A manoeuvrable special-purpose lorry for forestry work

• WIESE Fahrzeugbau has developed a special 2-axle roll-off tipper featuring two SAF forced-steering trailer axles for maximum manoeuvrability on narrow forest tracks.
• The forced-steering axles from SAF, combined with the VSE Advanced Steering electro-hydraulic steering system, improve manoeuvrability, reduce tyre wear and increase operational efficiency.
• The vehicle was developed in close collaboration between WIESE Fahrzeugbau, SAF-HOLLAND and the Austrian forestry contractor Johannes Suntinger.

Transporting wood chips from the forest places high demands on the vehicles used. The material is usually produced directly in the forest and then transported to temporary storage sites, where it is dried. A large load capacity and high manoeuvrability are crucial in order to be able to manoeuvre safely even on narrow forest paths and unpaved forest roads.

Against this backdrop, WIESE Fahrzeugbau, in collaboration with SAF-HOLLAND, developed a special vehicle concept for forestry use: a 2-axle tipper with forced-steering, drum-braked axles and the VSE Advanced Steering electro-hydraulic steering system, as well as a specially designed 50 m³ roll-off container.

The vehicle features three axles on the tractor unit and two forced-steering SAF axles on the trailer – a relatively rare configuration. Whilst conventional semi-trailers are usually fitted with three rigid axles, WIESE specifically opts for forced-steering axles to significantly improve manoeuvrability.

The trailer axles are controlled via the VSE Advanced Steering electro-hydraulic steering system. The system continuously analyses the vehicle’s speed, steering angle and direction of travel, and adjusts the steering movements of the axles in real time.

A key advantage: the solution operates completely independently and requires no additional connection to the tractor unit. This allows the system to be flexibly integrated into various trailer configurations.

The practical benefits of trailer steering are particularly evident during demanding operations on forest tracks. Active steering of the trailer axles significantly improves manoeuvrability and makes it easier to manoeuvre on narrow tracks or in confined storage areas.

Further benefits include reduced tyre wear and lower rolling resistance when cornering. The integrated hook lift offers additional flexibility. It enables the rapid dropping and picking up of roll-off containers – even on uneven terrain. This allows the driver to set down a loaded container, immediately pick up an empty one and reduce downtime.

“We see SAF steering technology, combined with VSE Advanced Steering, as a genuine innovation for trailer manufacturers and fleet operators alike. Particularly where manoeuvring space is tight and reversing manoeuvres are the order of the day, the system offers a clear advantage – be it on forest tracks, construction sites or in inner-city scenarios. Furthermore, our customers benefit from lower vehicle weight and thus greater cost-effectiveness,” says Alexandre Charpiot, Vice-President Sales EMEA at SAF-HOLLAND.