Tank Truck Transport

Cargo tanks and containers

The specification plate on a cargo tank tells you what it may carry. DOT-406 is the current specification for gasoline, diesel and other low-pressure liquids; MC-306 is its predecessor, still in service on older tanks but no longer built. Most fuel trailers have several compartments, so one load can deliver more than one grade to the same site.

Drivers, hours and endorsements

A driver hauling a placarded load of fuel needs a commercial driver's license with the tank vehicle (N) and hazardous materials (H) endorsements, often combined as X. The H endorsement requires a TSA security threat assessment. Hours of service under 49 CFR Part 395 cap driving at 11 hours within a 14-hour on-duty window, after 10 consecutive hours off.

• CDL with N and H endorsements, or X for both
• 30-minute break after 8 cumulative hours of driving
• 60 hours in 7 days or 70 hours in 8 days, reset by 34 hours off
• Electronic logging device records duty status
• Shipping papers with UN number, proper shipping name, hazard class and packing group
• Placards on all four sides of the cargo tank

At the loading rack

Terminal racks load trucks from the bottom. The driver connects API adapters to each compartment, connects the vapor hose and plugs in the overfill and ground cable. The rack will not pump until its permissive system confirms that the truck is grounded and the overfill sensors are dry. Preset meters stop each compartment at the ordered volume, and additives are injected in-line.

Vapor displaced from the compartments travels through the vapor hose to a vapor recovery unit or vapor combustor rather than venting to air. US bulk gasoline terminals are subject to EPA vapor-control rules, and gasoline cargo tanks that load at them must pass an annual vapor tightness test.

ISO tank containers

For small parcels, specialty chemicals and international moves, the ISO tank container is the flexible choice. It is a tank, usually stainless steel, in a standard 20-foot frame, commonly holding around 20,000 to 26,000 liters. It moves by truck chassis, rail flatcar and container ship without the product being transferred, and its portable tank instruction, such as T11 or T14, sets what it may carry under the UN Model Regulations and the IMDG Code.