propane and liquefied petroleum gas (LPG).

Not quite. The answer is side-to-side surge.

Some tanks have baffles: bulkheads with holes through which the liquid can flow forward or backward. These baffles significantly reduce forward-and-backward surge but not side-to-side surge, so the risk of surge causing a rollover remains.

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 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 stop braking, turn quickly, and countersteer.

To recover from a drive-wheel braking skid, first stop braking. The rear wheels will unlock and roll again so there will be no more tendency to slide sideways. Then quickly steer your vehicle back on course. You may find that your vehicle will overshoot and keep on turning, possibly skidding in the opposite direction. Countersteer to counteract this. Note: This maneuver takes some practice. You should become proficient in it before you actually need to use it.

Not quite. The answer is 5 mph slower.

On a steep downgrade, don't keep applying your brakes continuously because this might cause them to fade (become less effective). Instead, apply your brakes sparingly as a supplement to engine braking. Select a "safe" speed. Let your vehicle reach this speed. Brake gently until you are going 5 mph slower. Then let your speed increase back to the "safe" speed. Keep varying your speed up and down this way. This technique is known as snub braking or snubbing.

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 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 At the end of each working day

Oil and water can start to collect in the bottom of an air tank and can cause brake failure if it's not drained. Unless your vehicle automatically drains the air tanks, you should drain them at the end of each working day so the moisture and oil will not freeze or coagulate and cause your brakes to fail.

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 driving too fast for conditions.

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 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.