Feedback from Mr. Svensson (VBG Group) as pilot for dolly definition:

• Existing definitions
  • Mr. Svensson presented the results of his survey (document AECS-03-06 – Converter Dolly in Multi Vehicle Combinations) as a kind of “road book” of the issues that must be addressed by the group. Some additional issues should be discussed, such as national specific requirements, emergency valves on long vehicles, conventional vs. hinged drawbars dollies with regard to the braking capabilities.
  • It was pointed out that some existing definitions are based on the definition of a trailer (centre-axle trailer), transforming a semi-trailer into a full trailer.
• Definition of classes of dollies
  • The Chair questioned the necessity to keep two different types of dolly, i.e. hinged drawbar dollies and rigid drawbar dollies.
  • Hinged drawbar dollies are actually not anymore built in most European countries, yet AUS for example still use and build them. Yet rigid drawbar dollies are now state of the art, in particular in the frame of MVC. The Chair feared that the experts present in the group may lack experience in hinged drawbar dollies, while all have 30 years’ experience with rigid drawbar dollies. NL informed about bad experience with hinged drawbar (the dolly was spinning around its axles when braking). Most experts favoured focusing on rigid drawbar dollies, taking into account other possibilities in case they are of interest.
  • Definition of a trailer per RE.3:
    • “1.5. “Trailer” means any non-self propelled vehicle, which is designed and constructed to be towed by a power driven vehicle and includes semi–trailers”. Should the definition of a dolly be added into RE.3, then the definition of a trailer should be amended.
  • Definition of a trailer per the European Directive 2007/46, paragraph 12 in Chapter I, Article 3:
    • “12. ‘Trailer’ means any non-self-propelled vehicle on wheels which is designed and constructed to be towed by a motor vehicle”.
  • There was a proposal to take over the definition existing in the European Directive 2007/46, paragraph 5.9. of Annex 2, Part A.:
    • “5.9. Converter dolly: a vehicle of Category O equipped with a fifth-wheel coupling to support a semi-trailer with a view to converting the latter into a trailer.”
    • If such definition was adopted, then the dolly converts a semi-trailer into a trailer, i.e. with a hinged drawbar, which is contradictory to the decision of the informal group to focus on rigid drawbar dollies. Furthermore, it should not be understood that such a definition mean that the requirements for full-trailers in UN R13 would apply to dolly+semi-trailer. This would indeed not be applicable, since the approval applies to single vehicles. Thus the definition of a dolly should remain “neutral”, i.e. independent from other definitions like “centre-axle trailers” or “full-trailers”.
  • From this respect, another option takes a dolly as especially designed to tow a semi-trailer, i.e. “a towing trailer specially designed to tow a semi-trailer”.
• Proposal for requirements for coupling: All experts agreed that the provisions of UN R55 should apply. Yet the group must still investigate the details of the necessary requirements applicable to the MVCs and dollies.
• Proposal for requirements for braking: Some debate took place on the distribution of braking forces.

Conclusions:

• Group to limit the scope of discussions to rigid drawbar dollies because this could be a 1st step toward dolly approval. Principle agreement to be confirmed at next meeting.
• In parallel, group to get information from AUS on their experience with hinged drawbar dollies.
• Chair to request guidance from GRRF about the place where adding the definition of a “dolly” (in RE3 or in the regulations or both)
• The group decided to temporarily accept the following definition: “dolly means a towing trailer especially designed to tow a semi-trailer”, and to check it along the work to be performed with the definition of the performance requirements.