Type 0 requirements (value of deceleration)
Proposed approach: Dolly is a “tractor-like” towing trailer, thus 50% for type 0
MP (CLEPA/BPW) was of the opinion that the dolly should be considered as a truck for semi-trailer because that permits the combination “dolly + semitrailer” to have a braking capability average of 50% (i.e. 45 + 55%). Should the dolly take only 50%, then the combination would take less than 50%.
BS (CLEPA/VBG) presented some slides (MVC-05-03 and MVC-05-04 – summary of the Eindhoven study) showing dolly braking performances in case of high braking conditions. There was a debate on the load transfer in case of a combination of tractor/dolly/semi-trailer (Case D). In case of braking, one part of the load of the semi-trailer is transferred to the tractor (via the dolly). The experts wondered whether the dolly could take 50% of the braking. The chair feared that a too low value for the dolly could generate a jack-knife situation.
The transfer of load depends on the wheel length of the vehicles.
Conclusion:
All to read in details the Eindhoven study.
Group in favour of 50% braking on the dolly
Rate to be confirmed at MVC-06
Compatibility bands for dollies
Proposed approach: using the compatibility band of a central axle trailer
The group decided to postpone to the next meeting the decision this item (central axle trailer vs. tractor/semi-trailer combination).