EQUIPMENT
Chassis
A wheeled trailer frame designed to carry ISO shipping containers, towed by a drayage truck between terminals and delivery points.
A chassis is the wheeled trailer frame that a drayage truck uses to carry an ISO shipping container. The container sits on top of the chassis, locked in place with twist locks at the container's corner castings. The truck (also called the "power unit") and chassis are separate pieces of equipment — unlike a standard semi-trailer, where the cargo area is integrated with the wheels.
Chassis in the US come in several types: the standard 40' chassis (for 40' ISO containers), 20' chassis, 45' chassis, tri-axle chassis (for overweight containers), and powered chassis (for reefer containers). Most chassis at major US ports are owned by Intermodal Equipment Providers (IEPs) like DCLI, TRAC Intermodal, and Flexi-Van and accessed through the UIIA chassis pool. Some larger carriers own their own company chassis.
Chassis availability is one of the most significant operational variables in drayage. During port congestion events, chassis shortages can delay container pickups by days, even when the drayage carrier is available and ready. When chassis are unavailable at the terminal, carriers must either wait for chassis to cycle back or arrange a chassis split — picking up a chassis from a different location before returning to retrieve the container. Shippers planning time-sensitive cargo flows should ask potential carriers about their chassis access strategy before booking.