ISO 11406 pdf download.Commercial road vehicles — Mechanical coupling between towing vehicles with rear-mounted coupling and drawbar trailers — Interchangeability
1 Scope
This International Standard specifies the requirements for the various elements and dimensions of towing vehicles with rear-mounted coupling and of drawbar trailers, to ensure interchangeability. NOTE Annex B gives examples of different configurations of vehicle combinations; this International Standard deals only with No. B.1 .1 . This International Standard is applicable to road trains for commercial transport of cargo of the greatest possible variety; it does not cover dedicated or special combinations. Nor does it specify limitations of maximum gross mass and overall dimensions, which are generally laid down by legislative requirements. Vehicles whose couplings form the subject of this International Standard are not interchangeable with vehicles whose couplings are mounted forward and below (which form the subject of ISO 1 1 407 [1 ] ).
2 Interchangeability dimensions
2.1 Distance between drawbar coupling axis and rear end of towing vehicle The distance between drawbar coupling axis and rear end of towing vehicle (dimension A in Figure 1 ) shall not exceed 550 mm. NOTE It is recommended that dimension A lie within the range of 420 mm to 550 mm if compliance with the following conditions is required (e.g. in Europe): road train with a total length of 1 8,75 m (in accordance with Directive 96/53/EC [2] ); loading length/body length equal to 2 ? 7,45 m (two C745 swap bodies in accordance with EN 284 [3] ); S min = 80 mm (in accordance with 2.2); no close-coupling system. When dimension A exceeds 420 mm, a device that enables coupling actuation at a maximum distance of 420 mm from the outer bord of the body is required.
2.2 Front corner radius of trailer
The front corner radius of the trailer, dimension C in Figure 2, is the minimum horizontal distance between the drawbar coupling axis and the front corner of the trailer. The minimum value of C in a vehicle combination, dimension C min in Figure 2, in millimetres, is determined by the equation Based on practical experience, S shall not be less than 80 mm. This ensures that no contact is possible between the towing vehicle and the front of the trailer under normal operation. Calculation examples for C min are given in annex A. NOTE A smaller value of C, if required by the owner of the trailer, can allow contact and damage. Such a combination is considered a dedicated combination and is not covered by this International Standard. 2.3 Heights of towing attachments on towing vehicle and of drawbar articulation axis on trailer The height of towing attachments on towing vehicle, dimension H shown in Figure 1 , and the height of drawbar articulation axis on trailer shall be as given in Table 1 . These requirements apply equally to laden or unladen vehicles.