Document ID: chunk:federal_register_of_legislation:F2018C00339:body:0:p15
Version: federal_register_of_legislation:F2018C00339
Segment Type: other
Provision Reference: 
Character Range: 43636–46968

when in the "OFF" position; and,
         15.9.2.                           it must not allow additional energy to flow into the test rig 'Control Line' by way of its own 'Control Signal'; and
         15.9.3.                           it must be designed so that the manner of its operation has no effect on the output response of the test rig; and
         15.9.4.                           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 15.3.
16.                                      SERVICE BRAKE EFFECTIVENESS CALCULATION
16.1.                                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 21.4.
16.2.                                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'.

         16.2.1.                           In the case of two-'Axle' 'Dog Trailers'-the friction utilisation factors may be calculated according to

                 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.

         16.2.2.                           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 part 10.
         16.3.                                 The  'Established Retardation Coefficient' of the trailer must be calculated using the formula in clause 16.3.2 at levels of input 'Control Signal' starting no higher than 0.2 'E' and increasing in increments of not more than 0.2 'E' until an  'Established Retardation Coefficient' of not less than 0.45 is achieved.
         16.3.1.                           All calculated 'Established Retardation Coefficient' values must lie between the upper and lower boundaries of Figure 1 or Figure 2, as specified in clause 6.5.
         16.3.2.                          The  'Established Retardation Coefficient' must be calculated by

            where:

            e  is the value of   'E'

            C is the ratio of output Signal Level to 'Control Signal' strength for the 'Control System' for the 'Axle' concerned

            T  is the 'Brakes' output torque per unit input signal to the