## Technical Specification

Hitch and towing eye size

• Hole pattern in the crossbar of the towing vehicle
• Hole pattern in the hitch flange
• Pin size of the hitch

Characteristic values

• Value of the hitch
• Values of towing vehicle and trailer (see vehicle registration certificate)
• Values of the towing eye

## Truck and trailer: D-value ## Calculation

• Theoretical horizontal force between towing vehicle and trailer
• The D-value can only be calculated with the permissible total weight of both truck and trailer
• Calculation of the D-value (kN): T : total weight of the towing vehicle in t
R : total weight of the drawbar trailer in t
g : gravitation acceleration 9,81 m/s2

The calculated D-value can be equal to or lower than the D-value of the hitch and of the towing eye.

# D-Value calculation

## Towing vehicle and central-axle trailer: Dc-value Valid only in connection with the V-value
• Theoretical horizontal force between towing vehicle and trailer
• The Dc-value can only be calculated with the permissible total weight of both truck and trailer
• Calculation of the Dc-value (kN): T : total weight of the towing vehicle in t
C : sum of the axle loads of the central-axle trailer in t
g : gravitation acceleration 9,81 m/s2 The calculated

Dc-value can be equal to or lower than the Dc-value of the hitch and of the towing eye.

## Central-axle trailer: V-value Valid only in connection with the Dc-value
• Vertical force for central-axle trailer
• Dependent on the rear axle suspension of the towing vehicle
• Calculation of the V-value (kN): a : an equivalent vertical acceleration in the hitch point in m/s2
a = 1,8 for vehicles with air suspension
a = 2,4 for vehicles with other suspensions
l : theoretical drawbar length in meters