R55
Submitted by the manufacturer from Poland
Proposal for an amendment to Regulation No. 55 (Mechanical couplings)
Determine worst case conditions for physical test.
Annex 6 § 1.1. (re arrange)
1.1. Samples of coupling devices shall be tested for both strength and function. Physical testing
shall be carried out wherever possible but unless stated otherwise the type approval authority
or technical service may waive a physical strength test if the simple design of a component
makes a theoretical check possible.
Theoretical checks may be carried out to determine worst case conditions. In all cases,
theoretical checks shall ensure the same quality of results as with dynamic or static testing. In
cases of doubt it is the results of physical testing that are overriding.
See also paragraph 4.8 of this Regulation.
Add new point
1.1.1.Theoretical checks may be carried out to determine worst case conditions. The
relevant worst cases have to be identified by the manufacturer and the
technical service. The corresponding physical tests shall be representative for
the entire product range concerned.
Justification:
Usually when applying for approval one sample is chosen, but not always it is the worst
case from the approved coupling device or component.
E.g. in the approval of coupling head: Ø50 mm diameter coupling head is chosen.
However, no other coupling head variants (different according to shape and dimensions of
connectors, as well as placement, size and shape of mounting holes) listed in the
application for approval are tested.
Endurance tests of coupling heads with connectors diameter different than Ø50mm,
carried out according to the Regulation 55 (Annex 6; p. 3.2.1), within one type, might be
negative for different variation of product . It is highly probable that such state of affairs is
maintained since the beginning of production – it can be alleged that the mentioned
coupling head types did not undergo any control or testing by technical services or
approval authorities.
The lower endurance of coupling head can have big influence of safety of users of the
mechanical coupling devices and components and general road safety.
V.3 2015.06.1