How to choose a container chassis: 20, 40, 45

How to choose a container semi-trailer so it suits your actual routes, not just 'takes a container'? Before buying, you need to verify 20', 40', and 45' formats, container position on the frame, axle loads, compatibility with the tractor unit, and the condition of sliding mechanisms.

20, 40, and 45 feet: start with your cargo

First, list what the vehicle will transport most often: a single 20-foot container, 40' Standard or High Cube, 45' High Cube, or 2×20'. Typical dimensions and mass specifications for these formats can be verified against CMA CGM container specifications, but always check the parameters of a specific container by its marking.

If you're still comparing designs for different tasks, find out about types of semi-trailers and their purpose.

Fixed or sliding frame

A fixed container chassis makes sense if most trips are done with one format. For mixed transport, a sliding frame is more practical, but the word 'telescoping' alone doesn't mean the chassis suits all container types.

For example, for KRONE Box Liner eLTU5-2 the manufacturer specifies working positions for 40', 45', 2×20', and 20' in the centre. So before buying, you need to check the specific chassis diagram, the placement of container locks, and the available frame positions, not just its maximum length.

During the inspection, pay attention to:

• frame — inspect the longitudinal members, the neck near the kingpin, crossbars, and lock mounting points. Cracks, metal waves, heavy fresh welds, or misalignment may indicate repairs or geometry violations;
• container locks (twist locks) — they must fit into corner fittings without skew, lock completely, and have no critical play. Check them in each position you plan to use;
• extending mechanisms — unfold the chassis into all declared configurations. Sections should move without binding, and stops should clearly lock each position. Heavy corrosion of guides, deformation, or locking issues indicate risk of repairs and downtime after purchase.

If a container chassis is purchased for multiple formats, versatility must be verified in practice: check all required frame positions and lock compatibility with 20', 40', or 45' containers.

Container Position and Axle Load

For a heavy 20-foot container, what matters is not just its weight but where it stands relative to the kingpin and the axle assembly. Shifting back increases the load on the semi-trailer axles; forward — on the tractor's fifth wheel and rear axle.

Before signing, calculate at least two scenarios: the heaviest 20' and the heaviest 40'/45'. Following amendments to section 22.5 of the Traffic Rules for container transport in Ukraine, separate weight limits are provided: up to 42 tonnes for a two-axle tractor with a three-axle container chassis, and up to 44 tonnes for a three-axle tractor with a two- or three-axle container chassis when transporting one or more containers or swap bodies with a maximum combined length of 13.716 m as defined by container transport rules. Axle load limits must be monitored separately.

Container Chassis Compatibility with Tractor Unit

Before purchase, check:

• fifth wheel height and overall height of the road train;
• permissible load on the fifth wheel coupling;
• clearance between cab, container, and supports during turning;
• pneumatic and electrical connections, ABS/EBS;
• wheel formula and permissible weight of the road train.

The differences between 4×2, 6×2, and 6×4 for specific routes and cargo are discussed in detail in the article on selecting a tractor wheel formula.

How to Check a Used Container Chassis

Brakes and running gear

Check the EBS, discs or drums, brake chambers, hoses, air suspension, axles and tyres. Uneven tyre wear can indicate problems with geometry, suspension or axle. If you are evaluating equipment by photo and video, use the TIRKOMIS remote inspection checklist for commercial vehicles.

For comparison, you can open real container chassis from the TIRKOMIS semi-trailer catalogue: Berger 2003 with a tare of 4 900 kg and SAF axles, RENDERS 2002 with a tare of 5 900 kg and Mercedes axles or Dennison 2000 with ROR axles. However, the label 'container chassis' in the listing does not confirm that a specific chassis works with all 20/40/45 foot formats — the frame position and locking mechanism must be clarified before the deal.

What to choose

The algorithm is simple: first determine your typical containers and maximum load, then check the working frame positions, load distribution, compatibility with the tractor unit and technical condition. And only then compare brand, year and price. Call the manager — we will select options for you. And if you have a container chassis or other commercial vehicle for sale — bring it in on consignment to TIRKOMIS: the marketplace handles advertising, viewings and communication with buyers.