40ft Container Chassis — Skeletal Trailer for Port Drayage

A 40ft container chassis is the simplest trailer in the fleet and the one where build quality shows up fastest. There is no deck to hide a weak frame — the whole trailer is the frame, and it takes the full torsional load of a 30 ton box every time the tractor turns into a terminal gate.

The decision is normally between a fixed 40ft frame and an extendable one that adjusts between 20ft and 40ft.

Fixed 40ft or 20-40ft Extendable

Fixed 40ft — lighter, cheaper, stiffer, nothing to seize up. If your work is predominantly 40ft boxes, this is the right unit. Two 20ft boxes can still be carried on a fixed 40ft frame using the mid-position twist locks.

Extendable 20-40ft — the frame telescopes so the running gear sits under a 20ft box instead of behind it. Worth it when you run a genuinely mixed box mix and want the axle loads correct on 20ft heavy loads. It adds tare weight, cost, and a sliding mechanism that needs greasing.

Most export orders leave here as fixed 40ft. Buy the extendable if you know why you need it.

Tare Weight Is the Whole Argument

On a container chassis, tare weight is money. Every 500 kg the trailer saves is 500 kg you can carry inside the box before the weighbridge stops you. Our 3-axle 40ft frames run 5,800-7,200 kg depending on suspension and axle choice.

Beware of a chassis quoted at an unusually low tare — the weight normally comes out of the main beam plate thickness or the goose neck reinforcement, and it shows up as frame cracking around the king pin after 18 months of port work. Ask for the beam section drawing, not just the tare number.

Twist Locks and Box Positions

A 40ft skeletal frame carries 8 twist-lock sets: 4 corners for a single 40ft or 45ft box, plus mid-position locks so it can carry two 20ft boxes or a single 20ft box positioned over the bogie. All locks are ISO corner-casting standard and rotate through 90°.

Specify at order time if you regularly carry 45ft boxes — the frame gets a rear extension rather than a different chassis.

Suspension Choice for Port Work

Mechanical leaf spring — standard, cheapest, survives being overloaded, repairable in any yard. What we recommend for most African, South Asian and Middle Eastern destinations.

Air suspension — better ride, less shock into the box on rough terminal surfaces, and the one to pick if you are hauling fragile or high-value cargo on paved highway routes. More maintenance.

See the full container chassis range for 2-axle and extendable builds.