Document ID: chunk:federal_register_of_legislation:F2007C00493:front:0:p13
Version: federal_register_of_legislation:F2007C00493
Segment Type: other
Provision Reference: 
Character Range: 36375–39411

when the pressure in the least favoured brake actuator reaches 0.65 'E' (420 kPa).
16.9.                                With an initial service brake application level of 1.0 'E' (650 kPa) the brake release time must be taken from when the pressure level, measured between the control valve and the orifice, initially drops to the greater of when the pressure in the least favoured brake actuator reaches 0.05 'E' (35 kPa) or when the friction materials cease to contact each other.
16.10.                            The brake control valve must be of a configuration such that;
16.10.1.                      it permits energy to flow from the storage reservoir to the orifice (O) when in the "ON" position and from the orifice to waste when in the "OFF" position; and,
16.10.2.                      it must not allow additional energy to flow into the test rig 'Control Line' by way of its own 'Control Signal' ; and
16.10.3.                      it must be designed so that the manner of its operation has no effect on the output response of the test rig; and
16.10.4.                      it may be arranged to provide a modulated test rig output signal for other brake development purposes which will be rendered inoperative for the purpose of measuring trailer 'Brake System' response in accordance with clause 16.3.

17.                                      SERVICE BRAKE EFFECTIVENESS CALCULATION
17.1.                                In the case of an 'Axle Group' fitted with a 'Brake Reactive Suspension' the distribution of braking effort amongst the 'Axles' in an 'Axle Group' must be in the range of 'Skid Limit' values determined for the suspension in accordance with clause 22.4.
17.2.                                In the case of 'Dog Trailers' at least one front 'Axle' must have a higher friction utilisation than that of at least one rear 'Axle' at decelerations greater than:
         (a) 0.3 g in the case of 2 'Axle' 'Dog Trailers',
         (b) 0.15 g in the case of 'Dog Trailers' with 3 or more 'Axles'.
17.2.1.                          In the case of two-'Axle' 'Dog Trailers'-the friction utilisation factors may be calculated according to
Friction Utilisation =   Tangetial Force at Wheel
Factor                   Dynamic Load at Wheel

         so:

         and:

         T1  Tangential Force at front wheel (N)
         T2  Tangential Force at rear wheel (N)
         F1   Friction utilisation factor for front wheel
         F2   Friction utilisation factor for rear wheel.
         P 1  front 'Axle' static load (N)
         P 2  rear 'Axle' static load (N)
         P total static 'Axle Load' (N)
         h height of trailer and load centre of mass (m)
         L 'Wheel Base' (m)
         z deceleration, as a proportion of acceleration due to gravity.
17.2.2.                          No friction utilisation factor (F) must exceed 0.7 at z = 0.45 (a friction utilisation factor of greater than 0.7 is taken as to mean that wheel lock would have occurred in the physical test otherwise required by