Document ID: chunk:federal_register_of_legislation:F2025C00107:reg:4:p1
Version: federal_register_of_legislation:F2025C00107
Segment Type: reg
Provision Reference: reg 4 (pt 1/26)
Character Range: 85056–89902

4                  S S S S                 15.0
                   W1 W1 W1 W1 or D D D D  20.0
                   D D D D                 27.0 (RFS)(PBS)

         Tyre Type "a":

 S Single tyre per wheel
 D Dual tyres per wheel
 W1 'Wide Single Tyre' (375 to 450 mm width)
 W2 'Wide Single Tyre' (over 450 mm width)
 RFS 'Road Friendly Suspension' (Note: for information only. Not part of this standard)
 PBS 'Performance Based Standards' approved vehicle as defined under Division 3 of the Heavy Vehicle (General) National Regulation (Note: for information only. Not part of this standard)

       TABLE 3

       CONSTANTS FOR DETERMINING AVERAGE DECELERATION
TEST                               CATEGORY        K 1   K 2
Service Brake Effectiveness Tests  MB, MC, MD, ME  1.0   130
LEG, NA, NB, NC                    1.0             115
Secondary Brake Tests              MB, MC, MD, ME  1.0   65
LEG, NA, NB, NC                    1.67            115
Fade Effectiveness Checks          MB, MC, MD, ME  1.25  130
LEG, NA, NB, NC                    1.25            115

       TABLE 4

       BRAKE CHAMBER RATED VOLUMES
Brake chamber type (nominal area of piston in square inches)  Stroke[6]  Rated Volume
(inches)                                                      (mm)       (ml)
Type 9                                                        ≥ 1.75     ≥ 44.4        409
                                                              ≤ 2.10     ≤ 53.4
Type 12                                                       ≥ 1.75     ≥ 44.4        491
                                                              ≤ 2.10     ≤ 53.4
Type 14                                                       ≥ 2.25     ≥ 57.1        655
                                                              ≤ 2.70     ≤ 68.6
Type 16                                                       ≥ 2.25     ≥ 57.1        753
                                                              ≤ 2.70     ≤ 68.6
Type 18                                                       ≥ 2.25     ≥ 57.1        819
                                                              ≤ 2.70     ≤ 68.6
Type 20                                                       ≥ 2.25     ≥ 57.1        884
                                                              ≤ 2.70     ≤ 68.6
Type 24                                                       ≥ 2.50     ≥ 63.5        1097
                                                              ≤ 3.20     ≤ 81.3
Type 30                                                       ≥ 2.50     ≥ 63.5        1458
                                                              ≤ 3.20     ≤ 81.3
Type 36                                                       ≥ 3.00     ≥ 76.2        2212
                                                              ≤ 3.60     ≤ 91.5

TABLE 5

ALTERNATIVE TESTS AND PROCEDURES FOR PARTICULAR VEHICLES

Item No.*   Tests and Procedures                              Vehicle Category    Sub-type            Initial Speed  (km/h)  Maximum                  Vehicle Mass  Transmission Condition(s)
                                                                                                                             'Stopping Distance' (m)
3A.         Service Brake Lightly Laden Effectiveness Test**  ME                  All                 ≥ 96                   85.4                     L             N and/or †
NB2         All                                               94.5                L
NC          'Prime Mover'                                     71.7                L + (up to 500 kg)
All Others  94.5
4A.         Lightly Laden Secondary Brake Test***             ME                  All                 ≥ 96                   156.2                    L             N and/or †
NB2         All                                               174.7               L
NC          All                                               L + (up to 500 kg)
6A.         Service Brake Laden Effectiveness Test**          ME                  All                 ≥ 96                   85.4                     M             N and/or †
NB2         All                                               94.5
NC          'Prime Mover'                                     76.2
All Others  94.5
7A.         Laden Secondary Brake Test***                     ME                  All                 ≥ 96                   156.2                    M             N and/or †
NB2, NC     All                                               174.7

   * numeric part of Item No. also corresponds to sub-clause number of clause 8
    ** applicability is limited to vehicles incorporating a compressed air 'Brake System' and for which the service brake 'Control' solely modulates stored energy
    *** applicability is limited to vehicles incorporating a compressed air