Council Directive of 26 July 1971 on the approximation of the laws of the Member States relating to the braking devices of certain categories of motor vehicles and of their trailers (71/320/EEC) (repealed)

[F1 ANNEX XIV U.K. Alternative procedure for testing trailer anti-lock braking system (ABS)

Textual Amendments

F1 Inserted 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).

1. GENERAL U.K.

1.1. Testing of a trailer in accordance with Annex X of this Directive may be waived at the time of type-approval of the trailer provided that the anti-lock braking system (ABS) complies with the requirements of this Annex. U.K.

2. INFORMATION DOCUMENT U.K.

2.1. The manufacturer of the ABS shall supply to the technical service an information document of the system(s) requiring approval. This document shall contain at least the following information: U.K.

2.1.1. General U.K.

2.1.1.1. Name of manufacturer U.K.

2.1.1.2. System name U.K.

2.1.1.3. System variations U.K.

2.1.1.4. System configurations (e. g. 2S/1M, 2S/2M etc.) U.K.

2.1.1.5. Explanation of the basic function and/or philosophy of the system U.K.

2.1.2. Applications U.K.

2.1.2.1. List of trailer types and ABS configurations for which approval is required. U.K.

2.1.2.2. Schematic diagrams of the system configurations installed on the trailers defined in point 2.1.2.1 with consideration given to the following parameters: U.K.

• Sensor locations

• Modulator locations

• Lift axles

• Steering axles

• Tube: type — bore size(s) and lengths

2.1.2.3. Relationship of tyre circumference to the resolution of the exciter, including tolerances. U.K.

2.1.2.4. Tolerance on tyre circumference between one axle and another fitted with the same exciter. U.K.

2.1.2.5. Scope of application with respect to suspension type, e. g. balanced mechanical etc. with reference to the manufacturer and model/type. U.K.

2.1.2.6. Recommendations on differential brake input torque (if any) in relation to the ABS configuration and trailer bogie. U.K.

2.1.2.7. Test data shall be supplied to enable the worst-case axle loading to be determined for the purpose of the energy consumption test. This shall be determined by carrying out a series of tests with incremental axle loads. Operating within the axle load range of ±  10 000  N of the maximum energy consumption value, a minimum of five results within this range is required. Additional results shall be supplied to illustrate the trend outside of the maximum consumption range. Based on the above data the test trailer(s) shall be loaded to represent the determined worst-case. U.K.

2.1.2.8. Additional information (if applicable) to the application of the anti-lock braking system. U.K.

2.1.3. Component description U.K.

2.1.3.1. Sensor(s) U.K.

• Function

• Identification (e.g. part number(s))

2.1.3.2. Controller(s) U.K.

• General description and function

• Identification (e. g. part number(s))

• Failure modes as defined in point 4.1 of Annex X

• Additional features (e. g. retarder control, automatic configuration, variable parameters, diagnostics).

2.1.3.3. Modulator(s) U.K.

• General description and function

• Identification (e. g. part number(s))

• Limitations (e. g. maximum delivery volume to be controlled)

2.1.3.4. Electrical Equipment U.K.

• Circuit diagram(s)

• Powering methods

• Warning lamp sequence

2.1.3.5. Pneumatic Circuits U.K.

• Braking schematics covering the ABS configurations as applied to the trailer types defined in point 2.1.2.1

• Limitations on pipe/tube sizes and associated lengths that have an effect on system performance (e. g. between modulator and brake chamber)

2.1.4. Electro-magnetic compatibility (EMC) U.K.

2.1.4.1. Compliance with point 4.6. of Annex X concerning EMC in terms of susceptibility and emissions will be fulfilled on submission of a technical file or approval to a recognised standard (1) . The file or approval document shall include details of the test method, configurations(s) tested and results obtained. U.K.

3. DEFINITION OF TEST VEHICLE(S) U.K.

3.1. Based on the information supplied in the information document, in particular the trailer applications defined in point 2.1.2.1, the technical service shall carry out tests on representative trailers having up to three axles and equipped with the respective anti-lock braking system/configuration requiring approval — as defined in point 2.1.2.1 of this Annex. Additionally, when selecting the trailers for evaluation consideration shall also be given to the parameters defined in the following paragraphs. U.K.

3.1.1. Suspension type U.K.

The method of evaluating the performance of the anti-lock braking system relative to the suspension type will be selected in the following way:

Semi-trailers: For each suspension group e. g. balanced mechanical etc. a representative trailer shall be evaluated.

Full trailers: Evaluation to be carried out on a representative trailer equipped with any one suspension type.

3.1.2. Wheelbase U.K.

For semi-trailers the wheelbase shall not be a limiting factor but for full trailers the shortest wheelbase shall be evaluated.

3.1.3. Brake type U.K.

Approval shall be limited to cam brakes but should other brake types become available then comparative testing may be required.

3.1.4. Load sensing device U.K.

The utilisation of adhesion shall be determined with the load sensing device set to the laden and unladen conditions. To ensure full cycling of the ABS the load sensing device may be adjusted so that the static brake chamber pressure is 1 bar greater than the maximum ABS cycling pressure.

3.1.5. Brake actuation U.K.

Differentials in the level of actuation shall be recorded for evaluation during the tests to determine the utilisation of adhesion. Results obtained from tests for one trailer may be applied to other trailers of the same type.

3.1.6. Energy consumption U.K.

The trailer(s) selected to evaluate the ABS shall be such that it is possible to load the axles to the worst case load as defined in point 2.1.2.7.

3.2. For each type of trailer under test, documentation showing brake compatibility as defined by the Appendix to Annex II (diagrams 2 and 4) shall be made available to demonstrate conformity. U.K.

3.3. For the purpose of the approval semi-trailers and centre-axle trailers shall be deemed to be of the same vehicle-type. U.K.

4. TEST SCHEDULE U.K.

4.1. The following tests shall be conducted by the technical service on the vehicle(s) defined in point 3 of this annex for each ABS configuration — see point 2.1.4 — taking into consideration the application list defined in point 2.1.2.1. However, worst-case cross referencing may eliminate certain tests. If worst-case testing is actually used, this should be stated in the test report. U.K.

4.1.1. Utilisation of adhesion U.K.

Tests shall be carried out according to the procedure defined in point 6.2 of Annex X for each AS configuration and trailer type, as defined in the information document (point 2.1.2.1).

4.1.2. Energy consumption U.K.

4.1.2.1. Axle loading — The axle loadings of the trailer being evaluated shall be such as to represent the worst-case condition with respect to energy consumption (point 2.1.2.7). U.K.

4.1.2.2. Energy consumption test — Test shall be carried out according to the procedure defined in point 6 of annex X for each ABS configuration. U.K.

4.1.2.3. To enable trailers submitted for approval to be checked for conformity to the anti-lock energy consumption requirements (see point 6.1, Annex X), the following checks shall be carried out: U.K.

4.1.2.3.1. Prior to the commencement of the energy consumption test (point 4.1.2.2) the relationship (R ₁ ) of brake chamber push rod travel (s _T ) against brake lever length (l _T ) shall be determined for a brake chamber pressure of 6,5 bar. U.K.

Example: l _T  = 130mm, s _T  = 22 mm,

4.1.2.3.2. With the load sensing device set to the laden condition and the initial energy level set according to point 6.1.2 to Annex X the energy storage device(s) shall be isolated from further supply of air. The brakes shall be applied with a control pressure of 6,5 bar at the coupling head and then released. Further applications shall be made until the pressure in the brake chambers is the same as that obtained after following the test procedure defined in points 4.1.2.1 and 4.1.2.2. The number of equivalent brake applications (n _e ) shall be noted. U.K.

4.1.3. Split-friction test Where an anti-lock braking system is to be defined as a category A system then all such ABS configurations shall be subject to he performance requirements of point 6.3.2 of Annex X. U.K.

4.1.4. Low and high speed performance U.K.

4.1.4.1. With the trailer set as for the utilisation of adhesion evaluation, verification of the low and high speed performance shall be carried out according to 6.3.1 of Annex X. U.K.

4.1.4.2. Where a tolerance exists between the number of exciter teeth and tyre circumference, functional checks shall be carried out at the extremes of tolerance in accordance with point 6.3 of Annex X. This may be achieved by utilising different tyre sizes or by producing special exciters to simulate the frequency extremes. U.K.

4.1.5. Additional checks U.K.

The following additional checks shall be carried out with the towing vehicle unbraked and the trailer unladen:

4.1.5.1. When an axle/bogie passes from a high-adhesion surface (k _H ) to a low-adhesion surface (k _L ) where k _H ≥ 0,5 and k _H /k _L ≥ 2 with a control pressure at the coupling head of 6,5 bar, the directly controlled wheels shall not lock. The running speed and the instant of applying the trailer brakes is so calculated that with the anti-lock braking system fully cycling on the high-adhesion surface, the passage from one surface to the other being made at approximately 80 km/h and 40 km/h. U.K.

4.1.5.2. When a trailer passes from a low-adhesion surface (k _L ) to a high-adhesion surface (k _H ) where k _H ≥ 0,5 and k _H /k _L ≥ 2, with a control pressure at the coupling head of 6,5 bar, the pressure in the brake chambers shall rise to an appropriate high value within a reasonable time and the trailer shall not deviate form its initial course. The running speed and the instant of applying the brake is so calculated that, with the anti-lock braking system fully cycling on the low adhesion surface, the passage from one surface to the other occurs at approximately 50 km/h. U.K.

4.1.6. Failure mode simulation U.K.

A check shall be made on a test vehicle or simulation rig with respect to the external wiring and compliance to point 4.1 of Annex X.

5. APPROVAL REPORT U.K.

5.1. An approval report shall be produced, the content of which is defined in Appendix 1 to this Annex. U.K.

6. VERIFICATION U.K.

6.1. Verification of components and installation U.K.

The specification of the ABS installed on the trailer to be type approved shall be verified by satisfying each of the following criteria:

	Item	Criteria
6.1.1.	(a) Sensor(s)	No change allowed
	(b) Controller(s)	No change allowed
	(c) Modulator(s)	No change allowed
6.1.2.	Tube size(s) and lengths
	(a) Reservoir supply to modulator(s)
	Minimum inside diameter	May be increased
	Maximum overall length	May be reduced
	(b) Modulator delivery to brake chambers
	Inside diameter	No change allowed
	Maximum overall length	May be reduced
6.1.3.	Warning signal sequence	No change allowed
6.1.4.	Differentials in brake input torque within a bogie	Only approved differentials (if any) permitted
6.1.5.	For other limitations refer to section 4 of the test report as described in Appendix 1 to this Annex	Installation to be within the scope of the limitations defined No deviation allowed

6.2. Verification of reservoir capacity U.K.

6.2.1. As the range of braking systems and auxiliary equipment used on a trailer is diverse it is not possible to have a table of recommended reservoir capacities. To verify that adequate storage capacity is installed testing may be conducted according to point 6 of Annex X or the procedure defined below should be followed: U.K.

6.2.1.1. Brake adjustment shall be such as to represent the conditions of the test trailer(s) on which the anti-lock braking system(s) was approved. On the trailer to be approved the brake chamber push rod travel at a brake chamber pressure of 6,5 bar shall be calculated and set according to the following formula: U.K.

Note: U.K.

To provide a level of security with respect to the energy storage capacity a safety factor of + 20 % has been included. U.K.

Example:

l _v

=

150 mm, R _l = 0,169

S _v

=

150 × 1,2 × 0,169 = 30,4 mm

6.2.1.2. With the brakes adjusted according to point 6.2.1.1 — when a trailer is equipped with automatic wear adjustment devices the automatic adjustment mechanism shall be disabled for the purpose of the test or an equivalent manual adjusting device installed — and the load sensing device set to the laden condition and the initial energy level set according to point 6.1.2 of Annex X, the energy storage device(s) shall be isolated from further supply. The brakes shall be applied with a control pressure of 6,5 bar at the coupling head and then fully released. Further brake applications/releases shall be made up to the number n _e determined from the test conducted in accordance with point 4.1.2.3.2. During this application, the pressure in the operating circuit shall be sufficient to provide a total braking force at the periphery of the wheels equal to not less than 22,5 % of the maximum stationary wheel load and without causing automatic application of any braking system not being under the control of the anti-lock braking system. U.K.

6.3. Verification of function U.K.

6.3.1. This shall be limited to a dynamic functional check of the anti-lock braking system. To ensure full cycling it may be necessary to adjust the load sensing device or utilise a surface having a low tyre-to-road adhesion. U.K.

Appendix 1 Trailer anti-lock braking system approval report

Approval Report No: … U.K.

1. Identification U.K.

1.1. Manufacturer of the anti-lock braking system (name and address): U.K.

1.2. System name/model: U.K.

2. System(s) and installation(s) approved U.K.

2.1. ABS configuration(s) approved (e.g. 2S/1M, 2S/2M etc.): U.K.

2.2. Range of application (type of trailer and number of axles): U.K.

2.3. Methods of powering: U.K.

ISO 7638, ISO 1185, etc.

2.4. Identification of approved sensor(s), controller(s) and modulator(s): U.K.

2.5. Energy consumption — equivalent number of static brake applications and the ratio of actuator stroke against brake lever length: U.K.

2.6. Additional features e.g. retarder control, lift axle configuration etc: U.K.

3. Test data and results U.K.

3.1. Test vehicle data: U.K.

3.2. Test surface information: U.K.

3.3. Test results: U.K.

3.3.1. Utilisation of adhesion: U.K.

3.3.2. Energy consumption: U.K.

3.3.3. Split-friction test: U.K.

3.3.4. Low speed performance: U.K.

3.3.5. High speed performance: U.K.

3.3.6. Additional checks: U.K.

3.3.6.1. Transition from high to low-adhesion surfaces: U.K.

3.3.6.2. Transition from low to high-adhesion surfaces: U.K.

3.3.7. Failure mode simulation: U.K.

3.3.8. Functional checks of optional power connections: U.K.

3.3.9. Electro-magnetic compatibility: U.K.

4. Limitations of installation U.K.

4.1. Relationship of tyre circumference to the resolution of the exciter: U.K.

4.2. Tolerance on tyre circumference between one axle and another fitted with the same exciter: U.K.

4.3. Suspension type: U.K.

4.4. Differential(s) in brake input torque within a trailer bogie: U.K.

4.5. Wheelbase of full trailer: U.K.

4.6. Brake type: U.K.

4.7. Tube sizes and lengths: U.K.

4.8. Load sensing device application: U.K.

4.9. Warning lamp sequence: U.K.

4.10. Other recommendations/limitations (e.g. locations of sensors, modulator(s), lift axle(s), steering axle(s)): U.K.

5. Date of test U.K.

The anti-lock braking system described above complies with the requirements of Annex XIV of Directive 71/320/EEC as last amended by Directive 98/12/EC.

Technical service/approval authority (2) conducting the test:

Approval Authority if different from the Technical Service:

Attachment:

(Manufacturer's information document).

Appendix 2 Symbols and definitions

Symbol	Notes
s T	Brake chamber push rod travel of reference test trailer in mm
l T	Brake lever length of reference test trailer in mm
R 1	Ratio of s T /l T
n e	Number of equivalent static brake applications
l v	Brake lever length of trailer to be approved in mm
s v	Brake chamber push rod travel of trailer to be approved in mm]

(1)

[F1 This shall be demonstrated by compliance with the technical requirements laid down in Council Directive 72/245/EEC ( OJ L 152, 6.7.1972, p. 15 ), as last amended by Directive 95/54/EC ( OJ L 266, 8.11.1995, p. 1 ).

(2)

Delete as appropriate.]

Textual Amendments

F1 Inserted 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).