1971L0320 — EN — 22.08.1991 — 007.001 — 1
This document is meant purely as a documentation tool and the institutions do not assume any liability for its contents
►B COUNCILDIRECTIVE
of26July1971
ontheapproximationofthelawsoftheMember Statesrelating tothebrakingdevicesofcertain
categories ofmotorvehiclesandoftheirtrailers
(71/320/EEC)
(OJ L 202, 6.9.1971, p. 37)
Amended by:
Official Journal
No page date
►M1Commission Directive 74/132/EEC of 11 February 1974 L 74 7 19.3.1974
►M2Commission Directive 75/524/EEC of 25 July 1975 L 236 3 8.9.1975
►M3Commission Directive 79/489/EEC of 18 April 1979 L 128 12 26.5.1979
►M4Commission Directive 85/647/EEC of 23 December 1985 L 380 1 31.12.1985
►M5Commission Directive 88/194/EEC of 24 March1988 L 92 47 9.4.1988
►M6Commission Directive 91/422/EEC of 15 July 1991 L 233 21 22.8.1991
Amended by:
►A1Act of Accession of Denmark, Ireland and the United Kingdom of Great
Britain and Northern IrelandL 73 14 27.3.1972
Corrected by:
►C1Consolidated text of corrigenda to instruments published in Special
Editions 1952-72, p. 96 (71/320/EEC)
►C2Corrigendum, OJ L 247, 23.9.1975, p. 36 (75/524/EEC)
►C3Corrigendum, OJ L 275, 2.10.1991, p. 36 (91/422/EEC)
▼B
COUNCILDIRECTIVE
of26July1971
on the approximationof the lawsofthe Member States relating to
the braking devices of certain categories of motor vehicles and of
theirtrailers
(71/320/EEC)
THE COUNCIL OF THE EUROPEAN COMMUNITIES,
Having regard to the Treaty establishing the European Economic
Community, and in particular Article 100 thereof;
Having regard to the proposal from the Commission;
Having regard to the Opinion of the European Parliament(1);
Having regard to the Opinion of the Economic and Social
Committee(2);
Whereas the technical requirements which motor vehicles must satisfy
pursuant to national laws relate, inter alia , to the braking devices of
certain categories of motor vehicles and of their trailers;
Whereas those requirements differ from one Member State to another;
whereas it is therefore necessary that all Member States adopt the samerequirements either in addition to or instead of their existing rules, inorder, in particular, to allow the EEC type approval procedure whichwas the subject of the Council Directive 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 to be applied in respectof eachtype of veh icle(
3);
Whereas the harmonised requirements must ensure road safety
throughout the whole Community;
HAS ADOPTED THIS DIRECTIVE:
Article 1
1. For the purposes of this Directive, ‘vehicle’ means any motor
vehicle falling within one of the international categories listed belowand intended for use on the road, such vehicle being with or withoutbodywork, having at least four wheels and a maximum design speedexceeding 25 km/h, and its trailers, with the exception of vehicles
which run on rails, agricultural tractors and machinery and public
works vehicles:
(a) Category M: Motor vehicles having at least four wheels or having
three wheels when the maximum weight exceeds 1 metric ton, and
used for the carriage of passengers:
— Category M
1: Vehicles used for the carriage of passengers, and
comprising not more than eight seats in additionto the driver's seat;
— Category M
2: Vehicles used for the carriage of passengers,
comprising more than eight seats in addition to
the driver's seat, and having a maximum weight
not exceeding 5 metric tons;
— Category M3: Vehicles used for the carriage of passengers,
comprising more than eight seats in addition tothe driver's seat, and having a maximum weightexceeding 5 metric tons.1971L0320 — EN — 22.08.1991 — 007.001 — 2
(1) OJ No C 160, 18.12.1969, p. 7.
(2) OJ No C 100, 1.8.1969, p. 13.
(3) OJ No L 42, 23.2.1970, p. 1.
▼B
(b) Category N: Motor vehicles having at least four wheels or having
three wheels when the maximum weight exceeds 1 metric ton, andused for the carriage of goods:
— Category N
1: Vehicles used for the carriage of goods and
having a maximum weight not exceeding 3·5metric tons;
— Category N
2: Vehicles used for the carriage of goods and
having a maximum weight exceeding 3·5 but
not exceeding 12 metric tons;
— Category N3: Vehicles used for the carriage of goods and
having a maximum weight exceeding 12 metrictons.
(c) Category O: Trailers (including semi-trailers):
— Category O
1: Trailers witha maximum weigh t not exceeding
0·75 metric tons;
— Category O2: Trailers witha maximum weigh t exceeding 0·75
but not exceeding 3·5 metric tons;
— Category O3: Trailers witha maximum weigh t exceeding 3·5
but not exceeding 10 metric tons;
— Category O4: Trailers witha maximum weigh t exceeding 10
metric tons.
2. Articulated category M vehicles made up of two non-separable
but articulated units shall be considered to be single vehicles.
3. In the case of a category M or N drawing vehicle designed to be
coupled to a semi-trailer, the maximum weight to be taken into consid-eration when classifying that vehicle shall be the weight of the drawingvehicle in running order plus the maximum weight transferred to thedrawing vehicle by the semi-trailer and, where appropriate, the
maximum weight of the drawing vehicle's own load.
4. In the case of category N vehicles, the equipment and fittings of
certain special vehicles not intended for the carriage of passengers
(such as crane vehicles, workshop vehicles, publicity vehicles) shall
be considered to be goods.
5. The maximum weight to be taken into consideration when classi-
fying a category O semi-trailer shall be the weight transmitted to the
ground by the axle or axles of the semi-trailer when coupled to the
drawing vehicle and laden with a maximum load.
Article 2
No Member State may refuse to grant EEC type-approval or national
type-approval of a vehicle on grounds relating to its braking device ifthat vehicle is fitted with the devices specified in Annexes I to VIII andX to XII and if these devices satisfy the requirements set out therein.
Article 2a
No Member State may refuse or prohibit the sale, registration, entry
into service or use of a vehicle on grounds relating to its brakingdevices if that vehicle is equipped with the braking devices specifiedin Annexes I to VIII and if suchbraking devices satisfy th e require-ments set out therein.1971L0320 — EN — 22.08.1991 — 007.001 — 3
▼M4
▼A1
▼B
Article 3
The Member State which has granted type approval shall take the
necessary measures to ensure that it is informed of any modification
to a component or characteristic mentioned in item 1.1 of Annex I.
The competent authorities of that State shall decide whether the modi-fied prototype should be submitted to fresh tests and whether a freshreport should be drawn up thereon. If such tests reveal failure tocomply with the requirements of this Directive, the modification shallnot be authorised.
Article 4
Pending the entry into force of a separate Directive on the definition of
an ‘urban bus’, such vehicles shall continue to be submitted to the
Type II A test described in Annex II where their maximum weight
exceeds 10 metric tons.
Article 5
The amendments necessary for adjusting the requirements of the
Annexes so as to take account of technical progress shall be adoptedin accordance with the procedure laid down in Article 13 of theCouncil Directive of 6 February 1970 on the type approval of motorvehicles and their trailers.
Article 6
1. Member States shall put into force the provisions containing the
requirements needed in order to comply with this Directive within
eighteen months of its notification and shall forthwith inform the
Commission thereof.
2. Witheffect from 1 October 1974, th e provisions of item 2.2.1.4
of Annex I shall also apply to vehicles other than those in categoryM
3or category N3.
3. Member States shall ensure that the texts of the main provisions
of national law which they adopt in the field covered by this Directive
are communicated to the Commission.
Article 7
This Directive is addressed to the Member States.1971L0320 — EN — 22.08.1991 — 007.001 — 4
▼B
ANNEX I
DEFINITIONS,REQUIREMENTS,CONSTRUCTIONANDFITTING
1. DEFINITIONS
For the purpose of this Directive:
1.1.‘Typeofvehiclewithrespecttothebrakingdevices’
‘Type of vehicle with respect to the braking devices’ means vehicles
which do not differ in such essential respects as:
1.1.1.In the case of motor vehicles
1.1.1.1. the vehicle category, as defined in Article 1 of this
Directive
1.1.1.2. the ►M3maximum mass ◄, as defined in item 1.14
1.1.1.3. the distribution of ►M3mass◄among the axles
1.1.1.4. the maximum design speed1.1.1.5. a different type of braking device withparticular refer-
ence to the presence or otherwise of devices for
braking a trailer
1.1.1.6. the number and arrangement of the axles1.1.1.7. the engine type1.1.1.8. the number and ratios of gears1.1.1.9. ratio(s) of rear drive axle(s)1.1.1.10. the tyre dimensions
1.1.2.In the case of trailers
1.1.2.1. the vehicle category, as defined in Article 1 of this
Directive
1.1.2.2. the ►
M3maximum mass ◄, as defined in item 1.14
1.1.2.3. the distribution of ►M3mass◄among the axles
1.1.2.4. a different type of braking device1.1.2.5. the number and arrangement of the axles1.1.2.6. the tyre dimensions
1.2.‘Brakingdevice’
‘Braking device’ means the combination of parts whose function is
progressively to reduce the speed of a moving vehicle or to bring it to
a halt, or to keep it stationary if it is already halted. These functions
are specified in item 2.1.2. The device shall consist of the brake
control, the transmission and the brake proper.
1.3.‘Graduatedbraking’
‘Graduated braking’ means braking during which, within the normal
range of operation of the device, during either the application or the
releasing of the brakes,
— the driver can, at any time, increase or reduce the braking force
through action on the control,
— the braking force acts in the same direction as the action on the
control (monotonic function),
— it is easily possible to make a sufficiently fine adjustment to the
braking force.
1.4.‘Control’
‘Control’ means the part actuated directly by the driver (or, where
appropriate, in the case of a trailer, the driver's mate) to supply to the
transmission the energy required for braking or controlling it. This1971L0320 — EN — 22.08.1991 — 007.001 — 5
▼M4
▼B
▼B
energy may be the muscular energy of the driver, or energy from
another source controlled by the driver, or in appropriate cases the
kinetic energy of a trailer, or a combination of these various kinds of
energy.
1.5.‘Transmission’
‘Transmission’ means the combination of components situated between
the control and the brake and connecting the two operationally. The
transmission may be mechanical, hydraulic, pneumatic, electrical, or
mixed. Where the braking power is derived from or assisted by a
source of energy independent of the driver but controlled by him, the
reserve of energy in the device shall likewise be regarded as part of the
transmission.
1.6.‘Brake’
‘Brake’ means the part in which the forces opposing the movement of
the vehicle develop. It may be a friction brake (when the forces are
generated by the friction between two parts of the vehicle moving rela-
tively to one another); an electrical brake (when the forces are
generated by electromagnetic action between two parts of the vehicle
moving relatively to but not in contact withone anoth er); a fluid brake
(when the forces are generated by the action of a fluid situated between
two parts of the vehicle moving relatively to one another); or an engine
brake (when the forces are derived from a controlled increase in the
braking action of the engine transmitted to the wheels).
1.7.‘Differenttypesofbrakingdevices’
‘Different types of braking devices’ means equipment which differs in
suchessential respects as:
1.7.1. components having different characteristics,
1.7.2. a component made of materials having different characteristics
or a component different in shape or size,
1.7.3. a different assembly of the components.
1.8.‘Brakingsystemcomponent’
‘Braking system component’ means one of the individual parts which,
when assembled, constitute the braking device.
1.9.‘Continuousbraking’
‘Continuous braking’ means the braking of combinations of vehicles
through an installation having the following characteristics:
1.9.1. a single control which the driver actuates progressively, by a
single movement, from his driving seat,
1.9.2. the energy used for braking the vehicles constituting the combi-
nation of vehicles is supplied from the same source (which may
be the muscular energy of the driver),
1.9.3. the braking installation ensures simultaneous or suitably phased
braking of each of the constituent vehicles of the combination,
whatever their relative positions.
1.10.‘Semi-continuousbraking’
‘Semi-continuous braking’ means the braking of combinations of vehi-
cles through an installation having the following characteristics:
1.10.1. a single control which the driver can actuate progressively, by
a single movement, from his driving seat,
1.10.2. the energy used for braking the vehicles constituting the
combination of vehicles is supplied from two different sources
(one of which may be the muscular energy of the driver),
1.10.3. the braking installation ensures simultaneous or suitably phased
braking of each of the constituent vehicles of the combination,
whatever their relative positions.1971L0320 — EN — 22.08.1991 — 007.001 — 6
▼B
1.11.‘Automaticbraking’
‘Automatic braking’ means braking of the trailer or trailers occurring
automatically in the event of separation of components of the combina-
tion of coupled vehicles, including such separation through coupling
breakage, without the effectiveness of the remainder of the combina-
tion being affected.
1.12.‘Inertiaor“overrun”braking’
‘Inertia braking’ means braking by utilising the forces generated by the
trailer's moving up on the drawing vehicle.
1.13.‘Ladenvehicle’
‘Laden vehicle’ means, except where otherwise stated, a vehicle laden
to its ‘►M3maximum mass ◄’.
1.14.‘►M3 Maximummass ◄’
‘►M3Maximum mass ◄’ means the ►M3maximum mass ◄
stated by the vehicle manufacturer to be technically permissible (this
►M3mass◄may be higher than the ‘permissible ►M3maximum
mass◄’).
1.15.‘Hydraulicbrakingdevicewithstoredenergy’
‘Hydraulic braking device withstored energy’ means a braking system
where energy is supplied by a hydraulic fluid under pressure, stored in
one or more accumulators fed from one or more pressure pumps each
fitted with a means of limiting the pressure to a maximum value. This
value shall be specified by the manufacturer.
1.16.‘CategoryO3andO4trailer types’
1.16.1.‘Semi-trailer’
‘Semi-trailer’ means a towed vehicle in which the axle(s) is
(are) positioned behind the centre of gravity of the vehicle
(when uniformly loaded) and which is equipped with a
connecting device permitting horizontal and vertical forces to
be transmitted to the drawing vehicle.
1.16.2.‘Full trailer’
‘Full trailer’ means a towed vehicle having at least two axles,
and equipped witha towing device wh ichcan move vertically
(in relation to the trailer) and controls the direction of the front
axle(s), but which transmits no significant static load to the
drawing vehicle.
1.16.3.‘Centre-axle trailer’
‘Centre-axle trailer’ means a towed vehicle equipped with a
towing device which cannot move vertically (in relation to the
trailer), and in which the axle(s) is (are) positioned close to the
centre of gravity of the vehicle (when uniformly loaded) such
that only a small static vertical load, not exceeding 10 % of
that corresponding to the maximum mass of the trailer or load
of 1000 daN (whichever is the lesser) is transmitted to the
drawing vehicle.
The maximum mass to be taken into consideration when clas-
sifying a centre-axle trailer shall be the mass transmitted to the
ground by the axle(s) of the centre-axle trailer when coupled to
the drawing vehicle and laden with a maximum load.
1.17.‘Retarder’ (1)
‘Retarder’ means an additional braking system having the capability to
provide and to maintain a braking effect over a long period of time1971L0320 — EN — 22.08.1991 — 007.001 — 7
(1) Until uniform procedures have been agreed to calculate the effects of retarders on the
provisions in the Appendix to item 1.1.4.2 of Annex II, this definition does not cover
vehicles fitted with regenerative braking systems.▼M4
▼M6
▼M4
▼M4
without a significant reduction in performance. The term ‘retarder’
covers the complete system including the control device.
1.17.1.‘Independent retarder’
‘Independent retarder’ means a retarder whose control device is
separate from that of the service and other braking systems.
1.17.2.‘Integrated retarder’ (1)
‘Integrated retarder’ means a retarder whose control device is
integrated with that of the service braking system in such a
way that both retarder and service braking systems are applied
simultaneously or suitably phased by operation of the
combined control device.
1.17.3.‘Combined retarder’
‘Combined retarder’ means an integrated retarder which in
addition has a cut-out device, which allows the combinedcontrol to apply the service braking system alone.
1.18.‘Inter-urbanmotorcoach’
‘Inter-urban motor coach’ means a vehicle designed and equipped for
inter-urban transport, having no spaces specifically intended for
standing passengers, but able to carry for short distances passengers
standing in the gangway.
1.19.‘Long-distancetouringmotor-coach’
‘Long distance touring motor-coach’ means a vehicle designed and
equipped for long-distance journeys, arranged to ensure the comfort of
its seated passengers and which does not carry standing passengers.
1.20.‘Anti-lockdevices’
See Annex X, item 2.1.
2. CONSTRUCTION AND FITTING REQUIREMENTS
2.1.General
2.1.1.Braking device
2.1.1.1. The braking device must be so designed, constructed and
fitted as to enable the vehicle in normal use, despite the
vibration to which it may be subjected, to comply with
the undermentioned requirements.
2.1.1.2. In particular, the braking device must be so designed,
constructed and fitted as to be able to resist the corrosion
and ageing phenomena to which it is exposed.
2.1.2.Functions of the braking device
The braking device defined in item 1.2 must fulfil the following
conditions:
2.1.2.1. Service braking
The service braking must enable the driver to control the
movement of the vehicle and to halt it safely, speedily
and effectively, whatever its speed and load, on any up
or down gradient. It must be possible to graduate this
braking action. The driver must be able to achieve this
braking action from his driving seat without removing
his hands from the steering control.
2.1.2.2. Secondary braking1971L0320 — EN — 22.08.1991 — 007.001 — 8
(1) Until uniform procedures have been agreed to calculate the effects of retarders on the
provisions in the Appendix to item 1.1.4.2 of Annex II, vehicles equipped with an inte-grated retarder must also be equipped withan anti-lock device, acting on at least th eservice brakes of the axle controlled by the retarder, and on the retarder, and complying
withth e requirements specified in Annex X.▼M5
▼B
▼B
The secondary braking must make it possible to halt the
vehicle within a reasonable distance in the event of the
failure of the service braking. It must be possible to
graduate this braking action. The driver must be able to
obtain this braking action from his driving seat while
keeping at least one hand on the steering control. For
the purposes of these requirements, it is assumed that
not more than one failure of the service braking can
occur at one time.
2.1.2.3. Parking braking
The parking braking must enable the vehicle to be held
stationary on an up or down gradient even in the absence
of the driver, the working parts being then held in the
locked position by a purely mechanical device. The
driver must be able to achieve this braking action from
his driving seat, subject, in the case of a trailer, to the
requirements of item 2.2.2.10. ►M6The trailer air
brake and the parking brake of the drawing vehicle may
be operated simultaneously, provided that the driver isable to check, at any time, that the parking brake perfor-
mance of the vehicle combination, obtained by the
purely mechanical action of the parking brake device, is
sufficient. ◄
2.1.3.Pneumatic connections between motor vehicles and trailers
2.1.3.1. In the case of a braking device operated by compressed
air, the pneumatic link with the trailer must be of the
type withtwo or more lines. However, in all cases, all
the requirements of this Directive must be satisfied by
the use of only two lines. Shut-off devices which are
not automatically actuated shall not be permitted. In the
case of articulated vehicle combinations, the flexible
hoses shall be a part of the drawing vehicle. In all other
cases, the flexible hoses shall be a part of the trailer.
2.2.Characteristics ofbrakingdevices
2.2.1.Vehicles of categories M and N
2.2.1.1. The set of braking devices with which a vehicle is
equipped must satisfy the requirements laid down for
the service, secondary and parking brake
2.2.1.2. The devices providing service, secondary and parking
braking may have common components, provided that
they fulfil the following conditions:
2.2.1.2.1. there must be at least two controls, indepen-
dent of eachoth er and readily accessible to
the driver from his normal driving position.
For all categories of vehicles, except M
2and
M3, every brake control (excluding a retarder
control) shall be designed such that it returns
to the fully-off position when released. This
requirement shall not apply to a parking
brake control (or that part of a combined
control) when it is mechanically locked in
an applied position;
2.2.1.2.2. the control of the service braking device must
be independent of the control of the parking
braking device;
2.2.1.2.3. where the service and secondary braking
devices have the same control, the effective-
ness of the linkage between that control and
the various components of the transmission
systems must not be liable to diminishafter
a certain period of use;
2.2.1.2.4. where the service and secondary braking
devices have the same control, the parking
braking device must be so designed that it
can be actuated when the vehicle is in1971L0320 — EN — 22.08.1991 — 007.001 — 9
▼M4
▼B
▼M4
▼B
▼B
motion. ►M3This provision shall not apply
where an auxiliary control permits at least
partial actuation of the service braking
system, as provided for in Annex II, item
2.1.3.6; ◄
2.2.1.2.5. in the event of a breakage of any component
other than the brakes (as defined in item 1.6)
or the components specified in item 2.2.1.2.7,
or of any other failure of the service braking
device (malfunction, partial or total exhaus-
tion of an energy reserve), the secondary
braking device or that part of the service
braking device which is not affected by the
failure must be able to bring the vehicle to a
halt in the conditions prescribed forsecondary braking;
2.2.1.2.6. in particular, where the secondary braking
device and the service braking device have a
common control and common transmission;
2.2.1.2.6.1. where the service braking is
actuated by the muscular energy
of the driver assisted by one or
more energy reserves, the
secondary braking must, in the
event of failure of that assistance,
be capable of being ensured by
the muscular energy of the driver
assisted by the energy reserves, if
any, which are unaffected by the
failure, the force applied to the
control not exceeding the
prescribed maxima;
2.2.1.2.6.2. where the force for the service
braking and transmission depend
exclusively on the use of an
energy reserve controlled by the
driver, there must be at least two
completely independent energy
reserves, eachprovided withits
own independent transmission;
each of them may act on the
brakes of only two or more
wheels so selected as to be
capable of ensuring by them-
selves the prescribed degree of
secondary braking without
endangering the stability of thevehicle during braking; in addi-
tion, eachof th ese energy
reserves must be fitted witha
warning device as defined in
item 2.2.1.13;
2.2.1.2.7. certain parts, suchas th e pedal and its
bearing, the master cylinder and its piston(s)
(hydraulic systems), the control valve
(hydraulic and/or pneumatic systems), the
linkage between the pedal and the master
cylinder or the control valve, the brake cylin-
ders and their pistons (hydraulic and/or
pneumatic systems), and the lever-and-cam
assemblies of brakes, shall not be regarded
as liable to breakage if they are amply
dimensioned, are readily accessible for main-
tenance, and exhibit safety features at least
equal to those prescribed for other essential
components (suchas th e steering linkage) of
the vehicle. Where the failure of any suchpart would make it impossible to brake the
vehicle with a performance at least equal to
that prescribed for the secondary braking,
that part must be made of metal or of a mate-
rial withequivalent ch aracteristics and must1971L0320 — EN — 22.08.1991 — 007.001 — 10
▼M4
▼M4
not be subject to significant distortion in the
normal operation of the braking devices.
2.2.1.3. Where there are separate controls for the service and
secondary braking devices, simultaneous actuation of
the two controls must not render both the service and
secondary braking devices inoperative, either when
bothbraking devices are in good working order or
when one of them is faulty.
2.2.1.4. In the event of failure in a part of the transmission of
the service brake, the following conditions must be met:
2.2.1.4.1. a sufficient number of wheels must still be
braked by actuation of the service braking
device control, whatever the vehicle load;
2.2.1.4.2. these wheels must be so selected that the
residual performance of the service braking
device satisfies the requirements laid down
in item 2.1.4 of Annex II;
2.2.1.4.3. however, the above requirements shall not
apply to drawing vehicles for semi-trailers
when the transmission of the service braking
device of the semi-trailer is independent of
that of the drawing vehicle.
2.2.1.5. Where use is made of energy other than the muscular
energy of the driver, there need not be more than one
source of such other energy (hydraulic pump, air
compressor, etc.), but the means by which the device
constituting that source is driven must be as safe as
practicable.
2.2.1.5.1. In the event of failure in any part of the
transmission of a vehicle's braking devices,
the supply to the part not affected by the
failure must continue to be ensured where
this is required for the purpose ofhalting the
vehicle with the degree of effectiveness
prescribed for residual and/or for secondary
braking. This condition must be met by
means of devices which can be easily actu-
ated when the vehicle is stationary, or by
automatic means.
►M62.2.1.5.2. Furthermore, storage devices
located ◄down-circuit of this device must
be such that in the event of a failure in the
energy supply, after four full-stroke actua-
tions of the service brake control under the
conditions prescribed in item 1.2 of Annex
IV it is still possible to halt the vehicle at
the fifth application with the degree of effec-
tiveness prescribed for secondary braking.
2.2.1.5.3. However, for hydraulic braking devices with
stored energy, these provisions can be consid-
ered to be met, provided that the
requirements of item 1.2.2 of Annex IV,
section C, are satisfied.
2.2.1.6. The requirements of items 2.2.1.2, 2.2.1.4 and 2.2.1.5
must be met without the use of any automatic device
of a kind such that its ineffectiveness might pass unno-
ticed because the parts which are normally in an ‘at
rest’ position are actuated only in the event of failure
of the braking device.
2.2.1.7. The service braking device must act on all the wheels
on the vehicle.
2.2.1.8. The action of the service braking device must be appro-
priately distributed among the axles. In the case of1971L0320 — EN — 22.08.1991 — 007.001 — 11
▼B
▼M4
▼B
▼M4
▼B
▼M6
▼M6
vehicles with more than two axles, in order to avoid
wheel-locking or glazing of the brake linings, the brake
force on certain axles may be reduced to zero automati-
cally when carrying a much reduced load, provided that
the vehicle meets all the performance requirements
prescribed in Annex II.
2.2.1.9. The action of the service braking device must be
distributed between the wheels of the same axle
symmetrically in relation to the longitudinal median
plane of the vehicle.
2.2.1.10. The service braking device and the parking braking
device must act on braking surfaces permanently
connected to the wheels through components of
adequate strength. It must not be possible to disconnect
a braking surface from the wheels; however, in the case
of the servicing device and secondary braking device,
such disconnection of the braking surfaces shall be
permitted provided that it is only momentary, for
instance during a change of gear, and that both the
service braking and the secondary braking continue to
operate withth e prescribed degree of effectiveness. In
addition, any suchdisconnection sh all be permitted in
the case of the parking braking device, provided that it
is controlled exclusively by the driver from his driving
seat by a system which cannot be actuated by a leak(1).
2.2.1.11. Wear on the brakes must be easily compensated by
means of a system of manual or automatic adjustment.
In addition, the control and the components of the
transmission and of the brakes must possess a reserve
of travel and, if necessary, suitable means of compensa-
tion such that, when the brakes become heated or when
the brake linings have reached a certain degree of wear,
effective braking is ensured without immediate adjust-
ment being necessary.
2.2.1.11.1. Wear adjustment shall be automatic for the
service brakes. However, the fitting of auto-
matic adjustment devices is optional for off-
road vehicles of categories N2and N3, and
for rear brakes of vehicles of categories M1and N1. Automatic wear adjustment devices
shall be such that after heating followed by
cooling of the brakes, effective braking is
still ensured. In particular, the vehicle shall
remain capable of normal running after the
tests conducted in accordance withAnnex
II, item 1.3 (Type I test) and Annex II,
item 1.4 (Type II test).
2.2.1.11.2. It shall be possible to easily check this wear
on service brake linings, from the outside or
underside of the vehicle, utilizing only the
tools or equipment normally supplied with
the vehicle; for instance, by the provision
of appropriate inspection holes or by some
other means. Alternatively, acoustical or
optical devices warning the driver at his
driving position when lining replacement is
necessary are acceptable. The removal of
front and/or rear wheels is permitted for
this purpose on category M1and N1vehicles
only.
2.2.1.12. In hydraulic braking devices:
2.2.1.12.1. the filling ports of the fluid reservoirs must
be readily accessible; in addition, the1971L0320 — EN — 22.08.1991 — 007.001 — 12
(1) This item must be interpreted in the following way: The performance of the service and
secondary braking devices must remain within the limits prescribed in the Directive,
even during momentary disconnection.▼B
▼M4
▼M6
▼B
▼B
containers of reserve fluid must be so made
that the level of the reserve fluid can be
easily checked without the containers
having to be opened. Where this last condi-
tion is not fulfilled, a warning light must
indicate to the driver when the reserve fluid
falls to a level liable to cause a failure of
the braking device. The driver must be able
to check easily whether the light is func-
tioning properly;
2.2.1.12.2. the failure of a part of a hydraulic transmis-
sion 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 and remaining lit as long as the
failure persists and the ignition (start) switch
is in the ‘on’ (run) position. 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 from the
driver's seat. The failure of a component of
the device shall not entail total loss of effec-
tiveness of the braking device in question;
2.2.1.12.3. the type of fluid to be used in the hydraulic
transmission braking devices shall be identi-
fied in accordance withISO Standard 9128-
1987. The relevant symbol according to
figure 1 or 2 must be affixed in a visible
position in indelible form within 100 mm
of the filling ports of the fluid reservoirs;
additional information may be provided by
the manufacturers.
2.2.1.13. Any vehicle fitted with a service brake actuated by an
energy reservoir must, where the prescribed secondary
braking performance cannot be obtained by means of
this brake without the use of stored energy, be provided
witha warning device — in addition to a pressure
gauge, where fitted — giving an optical or acoustic
signal when the stored energy in any part of the system
falls to a value at which, without recharging of the
reservoir and irrespective of the load conditions of the
vehicle, it is possible to apply the service brake control
a fifthtime after four full-stroke actuations and obtain
the prescribed secondary braking performance (without
faults in the service-brake transmission device and
with the brakes adjusted as closely as possible). The
warning device must be directly and permanently
connected to the circuit. When the engine is running
under normal operating conditions and there are no
faults in the braking system, the warning device must
give no signal except during the time required for char-
ging the energy reservoir(s) after start-up of the engine.
2.2.1.13.1. However, in the case of vehicles which are
only considered to comply withth e require-
ments of item 2.2.1.5.1 by virtue of meeting
the requirements of item 1.2.2 of Annex IV,
section C, the alarm device shall consist of
an acoustic signal in addition to an optical
signal. These devices need not operate
simultaneously, provided that each of them
meets the above requirements and the
acoustic signal is not actuated before the
optical signal.
2.2.1.13.2. This acoustic device may be rendered inop-
erative while the handbrake is applied and/
or, at the choice of the manufacturer, in the1971L0320 — EN — 22.08.1991 — 007.001 — 13
▼M4
▼M6
▼M3
▼M4
▼M4
case of automatic transmission the selector
is in the ‘park’ position.
2.2.1.14. Without prejudice to the requirements of item 2.1.2.3,
where the use of an auxiliary energy source is essential
for the operation of a braking device, the energy reserve
must be such as to ensure that, should the engine stop,
or in the event of a failure of the means by which the
energy source is driven, the braking performance
remains sufficient to bring the vehicle to a halt in the
prescribed conditions. In addition, if the muscular
energy applied by the driver to the parking brake device
is reinforced by some aid, the actuation of the parking
braking must be ensured in the event of failure of that
aid, if necessary a reserve of energy independent of that
normally supplying suchaid. Th is reserve of energy
may be that indended for the service braking. The
expression ‘actuation’ also covers the action of
releasing.
2.2.1.15. In the case of a motor vehicle to which the coupling of
a trailer equipped witha brake controlled by th e driver
of the drawing vehicle is authorised, the service braking
device of the drawing vehicle must be fitted with a
device so designed that if the trailer braking device
should fail, or the air supply pipe (or such other type
of connection as may be adopted) between the drawing
vehicle and trailer should break, it will still be possible
to brake the drawing vehicle with the effectiveness
prescribed for the secondary braking; it is accordingly
prescribed, in particular, that this device be fitted to
the drawing vehicle(1).
2.2.1.16. The auxiliary equipment must draw its energy only in
such a way that its operation, even in the event of
damage to the energy source, cannot cause the reserves
of energy feeding the braking devices to fall below the
level indicated in item 2.2.1.13.
►M42.2.1.17. ◄Where the trailer belongs to category O3or
O4, the service braking device must be of a continuous
or semi-continuous type.
►M42.2.1.18. ◄In the case of a vehicle authorised to draw a
category O3or O4trailer, the braking devices must
satisfy the following conditions:
►M42.2.1.18.1. ◄when the secondary braking
device of the drawing vehicle is actuated,
there must also be a graduated braking
action on the trailer;
►M42.2.1.18.2. ◄should the main braking device
of the drawing vehicle fail, and if this
device is made up of at least two indepen-
dent sections, the section or sections not
affected by this failure must be able
partially or fully to actuate the trailer
brakes. It must be possible to graduate this
braking action. ►M3If this operation is
achieved by a valve which is normally at
rest, then such a valve may only be incorpo-
rated if its correct functioning can easily be
checked by the driver, either from within
the cab or from outside the vehicle, without
the use of tools; ◄
2.2.1.18.3. in the case of a break or leak in one of the
air supply pipes (or in suchoth er type of1971L0320 — EN — 22.08.1991 — 007.001 — 14
(1) This point is to be interpreted in the following way: It is essential, in all cases, that the
service braking device should be fitted with a device (for instance a limiting valve)ensuring that the vehicle can still be braked by the service brake, but with a perfor-
mance equal to that of the secondary brake.▼B
▼M4
▼B
▼M6
▼M6
connection as may be adopted), it must
nevertheless be possible for the driver to
fully or partially actuate the trailer brakes,
by means either of the service braking
control or of the secondary braking control
or of the parking braking control, unless
the break or leak automatically causes the
trailer to be braked withth e performance
prescribed in item 2.2.3 of Annex II;
2.2.1.18.4. in the case of a two-line air supply system,
the requirement in item 2.2.1.18.3 above
shall be considered to be met if the
following conditions are fulfilled:
2.2.1.18.4.1. when the designated brake
control of the controls
mentioned in item 2.2.1.18.3
above is fully actuated, the
pressure in the supply line
must fall to 1,5 bar within the
following two seconds;
2.2.1.18.4.2. when the supply line is evacu-
ated at the rate of at least 1 bar/
s, the automatic braking of the
trailer must start to operate
before the pressure in the
supply line falls to 2 bar.
►M42.2.1.19. ◄Except in the case of ‘urban buses’, vehicles
used for the carriage of passengers comprising more
than eight seats in addition to the driver's seat, and
having a ►M3maximum mass ◄exceeding 10
metric tons, must satisfy the Type II A test described
in item 1.5 of Annex II and not the Type II test
described in item 1.4 of that Annex.
2.2.1.20. In the case of a motor vehicle equipped to draw a trailer
withelectric service brakes, th e following requirements
shall be met:
2.2.1.20.1. the power supply (generator and battery) of
the motor vehicle shall have a sufficient
capacity to provide the current for an elec-
tric braking system. Withth e engine
running at the idling speed recommended
by the manufacturer and all electric devices
supplied by the manufacturer as standard
equipment of the vehicle switched on, the
voltage in the electrical lines shall at
maximum current consumption of the elec-
tric braking system (15 A) not fall below
the value of 9,6 V measured at the connec-
tion. The electrical lines shall not be
capable of short-circuiting even when over-
loaded;
2.2.1.20.2. in the event of a failure of the drawing vehi-
cle's service braking device, where that
device consists of at least two independent
units, the unit or units not affected by the
failure shall be capable of partially or fully
actuating the brakes of the trailer;
2.2.1.20.3. the use of the stop-light switch and circuit
for actuating the electric braking system is
permissible only if the actuating line is
connected in parallel with the stop-light
and the existing stop-light switch and circuit
are capable of taking the extra load.
2.2.1.21. In the case of a pneumatic service braking device
comprising two or more independent sections, any
leakage between those sections at or downstream of
the control shall be continuously vented to atmosphere.1971L0320 — EN — 22.08.1991 — 007.001 — 15
▼M4
▼M6
▼B
▼M4
▼M5
2.2.1.22. Certain motor vehicles shall be fitted with anti-lock
devices in accordance with Annex X, as shown in the
following table:
VehicleMaximum
massAnti-lock
categoryCategory Description
M3Inter-urban motor coaches
and long distance touring
motor coaches> 12 tonnes 1
N3Motor vehicles authorized to
tow category O4trailers> 16 tonnes 1
2.2.1.23. If motor vehicles not mentioned in item 2.2.1.22 above
are fitted with anti-lock devices, they shall comply with
the requirements of Annex X.
2.2.1.24. In the case of a motor vehicle authorized to draw a
trailer of category O3or O4, the service braking device
of the trailer may only be operated in conjunction with
the service, secondary or parking braking device of the
drawing vehicle.
2.2.2.Vehicles of category O
2.2.2.1. Trailers of category O1need not be fitted witha service
braking device; however, if trailers of this category are
equipped witha service braking device th is must
comply with the same requirements as those of category
O2.
2.2.2.2. Every trailer of category O2must be fitted witha
service braking device either of the continuous or
semi-continuous type or of the inertia (overrun) type.
The latter type shall be authorized only for trailers other
than semi-trailers. However, electric service brakes
conforming to the requirements of Annex XI shall be
permitted.
2.2.2.3. Every trailer of category O3or O4must be fitted witha
service braking device of the continuous or semi-contin-
uous type.
2.2.2.4. The service braking device must act on all the wheels
of the trailer.
2.2.2.5. The action of the service braking device must be
suitably distributed among the axles.
2.2.2.6. The action of every braking device must be distributed
between the wheels of each axle symmetrically in rela-
tion to the longitudinal median plane of the vehicle.
2.2.2.7. The braking surfaces required to attain the prescribed
degree of effectiveness must be in constant contact
with the wheels, either rigidly or through components
not liable to failure.
2.2.2.8. Wear on the brakes must be easily compensated by a
system of manual or automatic adjustment. In addition,
the control and the components of the transmission and
of the brakes must possess a reserve of travel and if
necessary, suitable means of compensation suchth at,
when the brakes become heated or when the brake
linings have reached a certain degree of wear, effective
braking is ensured without immediate adjustment being
necessary.
2.2.2.8.1. Wear adjustment shall be automatic for the
service brakes. However, the fitting of auto-
matic adjustment devices is optional for
vehicles of categories O1and O2. Automatic1971L0320 — EN — 22.08.1991 — 007.001 — 16
▼M6
▼B
▼M4
▼B
▼M4
▼M6
▼M6
wear adjustment devices shall be such that
after heating followed by cooling of the
brakes, effective braking is still ensured.
In particular, the vehicle shall remain capable
of normal running after the tests conducted in
accordance withAnnex II, item 1.3 (Type I
test) and Annex II, item 1.4 (Type II test).
2.2.2.8.2. It shall be possible to easily check this wear
on service brake linings, from the outside or
underside of the vehicle, utilizing only the
tools or equipment normally supplied with
the vehicle; for instance, by the provision of
appropriate inspection holes or by some other
means.
2.2.2.9. The braking devices must be such that the trailer is
stopped automatically if the coupling
►M6separates ◄while the trailer is in motion.
However, this requirement shall not apply to
►M6 ◄trailers witha
►M3maximum mass ◄not exceeding 1·5 metric
tons provided that the trailers are fitted, in addition to
the main coupling, with a secondary coupling (chain,
cable, etc.) which, in the event of ►M6separation ◄
of the main coupling, can stop the drawbar from
touching the ground and provide some residual steering
action on the trailer.
2.2.2.10. On every trailer which is required to be fitted with a
service braking device, parking braking must be
ensured even when the trailer is separated from the
drawing vehicle. It must be possible for a person
standing on the ground to actuate the parking braking
device; however, in the case of a trailer used for the
carriage of passengers, it must be possible to actuate
this brake from inside the trailer. The expression
‘actuate’ also covers the action of releasing.
2.2.2.11. If the trailer is fitted with a device enabling
compressed-air actuation of the braking device, other
than the parking braking device, to be cut out, the
first-mentioned device must be so designed and
constructed that it is positively restored to the ‘at rest’
position not later than on the resumption of the supply
of compressed air to the trailer.
2.2.2.12. Trailers of categories O3and O4fitted witha two-line
air supply system shall satisfy the conditions specified
in item 2.2.1.18.4 above.
2.2.2.13. Trailers of category O4shall be fitted with anti-lock
devices in accordance withAnnex X.
2.2.2.14. If trailers not mentioned in item 2.2.2.13 above are
fitted with anti-lock devices, they shall comply with
the requirements of Annex X.1971L0320 — EN — 22.08.1991 — 007.001 — 17
▼B
▼M6
▼M4
▼M5
▼B
ANNEX II
BRAKINGTESTSANDPERFORMANCEOFBRAKINGDEVICES
1. BRAKING TESTS
1.1.General
1.1.1. The performance prescribed for braking devices shall be based on
the stopping distance and/or the mean fully developed decelera-
tion. The performance of a braking device shall be determined
by measuring the stopping distance in relation to the initial speed
of the vehicle and/or by measuring the mean fully developed
deceleration during the test.
1.1.2. The stopping distance shall be the distance covered by the vehicle
from the moment when the driver begins to actuate the control of
the device until the moment when the vehicle stops; the initial
speed shall be the speed at the moment when the driver begins
to actuate the control of the device. In the formulae given below,
for the measurement of braking performance,
v = initial speed in km/h
s = stopping distance in metres.
1.1.3. For the type approval of any vehicle, the braking performance
shall be measured during road tests conducted in the following
conditions:
1.1.3.1. the vehicle's condition as regards ►M3mass◄must
be as prescribed for eachtype of test and be specified
in the test report;
1.1.3.2. the test must be carried out at the speeds prescribed for
each type of test. Where a vehicle is so constructed that
its maximum speed is lower than that prescribed for a
test, the test must be performed at the maximum speed
of the vehicle;
1.1.3.3. during the tests the force applied to the brake control in
order to obtain the prescribed performance must not
exceed the maximum laid down for the test vehicle's
category;
1.1.3.4. ►M2without prejudice to the requirements contained in
item 1.1.4.2 below, the road shall possess a surface
having good adhesion; ◄
1.1.3.5. the tests must be performed when there is no wind liable
to affect the results;
1.1.3.6. at the start of the tests the tyres must be cold and at the
pressure prescribed for the load actually borne by the
wheels when the vehicle is stationary;
1.1.3.7. the prescribed performance must be obtained without
locking of the wheels, without deviation of the vehicle
from its course, and without abnormal vibration.
►M6Wheel-locking is permitted where specifically
mentioned. ◄
1.1.4.Behaviour of the vehicle during braking
1.1.4.1. In braking tests, and in particular in those at high speed,
the general behaviour of the vehicle during braking must
be checked.
1.1.4.2. The behaviour of vehicles in categories M1,M2,M3,N1,
N2,N3,O3and O4on a road surface having reduced adhe-
sion shall fulfil the conditions laid down in the
Appendix.
1.2.TypeOtest
(ordinary performance test withbrakes cold)1971L0320 — EN — 22.08.1991 — 007.001 — 18
▼M6
▼B
▼M2
▼B
▼B
1.2.1.General
1.2.1.1. The brakes must be cold. A brake is deemed to be cold
when the temperature measured on the disc or on the
outside of the drum is below 100ºC.
1.2.1.2. The test must be conducted in the following conditions:
1.2.1.2.1. the vehicle must be laden, the distribution of
its►M3mass◄among the axles being that
stated by the maker. Where provision is made
for several arrangements of the load on the
axles the distribution of the ►M3maximum
mass◄among the axles must be such that
the load on each axle is proportional to the
maximum permissible load for eachaxle.
►M4In the case of tractive units for semi-
trailers, the load may be re-positioned approxi-
mately half-way between the kingpin position
resulting from the above loading conditions
and the centreline of the rear axle(s); ◄
1.2.1.2.2. every text must be repeated on the unladen
vehicle. In the cae of a motor vehicle there
may be, in addition to the driver, a second
person on the front seat who is responsible
for noting the results of the test. In the case
of a motor vehicle designed to draw a semi-
trailer, the unladen tests will be conducted
with the vehicle in its solo condition, including
a mass representing the fifth wheel. It will also
include a mass representing a spare wheel, if
this is included in the standard specification
of the vehicle. In the case of a vehicle
presented as a bare chassis-cab, a supplemen-
tary load may be added to simulate the mass
of the body, not exceeding the minimum mass
declared by the manufacturer in Annex IX;
1.2.1.2.3. the limits prescribed for minimum perfor-
mance, both for tests with the vehicle unladen
and for tests with the vehicle laden, shall be
those laid down hereunder for each category
of vehicle. ►M6The vehicle must satisfy
both the prescribed stopping distance and the
prescribed mean fully developed deceleration
for the relevant vehicle category, but it may
not be necessary to actually measure both
parameters; ◄
1.2.1.2.4. the road must be level.
1.2.2.Type O test with engine disconnected
1.2.2.1. The test must be carried out at the speed prescribed for
the category to which the vehicle belongs, the figures
prescribed in this connection being subject to a certain
margin of tolerance. The minimum performance
prescribed for eachcategory must be attained.
1.2.3.Type O test with engine connected
1.2.3.1. Apart from the test prescribed in item 1.2.2, additional
tests shall be carried out at various speeds with the
engine connected, the lowest being equal to 30 % of the
maximum speed of the vehicle and the highest being
equal to 80 % of that speed. The maximum practical
performance figures shall be measured and the behaviour
of the vehicle shall be recorded in the test report. Trac-
tive units for semi-trailers, artificially loaded to simulate
the effects of a lade semi-trailer, shall not be tested
beyond 80 km/h.
1.2.3.2. Further tests shall be carried out with the engine
connected, from the speed prescribed for the category to
which the vehicle belongs. The minimum performance
prescribed for eachcategory must be attained. Tractive1971L0320 — EN — 22.08.1991 — 007.001 — 19
▼M4
▼B
▼M4
▼M6
▼M6
units for semi-trailers, artificially loaded to simulate the
effects of a laden semi-trailer, shall not be tested beyond
80 km/h.
1.2.4.Type O test for vehicles of category O equipped with compressed
air brakes
1.2.4.1. The braking performance of the trailer can be calculated
either from the braking rate of the drawing vehicle plus
the trailer and the measured thrust on the coupling or, in
certain cases, from the braking rate of the drawing
vehicle plus the trailer with only the trailer being braked.
The engine of the drawing vehicle must be disconnected
during the braking test. In the case where only the trailer
is braked, to take account of the extra mass being
retarded, the performance will be taken to be the mean
fully developed deceleration.
1.2.4.2. Withth e exception of cases according to items 1.2.4.3
and 1.2.4.4, it is necessary for the determination of the
braking rate of the trailer to measure the braking rate of
the drawing vehicle plus the trailer and the thrust on the
coupling. The drawing vehicle must meet the require-
ments laid down in the Appendix to item 1.1.4.2 of
Annex II with regard to the relation between the ratio
Tm
Pmand the pressure pm. The braking rate of the trailer
is calculated according to the following formula:
zR¼zRþMþD
PR
where:
zR= braking rate of the trailer,
zR+M= braking rate of the drawing vehicle plus the
trailer,
D = thrust on the coupling
(tractice force D = > 0)
(compressive force D = < 0).
1.2.4.3. If a trailer has a continuous or semi-continuous braking
device where the pressure in the brake actuators does
not change during braking despite the dynamic axle
load shifting, and in the case of semi-trailers, the trailer
alone may be braked. The braking rate of the trailer is
calculated according to the following formula:
zR¼zRþM/C0R ðÞ /C1PMþPR
PRþR
where:
R = rolling resistance value = 0,01.
1.2.4.4. Alternatively, the evaluation of the braking rate of the
trailer may be done by braking the trailer alone. In this
case the pressure used shall be the same as that measured
in the brake actuators during the braking of the combina-
tion.
1.3.TypeItest
(fade test)1.3.1.With repeated braking
1.3.1.1. The service brakes of vehicles in categories M
1,M2,M3,
N1,N2and N3shall be tested by successively applying
and releasing the brakes a number of times, the vehicle
being laden, in accordance with the conditions shown in
the following table:
Conditions
Category
of vehiclev1
km/hv2
km/h∆t
secsn
M180% vmax-≤120½v145 151971L0320 — EN — 22.08.1991 — 007.001 — 20
▼M4
▼B
▼B
Conditions
Category
of vehiclev1
km/hv2
km/h∆t
secsn
M280% vmax-≤100½v155 15
M380% vmax-≤60½v160 20
N180% vmax-≤120½v155 15
N280% vmax-≤60½v160 20
N380% vmax-≤60½v160 20
where:
v1= initial speed, when braking starts,
v2= speed at end of braking,
vmax= maximum speed of the vehicle,
n = number of times brakes applied,
∆t = duration of a braking cycle (time elapsing
between the initiation of one brake application
and the initiation of the next).
1.3.1.2. If the characteristics of the vehicle do not allow for the
period of time prescribed for ∆t, the duration may be
increased; in any event, in addition to the time necessary
for braking and accelerating the vehicle, a period of 10
seconds must be allowed in eachcycle for stabilising
the speed v1.
1.3.1.3. In these tests, the force applied to the control must be so
adjusted as to attain a mean fully developed deceleration
of 3 m/s2at the first application of the brakes. This force
must remain constant throughout the succeeding brake
applications.
1.3.1.4. During brake applications the highest gear ratio
(excluding overdrive, etc.) must be continuously
engaged.
1.3.1.5. For regaining speed after braking, the gearbox must be
used in sucha way as to attain th e speed v1in the
shortest possible time (maximum acceleration allowed
by the engine and gearbox).
1.3.2.With continuous braking
1.3.2.1. ►M3The service brakes of trailers of categories O2,O3and O4shall be tested in such a manner that ◄,t he
vehicle being laden, the energy input to the brakes is
equivalent to that recorded in the same period of time
witha laden veh icle driven at a steady speed of 40 km/
hon a 7% down gradient for a distance of 1·7 km.
1.3.2.2. The test may be carried out on a level road, the trailer
being drawn by a motor vehicle; during the test, the
force applied to the control must be adjusted so as to
keep the resistance of the trailer constant (7% of the
►M3mass◄of the trailer). If the power available for
hauling is insufficient, the test can be conducted at a
lower speed but over a greater distance, as shown in the
following table:1971L0320 — EN — 22.08.1991 — 007.001 — 21
▼M6
▼B
▼B
Speed
(km/h)Distance
(metres)
40 1 700
30 1 950
20 2 500
15 3 100
1.3.3.Hot performance
►M61.3.3.1. At the end of the Type I test ◄(test described in
item 1.3.1 or test described in item 1.3.2 of this Annex)
►M6the hot performance of the service braking
device◄shall be measured under the same conditions
(and in particular at a constant control force no greater
than the mean force actually used) as for the Type O
test with the engine disconnected (the temperature condi-
tions may be different). ►M6For motor vehicles, this
hot performance ◄must not be less than 80 % of that
prescribed for the category in question nor less than
60 % of the figure recorded in the Type O test with the
engine disconnected. ►M6However, in the case of trai-
lers, the hot brake force ◄at the periphery of the
wheels when tested at 40 km/h must not be less than
36 % of the force corresponding to the maximum mass
borne by the wheels when the vehicle is stationary, nor
less than 60 % of the figure recorded in the Type O test
at the same speed.
1.3.3.2. In the case of a motor vehicle which satisfies the 60 %
requirement specified in item 1.3.3.1 above, but which
cannot comply withth e 80 % requirement specified in
item 1.3.3.1 above, a further hot performance test may
be carried out using a control force not exceeding that
specified in item 2.1.1.1 of this Annex. The results of
both tests shall be entered in the report.
1.4.TypeIItest
(downhill behaviour test)
1.4.1. Laden vehicles shall be tested in such a manner that the energy
input is equivalent to that recorded in the same period of time
witha laden veh icle driven at an average speed of 30 km/hon a
6% down gradient for a distance of 6 km, withth e appropriate
gear engaged (if the vehicle is a motor vehicle) and the retarder,
if the vehicle is fitted with one, being used. The gear engaged
must be such that the rpm of the engine does not exceed the
maximum value prescribed by the manufacturer.
1.4.2. For vehicles in which the energy is absorbed by the braking
action of the engine alone, a tolerance of ± 5 km/h on the average
speed shall be permitted, and the gear enabling the speed to be
stabilised at the value closest to 30 km/h on the 6% downgradient shall be engaged. If the performance of the braking
action of the engine alone is determined by a measurement of
deceleration, it shall be sufficient if the mean deceleration
measured is at least 0·5 m/sec
2.
►M61.4.3. At the end of the test, the hot performance of the service
braking device ◄shall be measured in the same conditions as
for the Type O test with the engine disconnected (the temperature
conditions, of course, are different). ►M6For motor vehicles,
this hot performance must give a stopping distance not exceeding
the following values and a mean fully developed deceleration not
less than the following values, using a control force not
exceeding 700 N:
category M3:s ¼0;15 V þ1;33 V2
130(the second term corresponding to a mean
fully developed deceleration of 3,75 m/s2);1971L0320 — EN — 22.08.1991 — 007.001 — 22
▼M6
▼M4
▼M6
▼B
▼M4
▼M4
category N3:s ¼0;15 V þ1;33 V2
115(the second term corresponding to a mean
fully developed deceleration of 3,3 m/s2).
However, in the case of trailers the hot brake force at the
periphery of the wheels ◄when tested at 40 km/h must not be
less than 33 % of the force corresponding to the maximum mass
borne by the wheels when the vehicle is stationary.
1.5.TypeIIAtest
(test for vehicles, other than ‘urban buses’, used for the carriage of
passengers comprising more than eight seats in addition to the driver's
seat and having a ►M3maximum mass ◄exceeding 10 metric tons)
1.5.1. Laden vehicles shall be tested in such a manner that the energy
input is equivalent to that recorded in the same period of time
witha laden veh icle driven at an average speed of 30 km/hon a
7% down gradient for a distance of 6 km. During the test, the
service, secondary and parking braking devices must not be
engaged. The gear engaged must be such that the rpm of the
engine does not exceed the maximum value prescribed by the
manufacturer. ►M4An integrated retarder may be used,
provided that it is suitably phased such that the service brakes
are not applied; this may be verified by checking that these
brakes remain cold, as defined in item 1.2.1.1 of this Annex. ◄
1.5.2. For vehicles in which the energy is absorbed by the braking
action of the engine alone, a tolerance of ± 5 km/h on the average
speed shall be permitted and the gear enabling the speed to be
stabilised at the value closest to 30 km/h on a 7% down gradient
shall be engaged. If the performance of the braking action of the
engine alone is determined by a measurement of deceleration, it
shall be sufficient if the mean deceleration measured is at least
0·6 m/sec2.
2. PERFORMANCE OF BRAKING DEVICES
2.1.Vehiclesofcategories MandN
2.1.1.Service braking devices
2.1.1.1. Provisions relating to tests
2.1.1.1.1. The service brakes of vehicles of cateogries M
and N shall be tested under the conditions
shown in the following table:
Type of
testM1M2M3N1N2N3
O-I O-I O-I-II O-I O-I O-I-II
Type O test
withengine
disconnectedV 80 km/h 60 km/h60 km/h80 km/h60 km/h60 km/h
s≤0;1VþV2
1500;15 V þV2
130
dm≥ 5,8 m/s25 m/s2
Type O test
withengine
connectedV = 80 %
max
but≤160 km/h 100 km/h90 km/h120 km/h100 km/h90 km/h
s≤0;1VþV2
1300;15 V þV2
103 ;5
dm≥ 5 m/s24 m/s2
F≤ 500 N 700 N1971L0320 — EN — 22.08.1991 — 007.001 — 23
▼B
▼M6
▼C3
▼M6
▼M6
where:
V = test speed
s = stopping distance
dm= mean fully developed deceleration
f = force applied to foot control
Vmax= maximum speed of the vehicle
2.1.2.Secondary braking devices
2.1.2.1. The secondary braking device, even if the control which
actuates it is also used for other braking functions, must
give a stopping distance not exceeding the following
values and a mean fully developed deceleration not less
than the following values:
category M1:s ¼0;1Vþ2V2
150(the second term corresponding to
a mean fully developed decelera-
tion of 2,9 m/s2);
category M2,M3:s ¼0;15 V þ2V2
130(the second term corresponding to
a mean fully developed decelera-
tion of 2,5 m/s2);
category N: s ¼0;15 V þ2V2
115(the second term corresponding to
a mean fully developed decelera-
tion of 2,2 m/s2).
2.1.2.2. If the secondary braking control is a manual control, the
prescribed performance must be obtained by applying to
the control a force not exceeding ►M3400 N◄in the
case of category M1vehicles and ►M3600 N◄in the
case of other vehicles, and the control must be so placed
that it can be easily and quickly grasped by the driver.
2.1.2.3. If the secondary braking control is a foot control, the
prescribed performance must be obtained by applying to
the control a force not exceeding ►M3500 N◄in the
case of category M1vehicles and ►M3700 N◄in the
case of other vehicles, and the control must be so placed
that it can be easily and quickly actuated by the driver.
2.1.2.4. The performance of the secondary braking device shall
be checked by the Type O test with the engine discon-
nected from the following initial speeds:
M1= 80 km/h
N1= 70 km/h
M2= 60 km/h
N2= 50 km/h
M3= 60 km/h;
N3= 40 km/h.
2.1.2.5. The secondary braking effectiveness test shall be
conducted by simulating the actual failure conditions in
the service braking system.
2.1.3.Parking braking devices
2.1.3.1. The parking braking device must, even if it is combined
with one of the other braking devices, be capable of
holding a laden vehicle stationary on an 18% up or
down gradient.
2.1.3.2. On vehicles to which the coupling of a trailer is
authorised, the parking braking device of the drawing
vehicle must be capable of holding the combination of
vehicles stationary on a 12% gradient.1971L0320 — EN — 22.08.1991 — 007.001 — 24
▼B
▼M6
▼B
▼M4
▼M6
▼B
▼B
2.1.3.3. If the control is a manual control, the force applied to it
must not exceed ►M3400 N◄in the case of category
M1vehicles and ►M3600 N◄in the case of all other
vehicles.
2.1.3.4. If it is a foot control, the force exerted on the control
must not exceed ►M3500 N◄in the case of category
M1vehicles and ►M3700 N◄in the case of all other
vehicles.
2.1.3.5. A parking braking device which has to be actuated
several times before attaining the prescribed performance
is admissible.
►M42.1.3.6. To check compliance with the requirements of
Annex I, item 2.2.1.2.4, a Type O test must be carried
out with the engine disconnected at the initial speed
specified in item 2.1.2.4 for the relevant vehicle cate-
gory. The mean fully developed ◄deceleration on
application of either the parking brake or the auxiliary
control of the service brake, and the deceleration imme-
diately before the vehicle stops, shall be not less than
1·5 m/s2. The test shall be carried out with the vehicle
laden, and compliance with the requirements shall be
deemed to be met if the braking performance has been
achieved once. The force exerted on the braking control
shall not exceed the specified values. In the case of vehi-
cles of category M1or N1, fitted witha parking brake
using friction linings other than those for the service
braking system, the test may be carried out from 60 km/
h at the request of the manufacturer. In this case, the
mean fully-developed deceleration must be not less than
2·0 m/s2; deceleration immediately before the vehicle
stops must not be less than 1·5 m/s2.
2.1.4.Residual service braking after transmission failure
2.1.4.1. The residual performance of the service braking device,
in the event of failure in a part of its transmission, must
give a stopping distance not exceeding the following
values and a mean fully developed deceleration not less
than the following values, using a control force not
exceeding 700 N, when checked by the Type O test
with the engine disconnected from the following initial
speeds for the relevant vehicle category:
Stoppingdistance(m)andmeanfullydevelopeddeceleration (m/s2)
(km/
h)Laden Unladen
M180 0 ;1Vþ100
30V2
150(1,7) 0 ;1Vþ100
25V2
150(1,5)
M260 0 ;15Vþ100
30V2
130(1,5) 0 ;15Vþ100
25V2
130(1,3)
M360 0 ;15Vþ100
30V2
130(1,5) 0 ;15Vþ100
30V2
130(1,5)
N170 0 ;15Vþ100
30V2
115(1,3) 0 ;15Vþ100
25V2
115(1,1)
N250 0 ;15Vþ100
30V2
115(1,3) 0 ;15Vþ100
25V2
115(1,1)
N340 0 ;15Vþ100
30V2
115(1,3) 0 ;15Vþ100
30V2
115(1,3)1971L0320 — EN — 22.08.1991 — 007.001 — 25
▼M3
▼M4
▼M6
▼M4
▼M6
2.1.4.2. The residual braking effectiveness test shall be conducted
by simulating the actual failure conditions in the service
braking system.
2.2.Vehiclesofcategory O
2.2.1.Service braking devices
2.2.1.1. Requirement relating to tests of category O1vehicles.
2.2.1.1.1. Where the provision of a service braking
device is mandatory, the performance of the
device must meet the requirements laid down
for category O2.
2.2.1.2. Requirements relating to tests of category O2vehicles.
►M62.2.1.2.1. If the service braking device is of the
ocntinuous or semi-continuous type, the sum
of the forces exerted at the periphery of the
braked wheels ◄must be equal to not less
than X % of the force corresponding to the
maximum mass borne by the wheels when the
vehicle is stationary, X having the following
values:
full trailer, laden and unladen 50,
semi-trailer, laden and unladen 45,
centre-axle trailer, laden and unladen 50.
Where the trailer is fitted with compressed-air
brakes, the pressure in the control line and in
the supply line must not exceed 6,5 bar(1)
during the brake test. The test speed is 60 km/
h. A supplementary test at 40 km/h must be
carried out with the laden vehicle for compar-
ison withth e Type I test result.
2.2.1.2.2. Where the braking device is of the inertia
type, it must comply withth e conditions laid
down in Annex VIII.
2.2.1.2.3. In addition, these vehicles must be subjected
to the Type I test.
2.2.1.2.4. In the Type I test of a semi-trailer, the
►M3mass◄braked by its axles must be
that corresponding to the load on the axle or
axles of the semi-trailer when the latter is
carrying its maximum load.
2.2.1.3. Requirements relating to the testing of category O3vehi-
cles. The same requirements apply as to category O2.
2.2.1.4. Requirements relating to tests of category O4vehicles.
2.2.1.4.1. The same requirements apply as apply to cate-
gory O2; in addition, these vehicles must be
subjected to the Type II test.
2.2.1.4.2. In the Type I and Type II tests of a semi-
trailer, the ►M3mass◄braked by its axles
must be that corresponding to the load on the
axle or axles of the semi-trailer when the latter
is carrying its maximum load.
2.2.2.Parking braking devices
2.2.2.1. The parking brake with which the trailer or semi-trailer
is fitted must be capable of holding the laden trailer or
semi-trailer stationary, when separated from the drawing1971L0320 — EN — 22.08.1991 — 007.001 — 26
(1) The pressures specified here and in the following Annexes are relative pressures
measured in bars.▼B
▼M4
▼B
▼M3
▼B
▼M3
▼B
▼B
vehicle, on an 18% up or down gradient. The force
applied to the control must not exceed ►M3600 N◄.
2.2.3. Automatic braking
2.2.3.1. The automatic braking performance in the event
of a total pressure loss in the air supply line,
when testing the laden vehicle from 40 km/h,
must not be less than 13,5 % of the force corre-
sponding to the maximum mass borne by the
wheels when the vehicle is stationary. Wheel-
locking at performance levels above 13,5 % is
permitted.
2.3.Reactiontime
Where a vehicle is fitted with a service braking device which is totally
or partially dependent on a source of energy other than the muscular
effort of the driver, the following requirements must be satisfied:
2.3.1. in an emergency manoeuvre, the time clapsing between the
moment when the control begins to be actuated and the moment
when the braking force on the least favourably placed axle
reaches the level corresponding to the prescribed performance
must not exceed 0·6 seconds;
2.3.2. in the case of vehicles fitted with compressed air braking devices,
the requirements of item 2.3.1 are considered to be satisfied if the
vehicle complies with the provisions of Annex III;
2.3.3. in the case of vehicles fitted with hydraulic braking devices, the
requirements of item 2.3.1 are considered to be satisfied if, in an
emergency manœuvre, the deceleration of the vehicle, or the
pressure at the least favourable brake cylinder, reaches a level
corresponding to the prescribed performance within 0,6 seconds.1971L0320 — EN — 22.08.1991 — 007.001 — 27
▼M6
▼B
▼M3
▼M4
▼M1
Appendix (See 1.1.4.2)
DISTRIBUTIONOFBRAKINGEFFORTAMONGVEHICLEAXLES
1. GENERAL REQUIREMENTS
Vehicles of categories M, N, O3and O4which are not equipped with
an anti-lock device as defined in Annex X shall meet all the require-
ments of this 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
z = braking rate of vehicle = J/g(2)
P= ►M3mass◄of vehicle
h = height of centre of gravity specified by the manufacturer
and agreed by the Technical Services conducting the
approval test
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 ►M3maximum mass ◄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
specified by the manufacturer and agreed by the Technical
Services conducting the approval test1971L0320 — EN — 22.08.1991 — 007.001 — 28
(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 ►M3mass◄on the
semi-trailer axle(s).▼M4
▼M2
▼M4
▼M2
▼M4
▼M2
3. REQUIREMENTS FOR MOTOR VEHICLES
3.1.Twoaxlevehicles.
3.1.1.(1) For all categories of vehicles for k values between 0,2 and 0,8:
z/C210;1þ0;85 k /C00;2 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 rates of between 0,15 and 0,8 in the case of vehicles
of category M1.
However, for vehicles of this category over the range of z values
between 0,3 and 0,45, 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 0,05 the line defined by
the formula k = z (line of ideal adhesion utilization — see diagram
1 A),
— for all braking rates of between 0,15 and 0,5 in the case of vehicles
of category N1(2).
This condition is also considered satisfied if, for braking rates
between 0,15 and 0,30, the adhesion utilization curves for each
axle are situated between two parallels to the line of ideal adhesion
utilization given by the equations k = z + 0,08 and k = z − 0,08 as
shown in diagram 1 C, where the adhesion utilization curve for the
rear axle may cross the line k = z − 0,08 and, for braking rates
between 0,3 and 0,5, complies withth e relation z ≥k − 0,08,
and between 0,5 and 0,61 withth e relation z ≥0,5 k + 0,21,
— for all braking rates of between 0,15 and 0,30, in the case of other
categories.
This condition is also considered satisfied if, for braking rates
between 0,15 and 0,30, the adhesion utilization curves for each
axle are situated between two parallels to the line of ideal adhesion
utilization given by the equations k = z + 0,08 and k = z − 0,08, as
shown in diagram 1 B, and the adhesion utilization curve for the
rear axle, for braking rates z ≥0,3 complies withth e relation
z≥0,3 + 0,74 (k − 0,38).
3.1.2. In the case of a motor vehicle authorised to draw trailers of category
O3or O4fitted withcompressed air brake systems, wh en tested with
the energy source stopped, the supply line blocked off and a reservoir
of 0,5 litre capacity connected to the control line, and the system at
cut-in and cut-out pressures, the pressure at full application of the
braking control must be between 6,5 and 8,5 bar at the coupling heads
of the supply line and the control line, irrespective of the load condi-
tions of the vehicle. These pressures must be demonstrably present in
the drawing vehicle when uncoupled from the trailer. The compat-
ibility bands in diagrams 2, 3 and 4A should not be extended beyond
7,5 bar.
3.1.3. In order to verifiy the requirement of item 3.1.1, the manufacturer
shall provide the adhesion utilization curves for the front and rear
axles calculated by the formulae:
f1¼T1
N1¼T1
P1þzh
EP;1971L0320 — EN — 22.08.1991 — 007.001 — 29
(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 braking
efficiencies are obtained which are higher than those prescribed in Annex II, the provi-
sions relating to the adhesion utilization curve shall be applied within the areas ofdiagrams IA and IB defined by the straight lines k = 0·8 and z = 0·8.
(
2) Vehicles of category N1witha laden/unladen rear axle loading ratio not exceeding 1,5
or having a maximum mass of less than 2 tonnes will have comply with the require-
ments for category M1vehicles of this item from 1 October 1990.▼M4
▼M6
▼M4
▼M4
f2¼T2
N2¼T2
P2/C0zh
EP:
The graphs shall be plotted for both the following load conditions:
— unladen, in running order withth e driver on board.
In the case of a vehicle presented as a bare chassis-cab, a supple-
mentary load may be added to simulate the mass of the body, not
exceeding the minimum mass declared by the manufacturer in
Annex IX,
— laden.
Where provision is made for several possibilities of load distribu-
tion, the one whereby the front axle is the most heavily laden shall
be the one to be taken into consideration.
3.1.4. Vehicles other than tractive units for semi-trailers.
3.1.4.1. In the case of a motor vehicle authorized to draw trailers of category
O3or O4fitted withcompressed air braking systems, th e permissible
relationship between the braking rateTM
PMand the pressure pmshall 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 withth e 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 mass applied at the coupling king-pin equal
to 15 % of the maximum mass on the coupling. 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 withladen semi-trailer
A laden articulated combination is considered to be a tractive unit in
running order withth e 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 ►M3mass◄Psapplied at the coupling
king-pin equal to:
Ps¼Pso1þ0/C145 z ðÞ
where Psorepresents the difference between the maximum laden
►M3mass◄of the tractive unit and its unladen ►M3mass◄.
For h the following value shall be taken: h ¼hoPoþhsPs
P
where:
hois the height of the centre of gravity of the tractive unit
hsis the height of the coupling on which the semi-trailer rests
Pois the unladen ►M3mass◄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 pmshall be within the areas shown in diagram 3.
3.2.Vehicleswithmorethantwoaxles
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 rates1971L0320 — EN — 22.08.1991 — 007.001 — 30
▼M2
▼M6
▼M2
▼M4
▼M2
▼M2
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
4.1.Forsemi-trailers fittedwithcompressed-airbrakingsystems
The permissible relationship between the braking rateTR
PRand the pres-
sure pmshall 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.
4.2. If the requirements of item 4.1 cannot be satisfied in conjunction with
the requirements of item 2.2.1.2.1 of Annex II for semi-trailers with a
Kcfactor less than 0,8 then the semi-trailer must meet the minimum
braking performance specified in item 2.2.1.2.1 of Annex II and be
fitted withan anti-lock device complying withAnnex X, except th e
compatibility requirement in item 1 of that Annex.
5. REQUIREMENTS FOR FULL AND CENTRE-AXLE TRAILERS
5.1.Forfulltrailers fittedwithcompressed-airbrakingsystems
5.1.1. The requirements set out in item 3.1 shall apply to twin-axle trailers
(except where the axle spread is less than 2 metres).
5.1.2. Full trailers with more than two axles shall be subject to the require-
ments contained in item 3.2.
5.1.3. The permissible relationship between the braking rateTR
PRand the pres-
sure pmshall lie within the designated areas in diagram 2 for the laden
and undladen stated of load.
5.2.Forcentre-axletrailersfittedwithcompressed-airbrakingsystems
5.2.1. The permissible relationship between the braking rateTR
PRand the pres-
sure pmshall lie within two areas derived from diagram 2, by
multiplying the vertical scale by 0,95, for the laden and unladen states
of load.
5.2.2. If the requirements of item 2.2.1.2.1 of Annex II cannot be satisfied
due to lack of adhesion, then the centre-axle trailer must be fitted
withan anti-lock device complying withAnnex X.
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
to stop the vehicle under the conditions prescribed for secondary
braking in the case of motor vehicles; in the case of trailers and
semi-trailers in 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 require-
ments 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.1971L0320 — EN — 22.08.1991 — 007.001 — 31
▼M4
▼M6
▼M4
▼C2
▼M2
▼M4
8. PRESSURE TEST CONNECTIONS
8.1. Braking systems incorporating the devices referred to in item 7.2 shall
be fitted withpressure test connections in th e pressure line upstream
and downstream of the device, at the closest readily accessible posi-
tions. The downstream connection shall not be required, if the
pressure at that point can be checked at the connection required by
item 4.1 of Annex III.
8.2. The pressure test connections shall comply with clause 4 of ISO Stan-
dard 3583-1984.1971L0320 — EN — 22.08.1991 — 007.001 — 32
▼M6
▼M2
DIAGRAM 1 A
VEHICLES OF CATEGORY M1, ANDCERTAIN VEHICLES OF CATEGORY N1FROM 1
OCTOBER1990
(see item 3.1.1)
1971L0320 — EN — 22.08.1991 — 007.001 — 33
▼M4
▼M2
▼M2
DIAGRAM 1 B
VEHICLESOTHERTHANVEHICLESOFCATEGORYM1ANDN1
(see item 3.1.1)
Note:
The lower limit of the corridor is not applicable for the adhesion utilization of the rear axle.1971L0320 — EN — 22.08.1991 — 007.001 — 34
▼M4
▼M2
▼M4
▼M4
DIAGRAM 1 C
VEHICLESOFCATEGORYN1(WITHCERTAINEXCEPTIONSFROM1OCTOBER1990)
(see item 3.1.1)
Note:
The lower limit of the corridor is not applicable for the adhesion utilization of the rear axle.1971L0320 — EN — 22.08.1991 — 007.001 — 35
▼M2
DIAGRAM 2
DRAWINGVEHICLESANDTRAILERS
(see item 3.1.4.1)
Note:►
M4(1)◄It is understood that between the valuesTM
PM¼0 andTM
PM¼0/C11o rTR
PR¼0 and
TR
PR¼0/C11 it is not necessary that there should be proportionality between the braking rateTM
PM
orTR
PRand the control 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.1971L0320 — EN — 22.08.1991 — 007.001 — 36
▼M4
▼M2
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 proportion-
ality 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.1971L0320 — EN — 22.08.1991 — 007.001 — 37
▼M2
DIAGRAM 4 A
SEMI-TRAILERS
(see item 4)
It is understood that, between the valuesTR
PR¼O andTR
PR¼0;1;it is not necessary that there should
be proportionality between braking rateTR
PRand the control line pressure as measured at the coupling
head.
The relationship between the braking rateTR
PRand control line pressure for the laden and unladen
condition is determined as follows:
The factors Kc(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.1971L0320 — EN — 22.08.1991 — 007.001 — 38
▼M6
▼M2
▼M2
DIAGRAM 4 B
(see item 4)
1971L0320 — EN — 22.08.1991 — 007.001 — 39
▼M2
Explanatorynoteontheuseofdiagram4B
1. Formula from which Diagram 4 B is derived 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/C21hR/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 factors Kcand Kvfor
the following vehicle where:
Laden Unladen
P 24 t 4·2 t
PR 15 t 3 tPR
max15 t 15 t
hR1·8 m 1·4 m
ER6·0 m 6·0 m
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 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, Kcis the 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 curves nearest to vertical axis
(PR/PRmax= 0·2)
(c) Move vertically to horizontal axis and 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 axis and 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: K v¼K1/C0K2Kv¼1/C166 ðÞ :1971L0320 — EN — 22.08.1991 — 007.001 — 40
▼B
ANNEX III
METHODOF MEASURING THE REACTION TIME FOR VEHICLES
FITTEDWITHCOMPRESSEDAIRBRAKINGDEVICES
1. GENERAL REQUIREMENTS
1.1. The reaction time for the braking device shall be determined with the
vehicle stationary, the pressure being measured at the opening of the
least favourable brake cylinder. In the case of vehicles fitted with
combined compressed-air/hydraulic braking systems, the pressure may
be measured at the opening of the least favourable pneumatic unit.
►M6For vehicles equiped with load-sensing valves, these devices
must be set in the laden position. ◄
1.2. During the tests, the stroke of the brake cylinders of the individual axles
must be that corresponding to the most closely adjusted brakes.
1.3. The times determined in implementing the provisions of this Annex
shall be rounded to the nearest 10th of a second. If the figure repre-
senting the 100ths is five or more, the reaction time shall be rounded
up to the next higher 10th.
2. MOTOR VEHICLES
2.1. At the start of each test, the pressure in the reservoirs must be equal to
the minimum pressure at which the governor starts feeding the installa-
tion again. In installations not fitted witha governor (e.g. pressure
limited compressor) the pressure in the reservoir at the start of each
test must be equal to 90% of the pressure stated by the manufacturer,
as defined in item 1.2.2.1 of Annex IV, to be used for tests prescribed
in this Annex.
2.2. Reaction times in terms of actuation time (tf) shall be obtained by a
series of actuations to the fullest extent, starting from the shortest
possible up to a time of about 0·4 seconds. The values measured must
be given on a diagram.
2.3. Reaction times corresponding to an actuation time of 0·2 seconds shall
be determinant for the test. This reaction time can be obtained from the
diagram by interpolation.
2.4. In the case of the actuation time of 0·2 seconds, the time elapsing
between the beginning of actuation of the control pedal and the moment
when the pressure in the brake cylinder reaches 75% of its asymptotic
value must not exceed 0·6 seconds.
2.5. In the case of motor vehicles having a brake coupling for trailers, in
addition to the requirements of item 1.1 the reaction time must bemeasured at the extremity of a pipe 2·5 m long with an internal diameter
of 13 mm which shall be joined to the coupling head of the control line
of the service brake. During this test a volume of 385 ± 5 cm
3(which is
deemed to be equivalent to the volume of a pipe 2·5 m long with an
internal diameter of 13 mm and under a pressure of 6·5 bar) shall be
connected to the coupling head of the supply line.
Tractive units for semi-trailers must be equipped withflexible pipes for
making the connection to semi-trailers. The coupling heads will there-
fore be at the extremity of those flexible pipes. The length and internal
diameter of the pipes shall be entered at item 14.6 of the document
corresponding to the model described in Annex IX.
2.6. The time which elapses between the start of the activation of the control
pedal and the moment when the pressure measured at the coupling head1971L0320 — EN — 22.08.1991 — 007.001 — 41
▼M3
▼B
▼M4
▼B
▼M3
▼B
▼M3
▼B
▼B
of the control pipe reaches x% of its asymptotic value must not exceed
the values listed in the table below:
x (%) t (seconds)
10 0·2
75 0·4
2.7. In the case of motor vehicles authorized to draw trailers of category O3or O4fitted withcompressed air braking systems, in addition to th e
above mentioned requirements, the prescriptions in item 2.2.1.18.4.1 of
Annex I shall be verified by conducting the following test:
(a) by measuring the pressure at the extremity of a pipe 2,5 m long with
an internal diameter of 13 mm which shall be joined to the coupling
head of the supply line;
(b) by simulating a failure of the control line at the coupling head;
(c) by actuating the service braking control device in 0,2 seconds, as
described in item 2.3 above.
3. TRAILERS (including semi-trailers)
3.1. The reaction times for trailers shall be measured without a drawing
vehicle. To simulate the drawing vehicle it is necessary to provide a
simulator to which the coupling heads of the control pipe and of the
feed pipe of the trailer are to be connected.
3.2. The pressure in the feed pipe must be 6·5 bars. ►M3 ◄
3.3. The simulator must have the following features:
3.3.1. It must have a reservoir with a capacity of 30 litres which shall
be charged to a pressure of 6·5 bar before each test and which
must not be recharged during each test. At the outlet of the
braking control device the simulator must incorporate an orifice
witha diameter of from 4·0 to 4·3 mm inclusive. Th e volume of
the pipe measured from the orifice up to and including the
coupling head shall be 385 ± 5 cm3(which is deemed to be
equivalent to the volume of a pipe 2·5 m long with an internal
diameter of 13 mm and under a pressure of 6·5 bar). The control
line pressures referred to in item 3.3.3 shall be measured immedi-
ately downstream of the orifice.
3.3.2. The braking control device must be so designed that its perfor-
mance in use is not affected by the tester.
3.3.3. The simulator must be set, e.g. through the choice of orifice in
accordance withitem 3.3.1, in sucha way th at, if a reservoir of
385 ± 5 cm3is joined to it, the time taken for the pressure to
increase from 0·65 to 4·9 bar (10 and 75% respectively of the
nominal pressure of 6·5 bar), shall be 0·2 ± 0·01 second. If a
reservoir of 1 155 ± 15 cm3is substituted for the abovementioned
reservoir, the time taken for the pressure to increase from 0·65 to
4·9 bar without further adjustment shall be 0·38 ± 0·02 second.
Between these two pressure values the pressure must increase in
an approximately linear way. These reservoirs shall be connected
to the coupling head without using flexible pipes and shall have
an internal diameter of not less than 10 mm.
3.3.4. The diagram in the Appendix to this Annex gives an example of
the correct configuration and use of the simulator.
3.4. The time elapsing between the moment when the pressure produced in
the control line by the simulator reaches 0·65 bar and the moment when
the pressure in the brake actuator of the trailer reaches 75% of its
asymptotic value must not exceed 0·4 second.
4. PRESSURE TEST CONNECTIONS
4.1. On eachindependant circuit of th e braking system a pressure test
connection shall be fitted at the closest readily accessible position to
the brake cylinder which is the least favourably placed as far as reaction
time is concerned.1971L0320 — EN — 22.08.1991 — 007.001 — 42
▼M6
▼B
▼M3
▼M4
▼M6
4.2. The pressure test connections shall comply with clause 4 of ISO Stan-
dard 3583-1984.1971L0320 — EN — 22.08.1991 — 007.001 — 43
▼M3
APPENDIX
EXAMPLEOFASIMULATOR(SEEANNEXIII,ITEM3)
1. Setting the simulator
2. Testing the trailer
A = supply connection withsh ut-off valve
C1 = pressure switchin th e simulator, set at 0·65 bar and at 4·9 barC2 = pressure switch to be connected to the brake actuator of the trailer, to operate at 75% of
the asymptotic pressure in the brake actuator CF
CF = brake actuatorL = line from orifice O up to and including its coupling head TC, having an inner volume of
385 ± 5 cm
3under a pressure of 6·5 bar
M = pressure gaugeO = orifice with a diameter of not less than 4 mm and not more than 4·3 mmPP = pressure test connectionR1 = 30 litre air reservoir withdrain valveR2 = calibrating reservoir, including its coupling head TC, to be 385 ± 5 cm
3
R3 = calibrating reservoir, including its coupling head TC, to be 1 155 ± 15 cm3
RA = shut-off valve1971L0320 — EN — 22.08.1991 — 007.001 — 44
▼M3
TA = coupling head, supply line
TC = coupling head, control lineV = braking control deviceVRU = emergency relay valve1971L0320 — EN — 22.08.1991 — 007.001 — 45
▼B
ANNEX IV
ENERGYRESERVOIRSANDSOURCESOFENERGY
A.COMPRESSED-AIR BRAKING SYSTEMS
1. CAPACITY OF RESERVOIRS
1.1.General requirements
1.1.1. Vehicles on which the operation of the braking devices depends
on the use of compressed air must be fitted with reservoirs of a
capacity meeting the requirements of items 1.2 and 1.3 below.
1.1.2. Nevertheless, the capacity of reservoirs shall not be laid down
where the braking system is such that in the absence of any
energy reserve it is possible to achieve a braking performance at
least equal to that prescribed for the secondary braking.
1.1.3. When verifying compliance with the requirements of items 1.2
and 1.3 the brakes must be adjusted as closely as possible.
1.2.Motorvehicles
1.2.1. The air brake reservoirs of motor vehicles shall be so designed
that after eight full-stroke actuations of the service brake control
the pressure remaining in the air brake reservoir shall be not less
than the pressure required to obtain the specified secondary
braking performance.
1.2.2. During the test, the following requirements are to be satisfied:
1.2.2.1. The initial pressure in the reservoirs must be that indi-
cated by the manufacturer. This pressure must be such
as to enable the prescribed performance for the service
braking to be achieved;
1.2.2.2. The reservoir or reservoirs must not be replenished; in
addition, the reservoir or reservoirs of auxiliary equip-
ment must be isolated;
1.2.2.3. In the case of motor vehicles to which the coupling of a
trailer or semi-trailer is authorised, the feed line must be
blocked off and a reservoir of 0·5 litre capacity must be
connected to the control line. The pressure in this reser-
voir must be exhausted before each actuation of the
brakes. After the test referred to in item 1.2.1 the pres-
sure in the control line must not be less than one half of
the pressure obtained at the first brake application.
1.3.Trailers (includingsemi-trailers)
1.3.1. Reservoirs fitted to trailers must be such that after eight full
stroke actuations of the drawing vehicle's service braking device,
the pressure supplied to the operating parts using it does not fall
below a level equivalent to one-half the figure obtained at the
first brake application and without actuating either the automatic
or the parking braking device of the trailer.
1.3.2. During the test, the following requirements are to be satisfied:
1.3.2.1. The pressure in the reservoirs at the beginning of the test
shall be 8,5 bar;
1.3.2.2. The feed line must be blocked off; in addition, the
auxiliary equipment reservoirs must be isolated;
1.3.2.3. The reservoir shall not be replenished during the test;1971L0320 — EN — 22.08.1991 — 007.001 — 46
▼M4
▼B
▼M3
▼B
▼M6
▼B
▼M6
▼B
▼M4
▼B
1.3.2.4. For each application of the brakes, the pressure in the
control pipe must correspond to the maximum specified
by the manufacturer.
2. CAPACITY OF ENERGY SOURCES
2.1.General provisions
Compressors must satisfy the requirements laid down in the following
items:
2.2.Definitions
2.2.1. p1is the pressure corresponding to 65% of the pressure p2defined
in item 2.2.2
2.2.2. p2is the value specified by the manufacturer and referred to in
item 1.2.2.1
2.2.3. T1is the time required for the relative pressure to rise from O to
p1;T2is the time required for the relative pressure to rise from O
to p2.
2.3.Conditionsofmeasurement
2.3.1. In all cases the rpm speed of the compressor shall be that
obtained when the engine is running at the speed corresponding
to its maximum power or at the speed allowed by the control
valve.
2.3.2. The auxiliary equipment reservoirs shall be isolated during the
tests for determining the periods T1and T2.
2.3.3. On motor vehicles constructed to draw trailers, the trailer shall be
represented by a reservoir whose maximum relative pressure p
(expressed in bars) is that which can be supplied through the
feed circuit of the drawing vehicle and whose volume V
(expressed in litres) is given by the formula p · V = 20 R (R
being the permissible maximum load, expressed in metric tons,
on the axles of the trailer or semi-trailer).
2.4.Interpretationofresults
2.4.1. The time T1for the least efficient reservoir must not exceed:
— three minutes in the case of vehicles to which the coupling of
a trailer or semi-trailer is not authorised;
— six minutes in the case of vehicles to which the coupling of a
trailer or semi-trailer is authorised.
2.4.2. The time T2for the least efficient reservoir must not exceed:
— six minutes in the case of vehicles to which the coupling of a
trailer or semi-trailer is not authorised;
— nine minutes in the case of vehicles to which the coupling of
a trailer or semi-trailer is authorised.
2.5.Additionaltest
2.5.1. When the vehicle is equipped with an auxiliary equipment reser-
voir or reservoirs witha total capacity exceeding 20% of th e total
capacity of the brake reservoirs, an additional test must be carried
out during the course of which there must be no interference with
the functioning of the valves controlling the filling of the
auxiliary equipment reservoir(s). A check must be made during
the course of this test that the period T3required to bring about
a rise in the pressure in the brake reservoirs from O to p2is less
than:
— eight minutes in the case of vehicles to which the coupling of
a trailer or semi-trailer is not authorised;
— eleven minutes in the case of vehicles to which the coupling
of a trailer or semi-trailer is authorised.
2.6.Drawingvehicles
2.6.1. Vehicles to which the coupling of a category O vehicle is author-
ized shall also comply with the above requirements for vehicles
not so authorized. In that case, the tests in items 2.4.1, 2.4.21971L0320 — EN — 22.08.1991 — 007.001 — 47
▼M4
▼M4
(and 2.5.1) will be conducted without the reservoir mentioned in
item 2.3.3 of this Annex.
3. PRESSURE TEST CONNECTIONS
3.1. A pressure test connection must be fitted at the closest readily accessible
position to the least favourably placed reservoir within the meaning of
item 2.4 of this Annex.
3.2. The pressure test connections shall comply with clause 4 of ISO Stan-
dard 3583-1984.
B.VACUUM BRAKING SYSTEMS
1. CAPACITY OF RESERVOIRS
1.1.General
1.1.1. Vehicles on which operation of the braking device requires the
use of a vacuum shall be equipped with reservoirs of a capacity
meeting the requirements of items 1.2 and 1.3 below.
1.1.2. However, the reservoirs shall not be required to be of a
prescribed capacity if the braking system is such that in the
absence of any energy reserve it is possible to achieve a braking
performance at least equal to that prescribed for the secondary
braking system.
1.1.3. In verifying compliance withth e requirements of items 1.2 and
1.3 below, the brakes shall be adjusted as closely as possible.
1.2.Motorvehicles
1.2.1. The reservoirs of motor vehicles shall be such that it is still
possible to achieve the performance prescribed for the secondary
brake:
1.2.1.1. after eight full-stroke actuations of the service-brake
control where the energy source is a vacuum pump; and
1.2.1.2. after four full-stroke actuations of the service-brake
control where the energy source is the engine.
1.2.2. Testing shall be performed in conformity with the following
requirements:
1.2.2.1. the initial energy level in the reservoir(s) shall be that
specified by the manufacturer. It shall be such as to
enable the prescribed service-braking performance to be
achieved and shall correspond to a vacuum not
exceeding 90 % of the maximum vacuum furnished by
the energy source(1);
1.2.2.2. the reservoir(s) shall not be fed. During the test the
auxiliary-service reservoir(s) shall be isolated;
1.2.2.3. on a motor vehicle to which the coupling of a trailer is
authorized, the supply line shall be stopped and a reser-
voir of 0,5-litre capacity shall be connected to the control
line. After the test referred to in item 1.2.1, the vacuum
level provided at the control line shall not have fallen
below a level equivalent to one-half of the figure
obtained at the first brake application.
1.3.Trailers (category O1andO2only)
1.3.1. The reservoir(s) with which trailers are equipped shall be such
that the vacuum level provided at the user points shall not have
fallen below a level equivalent to one-half of the value obtained
at the first brake application after a test comprising four full-
stroke actuations of the trailer's service brake.1971L0320 — EN — 22.08.1991 — 007.001 — 48
(1) The initial energy level shall be stated in the approval document.▼M3
▼M4
▼M6
▼M4
▼M4
1.3.2. Testing shall be performed in conformity with the following
requirements:
1.3.2.1. The initial energy level in the reservoir(s) shall be that
specified by the manufacturer. It shall be such as to
enable the prescribed service braking performance to be
achieved(1).
1.3.2.2. The reservoir(s) shall not be fed. During the test the
auxiliary service reservoir(s) shall be isolated.
2. CAPACITY OF ENERGY SOURCES
2.1.General
2.1.1. Starting from the ambient atmospheric pressure, the energy
source shall be capable of achieving in the reservoir(s) in three
minutes, the initial level specified in item 1.2.2.1. In the case of
a motor vehicle to which the coupling of a trailer is authorized
the time taken to achieve that level in the conditions specified in
item 2.2 below shall not exceed six minutes.
2.2.Conditionsofmeasurement
2.2.1. The speed of the vacuum source shall be:
2.2.1.1. where the vacuum source is the vehicle engine, the
engine speed obtained with the vehicle stationary, the
neutral gear engaged and the engine idling;
2.2.1.2. where the vacuum source is a pump, the speed obtained
with the engine running at 65 % of the speed corre-
sponding to its maximum power output; and
2.2.1.3. where the vacuum source is a pump and the engine is
equipped with a governor, the speed obtained with the
engine running at 65 % of the maximum speed allowed
by the governor.
2.2.2. Where it is intended to couple to the motor vehicle a trailer
whose service braking system is vacuum-operated, the trailer
shall be represented by an energy storage device having a capa-city V in litres determined by the formula V = 15 R, where R is
the maximum permissible mass, in tonnes, on the axles of the
trailer.
C.HYDRAULIC BRAKING SYSTEMS WITH STORED ENERGY
1. CAPACITY OF STORAGE DEVICES (ENERGY ACCUMULATORS)
1.1.General
1.1.1. Vehicles on which the braking device requires the use of stored
energy provided by hydraulic fluid under pressure shall be
equipped withenergy storage devices (energy accumulators) of a
capacity meeting the requirements of item 1.2 below.
1.1.2. However, the energy storage devices shall not be required to be
of a prescribed capacity if the braking system is such that in the
absence of any energy reserve it is possible withth e service brake
control to achieve a braking performance at least equal to that
prescribed for the secondary braking system.
1.1.3. In verifying compliance withth e requirements of items 1.2.1,
1.2.2 and 2.1 below, the brakes shall be adjusted as closely as
possible and, for item 1.2.1, the rate of full-stroke actuations
must be suchas to provide an interval of at least one minute
between eachactuation.
1.2.Motorvehicles
1.2.1. Motor vehicles equipped with a hydraulic braking system with
stored energy shall meet the following requirements:
1.2.1.1. after eight full-stroke acutations of the service braking
control, it shall still be possible to achieve, on the ninth1971L0320 — EN — 22.08.1991 — 007.001 — 49
(1) The initial energy level shall be stated in the approval document.
▼M4
application, the performance prescribed for the secondary
braking system.
1.2.1.2. Testing shall be performed in conformity with the
following requirements:
1.2.1.2.1. testing shall commence at a pressure that may
be specified by the manufacturer but is not
higher than the cut-in pressure;
1.2.1.2.2. the accumulator(s) shall not be fed; in addi-
tion, the auxiliary equipment and its
accumulators, if any, shall be isolated.
1.2.2. Motor vehicles equipped with a hydraulic braking system with
stored energy which cannot meet the requirements of item
2.2.1.5.1 of Annex I shall be deemed to satisfy that item if the
following requirements are met:
1.2.2.1. After any single transmission failure it shall still be
possible after eight full-stroke actuations of the service
braking control, to achieve, at the ninth application, at
least the performance prescribed for the secondary
braking system or, where secondary performance
requiring the use of stored energy is achieved by a sepa-
rate control, it shall still be possible after eight full-
stroke actuations to achieve, at the ninth application, the
residual performance prescribed in item 2.2.1.4 of Annex
I.
1.2.2.2. Testing shall be performed in conformity with the
following requirements:
1.2.2.2.1. withth e energy source stationary or operating
at a speed corresponding to the engine idling
speed, any transmission failure may be
induced. Before inducing sucha failure th e
energy storage device(s) shall be at a pressure
that may be specified by the manufacturer but
not exceeding the cut-in pressure;
1.2.2.2.2. the auxiliary equipment and its accumulators,
if any, shall be isolated.
2. CAPACITY OF HYDRAULIC FLUID ENERGY SOURCES
2.1.The energy sources shall meet the requirements set out in the
followingparagraphs:
2.1.1.Definitions
2.1.1.1. ‘p1’ represents the maximum system operational pressure
(cut-out pressure) in the accumulator(s) specified by the
manufacturer.
2.1.1.2. ‘p2’ represents the pressure after four full-stroke actua-
tions withth e service brake control, starting at p1,
without having fed the accumulator(s).
2.1.1.3 ‘t’ represents the time required for the pressure to rise
from p2to p1in the accumulator(s) without application
of the brake control.
2.1.2.Conditions of measurement
2.1.2.1. During the test to determine the time t, the feed rate of
the energy source shall be that obtained when the engine
is running at the speed corresponding to its maximum
power or at the speed allowed by the over-speed
governor.
2.1.2.2. During the test to determine the time t, accumulator(s)
for auxiliary equipment shall not be isolated other than
automatically.
2.1.3.Interpretation of results
2.1.3.1. In the case of all vehicles except those of categories M3,
N2and N3, the time t shall not exceed 20 seconds.
2.1.3.2. In the case of vehicles of categories M3,N2and N3,t he
time t shall not exceed 30 seconds.1971L0320 — EN — 22.08.1991 — 007.001 — 50
▼M4
3. CHARACTERISTICS OF ALARM DEVICES
With the engine stationary and commencing at a pressure that may be speci-
fied by the manufacturer but does not exceed the cut-in pressure, the alarm
device shall not operate following two full-stroke actuations of the service
brake control.1971L0320 — EN — 22.08.1991 — 007.001 — 51
▼B
ANNEX V
SPRINGBRAKES
1. DEFINITIONS
1.1. ‘Spring brakes’ are braking devices for which the energy required for
braking is supplied by one or more springs acting as an energy accumu-
lator.
1.2. ‘Spring compression chamber’ means the chamber where the pressure
variation that induces the compression of the spring is actually
produced.
1.3. If the compression of the springs is obtained by means of a vacuum
device, ‘pressure’ shall mean negative pressure everywhere in this
Annex.
2. GENERAL REQUIREMENTS
2.1. A spring brake shall not be used as a service brake. However, in the
event of a failure in a part of the transmission of the service brake, a
spring brake may be used to achieve the residual performance prescribed
in item 2.2.1.4 of Annex I, provided that the driver can graduate this
action. In the case of motor vehicles, with the exception of drawing
vehicles for semi-trailers meeting the requirements specified in item
2.2.1.4.3 of Annex I, the spring brake shall not be the sole source of
residual braking.
Vacuum spring brakes shall not be used for trailers.
2.2. A small variation in any of the pressure limits which may occur in the
spring compression chamber feed circuit must not cause a significant
variation in the braking force.
2.3. The feed circuit to the spring compression chamber must either include
an own energy reserve or must be fed from at least two independent
energy reserves. The trailer supply line may be branched from this feed
line under the condition that a pressure drop in the trailer supply line
must not be able to apply the spring brake actuators. Auxiliary equip-
ment may only draw its energy from the feed line for the spring brake
actuators under the condition that its operation, even in the event of
damage to the energy source, cannot cause the energy reserve for the
spring brake actuators to fall below a level from which one release of
the spring brake actuators is possible. ►M6In any case during re-char-
ging of the braking system from zero pressure, the spring brakes must
not release until the pressure in the service braking system is sufficient
to ensure at least the prescribed secondary braking performance of the
laden vehicle, using the service brake control. ◄
This item does not apply to trailers.
2.4. In motor vehicles, the system must be so designed that it is possible to
apply and release the brakes at least three times if the initial pressure in
the spring compression chamber is equal to the maximum design pres-
sure. In the case of trailers, it must be possible to release the brakes at
least three times after the trailer has been uncoupled, the pressure in the
supply line being 6·5 bar before the uncoupling. These conditions must
be satisfied when the brakes are adjusted as closely as possible. In addi-
tion, it must be possible to apply and release the parking brake as
specified in Annex I, item 2.2.2.10, when the trailer is coupled to the
towing vehicle.
2.5. In the case of motor vehicles, the pressure in the spring compression
chamber beyond which the springs begin to actuate the brakes, the latter
being adjusted as closely as possible, must not be greater than 80 % of
the minimum level of the normal available pressure. In the case of trai-
lers, the pressure in the spring compression chamber beyond which the
springs begin to actuate the brakes must not be greater than that
obtained after four full-stroke actuations of the service brake in accor-
dance withAnnex IV, item 1.3. Th e initial pressure is fixed at 6,5 bar.
2.6. When the pressure in the line feeding energy to the spring compression
chamber — excluding lines of an auxiliary release device using a fluid1971L0320 — EN — 22.08.1991 — 007.001 — 52
▼M4
▼B
▼M4
▼M3
▼M4
▼M4
under pressure — falls to the level at which the brake parts begin to
move, an optical or audible warning device must be actuated. Provided
this requirement is met, the warning device may be that specified in
item 2.2.1.13 of Annex I. This provision does not apply to trailers.
2.7. On motor vehicles fitted with spring brakes and authorised to draw trai-
lers withcontinuous or semi-continuous brakes, automatic application of
the spring brakes must cause the trailer brakes to be applied.
3. RELEASE SYSTEM
3.1. A spring braking system must be so designed that, in the event of a
failure in that system, it is still possible to release the brakes. This may
be achieved by the use of an auxiliary release device (pneumatic,
mechanical, etc.). Auxiliary release devices using an energy reserve for
releasing, must draw their energy from an energy reserve which is inde-
pendent from the energy reserve normally used for the spring braking
system.
The pneumatic or hydraulic fluid in such an auxiliary release device
may act on the same piston surface in the spring compression chamber,
which is used for the normal spring braking system, under the condition
that the auxiliary release device uses a separate line. The junction of this
line with the normal line connecting the control device with the spring
brake actuators, shall be at each spring brake actuator immediately
before the port to the spring compression chamber, if not integrated in
the body of the actuator. This junction shall include a device which
prevents an influence of one line on the other. The requirements of
item 2.2.1.6 of Annex I also apply to this device.
3.2. If the operation of the auxiliary device referred to in item 3.1 requires
the use of a tool or spanner, the tool or spanner must be kept on the
vehicle.1971L0320 — EN — 22.08.1991 — 007.001 — 53
▼B
▼M4
▼B
▼B
ANNEX VI
PARKING BRAKING BY MECHANICAL LOCKING OF THE BRAKE
CYLINDERS
(lockactuators)
1. DEFINITION
‘Mechanical locking of the brake cylinders’ means a device for ensuring
parking braking by mechanical wedging of the brake piston rod.
Mechanical locking occurs when the locking chamber is emptied of
compressed air; the mechanical locking device shall be designed in such a
way that it can be released when the locking chamber is again subjected to
pressure.
2. SPECIAL PROVISIONS
2.1. When the pressure in the locking chamber approaches the level corre-
sponding to mechanical locking, an optical or audible warning system
must be actuated. ►M3This provision shall not apply to trailers. In
the case of trailers the pressure corresponding to mechanical locking
must not exceed 4 bar. It must be possible to achieve parking brake
performance after any single failure of the trailer service braking
system. In addition, it must be possible to release the brakes at least
three times after the trailer has been uncoupled, the pressure in the
supply line being 6·5 bar before the uncoupling. These conditions must
be satisfied when the brakes are adjusted as closely as possible. It must
also be possible to apply and release the parking brake as specified in
Annex I, item 2.2.2.10, when the trailer is coupled to the towing
vehicle. ◄
2.2. In the case of brake actuators fitted with a mechanical locking device,
the brake actuator must be capable of being actuated by either of two
energy reserves.
2.3. The locked brake cylinder may only be released if it is certain that the
brake can be operated again after suchrelease.
2.4. In the event of a failure of the source of energy supplying the locking
chamber, an auxiliary unlocking device (mechanical or pneumatic, for
instance) using, for example, the air in one of the tyres of the vehicle,
must be provided.
2.5. The control must be such that, when actuated, it performs the following
operations in sequence: it applies the brakes so as to provide the degree
of efficiency required for parking braking, locks the brakes in that posi-
tion and then cancels out the brake-application force.1971L0320 — EN — 22.08.1991 — 007.001 — 54
▼M3
▼B
ANNEX VII
CASESINWHICHTYPEIAND/ORII(ORIIA)TESTSDONOTHAVE
TO BE CARRIEDOUT ON A VEHICLE SUBMITTEDFOR TYPE
APPROVAL
1. Type I and/or II (or IIA) tests do not have to be carried out on a vehicle
submitted for type approval in the following cases:
1.1. where the vehicle in question is a motor vehicle, a trailer or a semi-
trailer which, in respect of tyres, braking energy absorbed by each axle
and method of fitting of tyres and brakes, is identical, as far as braking
is concerned, to a motor vehicle, a trailer, or a semi-trailer which:
1.1.1. has passed a Type I and/or II (or II A) test;
1.1.2. has been type approved, with regard to braking energy absorbed,
for axle ►M3masses ◄greater than or equal to those of the
vehicle submitted for type approval.
1.2. where the vehicle in question is a motor vehicle, a trailer or a semi-
trailer of which the axle or axles, in respect of tyres, braking energy
absorbed by eachaxle and meth od of fitting of tyres and brakes, is or
are identical, as far as braking is concerned, to an axle or axles which
has or have individually passed a Type I and/or II test for axle
►M3masses ◄greater than or equal to those of the vehicle submitted
for type approval, provided that the braking energy absorbed by each
axle does not exceed the energy absorbed by that axle during the refer-
ence test or tests carried out separately on that axle.
1.3. where the vehicle submitted for type approval is fitted with a retarder,
other than an engine brake, identical to a retarder which has already
been tested under the following conditions:
1.3.1. in a test carried out on a gradient of at least 6% (Type II test) or
of at least 7% (Type II A test), this retarder has, on its own, stabi-
lised the speed of a vehicle with a ►M3maximum mass ◄at
the time of testing at least equal to the ►M3maximum mass ◄
of the vehicle submitted for type approval;
1.3.2. in the above test, a check must be made as to whether the speed
of rotation of the revolving parts of the retarder is such that,
when the vehicle submitted for type approval is travelling at a
speed of 30 km/h, the retarding torque is at least equal to the
retarding torque in the test mentioned in item 1.3.1.
1.4. The vehicle concerned is a trailer equipped with S-cam air operated
brakes(1) which satisfies the verification requirements of Appendix 1 to
this Annex relating to a report of a reference axle test as shown in
Appendix 2 to this Annex.
2. The term ‘identical’ as used in items 1.1, 1.2 and 1.3 means identical as
regards the geometrical and mechanical characteristics of the vehicle parts
mentioned in those items, and also as regards the characteristics of the mate-
rials from which these parts are made.
3. When advantage is taken of the above provisions, the type approval commu-
nication in respect of braking (Annex IX) must contain the following
particulars:
3.1. where item 1.1 is applicable, the type of the approval number of the
vehicle on which the Type I and/or II (or II A) test serving as a refer-
ence test has been carried out (item 14.7.1 of Annex IX);
3.2. where item 1.2 is applicable, the table in item 14.7.2 of the model item
of the communication in Annex IV must be completed;
3.3. where item 1.3 is applicable, the table in item 14.7.3 of the model of the
communication in Annex IX must be completed;
3.4. where item 1.4 is applicable, the table in item 14.7.4 of the model of the
communication in Annex IX must be completed.1971L0320 — EN — 22.08.1991 — 007.001 — 55
(1) Other brake designs may be approved upon presentation of equivalent information.▼M4
▼B
▼M4
▼B
▼M4
▼B
4. When a person applying for type approval in a Member State refers to a type
approval granted in another Member State, that person must produce the
documents relating to suchapproval.1971L0320 — EN — 22.08.1991 — 007.001 — 56
▼M4
Appendix 1
ALTERNATIVEPROCEDURESFORTYPEIANDTYPEIITESTSFOR
TRAILERBRAKES
1. GENERAL
1.1. In accordance with item 1.4 of this Annex, the Type I and II fade
tests may be waived at the time of type approval of the vehicle
provided that the braking system components comply with the
requirements of this Appendix and that the resulting predicted
brake performance meets the prescriptions of this Directive for
the appropriate vehicle category.
1.2. Tests carried out in accordance with the methods detailed in this
Appendix shall be deemed to meet the above requirements.
2. SYMBOLS AND DEFINITIONS (The reference brake symbols
shall have the suffix ‘e’)
P = normal reaction of road surface on the axle under
static conditions
C = camshaft input torqueC
max= maximum technically permissible camshaft input
torque
C0= threshold camshaft input torque, i.e. minimum
camshaft torque necessary to produce a measurable
brake torque
R = tyre rolling radius (dynamic)
T = brake force at tyre/road interface
M = braking torque = T · Rz = braking rate
T
P¼M
RP
s = actuator stroke (working stroke plus free stroke)
Sp= effective stroke — the stroke at which the output
thrust is 90 % of the average thrust (ThA)
ThA= average thrust — the average thrust is determined by
integrating the values between one-third and two-thirds
of the total stroke (smax)
l = lever length
r = radius of brake drump = brake actuation pressure
3. TEST METHODS
3.1. Tracktests
3.1.1. The brake performance tests should preferably be carried out on a
single axle only.
3.1.2. The results of tests on a combination of axles may be used in
accordance withitem 1.1 provided th at eachaxle contributes1971L0320 — EN — 22.08.1991 — 007.001 — 57
▼M4
equal braking energy input during the drag and ►M6hot◄
brake tests.
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.
3.1.2.2. The result recorded for a combination of axles will be the average
value for these axles.
3.1.3. The axle(s) should preferably be loaded with the maximum static
axle mass, though this is not essential provided that due allow-
ance is made during the tests for the difference in rolling
resistance caused by a different mass on the test axle(s).
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.
3.1.5. The initial speed of the test shall be prescribed. The final speed
shall be calculated by the following formula:
v2¼v1ﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃ
P0þP1
P0þP1þP2r
where:
v1= initial speed (km/h)
v2= final speed (km/h)
Po= mass of the drawing vehicle (kg) under test conditions
P1= mass of the trailer borne by the non-braked axle(s) (kg)
P2= mass of the trailer borne by the braked axle (kg)
3.2. Inertiadynamometertests
3.2.1. The test machine shall have a rotary inertia simulating that part
of the linear inertia of the vehicle mass acting upon one wheel,
necessary for the cold performance and ►M6hot◄perfor-
mance tests, and capable of being operated at constant speed for
the purpose of the test described in items 3.5.2 and 3.5.3 below.
3.2.2. The test shall be carried out with a complete wheel, including the
tyre, mounted on the moving part of the brake, as it would be on
the vehicle. The inertia mass may be connected to the brake
either directly or via the tyres and wheels.
3.2.3. Air cooling at a velocity and air flow direction simulating actual
conditions may be used during the heating runs, the speed of air
flow being not greater than 10 km/h. The temperature of the
cooling air shall be the ambient temperature.
3.2.4. Where the tyre rolling resistance is not automatically compen-
sated for in the test, the torque applied to the brake shall be
modified by subtracting a torque equivalent to a rolling resistance
coefficient of 0,01.
3.3. Rollingroaddynamometertests
3.3.1. The axle should preferably be loaded with the maximum static
axle mass, though this is not essential provided that due allow-
ance is made during the tests for the difference in rolling
resistance caused by a different mass on the test axle.
3.3.2. Air cooling at a velocity and air flow direction simulating actual
conditions, may be used during the heating runs, the speed of air
flow being not greater than 10 km/h. The temperature of the
cooling air shall be the ambient temperature.
3.3.3. The braking time shall have a duration of 1 s after a maximum
build-up time of 0,6 s.
3.4. Testconditions
3.4.1. The test brake(s) shall be instrumented so that the following
measurements can be taken:
3.4.1.1. a continuous recording to enable the brake torque or force at the
periphery of the tyre to be determined;1971L0320 — EN — 22.08.1991 — 007.001 — 58
▼M4
3.4.1.2. a continuous recording of air pressure in the brake actuator;
3.4.1.3. speed during the test;
3.4.1.4. initial temperature on the outside of the brake drum;
3.4.1.5. brake actuator stroke used during the Type O test and Type I and
II residual brake stops.
3.5. Testprocedures
3.5.1. Supplementary cold performance test
3.5.1.1. This test is carried out at an initial speed equivalent to 40 km/h in
order to evaluate the ►M6hot◄braking performance at the
end of the Type I and Type II tests.
3.5.1.2. Three brake applications are made at the same pressure (p) and at
an initial speed equivalent to 40 km/h, with an approximately
equal initial brake temperature not exceeding 100 ºC, measured
at the outside surface of the drum. The applications shall be at
the brake actuator pressure required to give a brake torque or
force equivalent to a braking rate (z) of at least 0,50. The brake
actuator pressure shall not exceed 6,5 bar, and the camshaft input
torque (C) shall not exceed the maximum technically permissible
camshaft input torque (Cmax). The average of the three results
shall be taken as the cold performance.
3.5.2. Type I test
3.5.2.1. This test is carried out at a speed equivalent to 40 km/h with an
initial brake temperature not exceeding 100 ºC, measured at the
outside surface of the drum.
3.5.2.2. A braking rate is maintained at 0,07 including the rolling resis-
tance (see item 3.2.4).
3.5.2.3. The duration of the test is 2 minutes and 33 seconds or 1,7 km at
40 km/h. If the test velocity cannot be achieved then the duration
of the test can be lengthened according to item 1.3.2.2 of Annex
II.
3.5.2.4. Not later than 60 seconds after the end of the Type I fade test, a
►M6hot◄performance test is carried out in accordance with
item 1.3.3 of Annex II at an initial speed equivalent to 40 km/h.
The brake actuator pressure shall be that used during the cold
performance test.
3.5.3. Type II test
3.5.3.1. This test is carried out at a speed equivalent to 30 km/h with an
initial brake temperature not exceeding 100 ºC, measured at the
outside surface of the drum.
3.5.3.2. A braking rate is maintained at 0,06 including the rolling resis-
tance (see item 3.2.4).
3.5.3.3. The duration of the test is 12 minutes or 6 km at 30 km/h.
3.5.3.4. Not later than 60 seconds after the end of the Type II fade test, a
►M6hot◄performance test is carried out in accordance with
item 1.4.3 of Annex II at an initial speed equivalent to 40 km/h.
The brake actuator pressure used shall be that used during the
cold performance test.
3.6. Testreport
3.6.1. The result of tests carried out in accordance with item 3.5 shall
be reported on a form, a model of which is shown in Appendix
2 to this Annex.
3.6.2. The brake and the axle shall be identified. Particulars of the
brakes, the axle, the technically permissible mass and the number
of the corresponding test report shall be marked on the axle.
4. VERIFICATION4.1. Verificationofcomponents
The brake specification of the vehicle to be type approved shall
be verified by satisfying eachof th e following design criteria:1971L0320 — EN — 22.08.1991 — 007.001 — 59
▼M4
Item Criteria
4.1.1. (a) Brake drum cylindrical section No change allowed
(b) Brake drum material No change allowed
(c) Brake drum mass May change between − 0 and + 20 % of
the reference drum mass
4.1.2. (a) Proximity of wheel to outside surface
of brake drum (dimension E)/C148/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C149/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C150Tolerances to be determined by the
technical service conducting the
approval tests(b) Part of brake drum not covered by
wheel (dimension F)
4.1.3. (a) Brake lining material/C148/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C149/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C150No change allowed(b) Brake lining width
(c) Brake lining thickness
(d) Brake lining actual surface
(e) Brake lining method of attachment
4.1.4. Brake geometry (figure 2) No change allowed
4.1.5. Tyre rolling radius (R) May change subject to the requirements
of item 4.3.5 of this Appendix
4.1.6. (a) Average thrust (Th
A)/C148/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C149/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C147/C150May change provided that the predicted
performance meets the requirements of
item 4.3 of this Appendix(b) Actuator stroke (s)
(c) Lever length
(d) Brake actuation pressure (p)
4.1.7. Static mass (P) P shall not exceed P
e
4.2. Verificationofbrakeforcesdeveloped
4.2.1. The brake forces (T) for each subject brake (for the same control
line pressure pm) necessary to produce the drag force specified for
bothType I and Type II test conditions are determined by th e
method described in item 4.2.3.
4.2.2. For eachaxle, T sh all not exceed X · Pe.
4.2.3. T 1¼X/C1PRmaxV1
V1þV2þV3
where:
X = 0,07 for the Type I and 0,06 for the Type II tests,
V = the value of any component that varies the camshaft input
torque at eachaxle for a given control line pressure (pm)o r
the value of the actuator pressure at each axle (p) where it
is not common for a given control line pressure (pm).
Example:
Three-axled trailer having a PRmaxof 200 000 N where all compo-
nents are identical except the brake lever lengths which are:
axle 1 = 152, axle 2 = 127, axle 3 = 127
then (for Type I) T1¼0;07/C1200000 /C1152
152þ127þ127
= 14000 · 0,374 = 5 236 N
similary T2and T3¼0;07/C1200000 /C1127
152þ127þ127
= 14000 · 0,313 = 4 382 N1971L0320 — EN — 22.08.1991 — 007.001 — 60
▼M4
4.3. Verificationofresidualperformance
4.3.1. The brake force (T) for each subject brake for a specified pres-
sure (p) in the actuators and control line pressure (pm) used
during the Type O test of the subject trailer is determined by the
methods described in items 4.3.2 to 4.3.5.
4.3.2. The predicted actuator stroke (s) of the subject brake is deter-
mined from the following relationship
s¼l/C1se
le
s shall not exceed the effective stroke (sp)
4.3.3. The average thrust output (ThA) of the actuator fitted to the
subject brake at the pressure specified in item 4.3.1. is deter-
mined.
4.3.3. The camshaft input torque (C) is then given by
C¼ThA/C1l:
C shall not exceed Cmax.
4.3.5. The predicted brake performance for the subject brake is given
by:
T¼Te/C1C/C0C0 ðÞ
Ce/C0C0e ðÞ/C1Re
R
R shall not be less than 0,8 Re.
4.3.6. The predicted brake performance for the subject trailer is given
by:
TR
PR¼ΣT
ΣP
4.3.7. The ►M6hot◄performances following the Type I and II tests
shall be determined in accordance with items 4.3.2, 4.3.3, 4.3.4
and 4.3.5. The resulting predictions given by item 4.3.6 must
satisfy the requirements of this Directive for the subject trailer.
The value used for ‘the figure recorded in the Type O test’, as
prescribed in Annex II, item 1.3.3, shall be the figure recorded
in the Type O test of the subject trailer.1971L0320 — EN — 22.08.1991 — 007.001 — 61
▼M4
Appendix 2
MODELREFERENCEAXLETESTREPORTFORMASPRESCRIBEDINAPPENDIX1,ITEM
3.6
►(1)M61971L0320 — EN — 22.08.1991 — 007.001 — 62
▼M4
1971L0320 — EN — 22.08.1991 — 007.001 — 63
▼M4
Figure 2
BRAKEGEOMETRY
1971L0320 — EN — 22.08.1991 — 007.001 — 64
▼B
ANNEX VIII
CONDITIONSGOVERNINGTHETESTINGOFVEHICLESEQUIPPED
WITHINERTIA(OVERRUN)BRAKES
1. GENERAL PROVISIONS
1.1. The inertia (overrun) braking device of a trailer comprises the control
device, the transmission and the brakes proper, hereinafter called
‘brakes’.
1.2. The control device is the combination of components comprising the
coupling head.
1.3. The transmission is the combination of components comprised between
the coupling head and the first part of the brake.
1.4. The ‘brake’ is the part in which the forces opposing the movement of
the vehicle develop. The first part of the brake is either the lever
actuating the brake cam or similar parts (mechanical-transmission
inertia brake) or the brake cylinder (hydraulic-transmission inertia
brake).
1.5. Braking devices in which accumulated energy (for instance, electric,
pneumatic or hydraulic) is transmitted to the trailer by the drawing
vehicle and is only controlled by the force at the coupling shall not
be deemed to be inertia braking devices within the meaning of this
Directive.
1.6. Two axles with a wheelbase of less than one metre (tandem axle) shall,
for the purposes of this Annex, also be deemed to be one axle.
1.7.Tests
1.7.1. Determination of the main characteristics of the brake.1.7.2. Determination of the main characteristics of the control device
and testing as to whether that device conforms with the provi-
sions of this Directive.
1.7.3. Testing on the vehicle
— the compatibility of the control device and the brake
— the transmission.
2. SYMBOLS AND DEFINITIONS
2.1.Unitsused
2.1.1.►
M3Masses ◄and
forces: ►M3Newton (N) ◄
2.1.2. Torques and moments: ►M3Newton metre (Nm) ◄
2.1.3. Areas: cm2
2.1.4. Pressures: ►M3bar (bar) ◄
2.1.5. Lengths: units specified in each case.
2.2.Symbolsvalidforalltypesofbrakes (see diagram in Appendix 1, p.
771)
2.2.1. GA:‘►M3maximum mass ◄’ of the trailer declared to
be technically permissible by the manufacturer;
2.2.2. G ′A:‘►M3maximum mass ◄’ of the trailer which,
according to the manufacturer's declaration, can be
braked by the control device;
2.2.3. GB:‘►M3maximum mass ◄’ of the trailer which can
be braked by the joint operation of all the trailer
brakes
GB¼n/C1GBo
2.2.4. GBo: Fraction of the permissible ‘ ►M3maximum
mass◄’ which, according to the manufacturer's
declaration, can be braked by one brake;
2.2.5. B*: braking force required;1971L0320 — EN — 22.08.1991 — 007.001 — 65
▼B
2.2.6. B: required braking force taking account of rolling resis-
tance;
2.2.7. D*: permitted thrust on coupling;2.2.8. D: load on the coupling;2.2.9. P ′: control device output force;
2.2.10. K: supplementary force of control device by convention;
this is defined as the force D corresponding to the
point of intersection of the x axes of the extrapolated
curve expressing P ′in terms of D, measured withth e
control system in the mid-travel position (see graph in
Appendix 1, p. 772);
2.2.11. K
A: threshold force of control device—this is the
maximum force on the coupling head which can be
applied for a short period of time without producing
any output force on the control device. By convention,
KAis defined as the force measured when force begins
to be exerted on the coupling head at a speed of from
10 to 15 mm/s, the control device transmission being
uncoupled;
2.2.12. D1: this is the maximum force applied to the coupling
head when it is forced rearward at a speed of s mm/
s ± 10%, the transmission being uncoupled;
2.2.13. D2: this is the maximum force applied to the coupling
head when this is pulled forward at a speed of s mm/
s ± 10% from its rearmost position, the transmission
being uncoupled;
2.2.14. ηHo: efficiency of the inertia control device;
2.2.15. ηH1: efficiency of the transmission system;
2.2.16. ηH: total efficiency of the control device and of the trans-
mission
ηH¼ηHo/C1ηH1;
2.2.17. s: travel of control (expressed in millimetres);
2.2.18. s ′: effective travel of control (expressed in millimetres)
fixed in accordance withth e requirements of item
9.4.1;
2.2.19. s ′:►M4spare travel ◄of the master cylinder actuator,
measured in millimetres at the coupling head;
2.2.20. so: loss of travel, that is to say the travel, measured in
millimetres, of the coupling head when it is actuated
in sucha way as to travel from a point 300 mm above
the horizontal plane to a point 300 mm below, the
transmission remaining stationary;
2.2.21. 2sB: brake-shoe lift measured on the diameter parallel to
the operating mechanism and without the brakes being
adjusted during the test (expressed in millimetres);
2.2.22. 2sB*: minimum brake-shoe lift (expressed in millimetres)
2sB/C3¼2/C14þ4
1000/C12r;
2r being the diameter of the brake drum expressed in
millimetres (see diagram in Appendix 1, p. 773);
2.2.23. M: braking moment;
2.2.24. R: radius of pneumatic tyres (in metres) measured under
load from wheel centre to ground level on the vehicle
being tested (rounded to the nearest centimetre);
2.2.24. n: number of brakes;
2.3.Symbols for mechanical transmission brakes (see diagram in
Appendix 1, p. 774)
2.3.1. iHo: reduction ratio between travel of the coupling head
and travel of the lever at the output side of the control
device;1971L0320 — EN — 22.08.1991 — 007.001 — 66
▼B
2.3.2. iH1: reduction ratio between travel of the lever at the
output side of the control device and travel of the
brake lever (gearing down of transmission);
2.3.3. iH: reduction ratio between travel of the coupling head
and travel of the brake lever
iH¼iHo/C1iH1;
2.3.4. ig: reduction ratio between travel of the brake lever and
the brake-shoe centre lift (see diagram in Appendix 1,
page 773);
2.3.5. P: force applied to the brake control lever;
2.3.6. Po: brake retraction force; that is, in the graph M = f (P),
the value of the force P at the point of intersection of
the extrapolation of this function with the abscissa (see
graphin Appendix 1, p. 775);
2.3.7. ρ:characteristic of the brake defined by: M ¼ρP/C0Po ðÞ
2.4.Symbols for hydraulic-transmission brakes (see diagram in
Appendix 1, p. 776).
2.4.1. ih: reduction ratio between travel of the coupling head
and travel of the piston in master cylinder;
2.4.2. ig′: reduction ratio between travel of the actuation point of
the cylinders and the brake-shoe centre lift;
2.4.3. FRZ: surface area of piston in brake cylinder;
2.4.4. FHZ: surface area of piston in master cylinder;
2.4.5. p: hydraulic pressure in brake cylinder;
2.4.6. po: retraction pressure in brake cylinder; that is, in the
graph M = f(p), the value of the pressure p at the point
of intersection of the extension of this function with
the abscissa (see graph in Appendix 1, p. 775).
2.4.7. ρ′: characteristic of the brake defined by:
M¼ρ0p/C0po ðÞ :
3. GENERAL REQUIREMENTS
3.1. The transmission of braking power from the coupling head to the trai-
ler's brakes must be effected either by a rod linkage or by means of
one or more fluids. However, a sheathed cable (Bowden cable) may
be used to provide part of the transmission. This part must be as short
as possible.
3.2. All pins at joints must be adequately protected. In addition, these joints
must be either self-lubricating or easily accessible for lubrication.
3.3 Inertia braking devices must be arranged in such a way that, in the case
where the coupling head travels to its fullest extent, no part of the
transmission becomes jammed, or suffers any permanent distortion or
fails. This must be checked after uncoupling the first element of the
transmission from the brake control levers.
3.4. The inertia braking device must allow the trailer to be reversed with
the towing vehicle without imposing a sustained drag force exceeding
8 % of the force corresponding to the maximum mass of the trailer.
Devices used for this purpose must act automatically and disengage
automatically when the trailer moves forward.
3.5. Any special device incorporated for the purposes of item 3.4 shall be
such that the parking performance when facing up a gradient shall not
be adversely affected.
4. REQUIREMENTS FOR CONTROL DEVICES
4.1. The sliding members of the control device must be long enough to
enable the brake to be fully applied, even when the trailer is coupled.
4.2. The sliding members must be protected by a bellows or some equiva-
lent device. They must either be lubricated or be constructed of self-
lubricating materials. The surfaces in frictional contact must be made1971L0320 — EN — 22.08.1991 — 007.001 — 67
▼M4
▼B
▼B
of a material such that there is neither electrochemical torque nor any
mechanical incompatibility liable to cause the sliding members to
seize.
►M44.3.◄The threshold force of the control equipment (KA) must be
not less than 0·02 G ′Aand not more than 0·04 G ′A.
4.4. The maximum depression force of D1may not exceed 0,10 G ′Ain the
case of single-axle trailers and 0,067 G ′Ain the case of multi-axle trai-
lers.
►M44.5.◄The maximum towing force D2must be between 0·1 G ′Aand
0·5 G′A.
5. TESTS AND MEASUREMENTS TO BE CARRIED OUT ON THE
CONTROL SYSTEM
5.1. Compliance withth e requirements of items 3 and 4 above must be
verified on the control device submitted to the technical service
conducting the tests.
5.2. The following shall be measured in respect of all types of brakes:
5.2.1. the travel s and the available travel s ′;
5.2.2. the supplementary force K;
5.2.3. the threshold force KA;
5.2.4. the damping force D1;
5.2.5. the towing force D2.
5.3. In the case of mechanical-transmission inertia brakes, the following
shall be determined:
5.3.1. the reduction ratio iHo, measured at the mid-travel portion of the
control;
5.3.2. the force P ′at the output side of the control device as a function
of the thrust D on the drawbar.
The supplementary force K and the efficiency are derived from
the representative curve obtained from these measurements.
ηHo¼1
iHo/C1P0
D/C0K
(see graphin Appendix 1, p. 772)
5.4. In the case of hydraulic-transmission inertia brakes, the following shall
be determined:
5.4.1. the reduction ratio ihmeasured at the mid-travel position of the
control;
5.4.2. the pressure p at the output side of the master cylinder as a
function of the thrust D on the drawbar and of the surface area
FHZin the master cylinder piston, as specified by the manufac-
turer. The supplementary force K and the efficiency are derived
from the representative curve obtained from these measurements
ηHo¼1
ih/C1p/C1FHZ
D/C0K
(see graphin Appendix 1, page 772);
5.4.3. the ►M4spare travel ◄of the master cylinder actuator s ″
mentioned in item 2.2.19.
►M45.5.◄In the case of inertia brakes on multi-axle trailers, the loss
of travel somentioned in item 9.4.1 shall be measured.
6. REQUIREMENTS FOR BRAKES
6.1. The manufacturer must make available to the technical service respon-
sible for the tests, in addition to the brakes to be tested, drawings of1971L0320 — EN — 22.08.1991 — 007.001 — 68
▼M4
▼B
▼M4
▼B
▼M4
▼B
▼B
the brakes showing the type, dimensions and material of the main
parts, and the make and type of the linings. These drawings must indi-
cate the surface area FRZof the brake cylinders in the case of hydraulic
brakes. The manufacturer must also indicate the maximum braking
torque Mmaxwhich is allowed, as well as the ►M3mass◄GBomentioned in item 2.2.4.
6.2. The force P or the pressure p required to achieve the braking torque
Mmaxindicated by the manufacturer must be at least 1,8 times the force
P or at least 1,8 times the pressure p required to give a braking force of
0,50 GBO.
7. TESTS AND MEASUREMENTS TO BE CARRIED OUT ON THE
BRAKES
7.1. The brakes and items of equipment made available to the technical
service responsible for the tests must be tested to check whether theyconform to the requirements of item 6.
7.2. The following shall be determined:
7.2.1. the minimum shoe centre lift 2s
B*;
7.2.2. the shoe centre lift 2sB(which must be greater than 2sB*);
7.2.3. the braking moment M as a function of the force P applied to
the control lever in the case of devices with mechanical trans-
mission, and of the pressure p in the brake cylinder in the case
of devices withh ydraulic transmission.
The speed at which the braking surfaces rotate must correspond
to an initial vehicle speed of 60 km/h. The following shall be
deducted from the curve obtained from these measurements:
7.2.3.1. the retraction force P and the characteristic ρin the
case of mechanically actuated brakes (see graph in
Appendix 1, p. 775).
7.2.3.2. the retraction pressure poand the characteristic ρin the
case of hydraulically actuated brakes (see graph in
Appendix 1, p. 775).
8. TEST REPORTS
Where applications are made for type approval of trailers fitted with inertia
brakes, suchapplications are to be accompanied by th e test reports relating
to the control system and the brakes, as well as the test report on the
compatibility between the inertia control device, the transmission and the
brakes on the trailer; these reports are to include at least the particulars
shown in Appendices 2, 3 and 4 to this Annex.
9. COMPATIBILITY OF THE CONTROL DEVICE AND THE INERTIA
BRAKES OF A VEHICLE
9.1. A check must be made on the vehicle, taking into account the charac-
teristics of the control device (Appendix 2) and of the brakes
(Appendix 3) as well as the trailer characteristics mentioned in item 4
of Appendix 4, as to whether the inertia braking device of the trailer
complies withth e requirements laid down.
9.2.General testsforalltypesofbrakes
9.2.1. Those parts of the transmission which have not been tested at
the same time as the brake control device or the brakes must
be tested on the vehicle. The results of the test must be entered
in Appendix 4 (for example iH1andηH1).
9.2.2.►M3Mass◄
9.2.2.1. The ►M3maximum mass ◄of the trailer GAmust
not exceed the ►M3maximum mass ◄G′Afor which
the control device is authorised.1971L0320 — EN — 22.08.1991 — 007.001 — 69
▼M4
▼B
▼M4
▼B
▼B
9.2.2.2. The ►M3maximum mass ◄of the trailer GAmust
not exceed the ►M3maximum mass ◄GBwhich
can be braked by the joint operation of all the trailer
brakes.
9.2.3.Forces
9.2.3.1. The threshold force KAmust not be less than 0·02 GAnor greater than 0·04 GA.
9.2.3.2. The maximum damping force D1must not exceed
0·09 GAin the case of single-axle trailers, nor 0·06 GAin the case of multi-axle trailers.
9.2.3.3. The maximum pulling force D2must be between 0·1 GAand 0·5 GA.
9.3.Testofbrakingefficiency
9.3.1. The sum of the braking forces exerted on the circumference of
the trailer wheels must be at least B* = 0,5 GA, including a
rolling resistance of 0,01 GA.
This represents a braking force of B = 0,49 GA.
In this case, the maximum permitted thrust on the coupling shall
be:
D* = 0,067 GAin the case of multi-axle trailers,
D* = 0,10 GAin the case of single-axle trailers.
In order to check whether these conditions are observed, the
following inequalities must be applied:
9.3.1.1. In the case of inertia brakes with mechanical transmis-
sion:
B/C1R
ρþnPo/C20/C211
D/C3/C0K ðÞ /C1 ηH/C20iH
9.3.1.2. In the case of inertia brakes with hydraulic transmis-
sion:
B/C1R
n/C1ρ0þpo/C20/C211
D/C3/C0K ðÞ /C1 ηH/C20ih
FHZ
9.4.Controltraveltest
9.4.1. In the case of control devices for multi-axle trailers of which the
brake rod system is dependent upon the position of the towing
device, the travel of the control s must be greater than the avail-
able travel of the control s ′; the difference in length must be at
least equivalent to the loss of travel so. The travel so, must not
exceed 10 % of the effective travel s ′.
9.4.2. The available travel of the control s ′shall be determined in the
following way:
9.4.2.1. if the brake rod system is affected by the relative posi-
tion of the towing device, then:
s0¼s/C0so;
9.4.2.2. if there is no loss of travel, then:
s0¼s;
9.4.2.3. in the case of hydraulic braking systems:
s0¼s/C0s00:
9.4.3. The following inequalities shall be applied in order to check
whether the travel of the control is adequate:1971L0320 — EN — 22.08.1991 — 007.001 — 70
▼M4
▼B
▼M4
▼B
▼M4
▼B
▼B
9.4.3.1. in the case of inertia brakes with mechanical transmis-
sion:
iH/C20s0
sB/C3/C1ig
9.4.3.2. in the case of inertia brakes with hydraulic transmis-
sion:
ih
FHZ/C20s0
2sB/C3/C1nFRZ/C1i0
g
9.5.Additionaltests
9.5.1. In the case of inertia brakes with mechanical transmission, a
check shall be made as to whether the rod system by which the
forces are transmitted from the control device is correctly fitted.
9.5.2. In the case of inertia brakes with hydraulic transmission, a check
shall be made as to whether the travel of the master cylinder
actuator reaches a minimum level of s/ih.
A lower level will not be permitted.
9.5.3. A road test must be carried out to determine the general reaction
of the vehicle to braking.
10. GENERAL COMMENTS
The above provisions apply to the latest models of inertia brakes with
mechanical or hydraulic transmission; in the case of these models, in parti-
cular, all the wheels of the trailer are fitted with the same type of brake and
the same type of tyre.
When testing special models, the above requirements are to be adapted.1971L0320 — EN — 22.08.1991 — 007.001 — 71
▼B
Appendix 1
See 2.2
See 2.2.10 and 5.3.2 (devices with mechanical transmission)
1971L0320 — EN — 22.08.1991 — 007.001 — 72
▼B
See 2.2.10 and 5.4.2 (devices with hydraulic transmission)
1971L0320 — EN — 22.08.1991 — 007.001 — 73
▼B
See 2.2.22 and 2.3.4
Teststobecarried outonthebrakes1971L0320 — EN — 22.08.1991 — 007.001 — 74
▼B
Brakeswithmechanicaltransmission
See 2.3
1971L0320 — EN — 22.08.1991 — 007.001 — 75
▼B
See 2.3.6 and 7.2.3.1 (mechanical brake)
See 2.4.6 and 7.2.3.2 (hydraulic brake)
1971L0320 — EN — 22.08.1991 — 007.001 — 76
▼B
Brakeswithhydraulictransmission
See 2.4
1971L0320 — EN — 22.08.1991 — 007.001 — 77
▼B
Appendix 2
Testreportoninertia brakecontroldevice
►(1) (2)M3
►(3) (4)M41971L0320 — EN — 22.08.1991 — 007.001 — 78
▼B
Appendix 3
Braketestreport
►(1) (2) (3) (4)M3
►(5) (6) (7) (8) (9)M41971L0320 — EN — 22.08.1991 — 007.001 — 79
▼B
Appendix 4
Testreportonthecompatibilityoftheinertiacontroldevice,thetransmissionandthebrakesonthe
trailer
►(1) (3)M3
►(2) (4)M41971L0320 — EN — 22.08.1991 — 007.001 — 80
▼B
►(1) (2) (3)M41971L0320 — EN — 22.08.1991 — 007.001 — 81
▼B
ANNEX IX
►(1)M3
►(2) (3) (4)M4
►(5) (6) (7) (8) (9) (10)M61971L0320 — EN — 22.08.1991 — 007.001 — 82
▼B
►(1)M3
►(2) (3) (4) (5) (6) (7)M61971L0320 — EN — 22.08.1991 — 007.001 — 83
▼M4
►(1) (2)M61971L0320 — EN — 22.08.1991 — 007.001 — 84
▼B
►(1)M2
►(2) (3)M3
►(4) (5) (6) (7) (8)M4
►(9) (10) (11)(12) (13) (14)(15) (16)(17) (18)M61971L0320 — EN — 22.08.1991 — 007.001 — 85
▼M4
ANNEX X:REQUIREMENTSAPPLICABLETOTESTSFORVEHICLES
EQUIPPEDWITHANTI-LOCKDEVICES
1. GENERAL
1.1. The purpose of this Annex is to define the required performances
for braking systems withanti-lock devices fitted to road veh icles.
In addition, motor vehicles which are authorized to draw a trailer,
and trailers equipped withcompressed-air braking systems, sh all,
when the vehicles are laden, meet the requirements for compat-
ibility set out in the Appendix to item 1.1.4.2 of Annex II.
1.2. The devices known at present comprise a sensor or sensors, a
controller or controllers and a modulator or modulators. Any
devices of a different design which may be introduced in the
future will be deemed to be anti-lock devices within the meaning
of this Annex and the Appendix to item 1.1.4.2 of Annex II, if
they provide performances equal to those prescribed by this
Annex.
2. DEFINITIONS
2.1. An ‘anti-lock device’ is a component of a service braking system
which automatically controls the degree of slip, in the direction of
rotation of the wheel(s), on one or more wheels of the vehicle
during braking.
2.2. ‘Sensor’ means a component designed to identify and transmit to
the controller the conditions of rotation of the wheel(s) or the
dynamic conditions of the vehicle.
2.3. ‘Controller’ means a component designed to evaluate the data
transmitted by the sensor(s) and to transmit a signal to the modu-
lator.
2.4. ‘Modulator’ means a component designed to vary the braking
force(s) in accordance with the signal received from the
controller.
2.5. ‘Directly controlled wheel’ means a wheel whose braking force is
modulated according to data provided at least by its own
sensor(1).
2.6. ‘Indirectly controlled wheel’ means a wheel whose braking force
is modulated according to data provided by the sensor(s) of other
wheel(s) (1).
3. TYPES OF ANTI-LOCK DEVICE
3.1. A motor vehicle is deemed to be equipped with an antilock
device within the meaning of paragraph 1 of the Appendix to
item 1.1.4.2 of Annex II, if one of the following devices is fitted:
3.1.1. Category 1 anti-lock device:
A vehicle equipped with a category 1 anti-lock device shall meet
all the relevant requirements of this Annex.
3.1.2. Category 2 anti-lock device:
A vehicle equipped with a category 2 anti-lock device shall meet
all the relevant requirements of this Annex, except those of item
5.3.5.
3.1.3. Category 3 anti-lock device:
A vehicle equipped with a category 3 anti-lock device shall meet
all the relevant requirements of this Annex, except those of items
5.3.4 and 5.3.5. On suchveh icles, any individual axle (or bogie)
which does not include at least one directly controlled wheel
must fulfil the conditions of adhesion utilization and the wheel-
locking sequence of the Appendix to item 1.1.4.2 of Annex II,
instead of the adhesion utilization requirements prescribed in1971L0320 — EN — 22.08.1991 — 007.001 — 86
(1) Anti-lock devices withselect-h ighcontrol are deemed to include bothdirectly and
indirectly controlled wheels; in devices with select-low control, all sensed wheels are
deemed to be directly controlled wheels.▼M5
▼M4
▼M4
item 5.2 of this Annex. However, if the relative positions of the
adhesion utilization curves do not meet the requirements of item
3.1.1 of the Appendix to item 1.1.4.2 of Annex II, a check shall
be made to ensure that the wheels on at least one of the rear axles
do not lock before those on the front axle or axles under the
conditions prescribed in items 3.1.1 and 3.1.4 of the Appendix
to item 1.1.4.2 of Annex II withregard to th e braking rate and
the load respectively. These requirements may be checked on
high- or low-adhesion road surfaces (about 0,8 and 0,3
maximum) by modulating the service brake control force.
3.2. A towed vehicle is deemed to be equipped with an anti-lock
device within the meaning of item 1 of the Appendix to item
1.1.4.2 to Annex II, if at least two wheels on opposite sides of
the vehicle are directly controlled by an anti-lock device, and all
the relevant requirements of this Annex are satisfied. Further-
more, in the case of full trailers, at least one wheel on one front
axle and one (diagonally opposite) wheel on one rear axle must
be directly controlled by independent modulators.
4. GENERAL REQUIREMENTS
4.1. Any break in the supply of electricity to the device and/or in the
wiring external to the elctronic controller(s) shall be signalled to
the driver by a specific optical warning signal. This requirement
also applies to the anti-lock device(s) of towed vehicles which are
designed to be coupled to towing vehicles of categories other
than M1and N1. The warning device for the anti-lock device(s)
of the towed vehicle must not give a signal when a towed vehicle
without an anti-lock device, or when no towed vehicle, is
coupled. This requirement must be met automatically.
The warning signal shall light up when the anti-lock device is
energised and go off at the latest when the vehicle reaches a
speed of 10 km/hand no defect is present. Th e tell-tale lamps of
the warning devices must be visible even in daylight; it must be
easy for the driver to check that they are in working order(1).
4.2. Motor vehicles equipped with anti-lock devices and/or designed
to tow a trailer equipped withsuchdevices, withth e exception
of vehicles of categories M1and N1, shall be fitted with a separate
warning device for the anti-lock device(s) of the towed vehicle,
meeting the requirements of item 4.1 above, or shall be fitted
with an optical warning signal which shall light up not later than
any application of the brake to warn the driver if the attached
trailer is not equipped withan anti-lock device. Th is warning
signal shall be visible even in daylight and its good working
order shall be easily checked by the driver. It shall not convey
any signal if no trailer is attached. This function shall be auto-
matic (1).
4.3. Except for vehicles of categories M1and N1, the electrical
connections used for the anti-lock devices of towed vehicles shall
be effected by a special connector conforming to ISO Standard
7638/1985(1).1971L0320 — EN — 22.08.1991 — 007.001 — 87
(1) To ensure compatibility of all vehicles until the special ISO connector is in general use,
it shall be considered that the requirements of items 4.1, 4.2 and 4.3 concerning towedvehicles are fulfilled only if the vehicles satisfy the following two conditions:1. the supply of electricity to the anti-lock device(s) of the towed vehicle is provided:
(a) firstly, via the ISO 3731 (24S) connector (using pins 2 and 6 for failure warning
and power supply, respectively) or via the special anti-lock connectorconforming to ISO 7638; and
(b) secondly, via the ISO 1185 (24N) connector (using pin 4 without exceeding the
present limits of the stop lamp circuit); if this is not fulfilled, the requirements
of the Appendix to item 1.1.4.2 of Annex II shall be satisfied: for example, by
the installation of a brake load sensing device on the towed vehicle;
2. the towed vehicle is equipped with an optical device, within the field of view of the
driver's rear view mirror and visible even in daylight, to warn him of any break inthe supply of electricity and/or in the wiring external to the electronic controller of
the anti-lock device of the towed vehicle.▼M5
▼M4
▼M4
4.4. In the event of failure of the anti-lock device, the residual braking
performance must be that prescribed for the vehicle in question in
the event of failure of a part of the transmission to the service
brake (see item 2.2.1.4 of Annex I). This requirement shall not
be construed as a departure from the requirements concerning
secondary braking.
4.5. The operation of the device must not be adversely affected by
magnetic or electrical fields(1).
5. SPECIAL PROVISIONS CONCERNING MOTOR VEHICLES5.1. Energyconsumption
Braking systems equipped withanti-lock devices must maintain
their performance when the service brake is fully applied for
long periods. Compliance with this requirement shall be verified
by means of the following tests:
5.1.1. Test procedure
5.1.1.1. The initial energy level in the energy storage device(s) shall be
that specified by the manufacturer. This level shall be at least
suchas to ensure th e efficiency prescribed for service braking
when the vehicle is laden. The auxiliary service storage device(s)
must be isolated.
5.1.1.2. From an initial speed of not less than 50 km/h, on a surface with
a coefficient of adhesion of 0,3(
2) or less, the brakes of the laden
vehicle shall be fully applied for a time t, and all the wheels
equipped withan anti-lock device must remain under control
throughout that time.
5.1.1.3. The vehicle's engine shall then be stopped or the supply to the
energy storage device(s) cut off.
5.1.1.4. The service brake control shall then be fully actuated four times
in succession with the vehicle stationary.
5.1.1.5. When the brakes are applied for the fifth time, it must be possible
to brake the vehicle with at least the performance prescribed for
secondary braking of the laden vehicle.
5.1.1.6. During the tests, in the case of a motor vehicle authorized to
draw a trailer equipped witha compressed air braking system,
the supply line shall be stopped and an energy storage device of
0,5-litre capacity shall be connected to the control line (in accor-
dance with Annex IV, item 1.2.2.3). When the brakes are applied
for the fith time, as provided in item 5.1.1.5, the energy level
supplied to the control line must not be below half the level
obtained at a full application starting withth e initial energy level.
5.1.2. Additional requirements
5.1.2.1. The coefficient of adhesion of the road surface shall be measured
with the vehicle in question, by the method described in item 1.1of Appendix 1 to this Annex.
5.1.2.2. The braking test shall be conducted with the engine disconnected
and idling, and with the vehicle laden.
5.1.2.3. The braking time t shall be determined by the formula: t ¼Vmax
7
(but not less than 15 seconds) where t is expressed in seconds and
Vmaxrepresents the maximum design speed of the vehicle
expressed in km/h, with an upper limit of 160 km/h.
5.1.2.4. If the time t cannot be completed in a single braking phase,
further phases may be used, up to a maximum of four in all.
5.1.2.5. If the test is conducted in several phases, no fresh energy shall be
supplied between the phases of the test.
5.1.2.6. The performance prescribed in item 5.1.1.5 shall be deemed to be
satisfied if, at the end of the fourth application, with the vehicle1971L0320 — EN — 22.08.1991 — 007.001 — 88
(1) Until uniform test procedures have been agreed, the manufacturers shall provide the
Technical Services with their test procedures and results.
(2) Until suchtest surfaces become generally available, tyres at th e limit of wear, and
higher values up to 0,4 may be used at the discretion of the technical services. The
actual value obtained and the type of tyres and surface shall be recorded.
▼M4
stationary, the energy level in the storage device(s) is at or above
that required for secondary braking with the laden vehicle.
5.2. Utilizationofadhesion
5.2.1. The utilization of adhesion by the anti-lock device takes into
account the actual increase in braking distance beyond the theore-
tical minimum. The anti-lock device shall be deemed to be
satisfactory when the condition ε≥0,75 is satisfied, where ε
represents the adhesion utilized, as defined in item 1.2 of
Appendix 1 to this Annex. This requirement shall not be
construed as requiring a braking performance better than that
prescribed in Annex II for the vehicle in question.
5.2.2. The adhesion utilization εshall be measured on road surfaces
witha coefficient of adh esion of 0,3(1) or less, and of about 0,8
(dry road), withan initial speed of 50 km/h .
5.2.3. The test procedure to determine the coefficient of adhesion (K)
and the formulae for calculation of the adhesion utilization ( ε)
shall be those laid down in Appendix 1 to this Annex.
5.2.4. The utilization of adhesion by the anti-lock device shall be
checked on complete vehicles equipped with anti-lock devices of
categories 1 or 2. In the case of vehicles equipped with category
3 anti-lock devices, only the axle(s) with at least one directly
controlled wheel must satisfy this requirement.
5.2.5. The condition ε≥0,75 shall be checked with the vehicle laden
and unladen.
5.3. Additionalchecks
The following additional checks shall be carried out with the
vehicle laden and unladen.
5.3.1. The wheels directly controlled by an anti-lock device must not
lock when the full force(2) is suddenly applied on the control
device, on the two kinds of road surface specified in item 5.2.2
above, at low initial speeds V = 40 km/hand at h ighinitial
speeds V ≈0,8 Vmax≤120 km/h.
5.3.2. When an axle passes from a high-adhesion surface (K1) to a low-
adhesion surface (K2) where K1≥0,5 and K1/K2≥2(3), with
the full force (2) applied on the control device, the directly
controlled wheels must not lock. The running speed and the
instant of applying the brake shall be so calculated that, with the
anti-lock device fully cycling on the high-adhesion surface, the
passage from one surface to the other is made at high and at
low speed, under the conditions laid down in item 5.3.1 above.
5.3.3. When a vehicle passes from a low-adhesion surface (K2)t oa
high-adhesion surface (K1) where K1≥0,5 and K1/K2≥2,
withth e full force (2) applied on the control device, the decelera-
tion of the vehicle must rise to the appropriate high value within
a reasonable time and the vehicle must not deviate from its initial
course. The running speed and the instant of applying the brake
shall be so calculated that, with the anti-lock device fully cycling
on the low-adhesion surface, the passage from one surface to the
other occurs at approximately 50 km/h.
5.3.4. The provisions of this paragraph shall only apply to vehicles
equipped with anti-lock devices of categories 1 or 2. When the
right and left wheels of the vehicle are situated on surfaces with
differing coefficients of adhesion (K1and K2), where K1≥0,5
and K1/K2≥2, the directly controlled wheels must not lock
when the full force (2) is suddenly applied on the control device
at a speed of 50 km/h.
5.3.5. Furthermore, laden vehicles equipped with anti-lock devices of
category 1 shall, under the conditions of item 5.3.4 above, satisfy
the prescribed braking rate in Appendix 2 to this Annex.1971L0320 — EN — 22.08.1991 — 007.001 — 89
(1) See footnote to item 5.1.1.2.
(2) ‘Full force’ means the maximum force prescribed in Annex II for the category of
vehicle; a higher force may be used if required to activate the anti-lock device.
(3)K1is the high-adhesion surface coefficient.
K2is the low-adhesion surface coefficient.
K1and K2are measured as laid down in Appendix 1 to this Annex.
▼M4
5.3.6. However, in the tests provided for in items 5.3.1, 5.3.2, 5.3.3,
5.3.4 and 5.3.5 above, brief periods of wheel-locking shall be
allowed. Furthermore, wheel-locking is permitted when the
vehicle speed is less than 15 km/h; likewise, locking of indirectly
controlled wheels is permitted at any speed, but stability and
steerability must not be affected.
5.3.7. During the tests provided for in items 5.3.4 and 5.3.5 above,
steering correction is permitted if the angular rotation of the
steering control is within 120º during the initial 2 seconds and
not more than 240º in all. Furthermore, at the beginning of these
tests the longitudinal median plane of the vehicle must pass over
the boundary between the high- and low-adhesion surfaces and
during these tests no part of the (outer) tyres must cross this
boundary.
6. SPECIAL PROVISIONS CONCERNING TOWED VEHICLES
6.1. Energyconsumption
Braking systems equipped withanti-lock devices sh all be so
designed that, even after the service braking control has been
fully applied for some time, the vehicle retains sufficient energy
to bring it to a halt within a reasonable distance.
6.1.1. Compliance with the above requirement shall be checked by the
procedure specified below, with the vehicle unladen, on a straight
and level road with a surface having a good coefficient of adhe-
sion(1), and withth e brakes adjusted as closely as possible and
with the proportioning/load-sensing valve (if fitted) held in the
‘laden’ position throughout the test.
►M66.1.2. The initial energy level ◄in the energy storage device(s) shall
be the maximum specified by the vehicle manufacturer; in the
case of a standard assembly as referred to in item 3.1.2 of the
Appendix to item 1.1.4.2 of Annex II, the initial energy level
shall be ►M6equivalent to a pressure of 8,5 bar at the coupling
head of the trailer's supply line. ◄
6.1.3. The brakes shall be fully applied for a time t = 15 seconds,
during which all wheels equipped with an antilock device must
remain under control. During this test, the supply to the energy
storage device(s) shall be cut off.
6.1.4. If the axle or axles equipped with an anti-lock device receive
energy from an energy storage device or devices shared with
another axle or axles not equipped with an anti-lock device, the
supply to the axle or axles not so equipped may be cut off during
braking. However, the consumption of energy corresponding to
the initial application of the brakes on that axle or axles shall be
taken into account.
6.1.5. At the end of the braking, with the vehicle stationary, the service
braking control shall be fully actuated once. During this applica-
tion, the pressure in the operating circuits must be sufficient to
provide a total braking force at the periphery of the wheels equal
to not less than 22,5 % of the force corresponding to the
maximum mass borne by the wheels when the vehicle is
stationary and without causing an automatic application of any
braking system not being under the control of the anti-lock
device.1971L0320 — EN — 22.08.1991 — 007.001 — 90
(1) If the coefficient of adhesion of the test track is too high, preventing the anti-lock
device from cycling, then the test may be carried out on a surface with a lower coeffi-
cient of adhesion.▼M6
▼M4
6.2. Utilizationofadhesion
6.2.1. Braking systems equipped withan anti-lock device sh all be
deemed acceptable when the condition ε≥0,75 is satisfied,
where εrepresents the adhesion utilized, as defined in item 2 of
Appendix 1 to this Annex. This condition shall be verified with
the vehicle unladen, on a straight and level road with a surface
having a good coefficient of adhesion(1)
6.3. Additionalchecks
6.3.1. At speeds exceeding 15 km/h, the wheels directly controlled by
an anti-lock device must not lock when the full force is suddenly
applied on the control device. This shall be checked, under the
conditions prescribed in item 6.2 above, at a low initial speed
V = 40 km/hand at a h ighinitial speed V ≈80 km/h.
6.3.2. Brief periods of locking of the wheels shall, however, be allowed,
but stability must not be affected.1971L0320 — EN — 22.08.1991 — 007.001 — 91
(1) If the coefficient of adhesion of the test track is too high, preventing the anti-lock
device from cycling, then the test may be carried out on a surface with a lower coeffi-
cient of adhesion.
▼M4
Appendix 1
UTILIZATIONOFADHESION
1. METHOD OF MEASUREMENT FOR MOTOR VEHICLES
1.1. Determinationofthecoefficient ofadhesion(K)
1.1.1. The coefficient of adhesion (K) shall be determined as the
quotient of the maximum braking forces without locking the
wheels and the corresponding dynamic load on the axle being
braked.
1.1.2. The brakes shall be applied on only one axle of the vehicle under
test, at an initial speed of 50 km/h. The braking forces shall be
equally distributed between the wheels of the axle. The anti-lock
device shall be disconnected.
1.1.3. A number of tests at increments of line pressure shall be carried
out to determine the maximum braking rate of the vehicle (zm).
During eachtest, a constant input force sh all be maintained and
the braking rate will be determined by reference to the time taken
(t) for th e speed to reduce from 40 km/hto 20 km/husing th e
formula:
z¼0;56
t
zmis the maximum value of z; t is in seconds.
1.1.4. The braking forces shall be calculated from the measured braking
rate and the rolling resistance of the unbraked axle(s) which is
equal to 0,015 and 0,010 of the static axle load for a driven axle
and a non-driven axle, respectively.
1.1.5. The dynamic load on the axle shall be that given by the relations
in the Appendix to item 1.1.4.2 of Annex II.
1.1.6. The value of K shall be rounded to the second place of decimals.1.1.7. Example: in the case of a two-axle vehicle, with the front axle (1)
being braked, the coefficient of adhesion (K) is given by:
K¼
zm/C1P/C00;015/C1P2
P1þh
E/C1zm/C1P:
The other symbols (P, h, E) are defined in the Appendix to item
1.1.4.2 of Annex II.
1.2. Determinationoftheadhesionutilized( ε)
1.2.1. The adhesion utilized ( ε)is defined as the quotient of the
maximum braking rate withth e anti-lock device in operation
(zmax) and the coefficient of adhesion (K) i.e.
ε¼zmax
K
1.2.2. The maximum braking rate (zmax) shall be measured with the anti-
lock device in operation and based on the average value of three
tests, using the time taken for the speed to reduce from 40 km/h
to 20 km/has in item 1.1.3 above.
1.2.3. The value of εshall be rounded to the second place of decimals.
1.2.4. In the case of a vehicle equipped with an anti-lock device of cate-
gories 1 or 2, the value of zmaxwill be based on the whole
vehicle, with the anti-lock device in operation, and the adhesion
utilized ( ε)is given by the same formula quoted in item 1.2.1
above.
1.2.5. In the case of a vehicle equipped with an anti-lock device of cate-
gory 3, the value of zmaxwill be measured on each axle which has
at least one directly controlled wheel.1971L0320 — EN — 22.08.1991 — 007.001 — 92
▼M4
Example: for a two-axle vehicle with an anti-lock device acting
only on the rear axle (2), the adhesion utilized ( ε)is given by:
ε¼zmax/C1P/C00;010/C1P1
K/C1P2/C0h
E/C1zmax/C1P/C18/C19 :
This calculation shall be made for each axle having at least one
directly controlled wheel.
2. METHOD OF MEASUREMENT FOR TOWED VEHICLES
2.1. Where all the axles have at least one directly controlled wheel:
2.1.1. The test shall be conducted by braking one axle at a time; the
other axles shall not be braked and the engine of the towing
vehicle shall be disconnected.
2.1.2. The mean braking rate (z) shall be determined, taking into
account the rolling resistance of the unbraked axles. The test shall
be conducted at a speed of 50 km/hand th e rolling resistance
coefficient may be estimated at 0,01.
2.1.3. The following relation shall be verified for each axle:
ε¼z1
z0/C210;75
where:
ε= the adhesion utilized,
z0= the maximum braking rate obtained by braking one axle
without locking the wheels, the anti-lock device being
disconnected,
z1= the braking rate obtained by braking the same axle on the
same road surface, withth e anti-lock device in operation.
The values to be used for z1and z0shall be the arithmetic means
of three values measured in succession under the same test condi-
tions.
2.2. Where not all axles have at least one directly controlled wheel:2.2.1. In the case of full trailers, the coefficient of adhesion (K) and the
adhesion utilized ( ε)shall be determined in accordance with the
provisions for motor vehicles in items 1.1 and 1.2 of this
Appendix. The forces in the drawbar connection shall be taken
into account.
2.2.2. In the case of semi-trailers (and centre-axle trailers), the
following procedure shall be used:
2.2.2.1. The adhesion utilized shall be calculated by means of the
formula:
ε¼
zmax
z0
where:
z0= the maximum braking rate obtained by braking one
axle without locking the wheels, the anti-lock device
being disconnected and the wheels of the other axles
removed,
zmax= the braking rate obtained by braking all the axles
controlled by the anti-lock device, with the device in
operation.
2.2.2.2. The value of z0may be calculated by carrying out the procedure
described in item 1.1.3 of this Appendix to determine the
maximum braking rate (z*).
Then : z 0¼TR
PRdyn;1971L0320 — EN — 22.08.1991 — 007.001 — 93
▼M4
where:
TR = braking force = z* · (P + PM) − 0,01 · W
PRdyn= dynamic load ¼PR/C0TR/C1hsþP/C1z/C3hR/C0hs ðÞ
ER
and W is the static mass of the unbraked axles.
The other symbols are defined in the appendix to item 1.1.4.2 of
Annex II.
2.2.2.3. The value of zmaxmay be calculated by the same procedure:
measure z**, the braking rate with the anti-lock device in opera-
tion; calculate TR ′and PR′dynusing the formulae in item 2.2.2.2
above, and then
zmax¼TR0
PR0
dyn1971L0320 — EN — 22.08.1991 — 007.001 — 94
▼M4
Appendix 2
PERFORMANCEONDIFFERING-ADHESIONSURFACES
1. The prescribed braking rate referred to in item 5.3.5 of this
Annex may be calculated by reference to the measured coeffi-
cient of adhesion of the two surfaces on which this test is
carried out.
These two surfaces must satisfy the conditions prescribed in item
5.3.4 of this Annex.
2. The coefficient of adhesion (K1and K2) of the high- and low-
adhesion surfaces, respectively, shall be determined in accordance
with the provisions in item 1.1 of Appendix 1 to this Annex.
3. The prescribed braking rate (z3) for laden motor vehicles shall be:
z3/C210;75/C14K2þK1
5/C18/C19
and z3/C21K2:1971L0320 — EN — 22.08.1991 — 007.001 — 95
▼M4
ANNEX XI:TEST CONDITIONS FOR TRAILERS WITH ELECTRICAL
BRAKINGSYSTEMS
1. GENERAL
1.1. For the purposes of the following provisions electrical brakes are
service braking systems consisting of a control device, an electro-
mechanical transmission device, and friction brakes. The
electrical control device regulating the voltage for the trailer
must be situated on the trailer.
1.2. The electrical energy required for the electrical braking system is
supplied to the trailer by the motor vehicle.
1.3. Electrical braking systems shall be actuated by operating the
service braking system of the motor vehicle.
1.4. The nominal voltage rating shall be 12 V.1.5. The maximum current consumption shall not exceed 15 A.1.6. The electrical connection of the electrical braking system to the
motor vehicle shall be effected by means of a special plug andsocket connection corresponding to …(
1), the plug of which shall
not be compatible with the sockets of the lighting equipment of
the vehicle. The plug together with the cable shall be situated on
the trailer.
2. CONDITIONS CONCERNING THE TRAILER
2.1. If there is a battery on the trailer fed by the power supply unit of
the motor vehicle, it shall be separated from its supply line during
service braking of the trailer.
2.2. With trailers whose unladen mass is less than 75 % of their
maximum mass the braking force shall be automatically regulated
as a function of the loading condition of the trailer.
2.3. Electrical braking devices shall be such that even if the voltage in
the connection lines is reduced to a value of 7 V a braking effect
of 20 % of the force corresponding to the maximum mass of the
trailer is maintained.
2.4. Control devices for regulating the braking force, which react to
the inclination in the direction of travel (pendulum, spring-mass-
system, liquid-inertia-switch) shall, if the trailer has more than
one axle and a vartically adjustable towing device, be attached
to the chassis. In the case of single-axle trailers and trailers with
close-coupled axles where the axle spread is less than 1 metre,
these control devices shall be equipped with a mechanism indi-
cating its horizontal position (e.g. spirit level) and shall be
manually adjustable to allow the mechanism to be set in the hori-
zontal plane in line with the direction of travel of the vehicle.
2.5. The relay for actuating the braking current in accordance with
item 2.2.1.20.2 of Annex I, which is connected to the actuating
line, shall be situated on the trailer.
2.6. A dummy socket shall be provided for the plug.2.7. A tell-tale shall be provided at the control device, lighting up at
any brake application and indicating the proper functioning of the
trailer electric braking system.
3. PERFORMANCE
3.1. Electrical braking systems shall respond at a deceleration of the
tractor/trailer combination of not more than 0,4 m/s
2.
3.2. The braking effect may commence with an initial braking force,
which shall not be higher than 10 % of the force corresponding to
the maximum mass nor higher than 13 % of the force corre-
sponding to the unladen mass of the trailer.
3.3. The braking forces may also be increased in steps. At higher
levels of the braking forces than those referred to in item 3.21971L0320 — EN — 22.08.1991 — 007.001 — 96
(1) Under study. Until the characteristics of this special connection have been determined,
the type to be used will be indicated by the national authority granting the approval.
▼M4
these steps shall not be higher than 6 % of the force corre-
sponding to the maximum mass, nor higher than 8 % of the
force corresponding to the unladen mass of the trailer. However,
in the case of single-axle trailers having a maximum mass not
exceding 1,5 tonnes, the first step must not exceed 7 % of the
force corresponding to the maximum mass of the trailer. An
increase of 1 % of this value is permitted for the subsequent steps
(example: first step 7 %, second step 8 %, third step 9 %, etc.;
any further step should not exceed 10 %). For the purpose of
these provisions a two-axle trailer having a wheelbase shorter
than 1 metre will be considered as a single-axle trailer.
3.4. The prescribed braking force of the trailer of at least 50 % of the
force corresponding to its maximum mass shall be attained —
withmaximum mass — in th e case of a mean fully developed
deceleration of the tractor/trailer combination of not more than
5,9 m/s2withsingle-axle trailers and of not more th an 5,6 m/s2
withmulti-axle trailers. Trailers withclose-coupled axles wh erethe axle spread is less than 1 metre are also considered as
single-axle trailers within the meaning of this provision. More-
over, the limits as defined in the Appendix to this Annex must
be observed. If the braking force is regulated in steps, they shall
lie within the range shown in the Appendix to this Annex.
3.5. The test shall be carried out with an initial speed of 60 km/h.3.6. Automatic braking of the trailer shall be provided in accordance
with the conditions of item 2.2.2.9 of Annex I. If this automatic
braking action requires electrical energy, a trailer braking force of
at least 25 % of the force corresponding to its maximum mass
shall be guaranteed for at least 15 minutes to satisfy the above-
mentioned conditions.1971L0320 — EN — 22.08.1991 — 007.001 — 97
▼M4
Appendix
Compatibilityofthebrakingrateofthetrailerandthemeanfullydevelopeddecelerationofthe
tractor/trailer combination(trailer ladenandunladen)
Notes:
1. Limits indicated in the diagram refer to laden and unladen trailers. When the trailer unladen mass
exceeds 75 % of its maximum mass, limits shall be applied only to ‘laden’ conditions.
2. Limits indicated in the diagram do not affect the provisions of this Annex regarding the minimum
braking performances required. However, if braking performances obtained during test — in accor-
dance with provisions indicated in item 3.4 above — are greater than those requested, do not
exceed the limits indicated in the above diagram.
TR = sum of braking forces at periphery of all wheels of trailer.
PR = total normal static reaction of road surface on wheels of trailer.
J = mean fully developed deceleration of tractor/trailer combination.1971L0320 — EN — 22.08.1991 — 007.001 — 98
▼M4
ANNEX XII: INERTIA DYNAMOMETER TEST METHOD FOR BRAKE
LININGS
1. GENERAL
1.1. The procedure described in this Annex may be applied in the
event of a modification of vehicle-type resulting from the fitting
of brake linings of another type to vehicles which have been
approved in accordance withth is Directive.
1.2. The alternative types of brake linings shall be checked by
comparing their performance with that obtained from the brake
linings with which the vehicle was equipped at the time of
approval and conforming to the components identified in the rele-
vant information document, a model of which is given in Annex
IX.
1.3. The technical authority responsible for conducting approval tests
may at its discretion require comparison of the performance of
the brake linings to be carried out in accordance with the relevant
provisions contained in Annex II.
1.4. Application for approval by comparison shall be made by the
vehicle manufacturer or by his duly accredited representative.
1.5. In the context of this Annex ‘vehicle’ shall mean the vehicle-type
approved according to this Directive and for which it is requested
that the comparison shall be considered satisfactory.
2. TEST EQUIPMENT
2.1. A dynamometer having the following characteristics shall be
used:
2.1.1. it shall be capable of generating the inertia required by item 3.1
of this Annex, and have the capacity to meet the requirements
prescribed by items 1.3 and 1.4 of Annex II withrespect to
Type I and II fade tests;
2.1.2. the brakes fitted shall be identical with those of the original
vehicle-type concerned;
2.1.3. air cooling, if provided, shall be in accordance with item 3.4 of
this Annex;
2.1.4. the instrumentation for the test shall be capable of providing at
least the following data:
2.1.4.1. a continuous recording of disc or drum rotational speed;2.1.4.2. number of revolutions completed during a stop, to resolution not
greater than one-eighth of a revolution;
2.1.4.3. stop time;2.1.4.4. a continuous recording of the temperature measured in the centre
of the path swept by the lining or at mid-thickness of the disc or
drum or lining;
2.1.4.5. a continuous recording of brake application control line pressure
or force;
2.1.4.6. a continuous recording of brake output torque.
3. TEST CONDITIONS
3.1. The dynamometer shall be set as close as possible, with ± 5 %
tolerance, to the rotary inertia equivalent to that part of the total
inertia of the vehicle braked by the appropriate wheel(s)
according to the following formula:
I¼MR
2
Where:
I = rotary inertia (kgm2)
R = tyre rolling radius (m)
M = that part of the maximum mass of the vehicle braked by
the appropriate wheel(s). In the case of a single-ended
dynamometer, this mass shall be calculated from the
design braking distribution when deceleration corresponds1971L0320 — EN — 22.08.1991 — 007.001 — 99
▼M4
to the appropriate value given in item 2.1.1.1.1 of Annex
II, except in the case of category O trailers when the value
of M will be equivalent to the mass on the ground for the
appropriate wheel when the vehicle is stationary and
loaded to its maximum mass.
3.2. The initial rotational speed of the inertia dynamometer shall
correspond to the linear speed of the vehicle as prescribed in
this Directive and shall be based on the rolling radius of the tyre.
3.3. Brake linings shall be at least 80 % bedded and shall not have
exceeded a temperature of 180 ºC during the bedding procedure,
or alternatively, at the vehicle manufacturer's request, be bedded
in accordance withh is recommendations.
3.4. Cooling air may be used, flowing over the brake in a direction
perpendicular to its axis of rotation. The velocity of the cooling
air flowing over the brake shall be not greater than 10 km/h.
The temperature of the cooling air shall be the ambient tempera-
ture.
4. TEST PROCEDURE
4.1. Five sample sets of the brake lining shall be subjected to the
comparison test; they shall be compared with five sets of linings
conforming to the original components identified in the informa-
tion document concerning the first approval of the vehicle-type
concerned.
4.2. Brake lining equivalence shall be based on a comparison of the
results achieved using the test procedures prescribed in this
Annex and in accordance withth e following requirements:
4.3. TypeOcoldperformancetest
4.3.1. Three brake applications shall be made when the initial tempera-
ture is below 100 ºC. The temperature shall be measured in
accordance withth e provisions of item 2.1.4.4.
4.3.2. In the case of brake linings intended for use on vehicles of cate-
gories M and N, brake applications shall be made from an initial
rotational speed equivalent to that given in item 2.1.1.1.1 of
Annex II and the brake shall be applied to achieve a mean torque
equivalent to the declaration prescribed in that item. In addition,
tests shall be carried out at several rotational speeds, the lowest
being equivalent to 30 % of the maximum speed of the vehicle
and the highest being equivalent to 80 % of that speed.
4.3.3. In the case of brake linings intended for use on vehicles of cate-
gory O, brake applications shall be made from an initial rotational
speed equivalent to 60 km/h, and the brake shall be applied to
achieve a mean torque equivalent to that prescribed in item 2.2.1
of Annex II. A supplementary cold performance test from an
initial rotational speed equivalent to 40 km/hsh all be carried out
for comparison withth e Type I and II test results as described in
item 2.2.1.2.1 of Annex II.
4.3.4. The mean braking torque recorded during the above cold perfor-
mance tests on the linings being tested for the purpose of
comparison shall, for the same input measurement, be within the
test limits ± 15 % of the mean braking torque recorded with the
brake linings conforming to the component indentified in the
relevant application for vehicle type approval.
4.4. TypeItest:
4.4.1. With repeated braking
4.4.1.1. Brake linings for vehicles of category M and N shall be tested
according to the procedure given in paragraph 1.3.1 of Annex II.
4.4.2. With continuous braking
4.4.2.1. Brake linings for trailers of category O shall be tested in accor-
dance withitem 1.3.2 of Annex II.
4.4.3. ►M6Hot◄performance
4.4.3.1. On completion of the tests required under item 4.4.1 and 4.4.2
above, the ►M6hot◄braking performance test specified in
item 1.3.3 of Annex II shall be carried out.1971L0320 — EN — 22.08.1991 — 007.001 — 100
▼M4
4.4.3.2. The mean braking torque recorded during the above
►M6hot◄performance tests on the linings being tested for
the purpose of comparison shall, for the same input measurement,
be within the test limits ± 15 % of the mean braking torque
recorded with the brake linings conforming to the component
identified in the relevant application for vehicle type approval.
4.5. TypeIItest
4.5.1. This test is required only if, on the vehicle type in question, the
friction brakes are used for the Type II test.
4.5.2. Brake linings for motor vehicles of category M3(except those
required under item 2.2.1.19 of Annex I to undergo a Type II A
test) and category N3, and trailers of category O4shall be tested
according to the procedure set out in item 1.4.1 of Annex II.
4.5.3. ►M6Hot◄performance
4.5.3.1. On completion of the test required under item 4.5.2 above, the
►M6hot◄performance test specified in item 1.4.3 of Annex
II shall be carried out.
4.5.3.2. The mean braking torque recorded during the above
►M6hot◄performance tests on the linings being tested for
the purpose of comparison shall, for the same input measurement,
be within the test limits ± 15 % of the mean braking torque
recorded with the brake linings conforming to the component
identified in the relevant application for type approval.
5. INSPECTION OF BRAKE LININGS
5.1. Brake linings shall be visually inspected on completion of the
tests outlined above to check that they are in satisfactory condi-
tion for continued use in normal service.1971L0320 — EN — 22.08.1991 — 007.001 — 101