Document ID: chunk:federal_register_of_legislation:F2006L03061:body:0:p19
Version: federal_register_of_legislation:F2006L03061
Segment Type: other
Provision Reference: 
Character Range: 52453–55338

physical test otherwise required by clause 38.3.3.2.2 (service brake effectiveness).

38.4.1.3.3.              For 'Dog Trailers' with more than two 'Axles' where it is not practical to calculate the friction utilization factors, a skid test on a loose surface at 'LTM' to ensure that at least one front 'Axle' skids before a rear 'Axle' is sufficient evidence.

38.4.1.4.                    The braking ratio        (Total brake force)
 ('Total Trailer Axle Load')

of the trailer for various levels of input 'Control Signal' as determined on the basis of data provided under clause 38.4.6.1 for the 'Control System' and clause 38.4.6.2 for the 'Foundation Brakes', shall lie between the upper and lower bounds of Figure 1. e.g.
  e (C1T1 + C2T2 + … etc
     total brake force at e   =        R          R                .
         'Total Trailer Axle Load'  (P1 + P2 + … etc

where :

e is values of 'E' in the range 0.2 - 1.0

C is the ratio of output to input signal strength for the 'Control System' for the 'Axle' concerned

T is the 'Brakes' output torque per unit input signal to the 'Brakes' actuator from the 'Control System' for the 'Axle' concerned

R is the rolling radius of the tyre on the wheel

P is the static load on the 'Axle' concerned 1,2,etc. are subscripts referring to a particular 'Axle'.

38.4.1.4.1.              The calculated 'ERC' corresponding to a 'Control Signal' of 1.0 'E' shall be not less than 0.45.

38.4.1.5.                    The provisions of clause 38.3.3.5 (computer simulation allowed) also apply to clause 38.4.1 (service effectiveness calculation).

38.4.2.                          Service Brake Fade Calculation

The 'Service Brake System' shall be considered to have sufficient brake fade resistance to meet the requirements of this Rule if the fade resistance of the individual axles rated according to the dynamometer test in clause 38.3.8 and clause 38.3.10, or the road fade test in clause 38.3.2 and clause 38.3.4 is greater than the requirement of clause 38.2.2.5 (distribution of effort).

38.4.3.                          'Emergency Brake System' Calculation

The 'ERC' for the 'Emergency Brake System' shall be determined by computing the total braking force at the wheels to which emergency brakes are fitted and dividing by the 'Total Trailer Axle Load'

38.4.3.1.                    The braking force at each 'Axle' shall be calculated according to

Where

F is the tangential force at the braked wheels on the 'Axle' concerned

A is the input to the emergency brakes actuator

T is the ratio of output torque to input signal for the emergency brakes

R is the rolling radius of the tyre fitted to the wheel.

In most cases this will be the same as for the 'Foundation Brakes'.

38.4.3.1.1.              Where the actuating force is dependent on the stroke, as in the case of spring brakes, the force