Documents (Latest posted on 16 Apr 2021)
Related Meetings : Informal Group on Amendments to UN R55.01 | Session 10
Documentation Discussion/Report

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.

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

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

Item 14 (2nd stage built) (R55-06-02)
Mr. Westphäling showed the product “Space extender” produced and marked by the company SMV. . 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

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

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

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.

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- 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.