[F1 ANNEX VII U.K. Cases in which Type I and/or II (or IIA) or III tests do not have to be carried out on a vehicle submitted for type-approval

Textual Amendments

F1 Substituted by Commission Directive 98/12/EC of 27 January 1998 adapting to technical progress Council Directive 71/320/EEC on the approximation of the laws of the Member States relating to the braking devices of certain categories of motor vehicles and their trailers (Text with EEA relevance).

Appendix 1 Alternative procedures for Type I and Type III tests for trailer brakes

3. TEST METHODS U.K.

3.1. Track tests U.K.

3.1.1. The brake performance tests should preferably be carried out on a single axle only. U.K.

3.1.2. The results of tests on a combination of axles may be used accordance with point 1.1 provided that each axle contributes equal braking energy input during the drag and hot brake tests. U.K.

3.1.2.1. This is ensured if the following are identical for each axle: brake geometry (Figure 2), lining, wheel mounting, tyres, actuation and pressure distribution in the actuators. U.K.

3.1.2.2. The result recorded for a combination of axles will be the average value for these axles. U.K.

3.1.3. The axle(s) should preferably be loaded with the maximum static axle load, though this is not essential provided that due allowance is made during the tests for the difference in rolling resistance caused by a different load on the test axle(s). U.K.

3.1.4. Allowance shall be made for the effect of the increased rolling resistance resulting from a combination of vehicles being used to carry out the tests. U.K.

3.1.5. The initial speed of the test is prescribed. The final speed shall be calculated by the following formula: U.K.

where

v ₁

=

initial speed (km/h)

v ₂

=

final speed (km/h)

v ₀

=

mass of the towing vehicle (kg) under test conditions

P ₁

=

mass of the trailer borne by the non-braked axle(s) (kg)

P ₂

=

mass of the trailer borne by the braked axle(s) (kg).]