Documents (Latest posted on 16 Apr 2021)
Related Meetings : Informal Group on Amendments to UN R55.01 | Session 3
Documentation Discussion/Report

Report on the subgroup on Agriculture coupling equipment (R55-03-18, R55-03-19)

Mr Westphäling reported that after that the German rules were translated into English and put forward as a proposal the workload for Mr. Schauer had changed drastically due to the parallel work with the upcoming frame directive for agricultural machines and vehicles. Hence Mr. Schauer is no longer able to lead the sub-group. Meanwhile the Italian delegation had identified a number of differences towards the national Italian rules. Those differences the Italians were not prepared to accept right away. Hence they had started a local workgroup to discuss the German proposal and possibly make an own proposal for agricultural coupling equipment. Also the French delegation had some comments on the German proposal. However it was decided to wait for the Italian initiative managed by UNACOMA. It was also noted that the time frame to be able to match the development of the European Frame directive is very tight.

The list of simple item processed during the second meeting

It was discussed whether the changes that will be proposed from this workgroup should be the base for a new revision or just amendments to the current series of amendments. It was concluded that at least the simple item could be in the current series of amendments. It was further observed that the simple items were to their character on the interpretation level and hence there should be no transition period needed.

Since the second meeting the proposals for the simple items had been reviewed by among others Mr. Stokreef. Concerning item number 17 it was observed that the proposed new §§ 6.4, 6.5 and 6.6 are already covered by Annex 5 §1.2, main text§ 5.3.3 and §4.3 respectively. Hence the only remaining new §6.7 is renumbered to §6.4.

Review of the list of items

Item 7 Simple
After having reconsidered this item it was observed that the requirement for a secondary coupling was in the regulation located under a heading for ball couplings. However there exist also pin couplings for light trailers. Hence the wording and location became more complicated. It was noted that the requirement for a secondary coupling applies only to light trailer. This may be a fact that could make the task somewhat simpler. Mr. Westphäling will work out a proposal to the next meeting.

Item 10 Simple Complex
This item has not been thoroughly investigated yet. The wording has to account for the differing test requirement that applies for class T as compared to class C. This started a discussion to what is a drawbar coupling. As Class C and Class T is said to be drawbar couplings the rest e.g. annex 5 and annex 6 become unclear. The concept “drawbar coupling” leads the comprehension to a coupling where a drawbar is part of the connection between towing and towed vehicle. Then you may argue that a hook type coupling Class K is also a drawbar coupling. Mr. Westphäling have in some context used the word clevis (Explanation found under a coupler shaped like the letter U with holes through each end so a bolt or pin can pass through the holes to complete the coupling; used to attach a drawbar to a plow or wagon or trailer etc.) It was agreed that Mr. Westphäling shall rework the Class C definition and review the consequences that such a rework will have for the rest of the regulation e.g. annex 5 and annex 6.

Item 11 Simple (R55-03-20, R55-03-21)
Mr. Tagliaferri referenced the discussion that he and Mr. Teyssier had had since last meeting. During the investigation in the details of the indication requirements they had identified some ambiguities. This was illustrated in the document R55-03-21. Further work need to be done on this item. Mr. Tagliaferri and Mr. Teyssier took on the task to do so. It was said that the rework should be done in the spirit of the ECE Regulation 121. (Comment from the secretary: the definition §2.9 has to be addressed in this context)

Item 12 Simple (R55-03-03, R55-03-07, R55-03-08)
Mr. Zander had prepared new drawings showing specification of the required free space around the coupling. These drawings were much improved as compared to the previous edition. A question arose however to how to secure the clearance above the main body of the coupling. The proposal as it was presented was judged to leave open the possibility to have less than 60 mm free space directly over the main coupling body. Mr. Algüera volunteered to adjust the drawings. A proposal was presented at the end of the meeting. There was not enough time to discuss. Hence Mr. Westphäling will distribute the sketched to the members of the workgroup. The members are expected to comment as soon as possible such that this matter can be closed at the next meeting.

Item 17 Simple
Requirements copied from 94/20/EC were agreed during the second meeting to be added. However as stated above some adjustments was decided at this meeting.

Item 22 Complex (R55-03-14, R55-03-23)
Since the second meeting Mr. Svensson had reworked this item and proposed a new simplified formula to account for the safety margin as the original procedure used in Sweden. This formula even though being much simpler than that procedure was judged to be too complicated still. The group is in favor of the general principle but would prefer a straight line for the relation. There was a short discussion on the trade-off between V and S performance. Mr. Turlier pointed to the fact that the loading condition was multi-axial. Hence some investigations into this circumstance are called for. He volunteered to make such investigation together with Mr. Svensson.

Mr. Westphäling agreed to send to the secretary the German FS5 procedure.

Item 2 Complex (R55-03-09, R55-03-10, R55-03-11)
It was noted that the auxiliary use of couplings, in particular Class A, is increasing. As electro powered bicycles are becoming more popular the weight carried on the auxiliary carriers attached to the coupling is increasing. Hence an increasing number of claims are expected. The group is considering a separate set of requirements in order to cover these applications. A proposal to amend Annex 6 § 1.5 adding to the end of that paragraph:

Every other use of coupling device as well as mounting of supplement devices (such as stabilizators, luggage carrier, short coupling devices, fixing points for positive steering, and else), by which supplement forces or torques are caused to the coupling devices, has to be taken into account. The permission of using this kind of devices as well as the relating B-value shall be noticed on the manufacturer’s plate and in the mounting instructions.

In order to do this some extra investigation is required. Mr. Ittersum accepted the task to start these investigations. As the discussions vent on the issue coupling brakes addressing wobbling instabilities came up. There was no good knowledge about the size of those forces. Mr. Turlier was asked to give some information about the forces that the Lohr design for such brakes on commercial trailers. This will be on the agenda at the next meeting. Also AL-KO will look into what forces such brakes cause. Mr. Ittersum, Mr. Preud’homme and Mr. Westphäling will work together on an improved proposal.

Item 13 Complex
The extended contacts with more people that have historically been involved in this matter did not shed any new light on the subject. The group is still convinced that something need to be done. Indication of the appropriate Av1 and Av2 values on the type approval plate is the main direction. In order to get forward Mr. Svensson proposed to get in contact with Mr. Geoff Walsh from New Zeeland who has been involved in their redesign of their requirement gathered in the document NZS5446:2007. There they put in a very detailed handling of the lateral strength of drawbars. What change has that brought?

Item 5 Complex
This item was started for some different reasons. First it is not as open in regulation 55 as it is in directive 94/20/EU, Secondly there is a risk that Class S becomes like a “dust bin” where everything that could not be classified in any other Class will be certified. The actual trigger is the classification of emerging fully automatic coupling systems.

It was noted that fully automatic coupling systems that in effect is a coupling system of an existing Class, e.g. Class C or Class G, that has got additional functionality to handle electric and pneumatic connections will remain Class C or Class G or whatever is the base. Any other design that is quite unique and that does not fit into any of the existing classes need to be handled more strict. The proposal is to design a new Class, W, where unique fully automatic coupling systems are certified. This new Class shall clarify:
- the required level of automation
- declaring any exemptions needed
- underlining the requirements of ECE R55 to be fulfilled anyway.
- clearing the discussion of interchangeability

Mr. Gunneriusson and Mr. Svensson accepted the task to outline proposal for the definition of this new Class W.
It was in this context noted the Annex 7 §1.5.2 already envision a fully automatic fifth wheel coupling. That paragraph put a requirement that such coupling systems shall have landing legs that are operated automatically. Mr Algüera volunteered to look into this matter and possibly outline a new proposal for the text.

Item 3 Complex
Information from DLG is awaited.

Item 4 Complex
No proposal had been compiled yet. The meeting time schedule was tight and this item did henceforth not appear on the agenda.

Item 24 Complex (R55-03-24)
The requirements on the rubbing plate and the installation of the king-pin were discussed. Mr. Algüera noted that the Regulation 55 put requirements to the king-pin itself and the usually circular piece welded in to the rubbing plate. The remaining structure, i.e. the rubbing plate and its backing stiffeners, transferring the forces from the king-pin to the semitrailer side members go without any requirements. Even though this is analogue to mounting plate and drawbeams on the tractor/truck side industry seem reluctant to put up requirements. From the perspective of the company of Mr. Algüera they are getting more and more claims where the king-pin installation has been torn away from the semitrailer. Currently there are 10 to 15 such claims a year while it was none 15 years ago.

Within ISO there has been some work on deformation and stiffness requirements for the rubbing plate. See ISO 1726-3.

In this context it was also discussed the need to have a more stringent definition on what is coupling equipment.

The history of how to handle trailers varies between the different countries. The Netherlands abandoned trailer testing some 30 years ago. Italy has a format calculation procedure. Mr. Tagliaferri promised to send a copy of that procedure to the secretary.

A general discussion on this item brought up some odd cases where the stress on the forward structure on a semi-trailer is becoming extreme. Those include transports on trains and on ships.

To bring this item forward it was proposed that the participants with access to accident statistics shall try to get some supporting material for a continued discussion at the next meeting. Statistics may be available at least from KBA, RDW, TS (Sweden).

Item 25 Complex
Mr. Stokreef presented a proposal to introduce requirements on minimum articulation angles for couplings as installed on the vehicle. The proposed limiting angles gave reason for a vivid discussion. For example the proposal for vertical angles was ±20°. Putting this in the context of the standardized under slung mounting positions that limiting angle requires approximately 690 mm free space above the coupling at 1900 mm under slung position. It was hard to come to a common position on this item. It was decided that each country represented around the table should investigate what limiting anles the national legislations apply if any.

Discussed under item 3 above.

Please see the meeting report for the list of decisions and action items.