Connection with full trailer Connection with centre axle trailer
D-value calculation with full trailers
The D-value is defined as the theoretical reference force for the hoizontal force between towing vehicle and trailer resulting from the permissible max. masses of the towing vehicle and full trailer (with vertically adjustable drawbar).
T = permissible max. mass of towing vehicle R = permissible max. mass of trailer
The permissible D-value of the trailer coupling must be greater than or equal to the calculated D-value.
Calculation of the trailer load R (tonnes)
T = permissible max. mass of towing vehicle D = the theoretical reference force for the horizontal force
Trailer couplings with EEC type approval
a = equivalent vertical accelation in the coupling point in m/s dependent on the kind of suspension on the rear axle of the towing vehicle (1,8 m/qs for vehicles with air suspension, 2,4 m/qs for vehicles with other suspension).
C = sum of the axle loads of the centre axle trailer carrying maximum permissible load in tonnes
l = theoretical drawbar length in metres
X = length of the loading area of the trailer in metres
(x2/l2 min. 1,0 for calculation) The permissible Dc-value of the trailer coupling must be greater than or equal to the calculated Dc-value. The permissible V-value of the trailer coupling must be greater than or equal to the calculated V-value.
T = permissible max. mass of the towing vehicle in t C = sum of the axle loads of the centre axle trailer carrying maximum permissible load in t
The permissible Dc-value of the trailer coupling must be greater than or equal to the calculated Dc-value.
