HS for heavy and special transport

HS Hydraulic Steering System

The HS steering arrangement is an hydraulic system which is used primarily in heavy and special transport. This system steers one until maximum four rigid axles by using turntables. Optionally in combination with non-steered rigid axles. A HS steering system can also be used at extendable trailers and self-tracking dollies. Besides the fact that the HS steering system allows the trailer to meet the turning circle requirements, it provides better manoeuvrability and reduction of tyre wear. The manoeuvrabilty of the trailer can be enlarged by extending the HS system with TRITRONIC manual steering.

Savings on

  • Time, through better manoeuvrability
  • Fuel consumption
  • Tyre wear
  • Vehicle maintenance
  • Vehicle damage

Steering principle

While making a turn, the movement between the truck and trailer is transmitted by the fifth wheel plate, locked into the fifth wheel coupling by the steering wedge. The movement of the fifth wheel plate activates 2 cylinders in the fifth wheel unit which are connected to 2 cylinders at the axle mounting frame. In case more than 1 axle is steered the steering motion from the rear axle is transmitted to the other axle(s) with steering rods.

HS for heavy and special transport


  • A HS system enables you to steer 1 to 4 axles on a trailer.
  • 2 versions available; for 2 beam chassis and for central beam chassis.
  • RDW test report according EEC guideline (70/311) for most common HS configurations available at request (no. 56210053).
  • Special TRIDEC spline bolts used for most bolt connections. No loosening of bolts and re-tightening not necessary.
  • Gross weight: 760 kg (1 axle steered), 1075 kg (2 axles steered). Net weight of steering system is reduced due to the replacement of a conventional rubbing plate with the TRIDEC fifth wheel unit and modifications to rear of chassis to accommodate the turntable.
  • Possible steering angles: up to 45º.
  • Components: fifth wheel unit, steering rods, axle mounting frame(s), hydraulic control box.