1975L0524 — EN — 31.07.1975 — 000.001 — 1
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►B COMMISSIONDIRECTIVE
of25July1975
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 ofmotorvehiclesandoftheirtrailers
(75/524/EEC)
(OJ L 236, 8.9.1975, p. 3)
Corrected by:
►C1Corrigendum, OJ L 247, 23.9.1975, p. 36 (75/524/EEC)
▼B
COMMISSIONDIRECTIVE
of25July1975
adaptingtotechnicalprogressCouncilDirective No71/320/EECof
26July1971ontheapproximationofthelawsoftheMemberStatesrelating to the braking devices of certain categories of motor
vehiclesandoftheir 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 lawsof the Member Statesrelating tothe type approval of motor vehiclesand their trailers , asamended 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 January1972, and in particular to Articles11, 12 and 13 thereof;
Having regard to Council Directive No 71/320/EEC(
3) of 26 July 1971
on the approximation of the lawsof the Member Statesrelating to thebraking devicesof certain categoriesof motor vehiclesand of theirtrailers, 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;
Whereasin 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; whereasthes e
provisions solely relate to braking-pressure distributors and not,therefore, to conditionsof compatibility; whereasin order to avoidcertain combinationsof vehicles(drawing and drawn vehicles ) whichare not likely to be able to provide every guarantee of safety from thepoint of view of braking, these provisions should be subject to
conditionsof compatibility between drawing and drawn vehicles ;
whereas technical progress now enables provisions on compatibilitynot only to be adopted but also enables them to be correctlyimplemented;
Whereasthe laying down of provis ionson the conditionsof
compatibility necessitates amendments to the provisions relating to thedevice which enables the braking pressure to be matched to the load andwhich 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 theseprovisions, it is consequently necessary to subject vehicles of all
categories, with the exception of those in categories O
1and O2, to the
provisions of this Directive, even if they are fitted with wheel anti-locking devices;
WhereasthisDirective providesfor an earlier date of entry into force of
the amended provisions and whereas it is therefore no longer justified toretain the provisions of paragraphs 2 and 3 of Article 2 of CommissionDirective No 74/132/EEC;
Whereasthe provis ionsof thisDirective are in accordance with the
Opinion of the Committee on the Adaptation to Technical Progress ofthe Directivesaimed at the Removal of Technical Barriersto Trade inthe Motor-Vehicle Sector,1975L0524 — EN — 31.07.1975 — 000.001 — 2
(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.
▼B
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 CouncilDirective of 26 July 1971 on the approximation of the lawsof the
Member Statesrelating to the braking devicesof certain categoriesof
motor vehiclesand of their trailersare res cinded with effect from thedate of adoption of thisDirective.
Article 2
1. AnnexesI, II and IX to Council Directive No 71/320/EEC of 26
July 1971 on the approximation of the lawsof the Member Statesrelating to the braking devicesof certain categoriesof motor vehiclesand their trailers, as amended by Commission Directive No 74/132/EEC
of 11 February 1974, are amended ass hown in the Annex to this
Directive.
2. Pending the entry into force of special requirements on wheel anti-
locking systems, vehicles of categories M
1,M2,M3,N1,N2,N3,O3and O4which are fitted with these systems are submitted to the prescriptions ofthisDirective.
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) ofCouncil Directive No 70/156/EEC of 6 February 1970, or to grantnational 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 July1971, aslas t amended by thisDirective.
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 February1970 in respect of a type of vehicle of which the braking devices donot comply with the provisions of Council Directive No 71/320/EEC
of 26 July 1971 aslas t amended by thisDirective;
— may refuse to grant national type-approval in respect of a type of
vehicle of which the braking devicesdo not comply with the
provisions of Council Directive No 71/320/EEC of 26 July 1971 aslast amended by this Directive.
3. With effect from 1 October 1976 Member Statesmay prohibit the
entry into service of vehicles of which the braking devices do notcomply with the provisions of Council Directive No 71/320/EEC of 26July 1971 aslas t amended by thisDirective.
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.1975L0524 — EN — 31.07.1975 — 000.001 — 3
▼B
ANNEX
AmendmentstotheAnnexestoCouncilDirectiveNo71/320/EECof26July
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 itsres ervoirsfallsbelow 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 ANDPERFORMANCE 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 vehiclesin categoriesM1,M2,M3,N1,N2,N3,O3and O4on a road surface having reduced adhesion shall fulfil the
conditionslaid down in the Appendix.
Appendix (See 1.1.4.2): DISTRIBUTIONOFBRAKINGEFFORTAMONG
VEHICLEAXLES
1. GENERAL REQUIREMENTS
Vehiclesof categoriesM1,M2,M3,N1,N2,N3,O3and O4shall fulfil
the conditions of the present Appendix. If a special device is used,
thismus t 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 brakeson axle i under normal
braking conditionson the road
fi=Ti/Ni, adhesion used by axle i(1)
J = deceleration of vehicleg = acceleration due to gravity g = 10 m/s
2
z = braking rate of vehicle = J/g(2)
P = weight of vehicleh = height of centre of gravityE = wheelbasek = theoretical coefficient of adhesion between tyre and roadK
c= correction factor — semi-trailer laden
Kv= correction factor — semi-trailer unladen
TM = sum of braking forces at the periphery of wheels of
drawing vehiclesfor trailersor s emi-trailers1975L0524 — EN — 31.07.1975 — 000.001 — 4
(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.
(2) For semi-trailers, z is the braking force divided by the static weight on the semi-trailer
axle(s).
▼B
PM = total normal static reaction between road surface and
wheelsof drawing vehiclesfor trailer or s emi-trailer as
referred to in items3.1.4 and 3.1.5 res pectively
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.Twoaxlevehicles.
3.1.1.(1) For all categoriesof vehicle for k valuesbetween 0·2 and 0·8:
z/C210/C11þ0/C185 k /C00/C12 ðÞ
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 ratesof between 0·15 and 0·8 in the cas e of
vehiclesof category M1.
However, for vehiclesof thiscategory over the range of z values ,
between 0·3 and 0·45, an inversion of the adhesion utilization
curvesispermitted provided that the adhes ion utilization curve of
the rear axle doesnot exceed by more than 0·05 the line defined
by the formula k = z (line of ideal adhesion utilization — see
diagram 1A);
— for all braking ratesof between 0·15 and 0·30, in the cas e of
vehicles of other categories. This condition is also considered
satisfied if the adhesion utilization curves for each axle of
between 0·15 and 0·30 are situated between two parallels to the
line of ideal adhesion utilization given by the equation k = z ± 0·08
as shown in diagram 1 B and the adhesion utilization curve for
the rear axle for braking ratesz ≥0·3 complieswith the
relationship
z/C210/C13þ0/C174 k /C00/C138 ðÞ
3.1.2. The pressure at the service-line coupling head of a motor vehicle
authorized to draw a trailer fitted with air brakess hall not be affected
by the operation of the pressure-regulating devices on the axles of the
drawing vehicle.
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
axlescalculated by the formulas :
f1¼T1
N1¼T1
P1þzh
EPf2¼T2
N2¼T2
P2/C0zh
EP
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.1975L0524 — EN — 31.07.1975 — 000.001 — 5
(1) 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 brakingefficiencies are obtained which are higher than those prescribed in Annex II, theprovisions relating to the adhesion utilization curve shall be applied within the areas of
diagramsIA and IB defined by the s traight linesk = 0·8 and z = 0·8.
▼B
The height of the centre of gravity iss pecified 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 pmshall be within the areas shown in diagram 2.
3.1.5. Tractive units for semi-trailers.
3.1.5.1. Tractive unitswith unladen s emi-trailer
An unladen articulated combination iscons idered 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 relatingto the solo tractive unit shall be verified.
3.1.5.2. Tractive unitswith laden s emi-trailer
A laden articulated combination iscons idered 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 P
sapplied at the coupling king-pin
equal to:
Ps¼Pso1þ0/C145 z ðÞ
where Psorepresents the difference between the maximum laden
weight of the tractive unit and itsunladen weight.
For h the following value shall be taken: h ¼hoPoþhsPs
P
where:
hoisthe height of the centre of gravity of the tractive unit
hsis the height of the coupling on which the semi-trailer rests
Poisthe unladen weight of the s olo tractive unit
P¼PoþPs¼P1þP2:
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 pmshall be within the areas shown in diagram 3.
3.2.Vehicleswithmorethantwoaxles
The requirementsof item 3.1 s hall apply to vehicleswith more than
two axles. The requirements of item 3.1.1 with respect to wheel lock
sequence shall be considered tobe met, if, in the case of braking rates
of between 0·15 and 0·30, 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 pmshall lie within two areas derived from diagrams 4A and
4B 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 requirementss hall only apply to trailersfitted 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 requirementscontained in 5.1.
5.3. Trailers with more than two axles shall be subject to the requirements
contained in item 3.2.1975L0524 — EN — 31.07.1975 — 000.001 — 6
▼C1
6. CONDITIONS TO BE FULFILLED IN THE CASE OF FAILURE
OF THE BRAKING DISTRIBUTION SYSTEM
When the requirementsof thisAppendix are met by meansof 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 to stop the vehicle under the conditions prescribed for
secondary braking in the case of motor vehicles; in the case of
trailersand s emi-trailersin the event of failure of the control a
braking rate of at least 30 % of the service brake performance
prescribed for the vehicle in question shall be attained.
7. MARKINGS
7.1. Vehicles, other than those of category M1, which meet the
requirementsof thisAppendix by meansof 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 requirementsof thisAppendix are met by meansof 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 markingsreferred to under items7.1 and 7.2 above s hall 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.1975L0524 — EN — 31.07.1975 — 000.001 — 7
▼B
▼B
DIAGRAM 1 A
VEHICLESOFCATEGORYM1
(see item 3.1.1)
1975L0524 — EN — 31.07.1975 — 000.001 — 8
▼B
DIAGRAM 1 B
VEHICLESOTHERTHANVEHICLESOFCATEGORYM1
(see item 3.1.1)
1975L0524 — EN — 31.07.1975 — 000.001 — 9
▼B
DIAGRAM 2
DRAWINGVEHICLESANDTRAILERS
(see item 3.1.4.1)
Note:It isunders tood that between the values
TM
PM¼0 andTM
PM¼0/C11o rTR
PR¼0 andTR
PR¼0/C11 it isnot
necessary that there should be proportionality between the braking rateTM
PMorTR
PRand the control
pressure as measured at the coupling head.1975L0524 — EN — 31.07.1975 — 000.001 — 10
▼B
DIAGRAM 3
TRACTIVEUNITSFORSEMI-TRAILERS
(see item 3.1.5)
Note:(1) Between the values
TM
PM¼0 andTM
PM¼0/C11, it is not necessary that there should be proportionality
between the braking rateTM
PMand the service line pressure as measured at the coupling head.
(2) The relationships required by the diagram shall apply progressively for intermediate states of
loading between the laden and the unladen states and shall be achieved by automatic means.1975L0524 — EN — 31.07.1975 — 000.001 — 11
▼B
DIAGRAM 4 A
SEMI-TRAILERS
(see item 4)
The relationship between the braking rateTR
PRand control line pressure for the laden and unladen
condition isdetermined asfollows :
The factorsKc(laden), Kv(unladen) are obtained by reference to diagram 4 B.
Construct the laden and unladen bands by multiplying the upper and lower boundaries of the band in
diagram 4 A shown below by the two factors obtained, Kcand Kvrespectively.1975L0524 — EN — 31.07.1975 — 000.001 — 12
▼B
DIAGRAM 4 B
(see item 4)
1975L0524 — EN — 31.07.1975 — 000.001 — 13
▼B
Explanatorynoteontheuseofdiagram4B
1. Formula from which Diagram 4 B isderived is :
K¼1/C17/C00/C17P R
PRmax/C20/C21
1/C135/C00/C196
ER1/C10þhR/C01/C12 ðÞP
PR/C18/C19 /C20/C21
/C01/C10/C0PR
PRmax/C20/C21
hR/C01/C10
2/C15/C20/C21
2. Description of the method of use by means of a worked example.
2.1. The dashed lines shown on Diagram 4B refer to the determination of
the factorsKcand Kvfor the following vehicle where:
Laden Unladen
P 24 t 4·2 tPR 15 t 3 t
PR
max15 t 15 t
hR1·8 m 1·4 m
ER6·0 m 6·0 m
In the following itemsthe figuresin parenthes isrelate only to the
vehicle being used for the purpose of illustrating the method of use of
Diagram 4B.
2.2. Calculate the ratios
(a)P
PR/C20/C21
laden (= 1·6)
(b)P
PR/C20/C21
unladen (= 1·4)
(c)PR
PRmax/C20/C21
unladen (= 0·2)
2.3. Determination of the laden factor, Kc
(a) Start at appropriate hR(hR= 1·8 m)
(b) Move horizontally to the appropriate P/PR line (P/PR = 1·6)
(c) Move vertically to appropriate ERline (ER= 6·0) m
(d) Move horizontally to Kcscale, Kcisthe laden factor required
(Kc= 1·04).
2.4. Determination of the unladen factor, Kv.
2.4.1. Determination of the factor K2
(a) Start at appropriate hR(hR= 1·4) m
(b) Move horizontally to appropriate PR/PRmaxline in group of
curvesneares t to vertical axis(PR/PRmax= 0·2)
(c) Move vertically to horizontal axisand read off the value of K2(K2= 0·13 m).
2.4.2. Determination of factor K1
(a) Start at appropriate hR(hR= 1·4 m)
(b) Move horizontally to the appropriate P/PR line (P/PR = 1·4)
(c) Move vertically to the appropriate ERline (ER= 6·0 m)
(d) Move horizontally to the appropriate PR/PRmaxline in group of
curves furthest from the vertical axis.
(PR/PRmax= 0·2)
(e) Move vertically to horizontal axisand read off the value of K1(K1= 1·79).
2.4.3. Determination of factor Kv
The unladen factor Kvis obtained from the following expression:
Kv¼K1/C0K2Kv¼1/C166 ðÞ .1975L0524 — EN — 31.07.1975 — 000.001 — 14
▼B
ANNEX IX
MODEL COMMUNICATION CONCERNING THE EEC TYPE-
APPROVALOFAVEHICLEWITHREGARDTOBRAKING
After item 17, the following new items17 (a) and 17 (a) 1 s hall be added:
17 (a) Distribution of braking among the axles of a vehicle.
17 (a) 1. Doesthe vehicle fulfil the requirementscontained in the Appendix (s ee
item 1.1.4.2) … yes/no (4).1975L0524 — EN — 31.07.1975 — 000.001 — 15