Document ID: chunk:federal_register_of_legislation:F2025C00113:reg:4:p1
Version: federal_register_of_legislation:F2025C00113
Segment Type: reg
Provision Reference: reg 4 (pt 1/10)
Character Range: 70345–74129

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 2

       BRAKE CHAMBER RATED VOLUMES

Brake chamber type (nominal area of piston in square inches)  Stroke[1]  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

FIGURE 1

'GTM' (LADEN)

SERVICE BRAKE EFFECTIVENESS

FIGURE 21

'UTM' (UNLADEN)

SERVICE BREAK EFFECTIVENESS

Notes
        1.                      Only applicable to trailers not equipped with an 'Anti-lock System', but fitted with a 'Variable Proportioning Brake System'.
        2.                      The 'Upper Boundary' may be increased by up to 40 per cent, where permitted by clause 7.1.7.3 of this standard.

USE OF TRAILER COMPRESSED AIR BRAKE PNEUMATIC TEST RIG

FIGURE 3 – CALIBRATION OF PNEUMATIC TEST RIG

FIGURE 4 – TESTING THE TRAILER
NOMENCLATURE FOR FIGURES 3 AND 4
A = supply connection with single check valve and regulator set at 650 kPa
CF  = trailer brake actuator
L  = coupling hose, 13 mm nominal bore and 2.5 metres long
M  = pressure gauge
O  = orifice (see clause 16.4)
R1  = reservoir of not less than 30,000 ml
R2  = calibrating vessel of 800 ± 5 ml
RA  = shut off valve
TA  = coupling head - supply (emergency)
TC  = coupling head - control (service)
TOA  = transducer point for timing inlet to brake actuation time
TOR  = transducer point for timing inlet to brake release time
T1  = transducer point at end of R2 vessel for calibration
T2 = transducer point at end of R2 vessel for testing rear tow coupling of trailer
T3  = transducer point for testing trailer brake response
V  = brake control valve

FIGURE 5 – EXAMPLE ELECTRIC 'CONTROL LINE' TEST RIG

NOMENCLATURE FOR FIGURE