Document ID: chunk:federal_register_of_legislation:F2006L03060:body:0:p9
Version: federal_register_of_legislation:F2006L03060
Segment Type: other
Provision Reference: 
Character Range: 24807–27780

course greater than 300 millimetres.

38.3.3.                          Service Brake Effectiveness

38.3.3.1.                    Each 'Unique' trailer 'Service Brake System' shall be either tested in accordance with clause 38.3.2 (general test conditions) and clause 38.3.3.2 (service brake effectiveness test) or be shown by calculation, based on data for approved components, as detailed in clause 38.4.1 (service brake effectiveness calculation), to meet the requirements of clause 38.2.2.6 (refers to Figure 1).

38.3.3.2.                    Service Brake Effectiveness Test.

38.3.3.2.1.              The initial speed at the point where trailer braking commences shall be:

            (1)  for trailers having a 'Aggregate Trailer Mass' less than 45 tonnes and not being restricted by design speed limitations, 58 to 64 km/h.

            (2)  for trailers having a 'Aggregate Trailer Mass' greater than 45 tonnes, or special trailers having a design speed less than 58 km/h, not less than the 'Manufacturer's' nominated design speed.

38.3.3.2.2.              The trailer shall be laden to 'LTM' and braked to a stop from initial speed starting with a 'Control Signal' of 0.2 'E' and in increasing increments of not greater than 0.2 'E' for subsequent stops until an 'Established Retardation Co-efficient' of not less than 0.45 is achieved.

38.3.3.2.3.              In the case of a compressed air 'Brake System' the 'Control Signal', applied to the 'Control Line' at the front of the trailer, shall reach 65 per cent of the final value in less than 0.22 second.  Where the available 'Control Signal' is slower than 0.22 second the additional time will be allowed for entirely in clause 38.3.3.2.5 by adjusting the K1 or K3 term. The response of a vehicle control system should be determined by using an 800 millilitres vessel to simulate the trailer, with the pressure being measured at the point most remote from that of air entry.

38.3.3.2.4.              Either stopping distance or time from the point where the trailer brake control commences actuation from the off position, to the point where the trailer comes to a stop, may be used to calculate the 'ERC' according to the equations in clause 38.3.3.2.5. A calibrated decelerometer and chart recorder may also be used.

38.3.3.2.5.              The 'Service Brake System' Established Retardation Coefficient shall be determined according to the following as required:

where:

V is the initial speed  km/h

S is the 'Stopping Distance' metres

T is the 'Stopping Time' seconds

'Total Combination Mass' tonnes

'Total Trailer Axle Load' tonnes

K1 is the time delay constant referred to in clause 38.3.1.3 and should be set at 0.09 for air 'Brake Systems' unless it is shown that an alternative value should be used.

K3 is the effective time delay of 0.32 seconds referred to in clause 38.3.1.3 for air 'Brake System's' and this value should be used unless a more appropriate value can