3.7.3. Dynamic test
The fifth wheel coupling shall be subjected to alternating stress on a test rig (asynchronous dynamic test) with horizontal alternating and vertical pulsating forces acting simultaneously.
3.7.3.1.
In the case of fifth wheel couplings not intended for the positive steering of semitrailers, the following forces shall be used:
Horizontal: F
hw
= ± 0,6 × D
Vertical: F
sO
= g × 1,2 U
F
sU
= g × 0,4 U
These two forces shall be applied in the longitudinal median plane of the vehicle with the lines of action of both forces F
sO
and F
sU
passing through the centre of the joint of the coupling.
The vertical force F
s
alternates between the limits +g × 1,2 U and +g × 0,4 U and the horizontal force between ± 0,6 D.
3.7.3.2.
In the case of fifth wheel couplings intended for the positive steering of semitrailers the following forces shall be used:
Horizontal: F
hw
= ± 0,675 D
Vertical: F
sO
and F
sU
as in paragraph 3.7.3.1.
The lines of action of the forces are as given in paragraph 3.7.3.1.
3.7.3.3.
For the dynamic test of fifth wheel couplings, a suitable lubricating material shall be placed between the coupling plate and the trailer plate so that the maximum coefficient of friction, F, is 0,15.
3.8. Mounting plates for fifth wheel couplings
The dynamic test for fifth wheel couplings described in paragraph 3.7.3 and the static tests described in paragraph 3.7.2 shall also be applied to mounting plates. With mounting plates, it is sufficient to perform the lifting test on one side only. The test shall be based on the maximum designated installation height for the coupling, the maximum designated width and the minimum designated length of the mounting plate design. It is not necessary to carry out this test if the mounting plate in question is identical to one which has already undergone this test except that it is narrower and/or longer and the total height is lower. It is not permissible to use a calculation method as an alternative to physical testing.
3.9. Fifth wheel coupling pins of semitrailers
3.9.1. A dynamic test with alternating stress shall be performed on a sample mounted on a test rig. The testing of the coupling pin shall not be combined with the testing of the fifth wheel coupling. The test shall be conducted so that the force is also applied to the fixings needed for attaching the coupling pin to the semitrailer. It is not permissible to use a calculation method as an alternative to physical testing.
3.9.2. A dynamic test with an alternating horizontal force of F
hw
= ± 0,6 D shall be applied to the coupling pin in the operating position.
The line of action of the force shall pass through the centre of the smallest diameter of the cylindrical part of the coupling pin having a diameter of 50,8 mm for Class H50 (see annex 5, Figure 18).
3.10. Alternative endurance test for coupling balls and towing brackets with a D-value ≤ 14 kN.
Alternatively to the test procedure described in paragraph 3.1, coupling balls and towing brackets with a D-value ≤ 14 kN can be tested under the following conditions.
Feedback