Cab and Overall Truck Design
The cab and overall design of a tanker truck is similar to most other types of semitrailers, and some (but not all) are semitrucks that have simply been attached to a tanker trailer instead of a standard box trailer. The cab is seated over a single axle, and the trailer containing the cargo tank generally has two or three axles to help distribute the weight of the cargo more evenly and provide better cushioning for the tank on uneven roads. Smaller tanker trucks may have the entire body of the truck (including the cargo tank) as a single unit; larger semi-style tanker trucks have a separate cab and trailer section. Larger tanker trucks are able to haul several connected cargo tank trailers at once, allowing the transportation of large amounts of cargo in a manner similar to transport by train.
The cargo tanks of tanker trucks are generally well-insulated and reinforced so as to prevent accidental leakage or contamination of the cargo being hauled. The size of the tank may vary from one type of tanker truck to another, with larger trucks featuring tanks that range from a 5,500-gal. capacity to as much as 9,000 gal. The materials that make up the cargo tank and lining vary depending on the intended use of the tank; different materials are used to ensure compliance with food safety regulations, provide resistance to corrosion or chemical reaction, allow the cargo tank to be pressurized or refrigerated, and even to resist damage from rough or heavy materials that may be hauled within the cargo tank. All tanker truck cargo tanks must be equipped with diamond-shaped signs that tell of any danger presented by the cargo, such as flammability, risk of explosion due to pressurization or danger from the highly corrosive nature of the cargo.
Uses of Tanker Trucks
Though tanker trucks are most commonly used to transport liquids, they may also be used to transport gases and some solid materials. Liquids transported by tanker truck include milk, gasoline, various oils, solvents and assorted other chemicals. A number of chemicals in a gaseous state are transported under pressure by tanker truck as well, because a reinforced cargo tank can hold a large quantity of gas. Solids transported by tanker truck include concrete, soil, ore and assorted other dry bulk cargoes. Smaller tanker trucks may also be used to transport mixes of solid and liquid materials, such as waste materials being transported for disposal.