21. The expert from Poland introduced ECE/TRANS/WP.29/GRRF/2016/32 proposing to introduce requirements in Regulation No. 55 imposing that a coupling device can only be installed on an M1 vehicle which was designed for its installation. The intention of the proposal received a general support. The expert from Denmark proposed that it should also apply to vehicles of category N1. The experts from the Netherlands and Spain noted that the text of the Regulation already contained provisions in that sense (a list with such provisions is available in the IWG working paper R55-07-06). GRRF supported the idea proposed and agreed to revisit this item at its January 2017 session on the basis of a revised proposal that the experts from Denmark, the Netherlands, Poland and Spain volunteered to prepare.

21. The expert from Poland informed GRSG about the purpose of ECE/TRANS/WP.29/GRSG/2016/4, proposing to insert into UN Regulation No. 55 an amendment imposing a new general constraint for granting component type-approval for mechanical coupling devices dedicated to category M1 vehicles only if they were designed to tow trailers. He announced the submission of the document to GRRF for consideration at its next session in September. GRSG endorsed that position and agreed to remove the agenda item.

Item w14 (Coupling installed to vehicles without towable mass) (GRSG/2016/4)
This item was originating from Poland that had brought it up at the TAAM. It concerns retrofitting a coupling (class A) to a vehicle not having a towable mass assigned by the vehicle manufacturer. Would it be possible to have this installation approved? The general opinion was that it is not possible to have such a vehicle approved according to regulation 55. There is no a possibility make a change to regulation 55 to have such an approval. The argument around this issue went like this. Assigning a towable mass to a vehicle includes a rigorous testing and analysis by the vehicle manufacturer. There are uphill tests, stability test, slalom test, cooling system capacity tests, endurance test for the fixing points, braking system tests, … A vehicle not having a towable mass assigned by the vehicle manufacturer has not been subject to these tests. Accordingly it cannot have a coupling with D-, Dc-, S- or V- value installed. If such installations shall anyway be brought up for an approval it shall be shown that the relevant tests as required by the vehicle manufacturer to assign a towable mass have been carried out. It is the general opinion of the working group that it is a bad practice to install a class A coupling for the sole purpose to enable the usage of special appliances as e.g. bicycle carriers. If such arrangements are still on the agenda it is the opinion of this working group that measures shall be taken that excludes the installation can be used to tow a trailer. Detailed regulation for appliances aimed at other applications than towing a trailer shall be the subject for the GRSG to consider.