The United States used more than 20 million barrels of oil per day in 2007, reports Nation Master. Second place in consumption is China with approximately 7.5 million barrels per day. In the United States, the oil that is used for transportation is delivered by tanker trucks. (See reference 2.)
Single-tank trucks
Single-tank trucks that have two axles have a capacity of 3,000 gallons. Trucks with three axles have a capacity of 5,000 gallons. (See reference 1.)
Semi-trucks
Trucks with a semi-trailer have one tank. The tank is about 40 feet wide and has a 9,000-gallon capacity. (See reference 1.)
Materials
Tanks are typically made of aluminum. They are created to be lightweight to carry more fuel. (See reference 1.)
Construction
Tanks are typically made with two to four compartments. Bulkheads separate the different compartments. For tanks that carry different flammable material, double bulkheads are a requirement. (See reference 1.)
Unloading
Fuel is unloaded from tankers from the bottom. Gravity allows the fuel to flow through valves inside the tanker. The valves are run by air, mechanically or both. (See reference 1.)