Tanker Trailer

What is a Tanker Trailer

Tanker trailer or tanker is a specialized trailer used for safe transportation of liquid and gas commodities. Such as fuel, chemicals, food and beverage, and agricultural freight.
This article will delve into the design, types, and safety considerations of tanker trailers.

Design of Tanker Trailers

A tanker trailer typically consists of a cylindrical tank mounted on a trailer chassis. The tank’s cylindrical shape is structurally strong, allowing it to withstand the pressure of the stored liquids. Most tanks are made from high-strength materials like aluminum, stainless steel, or carbon steel, with the choice depending on the intended cargo.

The tank is often divided into multiple compartments or “baffles” to control the movement of the liquid load during transit. Each compartment has a hole that allows air pressure to balance throughout the tank, while the bulkheads prevent the liquid from sloshing excessively, thus maintaining stability.

Depending on the cargo type, a tanker trailer may feature insulation and a heating system to maintain the temperature of temperature-sensitive liquids. For certain volatile or hazardous liquids, the tank may require a pressure-vacuum relief valve system to manage pressure build-up and prevent tank rupture.

Types of Tanker Trailers

The specific design and features of tanker trailers can vary based on their intended use. Here are a few common types:

Fuel Tankers: These trailers transport petrol, diesel, and other types of fuel. They often have several compartments to carry different grades of fuel.
Chemical & Acid Tankers: These are designed to carry various chemicals and acids. They typically feature materials and linings that resist corrosion and damage from the carried substance.
Food Grade Tankers: These trailers transport liquid food products like milk, wine, or edible oils. They’re built to comply with strict sanitation standards and often feature temperature control mechanisms.
Gas Tankers: Used for transporting gases like propane or natural gas, these tankers are specially designed to handle high-pressure cargo. They are built with strong, durable materials to prevent leaks.

How Many Gallons Does a Tanker Truck Hold?

The capacity of a tanker truck can vary significantly depending on its size and configuration.
However, typically, the capacity of a semi-trailer tanker truck used for hauling liquids like gasoline or diesel is usually around 5,000 to 11,000 gallons. On the smaller end, smaller tanker trucks that might be seen making local deliveries, can hold around 2,000 to 4,000 gallons.

It’s important to note that, while a tanker might physically be able to hold a certain amount of liquid, regulatory limits on total vehicle weight often mean that a tanker cannot be fully filled. For instance, the weight of the fuel being carried must be taken into account to ensure that the total weight of the truck, including the tractor, trailer, and cargo, does not exceed legal limits. This is especially relevant when carrying heavier liquids.
For example, while water has a weight of about 8.34 pounds per gallon, gasoline is somewhat lighter, weighing about 6 to 6.3 pounds per gallon. This difference can significantly impact how much of a particular liquid a tanker truck can legally transport.

Always refer to local regulations and guidelines when determining the maximum allowable load for a specific tanker truck.

Tanker Trailer License Requirements

1. Commercial Driver’s License (CDL): To drive any commercial vehicle over a certain weight, including tanker trailers, the driver must hold a valid CDL.

2. Tanker Endorsement (N): This is a specific endorsement to the CDL required for drivers who operate a tanker vehicle. The endorsement requires passing a written knowledge test on the Federal Motor Carrier Safety Administration (FMCSA) regulations for tanker vehicles.
   Learn more about Tanker Endorsement here.

3. Hazardous Materials Endorsement (H): If a driver is transporting hazardous materials in a tanker, they must also have a Hazardous Materials (HazMat) endorsement on their CDL. This requires an additional knowledge test, a TSA security threat assessment, and a background check.
   Learn more about Hazardous Materials Endorsement here.

4. Special Skills: Operating a tanker trailer requires understanding of liquid surge and how it affects the stability of the vehicle. Drivers must also be adept at conducting pre-trip inspections to ensure that the tanker, its valves, and its hoses are in good condition.

5. Health Requirements: Drivers must meet certain physical health requirements, such as passing a Department of Transportation (DOT) physical exam, which includes vision and hearing tests.
   Learn more about DOT Medical Exam here.

6. Knowledge of Regulations: Drivers should have a thorough understanding of the Hours of Service regulations, which dictate how many hours a driver can operate without rest, as well as other FMCSA regulations.

These are the basic requirements, but individual employers may have additional qualifications. Always check the specific job posting or speak with the employer to confirm their requirements.

Safety Considerations

Operating a tanker trailer requires an understanding of its unique safety considerations. These include:

Load Distribution: Improperly distributed loads can affect the trailer’s center of gravity, making it unstable. Drivers must ensure the load is evenly distributed across all compartments.
Surge: When a tanker stops or starts moving, the liquid inside can surge back and forth, affecting the trailer’s stability. Drivers need to understand how to control their speed to manage surge effectively.
Hazardous Materials: Some tankers transport hazardous materials, requiring strict adherence to safety regulations. Drivers need special training and licensing (a Hazardous Materials Endorsement on their CDL) to haul these loads.
Maintenance: Regular maintenance checks for leaks, tire condition, braking systems, lighting, and the condition of the tanker’s shell are essential for safety.
Learn more about Maintenance here.

Tanker trailers are a specialized and vital type of transportation equipment, designed to safely and efficiently transport liquid and gas commodities. Understanding their design, the different types, and the safety approach to operating them is important. They continue to serve as an indispensable asset, supporting various sectors globally by ensuring that products reach their destination safely and efficiently.
To learn more about the types of trailers used in the trucking industry click here. 
Learn about Commercial Motor Vehicles (CMVs) here.
Click the link to learn about: Safety – Regulations – Documents.

External Links

Cargo Tank Safety – FMCSA website – click here.

Smart Trucking YouTube video about tanker truck driving jobs.