SAF 50S15 Manuel D'utilisation page 45

The specific value for the capacity of each kingpin is the D-value that can
be read on the bottom of the kingpin Fig. 1. The weight of a vehicle alone
is no equivalent for the forces that occur in the coupling devices. First, the
sum of the influencing factors or their relation determines the force that
acts upon the coupling device. This strength (called shaft strength or D-
value for short) is connected to the fifth wheel vertical load, the weight of
the fifth wheel tractor and the weight of the semi-trailer and will also be
disclosed in the type testing.
Calculation according to ECE-R55 chapter 2.11.1
The D-value can be calculated with the
following formula Fig. 4.
D-value calculation formula
Formula symbols, Fig. 4
D
g
T
R
U
t
The permitted capacity limits for products from SAF-HOLLAND can be
taken from the engraved product information Page 4 or valid type
approvals and our home page www.safholland.com. They apply to the
operation on sealed, tarred roads and road conditions that are customary
in West Europe. In the case of deviation from the installation requirements
XL-KP11695BM-en-DE Rev. A · 11.2013 · Errors and changes excluded · © SAF–HOLLAND
Fig. 4 · D-value calculation formula
Definition of terms
D-value in kN
Gravity; g = 9.81 m/s
Maximum permissible laden weight of
the tractor in t
Permitted total weight of the
articulated trailer in t
Permitted fifth wheel vertical load in t
Ton = 1000 kg
5 Installation
KP-0007
2
15