This document is meant purely as documentation tool and the institutions do not assume any liability for its contents
"BCOUNCIL DIRECTIVE
of 8 June 1970
on the approximation of the laws of the Member States relating to the steering equipment for motor
vehicles and their trailers
(70/311/EEC)
(OJ L 133, 18.6.1970, p. 10)
Amended by:
Official Journal
No page date
"M1 Commission Directive 92/62/EEC of 2 July 1992 L 199 33 18.7.1992
Amended by:
"A1 Act of Accession of Denmark, Ireland and the United Kingdom of
Great Britain and Northern IrelandL 73 14 27.3.19721970L0311 — EN — 18.07.1992 — 002.001 — 1
COUNCIL DIRECTIVE
of 8 June 1970
on the approximation of the laws of the Member States relating to
the steering equipment for motor vehicles and their trailers
(70/311/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 their steering equipment;
Whereas those requirements differ from one Member State to another;
whereas it is therefore necessary that all Member States adopt the same
requirements either in addition to or in place of their existing rules, in
order, in particular, to allow the EEC type approval procedure which was
the subject of the Council Directive (3) 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 respect of
each type of vehicle;
HAS ADOPTED THIS DIRECTIVE:
Article 1
For the purposes of this Directive, ‘vehicle’ means any motor vehicle
intended for use on the road, with or without bodywork, having at least
four wheels and a maximum design speed exceeding 25 kilometres per
hour, and its trailers, with the exception of vehicles which run on rails,
agricultural tractors and machinery and public works vehicles.
Article 2
No Member State may refuse to grant EEC type approval or national type
approval of a vehicle on grounds relating to its steering equipment if this
equipment satisfies the requirements set out in the "M1Annexes 3.
Article 2 bis
Les États membres ne peuvent refuser ou interdire la vente, l’imm-
atriculation, la mise en circulation ou l’usage des véhicules pour des
motifs concernant leurs dispositifs de direction si ceux-ci répondent aux
prescriptions figurant à l’annexe.
Article 3
The amendments necessary for adjusting the requirements of the Annex
so as to take account of technical progress shall be adopted in accordance
with the procedure laid down in Article 13 of the Council Directive of 6
February 1970 on the type approval of motor vehicles and their trailers.!B
(1) OJ No C 160, 18.12.1969, p. 7.
(2) OJ No C 10, 27.1.1970, p. 18.
(3) OJ No L 42, 23.2.1970, p. 1.!A1
!B1970L0311 — EN — 18.07.1992 — 002.001 — 2
Article 4
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. Member States shall ensure that the text of the main provisions of
national law which they adopt in the field covered by this Directive are
communicated to the Commission.
Article 5
This Directive is addressed to the Member States.!B1970L0311 — EN — 18.07.1992 — 002.001 — 3
!M1
LIST OF ANNEXES
Annex I: Definitions, application for EEC type-approval and specifications
Annex II: Information document
Annex III: Braking performance for vehicles using the same energy source for
steering and braking
Annex IV: Additional provisions for vehicles with auxiliary steering equipment
(ASE)
Annex V: Provisions for trailers having purely hydraulic steering transmissions
Annex VI: Type-approval certificate1970L0311 — EN — 18.07.1992 — 002.001 — 4
ANNEX I
DEFINITIONS, APPLICATION FOR EEC APPROV AL AND
SPECIFICATIONS
1. DEFINITIONS
For the purposes of this Directive:
1.1. Approval of a vehicle means the approval of a vehicle type with regard
to its steering equipment;
1.2. V ehicle type means a category of vehicle which does not differ with
respect to the manufacturer’s designation of the vehicle type and/or
variations which can affect its steering;
1.3. Steering equipment means all the equipment the purpose of which is to
determine the direction of movement of the vehicle.
The steering equipment consists of:— the steering control,— the steering transmission,— the steered wheels,— the energy supply, if any;
1.3.1. Steering control means the part of the steering equipment which
controls its operation, it may be operated with or without direct
intervention of the driver. For steering equipment in which the steering
forces are provided solely or partly by the muscular effort of the driverthe steering control includes all parts up to the point where the steeringeffort is transformed by mechanical, hydraulic or electrical means;
1.3.2. Steering transmission includes all parts of the steering equipment
which are the means of transmitting the steering forces between the
steering control and the steered wheels; it includes all parts down fromthe point where the steering control effort is transformed bymechanical, hydraulic or electrical means;
1.3.3. Steered wheels means the wheels the alignment of which may be
altered directly or indirectly in relation to the longitudinal axis the
vehicle in order to determine the direction of movement of the vehicle.(The steered wheels include the axis around which they are rotated inorder to determine the direction of movement of the vehicle);
1.3.4. Energy supply includes those parts of the steering equipment which
provide it with energy, control the energy and where appropriate,
process and store it. It also includes any storage reservoirs for theoperating medium and the return lines, but not the vehicle’s engine(except for the purposes of item 4.1.3) or its drive to the energy source;
1.3.4.1. Energy source means that part of the energy supply which provides the
energy in the required form e.g. hydraulic pump, air compressor;
1.3.4.2. Energy reservoir means that part of the energy supply in which the
energy provided by the energy source is stored;
1.3.4.3. Storage reservoir means that part of the energy supply in which the
operating medium is stored at or near to the atmospheric pressure.
1.4. Steering parameters
1.4.1. Steering control effort means the force applied to the steering control
in order to steer the vehicle;
1.4.2. Steering time means the period of time from the beginning of the
movement of the steering control to the moment at which the steeredwheels have reached a specific steering angle;
1.4.3. Steering angle means the angle between the projection of a
longitudinal axis of the vehicle and the line of intersection of thewheelplane (being the central plane of the tyre, normal to the spin axisof the wheel) and the road surface;
1.4.4. Steering forces mean all the forces operating in the steering
transmission;!
M11970L0311 — EN — 18.07.1992 — 002.001 — 5
1.4.5 Mean steering ratio means the ratio of the angular displacement of the
steering control to the mean of the swept steering angle of the steered
wheels for a full lock-to-lock turn;
1.4.6. Turning circle means the circle within which are located the
projections onto the ground plane of all the points of the vehicle,
excluding the external mirrors and the front direction indicators, when
the vehicle is driven in a circle;
1.4.7. Nominal radius of steering control means in the case of a steering
wheel the shortest dimension from its centre of rotation to the outeredge of the rim. In the case of any other form of control, it means thedistance between its centre of rotation and the point at which the
steering effort is applied. If more than one such point is provided, the
one requiring the greatest effort shall be used.
1.5. Types of steering equipment
Depending on the way the steering forces are produced, the following
types of steering equipment are distinguished:
1.5.1. Fo r m o t o r v e h i c l e s
1.5.1.1. Manual steering equipment in which the steering forces result solely
from the muscular effort of the driver;
1.5.1.2. Power assisted steering equipment in which the steering forces result
from both the muscular effort of the driver and the energy supply
(supplies);
1.5.1.2.1. Steering equipment in which the steering forces result solely from one
or more energy supplies when the equipment is intact, but in which thesteering forces can be provided by the muscular effort of the driveralone if there is a fault in the steering (integrated power systems), is
also considered to be power assisted steering equipment;
1.5.1.3. Full-power steering equipment in which the steering forces are
provided solely by one or more energy supplies;
1.5.1.4. Self-tracking equipment is a system designed to create a change of
steering angle on one or more wheels only when acted upon by forces
and/or moments applied to the tyre to road contact.
1.5.2. Fo r t r a i l e r s
1.5.2.1. Self-tracking equipment
see item 1.5.1.4 above.
1.5.2.2. Articulated steering equipment in which the steering forces are
produced by a change in direction of the towing vehicle and in which
the movement of the steered trailer wheels is firmly linked to therelative angle between the longitudinal axis of the towing vehicle andthat of the trailer;
1.5.2.3. Self-steering equipment in which the steering forces are produced by a
change in direction of the towing vehicle and in which the movementof the steered, trailer wheels is firmly linked to the relative anglebetween the longitudinal axis of the trailer frame or a load replacing it
and the longitudinal axis of the sub-frame to which the axle(s) is (are)
attached.
1.5.3. Depending on the arrangement of the steered wheels, the following
types of steering equipment are distinguished:
1.5.3.1. Front-wheel steering equipment in which only the wheels of the front
axle(s) are steered. This includes all wheels which are steered in the
same direction;
1.5.3.2. Rear-wheel steering equipment in which only the wheels of the rear
axle(s) are steered. This includes all wheels which are steered in the
same direction;
1.5.3.3. Multi-wheel steering equipment in which the wheels of one or more of
each of the front and the rear axle(s) are steered;
1.5.3.3.1. All-wheel steering equipment in which all the wheels are steered;
1.5.3.3.2. Buckle steering equipment in which the movement of chassis parts
relative to each other is directly produced by the steering forces.!
M11970L0311 — EN — 18.07.1992 — 002.001 — 6
1.5.3.4. Auxiliary Steering Equipment (ASE) in which the rear wheels of
vehicles of category M and N are steered in addition to the front
wheels, in the same direction or in the opposite direction to the front
wheels, and/or the steering angle of the front wheels and/or the rearwheels may be adjusted relative to vehicle behaviour.
1.6. Types of steering transmission
Depending on the way the steering forces are transmitted, the following
types of steering transmission are distinguished:
1.6.1. Purely mechanical steering transmission means a steering transmission
in which the steering forces are transmitted entirely by mechanicalmeans;
1.6.2. Purely hydraulic steering transmission means a steering transmission
in which the steering forces, somewhere in the transmission, aretransmitted only by hydraulic means;
1.6.3. Purely electric steering transmission means a steering transmission in
which the steering forces, somewhere in the transmission, aretransmitted only through electric means;
1.6.4. Hybrid steering transmission means a transmission in which part of the
steering forces are transmitted through one and the other part throughanother of the abovementioned means;
1.6.4.1. Hybrid mechanical steering transmission means a steering trans-
mission where a part of the steering forces is transmitted by purely
mechanical means and the other parts either by:
1.6.4.1.1. hydraulic or mechanical/hydraulic
or
1.6.4.1.2. electric or mechanical/electric
or
1.6.4.1.3. pneumatic or mechanical/pneumatic means.
In either case, where the mechanical part of the transmission is
designed only to give position feedback and is too weak to transmit the
total sum of the steering forces, this system shall be considered to be
purely hydraulic, respectively purely electric, or purely pneumaticsteering transmission;
1.6.4.2. Other hybrid steering transmission means any other combination of the
abovementioned steering transmissions.
2. APPLICATION FOR EEC TYPE-APPROV AL
2.1. The application for approval of a vehicle type with regard to the
steering equipment shall be submitted by the vehicle manufacturer.
2.2. It shall be accompanied by the information required by the information
document which is attached as Annex II.
2.3. A vehicle representative of the vehicle type to be approved shall be
submitted to the technical service responsible for conducting approval
tests.
3. EEC TYPE-APPROV AL
A certificate conforming to the model specified in Annex VI shall be
issued by the authority granting an EEC type-approval pursuant to this
Directive.
4. CONSTRUCTION PROVISIONS
4.1. General provisions
4.1.1. The steering equipment shall ensure easy and safe handling of the
vehicle up to its maximum design speed or, in the case of a trailer, upto its technically permitted maximum speed. There must be a tendency
to self-centre when tested in accordance with item 5. The vehicle shall
meet the requirements of item 5.2 in the case of motor vehicles and ofitem 5.3 in the case of trailers.!
M11970L0311 — EN — 18.07.1992 — 002.001 — 7
If a vehicle is fitted with ASE, it shall also meet the requirements of
Annex IV . Trailers equipped with purely hydraulic steering trans-
missions shall also comply with Annex V .
4.1.1.1. It must be possible to travel along a straight section of the road without
unusual steering correction by the driver and without unusual vibrationin the steering system at a maximum design speed of the vehicle.
4.1.1.2. There must be travel synchronization between the steering control and
the steered wheels, except for the wheels steered by ASE.
4.1.1.3. There must be time synchronization between the steering control and
the steered wheels except for the wheels steered by ASE.
4.1.2. The steering equipment shall be designed, constructed and fitted in
such a way that it is capable of withstanding the stresses arising duringnormal operation of the vehicle, or combination of vehicles. Themaximum steering angle shall not be limited by any part of steering
transmission unless specifically designed for this purpose.
4.1.2.1. Unless otherwise specified, it will be assumed that for the purposes of
this Directive, not more than one failure can occur in the steeringequipment at any one time and two axles on one bogie shall be
considered as one axle.
4.1.3. Should the engine stop or a part of the steering equipment fail, with the
exception of those parts listed in item 4.1.4, the steering equipmentshall always meet the requirements of item 5.2.6 in the case of motor
vehicles and of item 5.3 in the case of trailers.
4.1.4. For the purposes of this Directive the steered wheels, the steering
control and all mechanical parts of the steering transmission shall notbe regarded as liable to breakage if they are amply dimensioned, are
readily accessible for maintenance, and exhibit safety features at least
equal to those prescribed for other essential components (such as thebraking system) of the vehicle. Where the failure of any such partwould be likely to result in loss of control of the vehicle, that part must
be made of metal or of a material with equivalent characteristics and
must not be subject to significant distortion in normal operation of thesteering system.
4.1.5. Any failure in transmission other than purely mechanical shall clearly
be brought to the attention of the vehicle driver; in the case of a motor
vehicle, an increase in steering effort is considered to be a warningsignal; in the case of a trailer, a mechanical indicator is permitted.When a failure occurs, a change in the average steering ratio is
permissible if the steering effort given in item 5.2.6 below is not
exceeded.
4.1.6. Steering equipment with a purely pneumatic, purely electric or purely
hydraulic transmission or with hybrid transmissions other than those
described at item 1.6.4.1 are prohibited until specific requirements are
added to the requirements of this Directive.
4.1.6.1. This prohibition does not apply to:
— auxiliary steering equipment (ASE) with a purely electric or
purely hydraulic transmission for vehicles of Categories M and N,
— steering equipment with a purely hydraulic transmission for
vehicles of Category O.
4.2. Special provisions
4.2.1. S t e e r i n g c o n t r o l
4.2.1.1. If the steering control is directly handled by the driver,
4.2.1.1.1. it must be manageable;
4.2.1.1.2. the direction of operation of the steering control must correspond to the
intended change in direction of the vehicle;
4.2.1.1.3. except for ASE, there must be a continuous and monotonic relation
between the steering control angle and the steering angle.
4.2.2. S t e e r i n g t r a n s m i s s i o n
4.2.2.1. Adjustment devices for steering geometry must be such that after
adjustment a positive connection can be established between theadjustable components by appropriate locking devices.!
M11970L0311 — EN — 18.07.1992 — 002.001 — 8
4.2.2.2. Steering transmission which can be disconnected to cover different
configurations of a vehicle (e.g. on extendible trailers), must have
locking devices which ensure positive relocation of components; where
locking is automatic, there must be an additional safety lock which isoperated manually.
4.2.3. S t e e r e d w h e e l s
4.2.3.1. The steered wheels shall not be solely the rear wheels. This
requirement does not apply to semi-trailers.
4.2.3.2. Trailers (with the exception of semi-trailers) which have more than one
axle with steered wheels and semi-trailers which have at least one axlewith steered wheels must fulfil the conditions given in item 5.3 below.
However, for trailers with self-tracking equipment a test under item 5.3
is not necessary if the axle load ratio between the unsteered and theself-tracking axles equals or exceeds 1,6 under all loading conditions.
4.2.4. E n e r g y s u p p l y
4.2.4.1. The same energy source may be used to supply the steering equipment
and the braking device. However, in the case of a failure of either the
energy supply or a failure in one of the two systems the following
conditions must be fulfilled:
4.2.4.1.1. The steering equipment shall meet the requirements of item 5.2.6.
4.2.4.1.2. If an energy source failure occurs, the braking performance shall not
drop below the prescribed service brake performance, as given inAnnex III (
1), on the first brake application.
4.2.4.1.3. If an energy supply failure occurs, the braking performance must
comply with the prescriptions of Annex III (1).
4.2.4.1.4. If the fluid in the storage reservoir drops to a level liable to cause an
increase in steering or braking effort an acoustic or optical warning
must be given to the driver. This warning may be combined with adevice provided to warn of brake failure; the satisfactory condition ofthe signal must be easily verifiable by the driver.
4.2.4.2. The same energy source may be used to supply the steering equipment
and systems other than the braking device if, when the fluid level in thestorage reservoir drops to a level liable to cause an increase in steering
effort, an acoustic or optical warning is given to the driver; the
satisfactory condition of the signal must be easily verifiable by thedriver.
4.2.4.3. The warning devices must be directly and permanently connected to
the circuit. When the engine is running under normal operatingconditions and there are no faults in the steering equipment, the alarmdevice must give no signal except during the time required for charging
the energy reservoir(s) after start-up of the engine.
5. TEST PROVISIONS
5.1. General provisions
5.1.1. The test shall be conducted on a level surface affording good adhesion.
5.1.2. During the test(s), the vehicle shall be loaded to its technically
permissible maximum mass and its maximum technically permissible
load on the steered axle(s). In the case of axles fitted with ASE, thistest shall be repeated with the vehicle loaded to its technicallypermissible maximum mass and the axle equipped with ASE loaded to
its maximum permissible load.
5.1.3. Before the test begins, the tyre pressures shall be as prescribed by the
manufacturer for the load specified in item 5.1.2 when the vehicle isstationary.!
M1
(1) The requirements set out in Annex III may also be checked when Directive 71/320/EEC
is implemented.1970L0311 — EN — 18.07.1992 — 002.001 — 9
5.2. Provisions for motor vehicles
5.2.1. It must be possible to leave a curve with a radius of 50 m at a tangent
without unusual vibration in the steering equipment at the following
speed:
— category M 1vehicles: 50 km/h,
— category M 2,M 3,N 1,N 2and N 3vehicles: 40 km/h or the
maximum design speed if this is below the speeds given above.
5.2.2. The requirements of items 4.1.1.1, 4.1.1.2 and 5.2.1 shall also be
satisfied with a failure in the steering equipment.
5.2.3. When the vehicle is driven in a circle with its steered wheels at
approximately half lock and at a constant speed of at least 10 km/h, the
turning circle must remain the same or become larger if the steering
control is released.
5.2.4. During the measurement of the control effort, forces with a duration of
less than 0,2 seconds shall not be taken into account.
5.2.5. T h e m e a s u r e m e n t o f s t e e r i n g e f f o r t s o n m o t o r v e -
hicles with intact steering equipment
5.2.5.1. The vehicle shall be driven from straight ahead into a spiral at a speed
of 10 km/h. The steering effort shall be measured at the nominal radiusof the steering control until the position of the steering control
corresponds to turning radius given in the table below for the particular
category of vehicle with intact steering. One steering movement shallbe made to the right and one to the left.
5.2.5.2. The maximum permitted steering time and the maximum permitted
steering control effort with intact steering equipment are given in the
table below for each category of vehicle.
5.2.6. T h e m e a s u r e m e n t o f s t e e r i n g e f f o r t s o n m o t o r v e -
hicles with a failure in the steering equipment
5.2.6.1. The test described in item 5.2.5 shall be repeated with a failure in the
steering equipment. The steering effort shall be measured until theposition of the steering control corresponds to the turning radius givenin the table below for the particular category of vehicle with a failure in
the steering equipment.
5.2.6.2. The maximum permitted steering time and the maximum permitted
steering control effort with a failure in the steering equipment are given
in the table below for each category of vehicle.
Steering control effort requirements
Vehicle categoryIntact With a failure
Maximum effort
(daN)Time
(s)Turning radius
(m)Maximum effort
(daN)Time
(s)Turning radius
(m)
M1 15 4 12 30 4 20
M2 15 4 12 30 4 20
M3 20 4 12 45 6 20
N1 20 4 12 30 4 20
N2 25 4 12 40 4 20
N3 20 4 12 (1)4 5 (2)6 2 0
(1) Or full lock if 12 is not attainable.
(2) 50 for rigid vehicles with two or more steered axles excluding self-tracking equipment.
5.3. Provisions for trailers
5.3.1. The trailer must travel without excessive deviation or unusual vibration
in its steering equipment when the towing vehicle is travelling in a
straight line on a flat and horizontal road at a speed of 80 km/h or the!M11970L0311 — EN — 18.07.1992 — 002.001 — 10
technically permissible maximum speed indicated by the trailer
manufacturer if this is less than 80 km/h.
5.3.2. With the towing vehicle and trailer having adopted a steady state turn
so that the front outside edge of the towing vehicle is turning alongsidea circle of radius 25 m in accordance with item 1.4.6, at a constantspeed of 5 km/h, the circle described by the rearmost outer edge of the
trailer shall be measured. This manoeuvre shall be repeated under the
same conditions but a speed of 25 km/h ± 1 km/h. During thesemanoeuvres, the rearmost outer edge of the trailer travelling at a speedof 25 km/h ± 1 km/h shall not move outside the circle described at a
constant speed of 5 km/h by more than 0,7 m.
5.3.3. No part of the trailer must move more than 0,5 m beyond the tangent to
a circle with a radius of 25 m when towed by a vehicle leaving thecircular path described in item 5.3.2 along the tangent and travelling at
a speed of 25 km/h. This requirement must be met from the point the
tangent meets the circle to a point 40 m along the tangent. After thatpoint, the trailer must fulfil the condition specified in item 5.3.1.
5.3.4. The tests described in items 53.2 and 5.3.3 shall be conducted with one
steering movement to the left and one to the right.!
M11970L0311 — EN — 18.07.1992 — 002.001 — 11
ANNEX II
!M11970L0311 — EN — 18.07.1992 — 002.001 — 12
!M11970L0311 — EN — 18.07.1992 — 002.001 — 13
ANNEX III
BRAKING PERFORMANCE FOR VEHICLES USING THE SAME
ENERGY SOURCE TO SUPPLY STEERING EQUIPMENT AND
BRAKING DEVICE
1. If an energy source failure occurs, service braking performance on the
first brake application shall achieve the values given in the table below.
Category V (km/h) m/s2 Force (daN)
M1 80 5,8 50
M2and M 3 60 5,0 70
N1 80 5,0 70
N2and N 3 60 5,0 70
2. After any failure in the steering equipment, or the energy supply, it
shall be possible after eight full stroke actuations of the service brake
control, to achieve at the ninth application, at least the performanceprescribed for the secondary (emergency) braking system (see tablebelow).
In the case where secondary performance requiring the use of stored
energy is achieved by a separate control, it shall still be possible aftereight full stroke actuations of the service brake control to achieve at theninth application, the residual performance (see table below).
Secondary and residual efficiency
Category V (km/h)Secondary braking
(m/s2)Residual braking
(m/s2)
M1 80 2,9 1,7
M2 60 2,5 1,5
M3 60 2,5 1,5
N1 70 2,2 1,3
N2 50 2,2 1,3
N3 40 2,2 1,3
3. The tests referred to under points 1 and 2 shall be carried out with the
vehicle either laden or unladen, whichever is the less favourable casedefined by the testing body responsible for the tests.!
M11970L0311 — EN — 18.07.1992 — 002.001 — 14
ANNEX IV
ADDITIONAL PROVISIONS FOR VEHICLES EQUIPPED WITH ASE
1. GENERAL PROVISIONS
This Annex does not require vehicles to be fitted with ASE. However,
if vehicles are fitted with such a device, they shall comply with the
provisions of this Annex.
2. SPECIFIC PROVISIONS
2.1. Transmission
2.1.1. Mechanical steering transmissions
Item 4.1.4 of Annex I to this Directive applies.
2.1.2. Hydraulic steering transmissions
The hydraulic steering transmission must be protected from exceeding
the maximum permitted service pressure T.
2.1.3. Electric steering transmissions
The electric steering transmission must be protected from excess
energy supply.
2.1.4. Combination of steering transmissions
A combination of mechanical, hydraulic and electric transmissions
shall comply with the requirements specified in items 2.1.1, 2.1.2 and2.1.3 above.
2.2. Testing requirements for failure
2.2.1. Malfunction or failure of any part of the ASE (except for parts not
considered to be susceptible to breakdown as specified in item 4.1.4 ofAnnex I to this Directive) shall not result in sudden significant change
in vehicle behaviour and the requirements of items 5.2.1 to 5.2.4 and
5.2.6 of Annex I to this Directive shall still be met.
Furthermore, it must be possible to control the vehicle without
abnormal steering correction. This shall be verified by the followingtests:
2.2.1.1. C i r c u l a r t e s t
The vehicle shall be driven into a circle with a transverse acceleration
of 5 m/s
2and at a test speed of 80 km/h. The failure shall be introduced
when the test speed has been reached.
The test shall include driving in a clockwise direction, and in a
counter-clockwise direction.
2.2.1.2. Tr a n s i e n t t e s t
Until uniform test procedures have been agreed, the vehicle manu-
facturer shall provide the technical services with their test procedures
and results for transient behaviour of the vehicle in the case of a
failure.
2.3. Warning signals in case of failure
2.3.1. Except for parts of ASE not considered susceptible to breakdown as
specified in item 4.1.4 of Annex I of this Directive, the followingfailure of ASE shall be clearly brought to the attention of the driver:
2.3.1.1. A general cut-off of the ASE electrical or hydraulic control;
2.3.1.2. Failure of the ASE energy supply;2.3.1.3. A break in the external wiring of the electrical control if fitted.!
M11970L0311 — EN — 18.07.1992 — 002.001 — 15
2.4. Electromagnetic interference
2.4.1. The operation of the ASE must not be adversely affected by
electromagnetic fields. Until uniform test procedures have beenagreed, the vehicle manufacturer shall provide the technical services
with their test procedures and results.!
M11970L0311 — EN — 18.07.1992 — 002.001 — 16
ANNEX V
PROVISIONS FOR TRAILERS HA VING PURELY HYDRAULIC
STEERING TRANSMISSIONS
1. If vehicles are fitted with purely hydraulic steering transmissions, they
shall comply with the provisions of this Annex.
2. SPECIFIC PROVISIONS
2.1. Performance of hydraulic lines and hose assemblies
2.1.1. The hydraulic lines of purely hydraulic transmissions must be capable
of withstanding a pressure of at least four times the maximum normalservice pressure (T) specified by the manufacturer. Hose assembliesshall comply with the following ISO Standards: 1402 (1984), 6605
(1986) and 7751 (1983).
2.2. In systems dependent on an energy supply
2.2.1. The energy supply must be protected from excess pressure by a
pressure limiting valve which operates at the pressure T.
2.3. Protection of steering transmission
2.3.1. The steering transmission must be protected from excess pressure by a
pressure limiting valve which operates between 1,5T and 2,2T.
2.4. Tractor/trailer alignment
2.4.1. With the tractor of a tractor/trailer combination travelling in a straight
line, the trailer must remain in alignment with the tractor;
2.4.2. In order to maintain steering alignment in accordance with item 2.4.1
above, trailers shall be provided with a means of readjustment, whichmay be either automatic or manual.
2.5. Steerability with a failure in the steering transmission
2.5.1. The steerability of vehicles with purely hydraulic steering trans-
missions shall be maintained with a failure in any part of the
transmission. Vehicles shall be tested in this (failed) condition and
satisfy the requirements of item 5.3 of Annex I to this Directive. Inparticular the 5 km/h and 25 km/h tests specified at item 5.3.2 shall beconducted with the steering transmission in the intact and failed
conditions respectively.
2.6. Electromagnetic interference
2.6.1. The operation of steering equipment must not be adversely affected by
electromagnetic fields. Until uniform test procedures have beenagreed, the vehicle manufacturer shall provide the technical serviceswith his test procedures and results.!
M11970L0311 — EN — 18.07.1992 — 002.001 — 17
ANNEX VI
EEC TYPE-APPROV AL CERTIFICATE
MODEL
(maximum format: A4 (210 × 297 mm))
!M11970L0311 — EN — 18.07.1992 — 002.001 — 18
Appendix
!M11970L0311 — EN — 18.07.1992 — 002.001 — 19