Kentucky CDL: Tanker Vehicles Practice Test

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 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 joints.

When you're checking the pipes, connections, and hoses of your tank vehicle for leaks, you should pay special attention to joints. Pipe joints are among the weakest points in a piping system. Joints can deteriorate over time and start to leak.

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 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 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 Keep a steady foot on the brake and don't release the brake too soon.

To control the effects of surge, brake far in advance of a stop. Maintain steady pressure on the brakes and don't release them too soon.

Not quite. The answer is allowance for expansion of liquid.

When liquid heats up, it expands, and outage is the space in the tank that is 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 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 70%

It takes special skills to operate a tank vehicle safely. About 70% of tank truck drivers haul hazardous materials, such as gasoline. Doing so takes even more special skills. Such drivers must obtain both a tank vehicle (N) endorsement and a hazardous materials (H) endorsement on their CDLs, or a combination tank vehicle and hazardous materials (X) endorsement.

Not quite. The answer is 20 feet long.

An ISO standard portable tank is a metal tank enclosed in a steel frame. The frame is 19.8556 feet (6.05 meters) long, 7.874 feet (2.40 meters) wide, and either 7.874 feet (2.40 meters) high or 8.374 feet (2.55 meters) high.

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 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 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 Environment

The S.T.A.M.P.E.D. acronym is widely used to assist you in obtaining the correct hoses and fittings for your needs. S: the required size of the hose; T: the temperatures to which the hose will be subjected; A: the application (use) to which the hose will be put; M: the types of material (liquid, gas, etc.) that will have to flow through the hose; P: the maximum working pressure of the hose; E: the required fittings at the ends of the hose; D: the date at which the hose must be delivered to you.

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 Slow to a safe speed before entering, then accelerate slightly through the curve.

The posted speed for a curve may be safe for cars but not for tankers because of their relatively high center of gravity. Tests have shown that a tanker can roll over on a curve when traveling at the posted speed. The safest way to take a curve in a tanker is to slow down before the curve and then accelerate slightly through the curve. Braking in a curve risks a skid.

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 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 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.