For full trailers with more than two axles the requirements of paragraph 5.1.1 of this annex shall apply. The requirements of paragraph 5.1.1 of this annex with respect to wheel lock sequence shall be considered to be met if, in the case of braking rates between 0,15 and 0,30, the adhesion utilised by at least one of the front axles is greater than that utilised by at least one of the rear axles.
5.1.3.
The permissible relationship between the braking rate T
R
/P
R
and the pressure p
m
shall lie within the designated areas in diagram 2 of this annex for all pressures between 20 and 750 kPa, in both the laden and unladen states of load.
5.2. For centre-axle trailers fitted with compressed-air braking systems:
5.2.1.
The permissible relationship between the braking rate T
R
/P
R
and the pressure p
m
shall lie within two areas derived from diagram 2 of this annex, by multiplying the vertical scale by 0,95. This requirement shall be met at all pressures between 20 and 750 kPa, in both the laden and unladen states of load.
5.2.2.
If the requirements of paragraph 3.1.2.1 of Annex 4 to this Regulation cannot be satisfied due to lack of adhesion, then the centre-axle trailer shall be fitted with an anti-lock system complying with Annex 13 to this Regulation.
6. REQUIREMENTS TO BE MET IN CASE OF FAILURE OF THE BRAKING DISTRIBUTION SYSTEM
When the requirements of this annex are fulfilled by means of a special device (e.g. controlled mechanically by the suspension of the vehicle) or if the vehicle is equipped with such a special device, it shall be possible, in the event of the failure of its control, to stop the vehicle under the conditions specified for secondary braking in the case of power-driven vehicles; for those power-driven vehicles authorised to tow a trailer fitted with compressed-air braking systems, it shall be possible to achieve a pressure at the coupling head of the control line within the range specified in paragraph 3.1.3 of this annex. In the event of failure of the control of the device on trailers, a service braking performance of at least 30 per cent of that prescribed for the vehicle in question shall be attained.
7. MARKINGS
7.1. Vehicles which meet the requirements of this annex by means of a device mechanically controlled by the suspension of the vehicle or if the vehicle is equipped with such a device, shall be marked to show the useful travel of the device between the positions corresponding to vehicle unladen and laden states, respectively, and any further information to enable the setting of the device to be checked.
7.1.1. When a brake load sensing device is controlled via the suspension of the vehicle by any other means, the vehicle shall be marked with information to enable the setting of the device to be checked.
7.2. When the requirements of this annex are met by means of a device which modulates the air pressure in the brake transmission, the vehicle shall be marked to show the axle loads at the ground, the nominal outlet pressures of the device and an inlet pressure of not less than 80 per cent of the maximum design inlet pressure, as declared by the vehicle manufacturer, for the following states of load:
7.2.1.
Technically permissible maximum axle load for the axle(s) which control(s) the device;
7.2.2.