Click on the Couplings tab. Select Front Coupling and / or Rear Coupling to include front and rear couplings respectively.
The Type of coupling dictates what other units can be connected to this unit, i.e. the coupling types must match. The exception is that any coupling type can be linked to a generic coupling. Coupling type Active Steerable Coupling allows users to model vehicles with no conventional steered wheels but instead a articulation point whose angle is controlled by the driver, e.g. by hydraulic rams. A unit may only have one coupling of this type and it is always the primary steering.
The Capability of the coupling specifies whether it can tow other units, be towed or both.
The position of the coupling is defined by the Coupling offset which is measured relative to the datum point.
The Coupling height is used for vertical clearance analysis and defaults to a proportion of the wheel diameter. Enter an accurate figure if you have one.
The Maximum horizontal angle is the maximum possible articulation angle between the two connected units in the horizontal plane. Note that when this unit is coupled to another the articulation angle specified in the vehicle details form takes precedence if it is lower. Thus, a vehicle uses the lower of the articulation angle defined in the vehicle details and these values.
The Maximum vertical angle is the maximum possible articulation angle between the two connected units in the vertical plane and is used for vertical clearance analysis.
Select Assume coupling height matches rear coupling on previous unit if the front coupling is able to adjust to suit the height of the coupling on the towing unit.