CDL Tanker Practice Test — Questions and Answers
Question 1: Which factor(s) should you consider when determining how much liquid to load into a tank?
- Weight of the liquid
- Legal weight limits
- How much the liquid will expand during transit
- All of the above (Correct answer)
Correct answer: All of the above
When loading a tank, all these factors are critical for safe and legal transport. The weight of the liquid directly impacts the total vehicle weight, which must comply with legal limits. Additionally, liquids expand with temperature changes, so 'outage' (empty space) must be left to prevent rupture or spillage, making all considerations vital.
Question 2: The effects of liquid surge are reduced by
- Braking far in advance and increasing your stopping distance
- Starting, stopping and turning smoothly
- Hauling thicker liquids
- All of the above (Correct answer)
Correct answer: All of the above
Liquid surge, the sloshing movement of liquid inside a tank, can significantly affect vehicle stability. To reduce its effects, drivers should brake far in advance and increase stopping distance to allow for gradual deceleration. Starting, stopping, and turning smoothly minimizes sudden shifts in the liquid, and hauling thicker liquids naturally reduces surge due to their higher viscosity, making all options effective.
Question 3: What should you do to prevent a tanker from rolling over on a curve?
- Travel at the posted speed limit on a curve
- Brake aggressively throughout the curve
- Travel well below the posted speed limit on a curve (Correct answer)
- None of the above
Correct answer: Travel well below the posted speed limit on a curve
Tankers, especially those partially filled, have a high center of gravity and are prone to liquid surge, which significantly increases the risk of rollover on curves. To prevent this, drivers must significantly reduce their speed well below the posted limit before entering a curve. This minimizes the centrifugal force acting on the vehicle and the sloshing effect of the liquid, maintaining stability.
Question 4: A baffled tanker has
- Separate tanks inside the trailer
- Interior bulkheads with holes that let the liquid flow through (Correct answer)
- A smooth interior, and is often used to transport food products
- Dampers that float on the liquid to slow movement
Correct answer: Interior bulkheads with holes that let the liquid flow through
A baffled tanker is designed with interior bulkheads that have holes, allowing liquid to flow through while significantly reducing the effects of liquid surge. These baffles break up the large mass of liquid, preventing it from sloshing violently from front to back or side to side, thus improving vehicle stability and control, especially during braking or turning.
Question 5: A smooth bore tanker is often used to transport
- Gasoline
- Heavy liquid
- Corrosive or acidic liquids
- Milk or food products (Correct answer)
Correct answer: Milk or food products
Smooth bore tankers, also known as unbaffled tanks, have a completely smooth interior without any internal bulkheads or baffles. This design makes them easier to clean and sanitize, which is essential for transporting food-grade liquids like milk or other perishable food products where hygiene and preventing contamination are paramount.
Question 6: Which of the following characteristics make liquid tanker harder to handle?
- The density of the cargo
- Low center of gravity of the cargo
- High center of gravity of the cargo (Correct answer)
- Width of the cargo tank
Correct answer: High center of gravity of the cargo
The high center of gravity of liquid cargo is a primary factor making tankers harder to handle and increasing their rollover risk. Even if the tank itself is low, the liquid inside can shift, creating a dynamic high center of gravity. This makes the vehicle less stable, especially during turns, braking, or sudden maneuvers, requiring careful driving.
Question 7: Which of the following is often referred to as a smooth bore tank?
- Portable Tank
- Tank with a stainless steel interior
- Baffled liquid tanks
- Unbaffled liquid tank (Correct answer)
Correct answer: Unbaffled liquid tank
An unbaffled liquid tank is often referred to as a smooth bore tank because its interior is completely smooth, lacking any internal bulkheads or baffles. This design is preferred for certain types of cargo, such as food-grade liquids, because it allows for easier and more thorough cleaning, preventing contamination and ensuring product purity.
Question 8: What is the definition of outage?
- Free space left in a tanker to allow for expansion of the liquid from temperature changes (Correct answer)
- Amount of liquid that is lost during transportation due to spillage, evaporation etc.
- A disruption in the electrical system of the tractor
- A loss of power in the hydraulic system
Correct answer: Free space left in a tanker to allow for expansion of the liquid from temperature changes
Outage refers to the empty space intentionally left at the top of a tanker when loading liquid cargo. This crucial space accounts for the expansion of the liquid due to temperature increases during transit. Without sufficient outage, the expanding liquid could over-pressurize the tank, leading to leaks, spills, or even rupture, making it a critical safety measure.
Question 9: Under which conditions should you be extremely cautious when driving a smooth bore tanker?
- During loading
- During unloading
- When going up a hill
- When starting and stopping (Correct answer)
Correct answer: When starting and stopping
Smooth bore tankers are particularly challenging when starting and stopping due to the phenomenon of liquid surge. Without baffles to break up the liquid's movement, the entire mass of liquid can slosh violently forward or backward, creating significant forces that can push the truck. This makes it difficult to control and increases the risk of a crash during acceleration or deceleration.
Question 10: The movement of liquid in a partially filled tanker truck is known as what?
- Surge (Correct answer)
- Rolling
- Outage
- Baffle
Correct answer: Surge
The movement of liquid in a partially filled tanker truck is known as surge. This sloshing motion, especially in unbaffled tanks, can create powerful forces that push the vehicle forward, backward, or sideways. Surge significantly impacts vehicle stability and control, making smooth driving techniques essential to prevent loss of control.
CDL Tanker Practice Test
Which factor(s) should you consider when determining how much liquid to load into a tank?