CDL Tanker Endorsement Practice Test

Pick an answer for each question. You’ll see right away if it’s correct and why.

1. 1. Under 49 CFR 383.5, which setup makes a CMV a tank vehicle?

   A. Any tank over 119 gallons, with 1,000 gallons or more in total B. Any tank over 50 gallons C. Only tanks over 5,000 gallons D. Only tanks that are welded to the frame
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   Answer: A. Any tank over 119 gallons, with 1,000 gallons or more in total A tank vehicle carries liquid or gas in tanks with an individual capacity over 119 gallons and an aggregate capacity of 1,000 gallons or more, permanently or temporarily attached.

2. 2. Does the liquid have to be hazardous for you to need the N endorsement?

   A. Yes, only hazmat counts B. No, any liquid or gas counts if the tank size rule is met C. Only flammable liquids count D. Only if the truck weighs over 26,001 pounds empty
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   Answer: B. No, any liquid or gas counts if the tank size rule is met The tank rule is about the tank, not the cargo. Water, milk or fuel all count when the tanks meet the 119-gallon and 1,000-gallon thresholds.

3. 3. You'll haul gasoline in a cargo tank. Which endorsement do you need?

   A. T B. P C. X (hazmat plus tank) D. S
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   Answer: C. X (hazmat plus tank) Hauling hazmat in a tank needs both H and N, which appear together as the X endorsement code.

4. 4. You stop a partly loaded tanker on an icy road. What can the liquid surge do?

   A. Nothing once the truck has stopped B. Lift the steer axle off the road C. Lock the trailer brakes on its own D. Push the stopped truck forward, possibly into an intersection
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   Answer: D. Push the stopped truck forward, possibly into an intersection When the wave hits the end of the tank it shoves the truck in that direction. On a slippery surface that can push a stopped truck out into an intersection.

5. 5. What do baffles inside a tank help control?

   A. Front-to-back surge, but not side-to-side surge B. Side-to-side surge only C. All surge in every direction D. Tank temperature
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   Answer: A. Front-to-back surge, but not side-to-side surge Baffles are bulkheads with holes that slow front-to-back flow. Side-to-side surge still happens and can still cause a rollover.

6. 6. Why are tanks that haul milk and other food products often smooth bore (no baffles)?

   A. They are cheaper to build B. Sanitation rules forbid baffles because they are hard to clean C. Food liquids don't surge D. Baffles would make the tank overweight
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   Answer: B. Sanitation rules forbid baffles because they are hard to clean Baffles are hard to clean, so sanitation rules keep them out of many food tanks. That's why smooth bore tankers have very strong front-to-back surge.

7. 7. In a smooth bore tanker, when do you need to be most careful?

   A. Cruising at steady speed on the highway B. Parked at the loading rack C. Starting and stopping D. Driving in a straight line on a flat road
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   Answer: C. Starting and stopping With nothing inside to slow the liquid, starting and stopping send strong waves forward and back. Be very gentle with throttle and brakes.

8. 8. Why must you leave outage (empty space) when loading a tank?

   A. To lower the weight on the drive axles B. To stop the liquid from surging C. Because tanks may only be loaded half full D. Because liquids expand as they warm up
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   Answer: D. Because liquids expand as they warm up Liquids expand as they warm, so a tank is never loaded completely full. Different liquids expand differently, so know the outage needed for what you haul.

9. 9. You're hauling a very dense liquid, such as some acids. What's often true?

   A. The tank may only be partly filled to stay within legal weight B. The tank must be filled to the top so it won't surge C. Dense liquids need no outage D. You need a T endorsement
   Show the answer

   Answer: A. The tank may only be partly filled to stay within legal weight A full tank of a heavy liquid can go over legal weight limits, so dense products are often loaded only partly. How much depends on expansion, the liquid's weight and the legal limits.

10. 10. How should you take a curve or ramp in a loaded tanker?

    A. At the posted speed, since it's set for trucks B. Well below the posted speed, slowing before the curve C. Brake hard in the middle of the curve D. Coast through in neutral
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    Answer: B. Well below the posted speed, slowing before the curve Tests showed tankers can roll over at posted curve speeds. Slow down before the curve, then accelerate slightly through it.

11. 11. How should you brake when bringing a partly loaded tanker to a stop?

    A. Pump the brakes quickly the whole way B. Brake hard at first, then let off early C. Keep steady pressure and don't release too soon D. Use only the trailer hand valve
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    Answer: C. Keep steady pressure and don't release too soon Steady pressure, started well in advance, keeps surge under control. Releasing too soon lets the wave shove the truck forward.

12. 12. During inspection you find a manhole cover not fully closed. What's the rule?

    A. You can drive if the tank is mostly empty B. You can drive a short distance to the next stop C. Only valves matter, not manhole covers D. Never drive with open valves or manhole covers
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    Answer: D. Never drive with open valves or manhole covers Make sure manhole covers close properly with gaskets and that every valve is in the right position before you move. Never drive with open valves or covers.

13. 13. Why is a tank vehicle easier to roll over than many other trucks?

    A. Much of the load's weight rides high off the road B. Tankers have smaller tires C. Tankers have weaker brakes D. The cab is lighter
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    Answer: A. Much of the load's weight rides high off the road A high center of gravity makes the vehicle top-heavy. Combined with surge, that's why tankers need slow, smooth driving.

14. 14. How does an empty tank vehicle's stopping distance compare with a full one?

    A. Empty always stops shorter B. Empty may take longer to stop C. They are always exactly the same D. Empty can't skid
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    Answer: B. Empty may take longer to stop An empty tanker has less traction, so it may need more distance to stop than a full one. Leave extra following distance either way.

15. 15. A cargo tank used for hazmat is empty after delivery. Must you still stop at railroad crossings?

    A. No, the stop only applies when loaded B. Only if it still has placards C. Yes, stop 15 to 50 feet from the tracks, loaded or empty D. Just slow to 15 mph
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    Answer: C. Yes, stop 15 to 50 feet from the tracks, loaded or empty 49 CFR 392.10 requires the stop for cargo tanks used for hazmat whether loaded or empty. Stop 15 to 50 feet from the tracks and don't shift gears while crossing.

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