poolhaagised

Poolhaagised, or semi-trailers, are freight trailers designed to be towed by a tractor unit. They have no front axle; the forward part of the trailer is supported by the tractor via a kingpin that sits on a fifth-wheel coupling. The tractor carries most of the load through this connection, while the trailer provides the rear axle assembly and cargo space.

Typical poolhaagised consist of a rigid frame, a front neck containing the kingpin, rear axles with suspension and braking systems, and a cargo body. A front landing gear (support leg) is used for hookup and leveling when the trailer is detached. Various body styles exist to accommodate different cargoes, including dry vans, curtain-sided trailers, refrigerated trailers, flatbeds, and specialized configurations.

Most poolhaagised are two-axle or three-axle trailers, with multiple rear axles for higher payload and stability. Some have lift axles that can be raised when not loaded to reduce wear or improve efficiency. The overall design allows longer load lengths and easier loading at depots, compared with rigid trailers.

Poolhaagised are a core component of road freight in many regions, especially Europe. They are governed by national and supranational regulations governing weight, length, braking, and coupling safety. Proper coupling, hitching, and inspection are required to ensure safe operation.

By separating the load-bearing function from the towing vehicle, poolhaagised enable flexible, high-capacity transport and modular fleet management for freight operators.