Document ID: chunk:federal_register_of_legislation:F2021C00434:body:0:p17
Version: federal_register_of_legislation:F2021C00434
Segment Type: other
Provision Reference: 
Character Range: 48645–51732

as described in Table 1 (Item 8).
7.9.                                    Service Brake Fade Test
7.9.1.                              In the case of vehicles in categories MB, MC, MD and NA, 15 successive deceleration tests must be conducted at intervals no greater than 55 seconds apart, such that for an initial speed V1 and a final speed V2 (km/h)
       (V12 - V2 2 )  > 7,500.
7.9.2.                              In the case of vehicles in categories ME, NB and NC, 20 successive deceleration tests must be conducted each not more than 70 seconds after the preceding one and with the total of 20 applications completed within 20 minutes, such that for an initial speed V1 and a final speed V2  (km/h)
       (V12 - V2 2 )   2,700.
7.9.3.                              The initial speed must be maintained for at least 10 seconds prior to each deceleration.
7.9.4.                              If the vehicle is not capable of attaining the initial speed required by clause 7.9.1. or clause 7.9.2, then the speed employed in each mode for the initial speed must be not less than 80 percent of the 'Maximum Laden Vehicle Speed' and the final speed must not be greater than half the initial speed.
7.9.5.                              During all deceleration modes the lowest numerical overall drive ratios as specified in clause 6.7 must be continuously engaged.  Deceleration modes must be conducted from the initial speed to the final speed.
7.9.6.                              During acceleration periods the drive train must be employed to regain the initial speed in the shortest possible time.
7.9.7.                              Notwithstanding the foregoing requirements, changes of vehicle direction essential to testing and negotiation of curved sections of track may be undertaken at constant vehicle speed.
7.9.8.                              If the vehicle's performance characteristics are such as to preclude it from maintaining the specified maximum interval between successive brake applications, the time interval may be increased to the minimum time required by the vehicle to achieve the specified initial speed and to maintain it for 10 seconds before each successive deceleration mode.
7.9.9.                              Vehicles must attain a sustained deceleration of not less than 3 m/s2 during the first deceleration mode.  Subsequent deceleration must be conducted employing a 'Control' force not less than that established during the first deceleration mode without regard to the actual deceleration achieved.
7.9.10.                          The Service Brake Fade Test must be followed immediately by the Service Brake Fade Effectiveness Check.
7.10.                                Service Brake Fade Effectiveness Check
           The vehicle must be accelerated over a distance not exceeding 1.6 km from the final speed attained at the conclusion of the deceleration mode of the Service Brake Fade Test to the initial speed specified in Table 1 (Item 10) and the test carried out in accordance with that Item.  The vehicle must be deemed to satisfy the