Illinois CDL: Tanker Vehicles Practice Test

Not quite. The answer is can affect the handling of your vehicle.

Liquid surge can greatly affect your vehicle's handling. 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. On curves, side-to-side surge can cause a rollover even when traction is good.

Not quite. The answer is your vehicle will stay in a straight line.

If you must brake in an emergency, brake in a way that keeps your vehicle in a straight line while still letting you turn if necessary. You can use the "controlled braking" method or (in a vehicle without antilock brakes) the "stab braking" method.

Not quite. The answer is Much of the tanker's weight is high up off the ground.

An object with a high center of gravity is top-heavy; much of its weight is high off the ground. Top-heavy objects are more prone to toppling over. Loaded tankers tend to have a high center of gravity because the tanks are so tall. This makes liquid tankers more prone to rolling over. Tests have shown that tankers can roll over on curves even at the speeds posted. On curves, slow down well below the posted speeds.

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 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 the top of the tank

In general, the Maximum Allowable Working Pressure (MAWP) of a pressurized tank is the maximum pressure that the weakest part of the tank can handle in normal operation. For a cargo tank on a motor vehicle, the federal definition of MAWP assumes that the weakest part is at the top of the tank.

Source: 49 CFR 178.320

Not quite. The answer is leaks.

When you inspect your tank vehicle, the most important thing to check for is leaking tanks. It is illegal to knowingly carry liquids or gases in a leaking tank. Check around and underneath the vehicle for any signs of leaks. Also check all tanks, hoses, pipes, and connections for leaks.

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 distribution of weight.

If the tank is divided into several smaller tanks (compartments) by bulkheads, pay attention to the distribution of weight whenever you load or unload these tanks. Avoid putting too much weight on the front or the back of your vehicle.

Not quite. The answer is four

You placard your vehicle to warn everyone around you that you are transporting hazardous materials. Therefore, you must have placards on all four sides of your vehicle.

Not quite. The answer is If it has to stay very clean

For transporting food products such as milk, regulations prohibit baffled tanks because of the difficulty of cleaning the inside of a baffled tank.

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 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 There will be less front-to-back surge than there is in a tanker without baffles.

Baffled tanks have bulkheads with holes to reduce forward-and-backward surge. This will reduce the chance that forward surge will push your vehicle dangerously forward when you're slowing or stopping. However, these bulkheads don't significantly reduce side-to-side surge, so rollovers can still occur.

Not quite. The answer is You should not load a cargo tank completely full.

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. Different liquids expand at different rates as the temperature increases. In science, the percentage increase of expansion for a given change in temperature is called the coefficient of thermal expansion. This value depends on the type of liquid. You need to find out how much outage you will need to allow for the type of liquid you'll be hauling.

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 bulkheads.

Separators that divide a space into liquid-tight compartments are called bulkheads. The tank on a tanker vehicle may have bulkheads to divide the tank into separate compartments.

Not quite. The answer is MC-306 (DOT-406)

MC-306 (DOT-406) cargo tanks carry liquids under very low or no pressure (maximum allowable pressure of 3 psi for MC-306 and 4 psi for DOT-406). The cargo tank has an oval or elliptical cross section and is usually compartmented. These tanks are commonly used to carry gasoline, diesel fuel or fuel oil, and other flammable liquids.

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 You will continue in a straight line and keep moving forward no matter how you steer.

In a front-wheel skid, the front end of your vehicle tends to travel in a straight line regardless of how you turn the steering wheel. This type of skid is most often caused by driving too fast for the current driving conditions. Therefore, the best way to recover from this type of skid is to just let the vehicle slow down. Steer and brake only gently.