The workgroup chairman Jürgen Westphäling welcomed all experts to the meeting venue in Gothenburg, Sweden.

There were fourteen experts that attended the meeting. Apologizes were received from Pierre Teyssier, Alan Feltham, Anders Gunneriusson, Jan Stokreef, Joachim Zander and Philippe Jaumouille.

Comments on the report from meeting no. 9 if any
Mr. Alguëra commented that the task on simple designs had been allocated to him while it should have been allocated to Mr. Bröckling. The secretary noted this and will correct accordingly. With that remark the notes were filed.

Comments on the working documents submitted for the 80th session of GRRF

The deadline for the submission was at the 19th of June 2015.

The first document submitted was R55-10-02 about redefinition of Class S. The secretary commented that a small change was made in relation to the agreement at the 9th meeting of the working group. That was to include the class W that most likely will be approved during the 80th session of GRRF. This document was accepted by the working group without any changes.

The second document submitted was document R55-10-10. Concerning the proposal number 3 within the document R55-10-10 the working group had some comments on the distinction between hinged and rigid drawbars. This is not clear in the table 4. Hence the table was changed such that the row in the table that concerns drawbars was split into two rows. There is one for rigid drawbars and one for hinged drawbars. Furthermore a new column was added to handle the characteristic value Av. Through these changes the footnote to table 4 becomes obsolete. Hence it is removed. The changes are documented in the document R55-10-17. Furthermore it was observed in the fourth proposal within the working document that the definition of class W was unnecessary restricted to clevis type couplings. It shall be applicable to drawbar couplings in general. Hence the words “clevis type” were stricken out. This change was also documented in the document R55-10-17.

R55-10-02 | UN R55: Proposal for Class S amendments

R55-10-10 | Proposal for amendments to UN Regulation No. 55 Proposal to introduce amendments on: a) Requirements on remote indication; b) Availability of information on coupling fixing points for A50X couplings; c) On lateral strength of drawbars; d) Includes a new class definition for fully automatic drawbar couplings.

R55-10-17 | Draft update of UN Regulation No. 55 The text reproduced below was prepared by the experts of the informal group on UN Regulation No. 55 and introduces amendments on: a) Requirements on remote indication; b) Availability of information on coupling fixing points for A50X couplings; c) On lateral strength of drawbars; d) Includes a new class definition for fully automatic drawbar couplings.

Item 2 (Auxiliary usage Class A) (R55-03-09, R55-03-10, R55-03-11, R55-04-05, R55-04-06, R55-04-07, R55-05-17, R55-06-02, R55-07-12)
Mr. Westphäling reported that he had googled to find any information about accidents with bicycle carrier mounted on a trailer hitch. Using the keywords “fahrradträger verloren” he got a lot of hits. It is hard to judge from these articles whether it is a problem with the hitch per se or with the bicycle carrier itself. However some cases seem to indicate that there is fatigue of the hitch. The statistics in this area is very poor. Usually when there is an accident with a car running in to a lost bicycle carrier there is not focus on the hitch of a vehicle that lost that bicycle carrier. Hence you can expect an under reporting in this area.

Within the next three month the DIN/VDA will post a New Work Item Proposal with ISO. This proposal will address the auxiliary usage of trailer hitches. Mr. Westphäling will follow the development and report back to our working group. Next meeting

R55-10-12 | List of discussion items for the 10th R55 informal group session

Item 12 (Clearance around drawbar coupling) ( )
The picture in annex 7 § 1.3.6. shall remain as is. Item closed.

R55-10-12 | List of discussion items for the 10th R55 informal group session

Item 14 (2nd stage built) (R55-06-02)
Mr. Westphäling showed the product “Space extender” produced and marked by the company SMV. http://www.spaceextender.com/ . This is an extreme illustration of “second stage built” The experts were very puzzled with this design. However it was apparently approved under regulation 55. The discussion on this item showed that there were ties to agricultural applications as well. We have at earlier meetings discussed mobile homes in the context. However no solid proposal how to go forward with this has evolved. The discussion this time took an angle towards what is coupling equipment. Mr. Westphäling will follow up and report. Next meeting

R55-10-12 | List of discussion items for the 10th R55 informal group session

Item 20 (Heavy transports) (R55-02­­-13, R55-04­­-08, R55-04­­-12, R55-05-01, R55-05-06, R55-05-20, R55-05-21, R55-05-22, R55-07-18, R55-08-13, R55-09-06, R55-10-08; R55-10-09; R55-10-13)
Mr. Svensson had made some kinematic investigations to get some indications on speed dependence of coupling forces. This showed the peak longitudinal accelerations when traversing a sinusoidal wavy road to be related to the speed squared. Bearing in mind that this is an indication of the speed dependence of the most important coupling force generating mechanism it is a good basis for the discussion. It should be observed that this study is kinematic. It will in reality be influenced by the flexibility and masses in the vehicles involved. Mr. Svensson also pointed to the document R55-09-06 where the speed dependence of the range and standard deviation are plotted as dependent of speed. The dependence is very clear. Over long time VBG, according to Mr. Svensson, has applied a rule where the forces are dependent on square root of the speed. Based on these different observations Mr. Svensson proposed a linear dependence between 36 km/h and 80 km/h. Below 36 km/h the reduced value at 36 km/h applies.

Mr. Alguëra commented that his company had checked the proposal against their proposal. From that check he expressed a support for the proposal. Mr Tagliaferri also expressed support. Mr. Conrads was questioning whether the base speed should be 90 km/h rather than 80km/h. Mr Westphäling was hesitant and referred to Australian conditions. Mr. Mátyás pointed out the conditions are such that reducing requirements would at times kill the coupling in very short time of operation. In response to that it was concluded that the utilizing speed dependence as a mean to encompass heavy loads is only applicable to commercial road vehicles where the coupling equipment is designed for a base speed of 80 km/h. The experts will consider the proposal to the next meeting. Next meeting

R55-09-06 | Extreme Transports: Interrelationship between speed and dynamic forces on couplings Expanded version of the earlier information in document R55-08-13.

R55-10-08 | Proposal for amendments to UN Regulation No. 55 Proposal to introduce amendments on applications in multi-vehicle combinations.

R55-10-09 | Mechanical couplings: Theoretical sketch for the derivation of speed dependence

R55-10-12 | List of discussion items for the 10th R55 informal group session

R55-10-13 | Proposal concerning mechanical coupling test performance and speed dependence

Item 21 (Limiting cases for the usage of certified characteristic values) (R55-04­­-11, R55-05-05, R55-06-09, R55-07-06, R55-07-14, R55-08-03, R55-08-04, R55-08-05, R55-09-04, R55-09-05, R55-09-11, R55-09- 13, R55-10-03: R55-10-04; R55-10-05; R55-10-06; R55-10-07; R55-10-08; R55-10-15)
At the previous meeting Mr. Stokreef requested more of the background information to the ISO18868:2013 standard. In order to respond to that request Mr. Svensson had uploaded the documents R55-10-03: R55-10-04; R55-10-05; R55-10-06. The last of those documents was a history summary over the work with that standard going back to 2002. The document R55-10-07 was a summary of many recent measurements of coupling forces in different vehicle combinations. There is also a comparison with the requirements as calculated using the ISO18868:2013. It could be noted that the measure peak forces only at on instance came close to the fatigue test load corresponding to the performance required.

Mr. Westphäling at the 9th meeting argued that road conditions in Germany are worse than in Australia. To this meeting Mr. Svensson had gathered information that showed that the German Autobahn does not have worse conditions than the Australian roads. Hence the measured forces and the experience over 30 years supporting the ISO18868 are valid. Mr. Stokreef was not present but had prior to the meeting expressed support for the proposal for this item. Mr. Westphäling argued that different engine power and and brakes requirements would the still make the proposal questionable. In response to that Mr. Svensson showed the diagram in the document R55-10-07. There it could be seen that the real high coupling forces is generated neither by traction nor by braking but through interaction between unevenness in the road and the geometric layout of the vehicle combination. Hence the difference in engine power and braking performance is not a significant factor. While support for the proposal is converging Mr. Westphäling wanted to the next meeting to challenge OEM:s and trailer manufactures for more measurements. Mr. Alguëra was doubtful whether there are any better measurements available. Next meeting

R55-10-03 | Strength Requirements for Fifth Wheel Couplings in Road Trains and General Articulated Vehicles

R55-10-04 | Instrumentation for Measurement of Coupling forces in Road Trains

R55-10-05 | Australia: Strength Requirements for Tow Couplings in Road Trains Australia Road Research Board (ARRB) Internal Report related to ISO/TC22/SC15/WG4 N 535 Annex 5.

R55-10-06 | Historical review of the development of ISO 12357

R55-10-07 | Summary of measured extreme coupling forces

R55-10-08 | Proposal for amendments to UN Regulation No. 55 Proposal to introduce amendments on applications in multi-vehicle combinations.

R55-10-12 | List of discussion items for the 10th R55 informal group session

R55-10-15 | Data on road conditions in selected countries

Item 25 (Articulation angles as installed) (R55-02-05, R55-05-13, R55-07-10, R55-09-21)
As Mr. Stokreef was not present at this meeting it was decided to postpone this item to the next meeting.

Item 29 (Drawbar a separate technical unit) (R55-04-04, R55-05-02, R55-09-08; R55-10-xx)
Mr. Bröckling had volunteered to this task and had prepared a document where he through a number of illustrations showed how all part of a drawbar installation shall be considered as part of the drawbar to be approved. That is to say that, brackets, side plates and other attachments used to fix the main drawbar to the trailer chassis is subject to approval. As the calculations of such attachments are not always that easy Mr. Svensson argued that at least some guidance shall exist over how those calculations shall be carried out. This is needed to guarantee that these matters are handled in an equal manner across the different technical services. The discussion then became centered around when to apply approval based on calculations, i.e. simple designs. This part of the discussion is referenced under the item 30. Next meeting

Item 30 (Simple designs) (R55-02­­-09, R55-03-06, R55-05-09, R55-07-07, R55-09-08)
Continuing the discussion under Item 29 Mr. Svensson argued that the basic assumption shall be that a design approved on the basis of calculation shall withstand dynamic fatigue test according to annex 6 if tested. Mr. Westphäling said that this was not necessarily so. E.g. the fixing on the test bench is hard to make realistic according to Mr. Westphäling. Mr. Svensson then responded to say that in such cases it would also be difficult to set the relevant boundary conditions for the calculations. To come forward in this discussion Mr. Svensson offered to put on fatigue test one or two designs approved based on calculations. An alternative way to proceed according to Schedule 8 of the proposed revision of the 1958 agreement. Next meeting

The waiting list

According to the discussion on the future of this informal working group, the waiting list items are activated.

Item w1 (Approval based on worst case class B50x)(R55-07-19)
Mrs. Domagala presented document R55-10-19 as a proposal for this item. This was elaborated in the document R55-10-20. The French delegates argued that the last sentence of §1.1.1 might not be necessary. Mrs. Domagala was asked to rewrite the justification. (During a coffee break Mrs. Domagala and Mr. Svensson outlined an alternative justification as in R55-10-20. This was not reviewed by the group and Mrs. Domagala shall elaborate to the next meeting

Item w2 (Approval based on worst case class B50x)(R55-07-19)
This matter was dropped.

Item w3 (Alternative performance values)(R55-10-22)
KBA request a more stringent definition of alternative performance values. The base proposal assumed alternative values for a single component. However Mr. Westphäling showed that it is more to this than that. When broaden the scope to a family or range of products this becomes more complex. Mr. Hansen and Mr. Westphäling was assigned the task to outline a new proposal for the broader scope to the next meeting.

Item w7 (Class H50)( )
KBA requests to add a class H50 which seems missing. Considering the reference to the king-pin drawing in annex 5 Mr. Svensson argued that it might be such that the existing class H50-X is not really motivated. I.e. the class H50 –X shall be replaced by the class H50. Mr. Hansen will check this up to the next meeting.

Item w8 (Wedge angle)( R55-09-20)
Mr. Tagliaferri requested the drawing of the wedge in annex 5 §7.8.1. to changed. The changed drawing is shown in document R55-09-20. This was agreed.

Due to lack of time the remaining item were left to be processed later meetings.

R55-07-19 | UN Regulation No. 55 revision: Proposal for worst-case physical testing

R55-09-20 | Mechanical couplings: Wedge diagram

R55-10-20 | UN Regulation No. 55 revision: Proposal for worst-case physical testing

R55-10-22 | KBA proposal for definition of alternative values in UN R55 communication

Report from TFAC
Mr. Schauer made a report from the work in the TFAC.

First of all Mr. Schauer reported that compromises had been reached on all open technical issues.

Then he put forward a proposal from the taskforce that they considered to have the agricultural coupling regulation as a separate regulation. Mr. Westphäling was not at all in agreement with this proposal. The discussion on this item was long and intensive. The discussion resulted in an agreement that a fully elaborated proposal where the agricultural rules are integrated together with the rules for commercial vehicles. At least a sketch for a separate regulation shall be elaborated at the same time. These two documents shall be submitted to the GRRF for guidance. While elaborating the agricultural rules it should be born in mind that the number of coupling equipment classes shall be minimized. The concept from the commercial vehicles could serve as guidance in this effort. I.e. most of different installation alternatives can be handled in the annexes (for commercial vehicles annex 5) rather than in the definitions. Further the need for a new annex 1 resulting in annex 1A and 1B shall be challenged. May be a minor alteration to the existing annex 1 would be sufficient.

Approach towards the 80th session of the GRRF
Agreed items shall be put in a form such that a working document could be compiled to the deadline for the 80th session of the GRRF. Informal documents will be compiled to address agreed changes to the submitted working documents.

New Items to the waiting list (R55-10-18)
1. SPP-Proposal-Application for approval-2014-05-
a. SPP-Proposal-Application for approval-2013-05
2. SPP-Proposal-Conformity of production-2013-10
3. KBA Change request-UN ECE R55-2. Definitions-alternative values
4. KBA Change request-UN ECE R55-Annex 6-3.7.2.2-lever bearing at least 1,0…
5. KBA Change request-UN ECE R55-Annex 7-T = 32 t
6. JOST-Application for an amendment of R55-Jost-06-10-2014
7. KBA Change request-UN ECE R55-2 Definitions-Class H50 (R55-09-07-…)
8. Orlandi, Diagram correction wedge (R55-09-20-Wedge)
9. Fixing point information and vehicles N1
10. General review Class …-X
11. What masses to use when calculating required performance values for coupling equipment.

R55-09-07 | KBA change request for R55 class definitions KBA has noticed that class H50 couplings are not defined and so proposes to add this class and definitions to UN R55.

R55-09-20 | Mechanical couplings: Wedge diagram

R55-10-18 | Waiting list of GRRF request concerning the update of UN R55 List of pending proposals for the update to UN R55 from GRRF participants.

Any other business
Next meeting will be a two-day meeting to be held in the Germany. Mr. Algëra and Mr. Conrads will agree between themselves where to have the next meeting. Venue will be communicated at a later stage. The time for the meeting is 2015 October 20 – 21 starting at 1000 ending at 1500 hours.

It was noted that the target is to have all items managed such that the last GRRF for this Informal working group would be 2016 September.

The chairman thanked all participating experts for their contribution and wished them a safe journey home. Welcome back in October of 2015. The attendees expressed their gratitude for the hospitality by the VBG to host the meeting.