COMMISSION DIRECTIVE of 25 July 1975 adapting to technical progress Council Directive No 71/320/EEC 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 (75/524/EEC)

THE COMMISSION OF THE EUROPEAN COMMUNITIES

Having regard to the Treaty establishing the European Economic Community;

Having regard to Council Directive No 70/156/EEC (1) of 6 February 1970 on the approximation of the laws of the Member States relating to the type approval of motor vehicles and their trailers, as amended by the Act (2) annexed to the Treaty concerning the accession of the new Member States to the EEC and EAEC signed in Brussels on 22 January 1972, and in particular to Articles 11, 12 and 13 thereof;

Having regard to Council Directive No 71/320/EEC (3) 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, as amended by the Act (4) annexed to the Treaty concerning the accession of new Member States to the EEC and EAEC signed in Brussels on 22 January 1972, and in particular to Article 5 thereof;

Whereas in Directive No 74/132/EEC (5) of 11 February 1974, the Commission adopted provisions adapting to technical progress the Council Directive of 26 July 1971 mentioned above ; whereas these provisions solely relate to braking-pressure distributors and not, therefore, to conditions of compatibility ; whereas in order to avoid certain combinations of vehicles (drawing and drawn vehicles) which are not likely to be able to provide every guarantee of safety from the point of view of braking, these provisions should be subject to conditions of compatibility between drawing and drawn vehicles ; whereas technical progress now enables provisions on compatibility not only to be adopted but also enables them to be correctly implemented;

Whereas the laying down of provisions on the conditions of compatibility necessitates amendments to the provisions relating to the device which enables the braking pressure to be matched to the load and which are set out in the Annex to Council Directive No 74/132/EEC;

Whereas the provisions relating to wheel anti-locking systems will be adopted at a later date ; whereas, until the entry into force of these provisions, it is consequently necessary to subject vehicles of all categories, with the exception of those in categories O1 and O2, to the provisions of this Directive, even if they are fitted with wheel anti-locking devices;

Whereas this Directive provides for an earlier date of entry into force of the amended provisions and whereas it is therefore no longer justified to retain the provisions of paragraphs 2 and 3 of Article 2 of Commission Directive No 74/132/EEC;

Whereas the provisions of this Directive are in accordance with the Opinion of the Committee on the Adaptation to Technical Progress of the Directives aimed at the Removal of Technical Barriers to Trade in the Motor-Vehicle Sector, (1)OJ No L 42, 23.2.1970, p. 1. (2)OJ No L 73, 27.3.1972, pp. 115 and 157. (3)OJ No L 202, 6.9.1971, p. 37. (4)OJ No L 73, 27.3.1972, pp. 118, 119 and 158. (5)OJ No L 74, 19.3.1974, p. 7.

HAS ADOPTED THIS DIRECTIVE:

Article 1

Paragraphs 2 and 3 of Article 2 of Commission Directive No 74/132/EEC of 11 February 1974 adapting to technical progress the 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 are rescinded with effect from the date of adoption of this Directive.

Article 2

1. Annexes I, II and IX to Council Directive No 71/320/EEC 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 their trailers, as amended by Commission Directive No 74/132/EEC of 11 February 1974, are amended as shown in the Annex to this Directive.

2. Pending the entry into force of special requirements on wheel anti-locking systems, vehicles of categories M1, M2, M3, N1, N2, N3, O3 and O4 which are fitted with these systems are submitted to the prescriptions of this Directive.

Article 3

1. With effect from 1 January 1976 no Member State may on grounds relating to the braking devices: - refuse in respect of a type of vehicle to grant EEC type-approval, to issue the document referred to in the last indent of Article 10 (1) of Council Directive No 70/156/EEC of 6 February 1970, or to grant national type-approval ; or

- prohibit the entry into service of vehicles, if the braking devices of such type of vehicle or of such vehicles comply with the provisions of Council Directive No 71/320/EEC of 26 July 1971, as last amended by this Directive.

2. With effect from 1 October 1976 Member States: - may no longer issue the document referred to in the last indent of Article 10 (1) of Council Directive No 70/156/EEC of 6 February 1970 in respect of a type of vehicle of which the braking devices do not comply with the provisions of Council Directive No 71/320/EEC of 26 July 1971 as last amended by this Directive;

- may refuse to grant national type-approval in respect of a type of vehicle of which the braking devices do not comply with the provisions of Council Directive No 71/320/EEC of 26 July 1971 as last amended by this Directive.

3. With effect from 1 October 1976 Member States may prohibit the entry into service of vehicles of which the braking devices do not comply with the provisions of Council Directive No 71/320/EEC of 26 July 1971 as last amended by this Directive.

4. The Member States shall adopt and publish the provisions necessary in order to comply with this Directive not later than 1 January 1976 and shall forthwith inform the Commission thereof.

Article 4

This Directive is addressed to the Member States.

Done at Brussels, 25 July 1975.

For the Commission

The President

François-Xavier ORTOLI

ANNEX Amendments to the Annexes to Council Directive No 71/320/EEC of 26 July 1971

ANNEX I : DEFINITIONS, REQUIREMENTS, CONSTRUCTION AND FITTING

Item 2.2.1.12.2. shall read : The failure of a part of a hydraulic transmission system shall be signalled to the driver by a device comprising a red tell-tale lamp lighting up not later than on actuation of the control. However a device comprising a red tell-tale lamp lighting up when the level of the fluid in its reservoirs falls below the value specified by the manufacturer is admissible. The tell-tale lamp shall be visible even by daylight ; the satisfactory condition of the lamp must be easily verifiable by the driver. The failure of a component of the device shall not entail total loss of effectiveness of the braking device in question.

ANNEX II : BRAKING TEST AND PERFORMANCE OF BRAKING DEVICES

Item 1.1.3.4. shall read : Without prejudice to the requirements contained in item 1.1.4.2 below, the road shall possess a surface having good adhesion.

After item 1.1.4.1 add item

1.1.4.2. The behaviour of vehicles in categories M1, M2, M3, N1, N2, N3, O3 and O4 on a road surface having reduced adhesion shall fulfil the conditions laid down in the Appendix.

Appendix (See 1.1.4.2) : DISTRIBUTION OF BRAKING EFFORT AMONG VEHICLE AXLES

1. GENERAL REQUIREMENTS

Vehicles of categories M1, M2, M3, N1, N2, N3, O3 and O4 shall fulfil the conditions of the present Appendix. If a special device is used, this must operate automatically.

2. SYMBOLS

i = axle index (i = 1, front axle ; i = 2, second axle ; etc.)

Pi = normal reaction of road surface on axle i under static conditions

Ni = normal reaction of road surface on axle i under braking

Ti = force exerted by the brakes on axle i under normal braking conditions on the road

fi = Ti/Ni, adhesion used by axle i (1)

J = deceleration of vehicle

g = acceleration due to gravity g = 10 m/s2 (1)Adhesion curves used by each axle means curves showing the adhesion used by axle i plotted against the vehicle braking rate under the specified load conditions.

z = braking rate of vehicle = J/g (1)

P = weight of vehicle

h = height of centre of gravity

E = wheelbase

k = theoretical coefficient of adhesion between tyre and road

Kc = correction factor - semi-trailer laden

Kv = correction factor - semi-trailer unladen

TM = sum of braking forces at the periphery of wheels of drawing vehicles for trailers or semi-trailers

PM = total normal static reaction between road surface and wheels of drawing vehicles for trailer or semi-trailer as referred to in items 3.1.4 and 3.1.5 respectively

Pm = pressure at coupling head of service line

TR = sum of braking forces at periphery of all wheels of trailer or semi-trailer

PR = total normal static reaction of road surface on wheels of trailer or semi-trailer

PRmax = value of PR at maximum weight of semi-trailer

ER = distance between king-pin and centre of axle or axles of semi-trailer

hR = height above ground of centre of gravity of semi-trailer

3. REQUIREMENTS FOR MOTOR VEHICLES 3.1. Two axle vehicles. 3.1.1. (2) For all categories of vehicle for k values between 0 72 and 0 78: >PIC FILE= "T0007663">

For all states of load of the vehicle, the adhesion utilization curve of the front axle shall be situated above that for the rear axle: - for all braking rates of between 0 715 and 0 78 in the case of vehicles of category M1.

However, for vehicles of this category over the range of z values, between 0 73 and 0 745, an inversion of the adhesion utilization curves is permitted provided that the adhesion utilization curve of the rear axle does not exceed by more than 0 705 the line defined by the formula k = z (line of ideal adhesion utilization - see diagram 1 A);

- for all braking rates of between 0 715 and 0 730, in the case of vehicles of other categories. This condition is also considered satisfied if the adhesion utilization curves for each axle of between 0 715 and 0 730 are situated between two parallels to the line of ideal adhesion utilization given by the equation k = z ± 0 708 as shown in diagram 1 B and the adhesion utilization curve for the rear axle for braking >PIC FILE= "T0007664">

3.1.2. The pressure at the service-line coupling head of a motor vehicle authorized to draw a trailer fitted with air brakes shall not be affected by the operation of the pressure-regulating devices on the axles of the drawing vehicle. (1)For semi-trailers, z is the braking force divided by the static weight on the semi-trailer axle(s). (2)The provisions of item 3.1.1 do not affect the requirements of Annex II relating to the braking efficiency. However, if, when verifying the provisions of item 3.1.1 braking efficiencies are obtained which are higher than those prescribed in Annex II, the provisions relating to the adhesion utilization curve shall be applied within the areas of diagrams IA and IB defined by the straight lines k = 0 78 and z = 0 78.

3.1.3. In order to verify the requirement of item 3.1.1, the manufacturer shall provide the adhesion utilization curves for the front and rear axles calculated by the formulas: >PIC FILE= "T0007665">

3.1.4. Vehicles other than tractive units for semi-trailers. 3.1.4.1. The graphs shall be plotted for both the following load conditions: - unladen, in running order with the driver on board,

- laden. Where provision is made for several possibilities of load distribution, the one whereby the front axle is the most heavily laden shall be the one to be taken into consideration.

The height of the centre of gravity is specified by the manufacturer.

In the case of a vehicle fitted with air brakes, whether it is a trailer or a motor vehicle authorized to draw a trailer, the permissible relationship between the braking rate TR/PR or TM/PM and the pressure Pm shall be within the areas shown in diagram 2.

3.1.5. Tractive units for semi-trailers. 3.1.5.1. Tractive units with unladen semi-trailer

An unladen articulated combination is considered to be a tractive unit in running order, with the driver on board, coupled to an unladen semi-trailer. The dynamic load of the semi-trailer on the tractive unit shall be represented by a static weight applied at the coupling king-pin equal to 15 % of the maximum weight on the coupling.

For the solo tractive unit the height of the centre of gravity shall be that specified by the manufacturer. The braking forces must continue to be regulated between the state of the tractive unit with semi-trailer (unladen) and that of the solo tractive unit ; the braking forces relating to the solo tractive unit shall be verified.

3.1.5.2. Tractive units with laden semi-trailer

A laden articulated combination is considered to be a tractive unit in running order with the driver on board coupled to a laden semi-trailer. The dynamic load of the semi-trailer on the tractive unit shall be represented by a static weight Ps applied at the coupling king-pin equal to:

Ps = Pso (1 + 0 745 z)

where Pso represents the difference between the maximum laden weight of the tractive unit and its unladen weight. >PIC FILE= "T0007666">

where:

ho is the height of the centre of gravity of the tractive unit

hs is the height of the coupling on which the semi-trailer rests

Po is the unladen weight of the solo tractive unit

P = Po + Ps = P1 + P2.

3.1.5.3. In the case of a vehicle fitted with a compressed air braking system, the permissible relationship between the braking rate TM/PM and the pressure pm shall be within the areas shown in diagram 3.

3.2. Vehicles with more than two axles

The requirements of item 3.1 shall apply to vehicles with more than two axles. The requirements of item 3.1.1 with respect to wheel lock sequence shall be considered to be met, if, in the case of braking rates of between 0 715 and 0 730, the adhesion used by at least one of the front axles is greater than that used by at least one of the rear axles.

4. REQUIREMENT FOR SEMI-TRAILERS

For semi-trailers fitted with compressed-air braking systems:

The permissible relationship between the braking rate TR/PR and the pressure Pm shall lie within two areas derived from diagrams 4 A and 4 B for the laden and unladen states of load. This requirement shall be met for all permissible load conditions of the semi-trailer axles.

5. REQUIREMENTS FOR TRAILERS 5.1. The following requirements shall only apply to trailers fitted with air brakes. They shall not apply to single-axle trailers nor to twin-axle trailers where the axle spread is less than two metres.

5.2. The requirements set out in item 3.1 shall apply to twin-axle trailers not excluded by the requirements contained in 5.1.

5.3. Trailers with more than two axles shall be subject to the requirements contained in item 3.2.

6. CONDITIONS TO BE FULFILLED IN THE CASE OF FAILURE OF THE BRAKING DISTRIBUTION SYSTEM

When the requirements of this Appendix are met by means of a special device (e.g., controlled mechanically by the suspension of the vehicle), it shall be possible in the event of failure of this device or its control secondary to stop the vehicle under the conditions prescribed for braking in the case of motor vehicles ; in the case of trailers and semi-trailers in the event of failure of the control a service braking rate of at least 30 % of that prescribed for the vehicle in question shall be attained.

7. MARKINGS 7.1. Vehicles, other than those of category M 1 which meet the requirements of this Appendix by means of a device mechanically controlled by the suspension of the vehicle, shall be marked to show the useful travel of the device between the positions corresponding to vehicle unladen and laden states respectively.

7.2. When the requirements of this Appendix are met by means of a device actuated by compressed air, the vehicle shall be marked to show the pressure values at the outlet side of the device during full braking of the vehicle under both unladen and laden conditions.

7.3. The markings referred to under items 7.1 and 7.2 above shall be affixed in a visible position in indelible form.

8. VEHICLE INSPECTION

During the EEC type-approval testing of a vehicle the technical inspection authority shall verify conformity with the requirements contained in the present Appendix and carry out any further tests considered necessary to this end. The report on the additional tests shall be appended to the EEC type-approval certificate.

DIAGRAM 1 A VEHICLES OF CATEGORY M1 (see item 3.1.1)

>PIC FILE= "T0007667"> DIAGRAM 1 B VEHICLES OTHER THAN VEHICLES OF CATEGORY M1 (see item. 3.1.1)

>PIC FILE= "T0007668"> DIAGRAM 2 DRAWING VEHICLES AND TRAILERS (see item 3.1.4.1)

>PIC FILE= "T0007669"> DIAGRAM 3

>PIC FILE= "T0007670"> DIAGRAM 4 A SEMI-TRAILERS (see item 4)

>PIC FILE= "T0007671"> DIAGRAM 4 B (see item 4)

>PIC FILE= "T0007672"> Explanatory note on the use of diagram 4 B

1. Formula from which Diagram 4 B is derived is: >PIC FILE= "T0007673">

2. Description of the method of use by means of a worked example. 2.1. The dashed lines shown on Diagram 4 B refer to the determination of the factors Kc and Kv for the following vehicle where: >PIC FILE= "T0007674">

In the following items the figures in parenthesis relate only to the vehicle being used for the purpose of illustrating the method of use of Diagram 4 B.

2.2. Calculate the ratios >PIC FILE= "T0007675">

2.3. Determination of the laden factor, Kc (a) Start at appropriate hR (hR = 1 78 m)

(b) Move horizontally to the appropriate P/PR line (P/PR = 1 76)

(c) Move vertically to appropriate ER line (ER = 6 70) m

(d) Move horizontally to Kc scale, Kc is the laden factor required (Kc = 1 704).

2.4. Determination of the unladen factor, Kv. 2.4.1. Determination of the factor K2 (a) Start at appropriate hR(hR = 1 74) m

(b) Move horizontally to appropriate PR/PRmax line in group of curves nearest to vertical axis (PR/PRmax = 0 72)

(c) Move vertically to horizontal axis and read off the value of K2 (K2 = 0 713 m),

2.4.2. Determination of factor K1 (a) Start at appropriate hR (hR = 1 74 m)

(b) Move horizontally to the appropriate P/PR line (P/PR = 1 74)

(c) Move vertically to the appropriate ER line (ER = 6 70 m)

(d) Move horizontally to the appropriate PR/PRmax line in group of curves furthest from the vertical axis.

(PR/PRmax = 0 72)

(e) Move vertically to horizontal axis and read off the value of K1 (K1 = 1 779).

2.4.3. Determination of factor Kv

The unladen factor Kv is obtained from the following expression:

Kv = K1 - K2 (Kv = 1 766).

ANNEX IX MODEL COMMUNICATION CONCERNING THE EEC TYPE-APPROVAL OF A VEHICLE WITH REGARD TO BRAKING

After item 17, the following new items 17 (a) and 17 (a) 1 shall be added: 17 (a) Distribution of braking among the axles of a vehicle. 17 (a) 1. Does the vehicle fulfil the requirements contained in the Appendix (see item 1.1.4.2) ... yes/no (4).