L 373/50 EN Official Journal of the European Union 27.12.2006 
  
Only the original UN/ECE texts have legal effe ct under international public law. The status 
and date of entry into force of this Regulation should be checked in the latest version of the 
UN/ECE status document TRANS/ WP.29/343/Rev.X, available at: 
http://www.unece.org/trans/main/wp29/wp29wgs/wp29gen/wp29fdocstts.html . 
 
Regulation No 55 of the Economic Commiss ion for Europe of the United Nations 
(UN/ECE) – Uniform provisions concernin g the approval of mechanical coupling 
components of combinations of vehicles  
 
Addendum 54: Regulation No. 55 
 
Revision 1 
 
Incorporating all valid text up to: 
 
The 01 series of amendments - Date of entry into force: 16 September 2001 Corrigendum 1 to the 01 series of amendm ents, subject of depositary notification 
C.N.602.2002.TREATIES-1 dated 13 June 2002 
 
 
 
1. SCOPE  
1.1. This Regulation lays down the requirements which the mechanical 
coupling devices and components shall meet in order to be regarded 
internationally as being mutually compatible. 
1.2. This Regulation applies to devi ces and components intended for: 
1.2.1. motor vehicles and trailers intended to form a combination of vehicles1 
1.2.2. motor vehicles and trailers inte nded to form articulated vehicles 1, where 
the vertical load imposed on the motor vehicle by the trailer does not exceed  200 kN. 
1.3. This Regulation applies to: 1.3.1. standard devices and components as defined in paragraph 2.3.; 
1.3.2. non-standard devices and component s as defined in paragraph 2.4.; 
1.3.3. non-standard miscellaneous device s and components as defined in 
paragraph 2.5. 
2. DEFINITIONS  
                                                 
1 Within the meaning of the Convention on Road Tr affic (Vienna, 1968) article 1, subparagraphs (t) 
and (u).  
 
27.12.2006 EN Official Journal of the European Union L 373/51 
  For the purposes of this Regulation: 
2.1. "mechanical coupling devices and co mponents means" all those items on 
the frame, load-bearing parts of the bodywork and the chassis of the motor 
vehicle and trailer by mean s of which they are connected together to form 
the combination of vehicles or th e articulated vehicles. Fixed or 
detachable parts for the attachment  or operation of the mechanical 
coupling device or component are included. 
2.2. automatic coupling requirement is achieved if reversing the towing 
vehicle against the trailer is sufficien t to engage the coupling completely, 
to lock it automatically and to indi cate proper engagement of the locking 
devices without any ex ternal intervention. 
In the case of hook type couplings automatic coupling requirement is 
achieved if opening and closing of the coupling locking device takes place 
without any external intervention when the drawbar eye is inserted into the hook. 
2.3. standard mechanical  coupling devices and components conform to 
standard dimensions and characteristic values as given in this Regulation. They are interchangeable within their class, independent of manufacturer. 
2.4. non-standard mechanical couplin g devices and components do not 
conform in all respects to the sta ndard dimensions and characteristic 
values given in this Regulation but ca n be connected to standard coupling 
devices and components in the relevant class. 
2.5. non-standard miscellaneous mechani cal coupling devices and components 
do not conform to standard dimensions and characteristic values as given 
in this Regulation and cannot be conn ected to standard coupling devices 
and components. They include, for example, devices which do not correspond with any of the Classes A to L and T listed in paragraph 2.6. 
such as those intended for special, h eavy transport use and miscellaneous 
devices conforming to exis ting national standards. 
2.6. mechanical coupling devices and com ponents are classifi ed according to 
type as follows: 
2.6.1. Class A Coupling balls and towing brackets employing a 50 mm diameter 
spherical device and brackets on the towing vehicle for connecting to the 
trailer by means of a coupling head  - see annex 5, paragraph 1. 
2.6.1.1. Class A50-1 to 50-5 Standard 50 mm di ameter coupling balls with flange 
type bolted fixing. 
2.6.1.2. Class A50-X Non-standard 50 mm di ameter coupling balls and brackets. 
2.6.2. Class B Coupling heads fitt ed to the drawbar of tr ailers for connecting to 
the 50 mm diameter coupling ball on the towing vehicle - see annex 5, 
paragraph 2. 
L 373/52 EN Official Journal of the European Union 27.12.2006 
 2.6.2.1. Class B50-X Non-standard 50 mm diameter coupling heads. 
2.6.3. Class C Drawbar couplings with a 50 mm diameter pin and with a jaw and 
an automatic closing and locking pi n on the towing vehicle for connecting 
to the trailer by means of a drawba r eye - see annex 5, paragraph 3.: 
2.6.3.1. Class C50-1 to 50-7 Standard 50 mm pin diameter drawbar couplings. 
2.6.3.2. Class C50-X Non-standard 50 mm pin diameter drawbar couplings. 
2.6.4. Class D Drawbar eyes having a pa rallel hole suitable for a 50 mm 
diameter pin and fitted to the draw bar of trailers for connecting to 
automatic drawbar couplings - see annex 5, paragraph 4.: 
2.6.4.1. Class D50-A Standard 50 mm pin di ameter drawbar ey es for welded 
attachment. 
2.6.4.2. Class D50-B Standard 50 mm pin di ameter drawbar ey es for threaded 
attachment. 
2.6.4.3. Class D50-C and 50-D Standard 50 mm pin diameter drawbar eyes for 
bolted attachment. 
2.6.4.4. Class D50-X Non-standard 50 mm  pin diameter drawbar eyes. 
2.6.5. Class E Non-standard drawbars co mprising overrun devices and similar 
items of equipment mounted on the front  of the towed vehicle, or to the 
vehicle chassis, which are suitable fo r coupling to the towing vehicle by 
means of drawbar eyes, coupling head s or similar coupling devices - see 
annex 5, paragraph 5. 
Drawbars may be hinged to move freely in a vertical plane and not 
support any vertical load or be fixed in  a vertical plane so as to support a 
vertical load (Rigid drawbars). Rigid drawbars can be enti rely rigid or be 
flexibly mounted. 
Drawbars may comprise more than one component and may be adjustable 
or cranked. 
This Regulation applies to drawbars  which are separate units, not an 
integral part of the chassis of the towed vehicle. 
2.6.6. Class F Non-standard drawbeams co mprising all components and devices 
between the coupling devices, such  as coupling balls and drawbar 
couplings, and the frame (for example the rear cross member), the load-
bearing bodywork or the chassis of the towing vehicle - see annex 5, 
paragraph 6. 
2.6.7. Class G Fifth wheel couplings ar e plate type couplings having an 
automatic coupling lock and are fitted  to the towing vehicle for connecting 
with a 50 mm diameter fifth wheel coupling pin fitted to a semitrailer - see annex 5, paragraph 7. 
27.12.2006 EN Official Journal of the European Union L 373/53 
 2.6.7.1. Class G50 Standard 50 mm pin di ameter fifth wheel couplings. 
2.6.7.2. Class G50-X Non-standard 50 mm pi n diameter fifth wheel couplings. 
2.6.8. Class H Fifth wheel coupling pins, 50 mm diameter, are de vices fitted to a 
semitrailer to connect with the fifth wheel coupling of the towing vehicle - 
see annex 5, paragraph 8.: 
2.6.8.1. Class H50-X Non-standard 50 mm pin diameter fifth wheel coupling pins. 
2.6.9. Class J Non-standard mounting pl ates comprising all components and 
devices for attaching fifth wheel coupli ngs to the frame or chassis of the 
towing vehicle. The mounting plate may have provision for moving 
horizontally, that is to form a slid ing fifth wheel - see annex 5, paragraph 
9. 
2.6.10. Class K Standard, hook type couplings  intended for use with appropriate 
Class L type toroidal drawbar ey es - see annex 5, paragraph 10. 
2.6.11. Class L Standard toroidal drawbar ey es for use with appropriate Class K 
hook type couplings - see annex 5, paragraph 4. 
2.6.12. Class S Devices and components wh ich do not conform to any of the 
Classes A to L or T above and which are used, for example, for special heavy transport or are devices unique  to some countries and covered by 
existing national standards. 
2.6.13. Class T Non-standard, non-automatic dedicated drawbar type couplings 
which are able to be separated only by the use of tools and are typically 
used for trailers of car transporters . They shall be approved as a matched 
pair. 
2.7. Steering wedges are devices or co mponents mounted on semitrailers 
which control positive steering of the trailer in conjunction with the fifth wheel coupling. 
2.8. Remote control systems are devices and components which enable the 
coupling device to be operated from th e side of the vehicle or from the 
driving cab of the vehicle. 
2.9. Remote indicators are devices and components which give an indication 
in the vehicle cab that coupling has been effected and that the locking 
devices have engaged. 
2.10.  "type of coupling device or component" means a device or component 
which does not differ in su ch essential respects as: 
2.10.1. the manufacturer's or supp lier s trade name or mark; 
2.10.2. the class of coupling as defined in paragraph 2.6.; 2.10.3. the external shape, principal dimensions or fundamental difference in 
design including materials used; and 
L 373/54 EN Official Journal of the European Union 27.12.2006 
 2.10.4. the characteristic values D, Dc, S, V and U as defined in paragraph 2.11. 
2.11. The characteristic values D, Dc, S, V and U are defined or determined as: 
2.11.1. The D or Dc value is the theoretical reference value for the horizontal 
forces in the towing vehicle and the tr ailer and is used as the basis for 
horizontal loads in the dynamic tests. 
For mechanical coupling devices and components not designed to support 
imposed vertical loads, the value is: 
 D = g RTTxR
+KN 
For mechanical coupling devices and components fo r centre axle trailers 
as defined in 2.13, the value is: 
 D C = g RTTxC
+KN 
For fifth wheel couplings of Class G, fifth wheel coupling pins of Class H 
and mounting plates of Class J, as defined in paragraph 2.6., the value is: 
 D = g URTxTxR
−+6,0KN 
 where: 
T is the technically permissible ma ximum mass of the towing vehicle, 
in tonnes. Where relevant, this incl udes the vertical load imposed by a 
centre axle trailer.  
R is the technically permissible maxi mum mass, in tonnes, of a trailer 
with drawbar free to move in a vert ical plane, or of  a semitrailer. 2 
C is the mass, in tonnes, transmitted to the ground by the axle or axles of 
the centre axle trailer, as defined in  paragraph 2.13., when coupled to the 
towing vehicle and loaded to the te chnically permissible maximum mass 2. 
For Category O1 and O2 centre axle trailers 3 the technically permissible 
maximum mass will be that declared by the manufacturer of the towing 
vehicle. 
 g  is the acceleration due to gr avity (assumed to be 9.81 m/s2) 
                                                 
2 The mass T and R and the technically permissi ble maximum mass, may be greater than the 
permissible maximum mass prescribed by national legislation.  
3 See definitions in Regulation N°. 13 annexed to  the 1958 Agreement concerning the Adoption of 
Uniform Technical Prescriptions for wheeled vehicl es, Equipment and Parts which can be Fitted and/ 
or be Used on Vehicles and Conditions for Reciprocal Recognition of Approvals granted on the Basis 
of these Prescriptions. The definition is also contained in annex 7 of Consolidated Resolution on the 
Construction vehicles (R. E. 3) (document TRANS/ WP. 29/ 78/ Rev. 1/ Amend. 2).  
27.12.2006 EN Official Journal of the European Union L 373/55 
  U  is as defined in paragraph 2.11.2. 
 S  is as defined in paragraph 2.11.3. 
2.11.2. The U value is the vertical mass,  in tonnes, imposed on the fifth wheel 
coupling by the semitrailer of tec hnically permissible maximum mass 2 
2.11.3. The S value is the vertical mass,  in kilograms, imposed on the coupling, 
under static conditions, by the centre axle  trailer, as defined in paragraph 
2.13., of technically permissible maximum mass 2 
2.11.4. The V value is the theoretical reference value of the amplitude of the 
vertical force imposed on the coup ling by the centre axle trailer of 
technically permissible maximum ma ss greater than 3.5 tonnes. The V 
value is used as the basis for vertical forces in the dynamic tests. 
 V = 22
LaxCxX (seen the note below) 
 where: 
a is an equivalent vertical accele ration at the coupling depending on the 
type of suspension system of the rear axle of the towing vehicle. 
For air suspension (or suspension systems with equivalent damping 
characteristics) 
 a = 1.8 m/s2 
 For other types of suspension:  a = 2.4 m/s
2 
 X  is the length of the loading area of the trailer, in metres (see Figure 1) 
L is the distance from the centre of the drawbar eye to the centre of the 
axle assembly, in metres (see Figure 1) 
 Note: (If less than 1.0, the value of 1.0 shall be used) 
 22
LX≥ 1.0 

L 373/56 EN Official Journal of the European Union 27.12.2006 
 Figure 1 – Dimensions of the centre axle trailer 
 
2.12. Symbols and definitions used in annex 6 of this Regulation.  A
v = maximum permitted axle mass of the steered axle in tonnes. 
C = mass of centre axle trailer in t onnes - see paragraph 2.11.1. of this 
Regulation. 
 D = D value in kN - see paragraph 2.11.1. of this Regulation. 
Dc = Dc value in kN for centre axle traile rs - see paragraph 2.11.1. of this 
Regulation. 
R = mass of towed vehicle in tonnes - see paragraph 2.11.1. of this 
Regulation. 
T = mass of towing vehicle in tonnes - see paragraph 2.11.1. of this 
Regulation. 
Fa = static lifting force in kN. 
Fh = horizontal component of  test force in longitudi nal axis of vehicle in 
kN. 
Fs = vertical component of test force in kN. 
S = static vertical mass in kg. 
U = fifth wheel imposed vertical mass in tonnes. V = V-value in kN - see paragraph 2.11.4. of this Regulation. a = equivalent vertical acceleration f actor at the coupling point of centre 
axle trailers depending on the type of suspension of the rear axle(s) of the 
towing vehicle - see paragraph 2.11.4. of this Regulation. 
e = longitudinal distance between the coupling poi nt of coupling balls 
which can be dismantled and the verti cal plane of the fixing points (see 
Figures 20c to 20f) in mm. 
f = vertical distance between the co upling point of coupling balls which 
can be dismantled and the horizont al plane of the fixing points (see 
Figures 20c to 20f) in mm. 
g = acceleration due to gravity, assumed as 9.81 m/s
2. 
L = theoretical drawbar length between  the centre of the drawbar eye and 
the centre of the axle assembly in meters. 
27.12.2006 EN Official Journal of the European Union L 373/57 
 X = length of the loading area of a centre axle trailer in meters. 
Subscripts: O = maximum test force U = minimum test force a = static force h = horizontal p = pulsating res = resultant 
s = vertical 
w = alternating force 
2.13. "Centre axle trailer" means a tr ailer having a drawba r which cannot move 
in a vertical plane independent of th e trailer and having an axle or axles 
positioned close to the centre of gravity of the trailer, when uniformly loaded. The vertical load imposed on the coupling of the towing vehicle 
shall not exceed 10 per cent of the maximum mass of the trailer, or 1 000 kg, whichever is the lesser. 
The maximum mass of the centre axle trailer means the total mass 
transmitted to the ground by the axle or  axles of the trailer when coupled 
to a towing vehicle and when load ed to the technically permissible 
maximum mass 
4. 
2.14. "Positive mechanical engagement" m eans that the design and geometry of 
a device and its component parts shall be such that it will not open or 
disengage under the action of any forces  or components of forces to which 
it is subject during nor mal use or testing. 
2.15. "Vehicle type" means vehicles which do not differ in such essential 
respects as the structure, dimensi ons, shape and materials in areas to 
which the mechanical coupling device or component is affixed. This 
applies to both the towing vehicle and trailer. 
3. APPLICATION FOR APPROVAL  
3.1. The application for approval shall be submitted by the holder of the trade-
name or mark, or by his dul y accredited representative. 
3.2. or each type of mechanical couplin g device or component the application 
shall be accompanied by the followi ng information, for example, by 
means of the Communication form given in annex 1: 
                                                 
4 The technically permissible mass, may be greater than the maximum permissible mass prescribed by 
national legislation  
L 373/58 EN Official Journal of the European Union 27.12.2006 
 3.2.1. details of all manufacturer's or supplier's trade names or marks to be 
applied to the coupli ng device or component; 
3.2.2.  three sets of drawings which are sufficiently detailed to define the device 
or component and which specify how it is to be fitted to the vehicle; the drawings shall show the position and space provided for the approval 
number and other marking as  given in paragraph 7.; 
3.2.3. a statement of the values of D, D
c, S, V and U as applicable and as 
defined in paragraph 2.11. 
For Class A towing brackets a statem ent of the maximum permissible 
towing vehicle and trailer masses and the maximum permissible static vertical imposed load on the tow ba ll as advised by the manufacturer of 
the towing vehicle; 
3.2.3.1. The characteristic values shall be at least equal to those applicable to the 
maximum permissible towing vehicle,  trailer and combination masses. 
3.2.4. a detailed technical description of  the device or component, specifying, in 
particular, the type and the materials used; 
3.2.5. restrictions on the vehicles to wh ich the coupling may be fitted - see annex 
1, paragraph 12. and annex 5, paragraph 3.4.; 
3.2.6. one sample, plus additional samples as requested by the type approval 
authority or technical service; 
3.2.7. all samples shall be fully finished  with the final surf ace treatment applied. 
However, if the final treatment is by painting or epoxy powder coating, this should be omitted; 
3.2.8. in the case of a mechanical coupling device or component designed for a 
specific vehicle type, the manufacturer  of the device or component shall 
also submit the installation data gi ven by the vehicle manufacturer. The 
approval authority or tec hnical service may also request that a vehicle 
representative of the type be submitted. 
4. GENERAL REQUIREMENTS FOR MECHANICAL 
COUPLING DEVICES OR COMPONENTS  
4.1. Each sample shall conform to the dimensional and stre ngth specifications 
set out in annexes 5 and 6. Following the tests sp ecified in annex 6 there 
shall not be any cracks, fractures or  any excessive permanent distortion 
which would be detrimental to the sa tisfactory operation of the device or 
component. 
4.2. All parts of the mechanical coup ling device or component whose failure 
could result in separation of the vehi cle and trailer shall be made of steel. 
Other materials may be used provi ded that equiva lence has been 
demonstrated by the manufacturer to th e satisfaction of the type approval 
27.12.2006 EN Official Journal of the European Union L 373/59 
 authority or technical service of the Contracting Party applying this 
Regulation. 
4.3. The mechanical coupling devices or  components shall be safe to operate 
and coupling and uncoupling shall be possible by one person without the 
use of tools. With the exception of Class T couplings only devices which 
allow automatic coupling shall be allowed for the coupling of trailers having a maximum technically permissi ble mass greater than 3.5 tonnes. 
4.4. The mechanical coupling devices or components shall be designed and 
manufactured such that in normal us e and with correct maintenance and 
replacement of wearing parts they will continue to function satisfactorily and retain the characteristics prescribed by this Regulation. 
4.5. All mechanical coupling devices or  components shall be designed to have 
positive mechanical engagement and the closed position shall be locked at least once by further positive mechanical engagement unless further requirements are stated in annex 5. Alternatively there may be two or 
more separate arrangements to ensure the integrity of the device but each 
arrangement shall be designed to ha ve positive mechanical engagement 
and shall be tested individually to any requirements given in annex 6. 
Positive mechanical engagement shall be as defined in paragraph 2.14. 
Spring forces may be used only to close the device and to prevent the 
effects of vibration from causing com ponent parts of the device to move 
to positions where it may open or disengage. 
The failure or omission of any one single spring shall not allow the 
complete device to open or disengage. 
4.6. Every device or component shall be accompanied by installation and 
operating instructions giving suffici ent information for any competent 
person to install it correctly on the vehicle and operate it properly - see 
also annex 7. The instructions shall be in at least the language of the 
country in which it will be offered for sale. In the case of devices and 
components supplied for original equipment fitting by a vehicle manufacturer or bodybuilder, installati on instructions may be dispensed 
with but the vehicle manufacturer or  bodybuilder will be responsible for 
ensuring that the vehicle operator is supplied with the necessary instructions for correct operation of the coupling device or component. 
4.7. For devices and components of Class A, or Class S, if applicable, for use 
with trailers of maximum permissi ble mass not exceeding 3.5 tonnes, and 
which are produced by manufacturers not  having any association with the 
vehicle manufacturer and where the devices and components are intended 
for fitting in the after-market, the height and other installation features of the coupling shall, in all cases, be ve rified by the type approval authority 
or technical service in accordan ce with annex 7, paragraph 1. 
4.8. For heavy duty and other non-standa rd miscellaneous coupling devices or 
components, Class S and Class T, the relevant requirements in annexes 5, 
L 373/60 EN Official Journal of the European Union 27.12.2006 
 6 and 7 for the closest standard or no n-standard device or component shall 
be used. 
5. APPLICATION FOR APPROV AL OF A VEHICLE FITTED 
WITH A MECHANICAL CO UPLING DEVICE OR 
COMPONENT  
5.1. Where a vehicle manufacturer applies for approval of a vehicle fitted with 
a mechanical coupling device or com ponent or authorizes the use of a 
vehicle for towing any form of trailer,  then, at the request of a bona fide 
applicant for possible type  approval for a mechanical coupling device or 
component, or of the type approval au thority or technical service of a 
Contracting Party, the ve hicle manufacturer shall readily make available 
to that inquirer or authority or technical service, such information as required in paragraph 5.3 below, to enable a manufacturer of a coupling device or component to properly design and manu facture a mechanical 
coupling device or component for that vehicle. At the request of a bona 
fide applicant for possible type appr oval for a mechanical coupling device 
or component, any information given in paragraph 5.3 below which is held by the type approval authority sha ll be released to that applicant. 
5.2. The application for approval of a vehi cle type with regard to the fitting of 
a mechanical coupling device or component shall be submitted by the vehicle manufacturer or by hi s duly accredited representative. 
5.3. It shall be accompanied by the following information to enable the type 
approval authority to complete the co mmunication form given in annex 2. 
5.3.1. a detailed description of the vehi cle type and of the mechanical coupling 
device or component and, at the reques t of the type approval authority or 
technical service, a copy of the approval form for the device or component; 
5.3.2. The information shall also incl ude the maximum permissible masses of 
the towing and towed vehicles, the distribution of the maximum 
permissible mass of the towing vehicl e between the axles, the maximum 
permissible axle masses, the maximum permissible vertical loading to be 
imposed on the rear of the towing vehi cle and details and/or drawings of 
the installation mounting points for th e device or component and of any 
additional reinforcing plates, support brackets and so on, necessary for 
safe attachment of the mechanical coupling device or component to the 
towing vehicle; 
5.3.2.1. the loading condition at which th e height of the tow ball of M1 category 
vehicles is to be measured - see pa ragraph 2 of annex 7, appendix 1.  
5.3.3. three sets of drawings which are sufficiently detailed to identify the device 
or component and which specify how it is to be fitted to the vehicle; the drawings shall show the position and space provided for the approval 
number and other marking as  given in paragraph 7.; 
27.12.2006 EN Official Journal of the European Union L 373/61 
 5.3.4. a detailed technical description of  the device or component, specifying, in 
particular, the type and the materials used; 
5.3.5. a statement of the values of D, Dc, S, V and U as applicable and as 
defined in paragraph 2.11.; 
5.3.5.1. The characteristic values shall be at least equal to those applicable to the 
maximum permissible towing vehicle,  trailer and combination masses. 
5.3.6. a vehicle, representative of the type to be approved and fitted with a 
mechanical coupling device, shall be submitted to the type approval authority or technical service which may also request additional samples 
of the device or component; 
5.3.7. a vehicle not having all of the components appropr iate to the type may be 
accepted provided that the applicant can  show, to the satisfaction of the 
type approval authority or technica l service, that the absence of the 
components does not have any effect on the results of the inspection as far 
as the requirements of this  Regulation are concerned. 
6. GENERAL REQU IREMENTS FOR VEHICLES FITTED 
WITH A MECHANICAL CO UPLING DEVICE OR 
COMPONENT  
6.1. The mechanical coupling device or  component fitted to the vehicle shall 
be approved in accordance with the re quirements of paragraphs 3. and 4. 
and annexes 5 and 6 of this Regulation. 
6.2. The installation of the mechanical coupling de vice or component shall 
meet the requirements of annex 7 to this Regulation. 
6.3. Operating instructions  shall be provided for use of the coupling device or 
component which shall contain any sp ecial instructions for operations 
which are different from those norma lly associated with the type of 
coupling device or component and instructions for coupling and 
uncoupling with different modes of ope ration, for example, at various 
angles between the towing and towed vehicles. Each vehicle shall be 
accompanied by these operating instructi ons which shall be at least in the 
language of the country in which it will be offered for sale. 
7. MARKINGS  
7.1. Types of mechanical coupling devices and components submitted for 
approval shall bear the trade name or  mark of the manufacturer, supplier 
or applicant. 
7.2. There shall be a sufficiently larg e space for application of the approval 
mark referred to in paragraph 8.5. a nd shown in annex 3. This space shall 
be shown on the drawings refe rred to in paragraph 3.2.2. 
7.3. Adjacent to the approval mark referred to in paragraphs 7.2. and 8.5., the 
mechanical coupling device or component  shall be marked with the class 
L 373/62 EN Official Journal of the European Union 27.12.2006 
 of coupling, as defined in paragraph 2.6. and the relevant characteristic 
values as defined in paragraph 2.11.  and shown in annex 4. The position 
for these markings shall be show n on the drawings referred to in 
paragraph 3.2.2. 
The characteristic values need not be  marked in cases where those values 
are defined in the classification give n in this Regulation, for example, 
Classes A50-1 to A50-5. 
7.4. Where the mechanical coupling device or component is approved for 
alternative characteristic values wi thin the same class of coupling or 
device, a maximum of two alternatives  shall be marked on the device or 
component. 
7.5. If the application of the mechan ical coupling device or component is 
restricted in any way, for example, if it is not to be us ed with steering 
wedges, then that restriction shall be marked on the device or component. 
7.6. All markings shall be permanent and legible when the device or 
component is installed on the vehicle. 
8. APPROVAL  
8.1. If the sample(s) of a type of mechanical coupling device or component 
meets (meet) the requirements of this Regulation, approval shall be granted subject to the requirements of  paragraph 10. being satisfactorily 
met. 
8.2. An approval number shall be assigned to each type approved. Its first two 
digits shall indicate the series of amendments incorporating the most 
recent major technical amendments made  to the Regulation at the time of 
issue of the approval. The same C ontracting Party may not assign the 
same number to another type of devi ce or component referred to in this 
Regulation. 
8.3. Notice of approval or of extension, refusal or withdrawal of approval or of 
production definitely discontinued, re lating to a type of mechanical 
coupling device or component approved pursuant to this Regulation, shall 
be communicated to the Parties to the 1958 Agreemen t applying this 
Regulation, by means of a communica tion form conforming to the model 
in either annex 1 or annex 2 to this Regulation. 
8.4. In addition to the mark prescribed in paragraph 7.1., th ere shall be affixed 
to every mechanical coupling device  or component approved under this 
Regulation, in the space referred to in paragraph 7.2., an approval mark as 
described in paragraph 8.5. 
8.5. The approval mark shall be an  international mark comprising: 
27.12.2006 EN Official Journal of the European Union L 373/63 
 8.5.1. a circle surrounding the letter "E" followed by the distinguishing number 
of the country which has granted approval 5; 
8.5.2. the approval number pr escribed in paragraph 8.2.; 
8.5.3. the approval mark and number sh all be arranged as shown in the example 
in annex 3. 
9. MODIFICATIONS OF THE MECHANICAL COUPLING 
DEVICE OR COMPONENT, OR OF THE VEHICLE AND 
EXTENSION OF APPROVAL  
9.1. Any modification to the type of mechanical coupling device or 
component, or of the vehicle as de fined in paragraph 2.10. shall be 
notified to the type approval authorit y or technical service which granted 
the approval. The type approval author ity or technical service may then 
either: 
9.1.1. consider that the modifications  are unlikely to ha ve any appreciable 
adverse effect and that in any case th e device, component or vehicle still 
conforms to requirements; or 
9.1.2. require a further test report. 9.2. Confirmation of, or refusal of appr oval, specifying the modification, shall 
be communicated by the procedure pres cribed in paragraph 8.3. to the 
Contracting Parties appl ying this Regulation. 
9.3. The type approval auth ority or technical service issuing an extension of 
approval shall assign a series number for such an extension and shall inform the other Contracting Partie s applying this Regulation by the 
procedure prescribed in paragraph 8.3. 
10. CONFORMITY OF PR ODUCTION PROCEDURES  
10.1. The holder of the approval must ensu re that results of the conformity of 
production tests are record ed and that the annexed documents remain 
available for a period determined in ag reement with the approval authority 
                                                 
5 1 for Germany, 2 for France, 3 for Italy, 4 for the Netherlands, 5 for Sweden, 6 for Belgium, 7 for 
Hungary, 8 for the Czech Republic, 9 for Spain, 10 for Yugoslavia, 11 for the United Kingdom, 12 for 
Austria, 13 for Luxembourg, 14 for Switzerland, 15 (vacant), 16 for Norway, 17 for Finland, 18 for Denmark, 19 for Romania, 20 for Poland, 21 for Portugal, 22 for the Russian Federation, 23 for 
Greece, 24 for Ireland, 25 for Croatia , 26 for Slovenia, 27 for Slovakia,  28 for Belarus, 29 for Estonia, 
30 (vacant), 31 for Bosnia and Herzegovina, 32 for Latvia, 33 (vacant), 34 for Bulgaria, 35-36 (vacant), 37 for Turkey, 38-39 (vacan t), 40 for The former Yugoslav Repub lic of Macedonia, 41  (vacant), 42 for 
The European Community ( Approvals are granted by  its Member States using their respective ECE 
symbol), 43 for Japan, 44 (vacant), 45 for Australia  and 46 for Ukraine. Subsequent numbers shall be 
assigned to other countries in the chronological or der in which they ratify or accede to the Agreement 
concerning the Adoption of Uniform Technical Prescriptions for Wheeled Vehicles, Equipment and 
parts which can be Fitted and/ or be Used on Wh eeled Vehicles and the Conditions for Reciprocal 
Recognition of Approvals Granted on the basis of th ese Prescriptions, and the numbers thus assigned 
shall be communicated by the Secretary-General of th e United Nations to the Contracting Parties to the 
Agreement.  
L 373/64 EN Official Journal of the European Union 27.12.2006 
 or technical service. This period mu st not exceed 10 ye ars counted from 
the time when production is  definitely discontinued. 
10.2. The type approval authority or te chnical service whic h has granted type 
approval may at any time verify the c onformity control methods applied in 
each production facility. The normal fre quency of these verifications shall 
be once every two years. 
11. PENALTIES FOR NON-CO NFORMITY OF PRODUCTION  
11.1. The approval granted in respect of a type of mechanical coupling device 
or component pursuant to this Re gulation may be withdrawn if the 
requirements are not complied with or  if a device or component bearing 
the approval mark does not c onform to the type approved. 
11.2. If a Contracting Party to the Agreement applying this Regulation 
withdraws an approval it ha s previously granted, it shall forthwith so 
notify the other Contracting Parties applying this Regulation by means of 
a communication form conforming to the model in either annex 1 or annex 2 to this Regulation. 
12. PRODUCTION DEFINITELY DISCONTINUED  
12.1. If the holder of the approval comple tely ceases to manufacture a type of 
mechanical coupling device or com ponent approved in accordance with 
this Regulation, he shall so inform th e type approval authority or technical 
service which granted the approval. Upon receiving the relevant communication, that type approval au thority or technical service shall 
inform thereof the other Contrac ting Parties to the 1958 Agreement 
applying this Regulation by means of  a communication form conforming 
to the model in either annex 1 or annex 2 to this Regulation. 
13. TRANSITIONAL PROVISIONS  
Until the United Nations Secretary-General is notified otherwise, 
Contracting Parties applyi ng this Regulation that are Member States of the 
European Community (at the time of  adoption of the 01 series of 
amendments, Italy, Netherlands, Belgium, United Kingdom, Luxembourg, Finland and Greece) declare that, in relation to mechanical coupling 
devices and components, they will on ly be bound by the ob ligations of the 
Agreement to which this Regulation is annexed with respect to such devices and components intended for ve hicles of categories other than M
1.  
14. NAMES AND AD DRESSES OF TECHNICAL SERVICES 
RESPONSIBLE FOR APPROV AL TESTS AND OF 
ADMINISTRATIVE DEPARTMENTS  
14.1. The Contracting Parties to the 1958 Agreement applying this Regulation 
shall communicate to the United Nations Secretariat the names and addresses of the technical services  responsible for conducting approval 
tests and of the administrative departments which grant approval and to 
27.12.2006 EN Official Journal of the European Union L 373/65 
 which forms certifying approval or extens ion or refusal or withdrawal of 
approval, or production definitely disc ontinued, issued in other countries, 
are to be sent. 
L 373/66 EN Official Journal of the European Union 27.12.2006 
 Annex 1  
COMMUNICATION  
(maximum format: A4 (210 x 297 mm) 
1issued by: Name of administration: ....................... 
 
 
concerning: 2/  
APPROVAL GRANTED 
APPROVAL EXTENDED 
APPROVAL REFUSED APPROVAL WITHDRAWN 
PRODUCTION DEFINITELY DISCONTINUED
 
of a type of mechanical coupling device or component pursuant to Regulation No. 55 
Approval No .......... Extension No ........... 1. Trade name or mark of the device or component: 2. Manufacturer's name for the type of device or component: 
3. Manufacturer's name and address: 4. If applicable, name and address of the manufacturer's representative: 
5. Alternative supplier's names or trade marks applied to the device or component: 
6. Name and address of company or body taki ng responsibility for the conformity of 
production: 
7. Submitted for approval on:  8. Technical service responsible  for conducting approval tests: 
                                                
 
1 Distinguishing number of the country which has granted/ extended/ refused/ withdrawn approval (see 
approval provisions in the Regulation).  
2 Strike out what does not apply.    
 

27.12.2006 EN Official Journal of the European Union L 373/67 
 9. Brief description: 
9.1. Type and class of device or component: 9.2. Characteristic values:  9.2.1. Primary values: 
D.............. kN D
c................ kN S............... kg 
U...............tonnes V.................. kN 
Alternative values: D............. kN D
c................ kN S................ kg 
U...............tonnes V.................. kN 
9.3. For Class A mechanical coupling de vices or components, including towing 
brackets: 
Vehicle manufacturer's maximum permissible vehicle mass: ...............................kg Distribution of maximum permissibl e vehicle mass between the axles: 
Vehicle manufacturer's maximum perm issible towable trailer mass: .....................kg 
Vehicle manufacturer's maximum permissi ble static  mass on coupling ball: ....kg 
Maximum mass of the vehicle, with bodywork,  in running order, including coolant, 
oils, fuel, tools and spare wheel (i f supplied) but not including driver: 
..................................kg 
Loading condition under which the tow ball he ight of a mechanical coupling device 
fitted to category M1 vehicles is to be measured - see paragraph 2 of annex 7, 
appendix 1: .......  
10. Instructions for the atta chment of the coupling device or component type to the 
vehicle and photographs or drawings of th e mounting points given by the vehicle 
manufacturer: 
11. Information on the fitting of any special reinforcing brackets or plates or spacing 
components necessary for th e attachment of the coupling device or component: 
.............. 
12. Additional information where the use of the coupling device or component is 
restricted to special types of vehi cles - see annex 5, paragraph 3.4. 
................................... 
13. For Class K hook type couplings, details of  the drawbar eyes su itable for use with 
the particular hook type. 
14. Date of test report:  
L 373/68 EN Official Journal of the European Union 27.12.2006 
 15. Number of test report:  
16. Approval mark position:  17. Reason(s) for extension of approval: 18. Approval granted/exte nded/refused/withdrawn: 
2 
19. Place:  20. Date:  21. Signature:  22. The list of documents deposited with  the Administration Service which has 
granted approval is annexed to this co mmunication and may be  obtained on request. 
 
27.12.2006 EN Official Journal of the European Union L 373/69 
 Annex 2  
COMMUNICATION  
(maximum format: A4 (210 x 297 mm) 
1 issued by: Name of administration: ....................... 
 
 
 concerning: 2 
APPROVAL GRANTED 
APPROVAL EXTENDED 
APPROVAL REFUSED APPROVAL WITHDRAWN 
PRODUCTION DEFINITELY DISCONTINUED 
of a vehicle type with rega rd to the fitting of a m echanical coupling device or 
component pursuant to Regulation No. 55. 
Approval No.......... Extension No ............. 1. Trade name or mark of vehicle:  2. Vehicle type:  3. Manufacturer's name and address:  4. If applicable, name and address of  the manufacturer's representative:  
5. Vehicle category, for example, M1, N1:  6. Maximum permissible vehicle mass: ....kg Distribution of maximum permissibl e vehicle mass between the axles: 
                                                
 
1 Distinguishing number of the country which has granted/ extended/ refused/ withdrawn approval (see 
approval provisions in the Regulation).  
 
2 Strike out what does not apply.  
 

L 373/70 EN Official Journal of the European Union 27.12.2006 
 Maximum permissible towable trailer mass: ....kg 
Maximum permissible static mass on coupling ball: ....kg Maximum mass of the vehicle, with bodywork,  in running order, including coolant, 
oils, fuel, tools and spare wheel (if s upplied) but not including driver: ...........kg 
7. D.............. kN D
c................ kN S............... kg  
U...............tonnes V.............. kN 
8. Instructions for the attachment of th e coupling device or component type to the 
vehicle and photographs or draw ings of the mounting points: 
9. Information on the fitting of any special reinforcing brackets or plates or spacing 
components necessary for the attachment  of the coupling device or component: 
10. Trade name or mark of the mechanic al coupling device or component and the 
approval number: 
11. Class of coupling device or component:  12. Submitted for approval on:  13. Technical service responsible  for conducting approval tests: 
14. Date of test report:  15. Number of test report:  16. Approval mark position:  17. Reason(s) for extension of approval:  18. Approval granted/extended/ refused/withdrawn: A1_S4_F1 
2 
19. Place:  20. Date:  21. Signature:  22. The list of documents deposited with  the Administration Service which has 
granted approval is annexed to this co mmunication and may be  obtained on request. 
27.12.2006 EN Official Journal of the European Union L 373/71 
 Annex 3  
EXAMPLE OF AN ARRANGEME NT OF THE APPROVAL 
MARK  
 
a = 8 mm minimum 
The mechanical coupling device or component  or vehicle bearing the approval mark 
shown above is a device or component approved in the Netherlands (E4), under approval number 2439, meeting the requiremen ts of the 01 series of amendments to 
this Regulation. 
 Note: The approval number and additional sym bols shall be placed close to the circle 
and either above or below the letter 'E', or to  the right or left of that letter. The digits 
of the approval number shall be on the same si de of the letter 'E' and face in the same 
direction. The use of Roman numerals as a pproval numbers should be avoided so as to 
prevent any confusion with other symbols. 
 

L 373/72 EN Official Journal of the European Union 27.12.2006 
 Annex 4  
EXAMPLES OF ARRANGEMEN TS OF MARKING OF THE 
CHARACTERISTIC VALUES  
1. All mechanical coupling devices or components shall be marked with the 
class of the device or component. In addition ther e shall be marking to 
indicate the capacity in terms of characteristic values as defined in 
paragraph 2.11. of this Regulation . 
1.1. The height of all letters and numb ers shall be not less than those of the 
approval number, that is a/3 where a is 8 mm. 
1.2. The characteristic values applic able to each device or component which 
are to be marked are as shown in the table below - see also paragraph 7.3. 
of this Regulation: 
TABLE 1 - Relevant characteristics values  to be marked on coupling devices or 
components 
Relevant characteristic values to be marked Description of mechanical coupling 
device or component 
 Class D Dc S U V 
Coupling balls and towing brackets -
see annex 5, para. 1 of this Regulation * *    *      
Coupling heads * *   *     
Drawbar couplings * * * *   * 
Drawbar eyes * * * *   * 
Drawbars * * * *   * 
Drawbeams * * * *   * 
Fifth wheel couplings * *     *   
Fifth wheel pins * *         
Fifth wheel mounting plates * *     *   
Hook type couplings * * * *   * 
 
Examples: C50-X D130 Dc90 S1000 V35 would identif y a non-standard drawbar 
coupling of Class C50-X with a maximu m D value of 130 kN, a maximum permitted 
27.12.2006 EN Official Journal of the European Union L 373/73 
 Dc value of 90 kN, a maximum permitted st atic vertical imposed  mass of 1000 kg 
and a maximum permitted V value of 35 kN. 
A50-X D20 S120 would identify a standard  towing bracket with ball coupling of 
Class A50-X with a maximum D value of 20 kN and a maximum permitted static vertical imposed  mass of 120 kg. 
L 373/74 EN Official Journal of the European Union 27.12.2006 
 Annex 5  
REQUIREMENTS FOR MECHAN ICAL COUPLING DEVICES 
OR COMPONENTS  
1. COUPLING BALLS AND TOWING BRACKETS  
The requirements stated in paragraphs  1.1. to 1.5. of this annex are 
applicable to all coupling balls and towing brackets of Cl ass A. Paragraph 
1.6. details additional requirements which must be fulfilled by standard 50 mm diameter coupling balls with  flange type bolted fixings. 
1.1. Coupling balls of Class A shall conf orm to Figure 2 in external shape and 
external dimensions. 
1/ The connecting radius between the ball and the neck should be tangential both to 
the neck and to the lower horiz ontal surface of the coupling ball 
2/ See ISO/R 468 and ISO 1302, the roughne ss number N9 refers to an R
a value of 
6.3mm. 
Figure 2 - Coupling ball of Class A 

27.12.2006 EN Official Journal of the European Union L 373/75 
 1.2. The shape and dimensions of towi ng brackets shall meet the requirements 
of the vehicle manufacturer concer ning the attachment points and 
additional mounting devices or components if necessary. 
1.3. Removable coupling balls: 1.3.1. In the case of removable couplin g balls or components which are not fixed 
by bolts, for example Class A50-X, the point of c onnection and the 
locking arrangement shall be de signed for positive mechanical 
engagement. 
1.3.2. In the case of a removable c oupling ball or component which may be 
separately approved for use with a va riety of towing brackets for different 
vehicle applications, for example Cla ss A50-X, the clearance space when 
such a coupling ball is fitted to the to wing bracket shall be that prescribed 
in annex 7, Figure 25. 
1.4. Coupling balls and towing devices sha ll be able to satisfy the tests given 
in annex 6, paragraph 3.1. 
1.5. Manufacturers of towing brackets sh all incorporate attachment points to 
which either secondary couplings or de vices necessary to enable the trailer 
to be stopped automatically in the event of separation of the main coupling, may be attached. This requ irement is necessary to enable the 
vehicle to comply with the requiremen ts of paragraph 5.2.2.9. of UN/ECE 
Regulation No. 13 - Uniform Provisi ons concerning the approval of 
vehicles of categories M, N a nd O with regard to braking. 
1.5.1. The attachment points for a sec ondary coupling and/or breakaway cable 
shall be positioned such that when in use, the secondary coupling or breakaway cable does not restrict th e normal articulation of the coupling 
or interfere with the normal inertia braking system operation. 
A single attachment point shall be po sitioned within 100 mm of a vertical 
plane passing through the cen tre of articulation of th e coupling. If this is 
not practicable, two attachment points shall be provided, one on each side 
of the vertical centre line and eq uidistant from the centre line by a 
maximum of 250 mm. The attachment point (s) shall be as rearward and as 
high as practicable. 
1.6. Special requirements for standard coupling balls and flange type towing 
brackets of Classes A50- 1 to A50-5 inclusive: 
1.6.1. Dimensions of Class A50-1 c oupling balls and fl ange type towing 
brackets shall be as given in Figure 3 and Table 2. 
1.6.2. Dimensions of Class A50-2, A 50-3, A50-4 and A50- 5 coupling balls and 
flange type towing brackets shall be as given in Figure 4 and Table 2. 
1.6.3. Coupling balls and flange type towing brackets of the classes A50-1 to 
A50-5 inclusive, shall be suitable and tested for the characteristic values given in Table 3. 
L 373/76 EN Official Journal of the European Union 27.12.2006 
 Figure 3 - Dimensions of standard flan ge type ball couplings of Class A50-1 
(see Table 2) 
Figure 4 - Dimensions of standard flange  type ball couplings of Class A50-2 to 
A50-5 (see Table 2) 

27.12.2006 EN Official Journal of the European Union L 373/77 
 TABLE 2 -Dimensions of standa rd flange type ball couplin gs (mm), see Figures 3 and 
4. 
Class A50-1 A50-2, A50-4 A50-3, A50-5 Comments 
e1 90 83 120 ± 0.5 
e2 -- 56 55 ± 0.5 
d2 17 10.5 15 H13 
f 130 110 155 + 6.0 -0  
g 50 85 90 + 6.0 -0 
c 15 15 15 maximum 
l 55 110 120 ± 5.0 
h 70 80 80 ± 5.0 
 
TABLE 3 -Characteristic values for st andard flange type ball couplings 
 
Class A50-1 A50-2 A50-3 A50-4 A50-5 
D 17 20 30 20 30 
S 120 120 120 150 150 
 
 D = Maximum D value (kN)  S = Maximum static vertical  mass (kg) 1.7. Manufacturers of coupling balls an d towing brackets intended for fitment 
in the after-market and which do not  have any association with the 
relevant vehicle manufacturer shall be aware of the requirements for articulation of the coupli ng given in paragraph 2 of  this annex and shall 
comply with the appropriate requireme nts in annex 7 to this Regulation. 
 
L 373/78 EN Official Journal of the European Union 27.12.2006 
 2. COUPLING HEADS  
2.1. Coupling heads of Class B50 shall be  designed so that they can be used 
safely with the coupling balls describe d in paragraph 1 of this annex and 
thereby retain the prescribed characteristics. 
Coupling heads shall be designed in such a way that safe coupling is 
ensured, also taking into account the wear of the coupling devices. 
2.2. Coupling heads shall be  able to satisfy the tests laid down in annex 6, 
paragraph 3.2. 
2.3. Any additional device (e.g. braking,  stabilizer, etc.) shall not have any 
adverse effect on the mechanical connection. 
2.4. When not attached to the vehicle, horizontal rotation of  the coupling head 
shall be at least 90° to each side of the centre line of the coupling ball and mounting described in paragraph 1 of this annex. Simultaneously, there shall be an angle of free vertical  movement 20° above and below the 
horizontal. Also, in conjunction with the horizontal angle of rotation of 
90° it shall be possible for there to be  25° of roll in both  directions about 
the horizontal axis. The following articulation shall be possible at all 
angles of horizontal rotation: 
 (i) vertical pitch ±15° with axial roll ±25°  (ii) axial roll ±10° with vertical pitch ±20° 
3. DRAWBAR COUPLINGS  
The requirements of paragraphs 3.1. to 3.6. of this annex are applicable to 
all drawbar couplings of Class C50.  Additional requirements which must 
be fulfilled by standard drawbar couplings of Classes C50-1 to C50-6 are given in paragraph 3.7. 
3.1. Performance requirements - All drawbar couplings shall be able to satisfy 
the tests stated in annex 6, paragraph 3.3. 
3.2. Suitable drawbar eyes - Class C50 drawbar couplings shall be compatible 
with all Class D50 drawbar eyes and couplings with the specified 
characteristics. 
3.3. Jaw 
Class C50 drawbar couplings shall have a jaw which is designed such that 
the appropriate drawbar eye is  guided into the coupling. 
If the jaw, or a part supporting the jaw,  can pivot about the vertical axis, it 
shall establish itself automatically in the normal position and with the 
coupling pin open, be effectively rest rained in this position to give 
satisfactory guidance for the drawbar eye during the coupling procedure. 
27.12.2006 EN Official Journal of the European Union L 373/79 
 If the jaw, or a part supporting the jaw, can pivot about the horizontal 
transverse axis, the joint providi ng the rotation capability shall be 
restrained in its normal position by a locking torque. The torque shall be sufficient to prevent a force of 200 N acting vertically upwards on the top 
of the jaw producing any deflection of the joint from its normal position. The locking torque shall be greater th an that created by operation of the 
hand lever described in paragraph 3.6 of this annex. It shall be possible to 
bring the jaw to its normal position manually. A jaw that pivots about the 
horizontal transverse axis  is only approved for  b earing mass, S, of up to 
50 kg and a V-value of up to 5 kN. 
If the jaw, or a part supporting the jaw, is pivoted about the longitudinal 
axis, the rotation shall be restrained by a locking torque of at least 100 Nm. 
The minimum required size of the ja w depends on the D value of the 
coupling: 
D value 
≤ 18 kN - width 150 mm, height 100 mm 
D value > 18 kN ≤ 25 kN - width 280 mm, height 170 mm 
D value > 25 kN - width 360 mm, height 200 mm 
The external corners of the jaw may be radiused. Smaller jaws are permitted for Class C50-X drawbar couplings if their use 
is restricted to centre axle trailers up to 3.5 tonnes maximum permissible 
mass or if the use of a jaw from the above table is impossible due to technical reasons and if, furthermore, there are special circumstances such 
as visual aids for ensuring safe execution of the automatic coupling procedure and if the field of appli cation is restricted in the approval 
according to information given by the coupling manufacturer in the 
Communication form shown in annex 1. 
3.4. Minimum articulation of  the coupled drawbar eye 
The drawbar eye, when coupled to a drawbar coupling but not fitted to a 
vehicle, shall have the degrees of artic ulation given below. If part of the 
articulation is provided by a special joint (Class C50-X drawbar couplings 
only), the field of application, give n in the communication form shown in 
annex 1, shall be restricted  to the cases stated in annex 7, paragraph 1.3.8. 
3.4.1. ± 90° horizontally about the vertical  axis from the longitudinal axis of the 
vehicle - see Figure 5. 
 
   
L 373/80 EN Official Journal of the European Union 27.12.2006 
  
       
 
   
Figure 5 - Horizontal rotation of the coupled drawbar eye 
 
3.4.2. ± 20° vertically about  the transverse axis from the horizontal plane of the 
vehicle - see Figure 6. 
Figure 6 - Vertical rotation of the coupled drawbar eye 
 
3.4.3. ± 25° axial rotation about the long itudinal axis from the horizontal plane 
of the vehicle - see Figure 7. 
Horizontal plane 
Longitudinal axis of the towing vehicle 
27.12.2006 EN Official Journal of the European Union L 373/81 
  
       
 
Figure 7 - Axial rotation of the coupled drawbar eye 
3.5. Locking to prevent inadvertent uncoupling: 
In the closed position the coupling pin shall be locked by two positive 
mechanical engagement locking de vices each of whic h shall remain 
effective should the other fail. 
The closed and locked position of the coupling shall be clearly indicated 
externally by a mechanical device. It shall be possible to verify the 
position of the indicator by feel, for example, in the dark. 
The mechanical indication device sha ll indicate the engagement of both 
locking devices (an AND condition). 
However, it is sufficient for the enga gement of only one locking device to 
be indicated if, in this situation, engagement of the second locking device 
is an inherent feature of the design. 
3.6. Hand levers 
Hand levers shall be of a design suitable for easy use with the end rounded 
off. The coupling shall not have a ny sharp edges or points of possible 
pinching near the hand lever which c ould result in inju ry during operation 
of the coupling. The force needed to release the coupling, measured 
without the drawbar eye, shall not exceed 250 N perpendicular to the hand 
lever along the line of operation. 
3.7. Special requirements for standard drawbar couplings of  Class C50-1 to  
C50-6: 
3.7.1. The swivel motion of the drawbar eye about the transver se axis must be 
achieved through the spherical shape of the coupling pin (and not by 
means of a joint);  
Horizontal plane 
L 373/82 EN Official Journal of the European Union 27.12.2006 
 3.7.2. Tensile and compressive shock load s along the longitudinal axis due to the 
clearance between the coupling pi n and the drawbar eye shall be 
attenuated by spring and/or da mping devices (except C50-1). 
3.7.3. The dimensions shall be as  given in Figure 8 and Table 4. 
3.7.4. The couplings shall be suitable an d tested for the char acteristic values 
given in Table 5. 
3.7.5. The coupling shall be opened by m eans of a hand lever at the coupling (no 
remote control). 
 
Figure 8 - Dimensions of standard drawbar couplings (mm), see Table 4 
 

27.12.2006 EN Official Journal of the European Union L 373/83 
 TABLE 4 - Dimensions of standard drawbar couplings (mm), see Figure 8 
Class C50-1 C50-2 C50-3 C50-4 C50-5 C50-6 
C50-7 Remarks 
e1 83 83 120 140 160 160 ±0.5 
e2 56 56 55 80 100 100 ±0.5 
d1 -- 54 74 84 94 94 maximum
d2 10.5 10.5 15 17 21 21 H13 
F 110 110 155 180 200 200 +6.0 -0 
G 85 85 90 120 140 140 ±3.0 
A 100 170 200 200 200 200 +20.0 -0 
B 150 280 360 360 360 360 +20.0 -0 
C 20 20 24 30 30 30 maximum
H 150 190 265 265 265 265 maximum
l1 -- 150 250 300 300 300 maximum
l2 150 300 330 330 330 330 maximum
l3 100 160 180 180 180 180 ±20.0 
T -- 15 20 35 35 35 maximum
 
   
L 373/84 EN Official Journal of the European Union 27.12.2006 
 TABLE 5 - Characteristic values for standard drawbar couplings 
Class C50-1 C50-2 C50-3 C50-4 C50-5 C50-6 C50-7 
D 18 25 70 100 130 190 190 
Dc 18 25 50 70 90 120 130 
S 200 250 650 900 1000 1000 1000 
V 12 10 18 25 35 50 75 
 
 D = maximum D value (kN) 
Dc = maximum D value (kN) for centre axle trailer applications 
S = maximum static verti cal load on coupling (kg) 
V = maximum V value (kN) 
4. DRAWBAR EYES  
4.1. General requirements for drawbar eyes of Class D50: 
All drawbar eyes of Class D50 shall be able to satisfy the test stated in 
annex 6, paragraph 3.4. 
Class D50 drawbar eyes are intended for use with C50 drawbar couplings. 
Drawbar eyes shall not be able to rotate axially (because the respective 
couplings can rotate). 
If Class D50 drawbar eyes are fitted with sleeves, they shall comply with 
the dimensions shown in Figure 9 (not permitted for Class D50-C) or Figure 10. 
The sleeves must not be weld ed into the drawbar eyes. 
Class D50 drawbar eyes shall have the dimensions given in paragraph 4.2. 
The form of shank for drawbar eyes of Class D50-X is not specified. but 
for a distance of 210 mm from the centr e of the eye the height "h" and the 
width "b" shall be within the limits given in Table 6. 
27.12.2006 EN Official Journal of the European Union L 373/85 
 Figure 9 - Slotted sleeve for Class D50 drawbar eyes 
Figure 10 - Non-slotted sleeve fo r Class D50-C drawbar eyes 

L 373/86 EN Official Journal of the European Union 27.12.2006 
 TABLE 6 - Dimensions for draw bar eyes D50-A and D50-X, 
see Figure 11 
Class h (mm) b (mm) 
D50-A 65 +2/-1 60 +2/-1 
D50-X 80 maximum 62 maximum 
 
TABLE 7 - Characteristic values  for standard drawbar eyes 
Class D Dc S V 
D50-A 130 90 1 000 30 
D50-B 130 90 1 000 25 
D50-C 190 120 1 000 50 
D50-D 190 130 1000 75 
 
4.2. Special requirements for Class D50 drawbar eyes: 4.2.1. Class D50-A and D50-X drawbar eyes shall have the dimensions 
illustrated in Figure 11. 
 
27.12.2006 EN Official Journal of the European Union L 373/87 
  
       
 
      
Figure 11 - Dimensions of Classes D50- A and D50-X drawbar eyes, see Table 6 
 
4.2.2. Class D50-B drawbar eyes shall have  the dimensions illustrated in Figure 
12.  
Section A-A (shown without sleeve) 
Sphere 
 
L 373/88 EN Official Journal of the European Union 27.12.2006 
  
 
      
 
              
Figure 12 - Dimensions of Class D50-B dr awbar eyes, see other dimensions in 
Figure 11 
 
4.2.3. Classes D50-C and D50-D drawba r eyes shall have the dimensions 
illustrated in Figure 13.  
DRAWBAR EYE 
Front part of drawbar 
 
between plates 
 
27.12.2006 EN Official Journal of the European Union L 373/89 
  
1/ For Class D50-D drawbar eyes th is dimension shall be "80 max." 
Figure 13 - Dimensions of Classes D50- C and D50-D drawbar eyes, see other 
dimensions in Figure 11 
 
4.2.4. Classes D50-C and D50-D drawbar eyes shall be fitted with non slotted 
sleeves shown in Figure 10. 
4.3. Load values for standard drawbar eyes 
Standard drawbar eyes and the means of  attachment shall be suitable for, 
and tested for, the load values stated in Table 7. 
4.4. General requirements for Class L toroidal drawbar eyes: 4.4.1. Class L toroidal drawbar eyes ar e intended for use with Class K hook type 
couplings 
SECTION AA
L 373/90 EN Official Journal of the European Union 27.12.2006 
 4.4.2. When used with a Class K hook  type coupling they  shall meet the 
requirements for articulation given in  paragraph 10.2 of this annex. 
4.4.3. Class L toroidal drawbar eyes sh all have the dimensions given in Figure 
14 and Table 8 
 
Figure 14 - Dimensions of Class L to roidal drawbar eyes - see Table 8 
 
 4.4.4. Class L toroidal drawbar eyes sh all satisfy the tests given in annex 6, 
paragraph 3.4 and shall be suitable fo r the characteristic values given in 
Table 9. 
TABLE 8 - Dimensions of Class L toroidal  drawbar eyes - see Figure 14 (Dimensions 
in mm) 
Class L1 L2 L3 L4 L5 Remarks 
a 68+1.6/-0.0 76.2±0.8 76.2±0.8 76.2±0.8 68+1.6/-0.0   

27.12.2006 EN Official Journal of the European Union L 373/91 
 b 41.2±0.8 41.2±0.8 41.2±0.8 41.2±0.8 41.2±0.8   
c 70 65 65 65 70 Min 
 
TABLE 9 - Characteristic values for Class L toroidal drawbar eyes 
Class L1 L2 L3 L4 L5 
D kN 30 70 100 130 180 
Dc kN 27 54 70 90 120 
S kg 200 700 950 1000 1000 
V kN 12 18 25 35 50 
 
5. DRAWBARS  
5.1. Drawbars of class E shall satisf y the tests prescribed in annex 6, 
paragraph 3.3. 
5.2. In order to provide a connection to  the towing vehicle, the drawbars can 
be fitted either with coupling heads as in paragraph 2 or drawbar eyes as in paragraph 4 of this annex. The co upling heads and drawbar eyes can be 
attached by screwing, bolting or welding. 
5.3. Height adjusting de vices for hinged drawbars 
5.3.1. Hinged drawbars shall be fitted with devices for adjusting the drawbar to 
the height of the coupling device or ja w. These devices shall be designed 
so that the drawbar can be adjusted  by one person without tools or any 
other aids. 
5.3.2. Height adjusting devices shall be able to adjust the drawbar eyes or ball 
couplings from the horizontal above th e ground at least 300 mm upwards 
and downwards. Within this range the drawbar shall be adjustable 
steplessly, or in maximum steps of 50 mm measured at the drawbar eye or 
ball coupling. 
5.3.3. Height adjusting devices shall not interfere with the easy movement of the 
drawbar after coupling. 
5.3.4. The height adjusting devices shall not interfere with the action of any 
inertia, overrun type, brake. 
5.4. In the case of drawbars combin ed with inertia, overrun, brakes, the 
distance between the centre of the dr awbar eye and the end of the free 
shank of the drawbar eye shall not be less than 200 mm in the brake 
L 373/92 EN Official Journal of the European Union 27.12.2006 
 application position. With the shank of the drawbar eye fully inserted the 
distance shall not be less than 150 mm. 
5.5. Drawbars for use on centre axle trailers shall possess at least half the 
moment of resistance against lateral forces as against vertical forces. 
 
27.12.2006 EN Official Journal of the European Union L 373/93 
 6. DRAWBEAMS  
6.1. Drawbeams of Class F shall satisf y the tests prescribed in annex 6,  
paragraph 3.3 
6.2. The drilling pattern for mounting of  Class C standard drawbar couplings 
shall be in accordance with Figure 15 and Table 10 below. 
6.3. Drawbeams shall not be welded to the chassis, bodywork or other part of 
the vehicle. 
 
Figure 15 - Mounting dimensions for standa rd drawbar couplings (see Table 10) 
L 373/94 EN Official Journal of the European Union 27.12.2006 
  
TABLE 10 - Mounting dimensions for standa rd drawbar couplings (mm) - see Figure 
15 
Class C50-1 C50-2 C50-3 C50-4 C50-5 C50-6C50-7 Remarks 
e1 83 83 120 140 160 160 ±0.5 
e2 56 56 55 80 100 100 ±0.5 
d1 - 55 75 85 95 95 +1.0/-0.5 
d2 10.5 10.5 15 17 21 21 H13 
T - 15 20 35 35 35 maximum
F 120 120 165 190 210 210 minimum
G 95 95 100 130 150 150 minimum
L1 - 200 300 400 400 400 minimum
 
 
7. FIFTH WHEEL COUPLING S AND STEERING WEDGES  
The requirements of paragraphs 7.1 to 7.7 are applicable to all fifth wheel 
couplings of Class G50. 
Additional requirements which shall be fulfilled by standard coupling 
devices are given in paragraph 7.9. 
 Steering wedges shall satisfy the requirements listed in paragraph 7.8. 7.1. Suitable fifth wheel coupling pins 
Class G50 fifth wheel couplings shall be  designed so that they can be used 
with Class H50 coupling pins and,  together, provide the specified 
characteristics. 
7.2. Guides 
Fifth wheel couplings shall be equipp ed with a guide which ensures safe 
and correct engagement of the coupli ng pin. The entry width of the guide 
for standard 50 mm diameter fifth wh eel couplings shall be at least 350 
mm (see Figure 16). 
27.12.2006 EN Official Journal of the European Union L 373/95 
 For small, non-standard, fifth wheel c ouplings of Class G50-X and having 
a maximum "D" value of 25 kN, the en try width shall be at least 250 mm. 
bevelled edgeSection A-A
Enlarged view of coupling pin
Guide for the steering edge

L 373/96 EN Official Journal of the European Union 27.12.2006 
 Notes 
1/ To provide for the use of steering we dges, measure the reference dimension k = 
137 ±3 mm at 32 mm below the top surface and at a distance of 200 mm from the 
transverse centre line of the coupling. 
2/ The 40° +1°/-0° throat angle must be  maintained over a distance of 360 mm 
minimum from the transverse centre line of  the coupling. The entry width of 350 mm 
minimum may be obtained outside this dist ance by increasing the entry angle up to an 
included angle of 120° maximu m as shown in dotted line. 
3/ Elongated mounting holes  23 ± 2 mm x 17 +2/-0 mm 
or round mounting holes Dia. 17 +2/-0 mm could be used. 4/ When using elongated holes or holes > 18 mm diameter, washers 40 mm diameter, 
6 mm thick, or means of equal strength, e.g. flat steel plate, are to be used. 
Figure 16 - Dimensions of standard fifth wheel couplings (see Table 11) 
Figure 16a - Mounting holes tol erances for class J mounting plates for fifth wheel 
couplings (see para. 9.1. of this annex) 
 
Coupling pinLongitudinal axis of the vehicle
27.12.2006 EN Official Journal of the European Union L 373/97 
 TABLE 11 - Dimensions of standard fi fth wheel couplings (mm), see Figure 16 
Class G50-1 G50-2 G50-3 G50-4 G50-5 G50-6 
H 140-159 160-179 180-199 200-219 220-239 240-260 
 
7.3. Minimum articulation of  the fifth wheel coupling 
With the coupling pin engaged, wit hout the fifth wheel coupling being 
attached to a vehicle or  mounting plate, but taking into account the effect 
of the mounting bolts, the coupling shall permit, simultaneously, the following minimum values of arti culation of the coupling pin: 
7.3.1. ±90° about the vertical axis (not applicable to fifth wheel couplings with 
positive steering); 
7.3.2. ±12° about the horizontal axis tran sverse to the direc tion of travel. This 
angle does not necessarily cover off-road use. 
7.3.3. Axial rotation about the longitudinal axis of up to ±3° is permitted. 
However, on a fully oscillating fifth wheel coupling, this angle may be 
exceeded, providing that the locking m echanism enables the restriction of 
the rotation to ±3° maximum. 
7.4. Locking devices to prevent uncoupling of fifth wheel couplings 
The fifth wheel coupling shall be lo cked in the coupled position by two 
positive mechanical locking devices each of which shall remain effective should the other fail. 
The primary locking device shall opera te automatically but the secondary 
locking device may either be automatic or be engaged manually. The secondary locking device may be desi gned to work in conjunction with 
the primary device and provide an additional positive mechanical lock for the primary device. It shall only be  possible to engage the secondary 
locking device if the primary device is properly engaged. 
It shall not be possible for the locking devices to be released inadvertently. 
Release shall require intentional acti on by the driver or operator of the 
vehicle. 
The closed and locked position of the coupling shall be indicated visually 
by a mechanical device and it shall be possible to verify the position of the 
indicator by feel, for example, to a llow the position to be checked during 
darkness. The indication device shall indicate the engagement of both 
primary and secondary locking devices, however, it is sufficient for the 
engagement of only one device to be  indicated if, in this case, the 
engagement of the other device is a simultaneous and inherent feature of 
the design. 
L 373/98 EN Official Journal of the European Union 27.12.2006 
 7.5. Operating devices or release mechanisms 
In the closed position the operating de vices or release mechanisms shall 
be prevented from being operated in advertently or accidentally. The 
locking system shall be such as to require positive, conscious action to 
release the locking device in order to operate coupling release mechanism. 
7.6. Surface finish 
The surfaces of the coupling plate and coupling lock shall be functionally 
satisfactory and be carefully machined, forged, cast or pressed. 
7.7. Load requirements 
All fifth wheel couplings shall be able to satisfy the tests described in 
annex 6, paragraph 3.7. 
7.8. Steering wedges 7.8.1. The dimensions of steering wedges fo r the positive steering of semitrailers 
shall be as in Figure 17. 

27.12.2006 EN Official Journal of the European Union L 373/99 
  
 Notes: 1/ Only applicable to steering wedges over 60 mm thick. 2/ This dimension only refers to the func tional surface: the steer ing wedge itself can 
be longer. 
Figure 17 - Dimensions of spring-mounted steering wedges 
 
7.8.2. The steering wedge shall allow sa fe and correct coupling and shall be 
spring-mounted. The strength of the spri ng shall be selected so that it is 
possible to couple an unloaded semitraile r and so that, with  the semitrailer 
fully loaded the steering wedge is firmly in contact with the flanks of the coupling during use. Uncoup ling of the fifth wheel shall be possible with 
the semitrailer both loaded and unloaded. 
7.9. Special requirements for standard fifth wheel couplings: 7.9.1. the dimensions shall be as  shown in Figure 16 and Table 11. 
7.9.2. they shall be suitable for, and tested for, a D value of 150 kN and a U 
value of 20 tonnes. 
7.9.3. release shall be possible by a hand lever mounted directly on the coupling. 
7.9.4. they shall be suitable for the posi tive steering of sem itrailers by means of 
steering wedges - see paragraph 7.8. 
8. FIFTH WHEEL COUPLING PINS  
8.1. Fifth wheel coupling pins of Class H50 (ISO 337) shall have the 
dimensions shown in Figure 18 
 
L 373/100 EN Official Journal of the European Union 27.12.2006 
 Figure 18 - Dimensions of Class H50 fifth wheel coupling pins 
 
8.2. The coupling pins shall be able to satisfy the tests desc ribed in annex 6, 
paragraph 3.9.  
35 
27.12.2006 EN Official Journal of the European Union L 373/101 
 9. MOUNTING PLATES  
9.1. Class J mounting plates for fifth wheel couplings sha ll have circular 
mounting holes positioned as shown in Figure 16a if they are intended for 
standard fifth wheel couplings. Howe ver, the mounting holes shall be 17 
mm +2.0 mm/ -0.0 mm diam eter. The holes shall be circular, NOT slotted 
(see Figure 16a). 
9.2. Mounting plates for standard fifth wheel couplings shall be suitable for the 
positive steering of semitrailers (with  steering wedges). Mounting plates 
for non-standard fifth wheel couplings which are unsuitable for positive steering shall be marked appropriately. 
9.3. Mounting plates for fifth wheel coupli ngs shall be able to satisfy the tests 
described in annex 6, paragraph 3.8. 
10. HOOK TYPE COUPLINGS  
10.1. General requirements for Class K hook type couplings: 
10.1.1. All Class K hook type couplings shall satisfy the tests given in annex 6, 
paragraph 3.5 and shall be suitable fo r the characteristic values given in 
Table 13 
10.1.2. Class K hook type couplings shall ha ve the dimensions given in Figure 19 
and Table 12. Class K1 to K4 are non- automatic couplings for use only on 
trailers not exceeding 3.5 tonnes ma ximum permissible mass and Class 
KA1 to KA3 are automatic couplings. 
 
L 373/102 EN Official Journal of the European Union 27.12.2006 
 Figure 19 - Dimensions and articulation  of Class K hook type couplings 
 
10.1.3. A hook type coupling shall only be used with a toroid al drawbar eye and 
when used with a Class L toroidal drawbar eye the Class K coupling shall 
have the degrees of articulation give n in paragraph 10.2 of this annex. 
10.1.4. A Class K hook type coupling shall be used with a toroidal eye giving a 
minimum clearance, or free move ment, of 3 mm and a maximum 
clearance of 5 mm when new. Suitable drawbar eyes shall be declared by 
the coupling manufacturer on the Comm unication form shown in annex 1. 
10.2. A Class K coupling when used with a Class L toroidal eye, but not fitted 
to a vehicle, shall have the following non-simultaneous angles of articulation - see also Figure 19: 
10.2.1. ±90° horizontally about the vertical axis of the coupling; 
10.2.2. ±40° vertically about the horizon tal transverse axis of the coupling; 
10.2.3. ±20° axial rotation about the hor izontal longitudinal center line of the 
coupling. 

27.12.2006 EN Official Journal of the European Union L 373/103 
 10.3. Automatic Class K hook type coupli ngs shall have a jaw designed such 
that the drawbar eye is guided into the coupling. 
10.4. Locking to prevent inadvertent uncoupling: 
In the closed position the coupling shall be locked by two positive 
mechanical engagement locking de vices each of which shall remain 
effective should the other fail. 
The closed and locked position of the coupling shall be clearly indicated 
externally by a mechanical device. It shall be possible to verify the 
position of the indicator by feel, for example, in the dark. 
The mechanical indication device sha ll indicate the engagement of both 
locking devices (an AND condition). 
However, it is sufficient for the enga gement of only one locking device to 
be indicated if, in this situation, engagement of the second locking device 
is an inherent feature of the design. 
10.5. Hand levers 
Hand levers shall be of a design suitable for easy use with the end rounded 
off. The coupling shall not have a ny sharp edges or points of possible 
pinching near the hand lever which c ould result in inju ry during operation 
of the coupling. The force needed to release the coupling, measured 
without the drawbar eye, shall not exceed 250 N perpendicular to the hand 
lever along the line of operation. 
L 373/104 EN Official Journal of the European Union 27.12.2006 
  
TABLE 12 - Dimensions for Class K hook type couplings - see Figure 19 
Class K1 K2 K3 K4 KA1 KA2 KA3 Remarks 
e1 - 83 83 120 120 140 160 ±0.5 
e2 - 56 56 55 55 80 100 ±0.5 
e3 90 - - - - - - ±0.5 
d2 17 10.5 10.5 15 15 17 21 H13 
c 3 3 3 3 3 3 3 Min 
f 130 175 175 180 180 200 200 Max 
g 100 100 100 120 120 140 200 Max 
a 45 45 45 45 45 45 45 +1.6/-0.0 
L1 120 120 120 120 250 300 300 Max 
L2 74 74 63 74 90 90 90 Max 
L3 110 130 130 150 150 200 200 Max 
 
TABLE 13 - Characteristic values for Class K hook type couplings 
Class K1 K2 K3 K4 KA1 KA2 KA3 
D kN 17 20 20 25 70 100 130 
Dc kN - - 17 20 54 70 90 
S kg 120 120 200 250 700 900 1000 
V kN - - 10 10 18 25 35 
 
27.12.2006 EN Official Journal of the European Union L 373/105 
  
11. DEDICATED DRAWBAR TY PE COUPLINGS - CLASS T  
11.1. Class T dedicated drawbar type c ouplings are intended for use on specific 
vehicle combinations, for example, car transporters. These vehicles have special structures and may need pa rticular and unusual location of the 
coupling. 
11.2. Class T couplings shall be restricted  to use with centre axle trailers and 
this restriction shall be notified on the Communication form shown in 
annex 1. 
11.3. Class T couplings shall be approved as a matched pair and it shall not be 
possible to separate the coupling ot her than in a workshop using tools 
which are not normally carried on the vehicle. 
11.4. Class T couplings shall not be automatic in operation. 11.5. Class T couplings shall satisfy the relevant test requirements given in 
annex 6, paragraph 3.3., except paragraph 3.3.4. 
11.6. The following minimum and simultane ous angles of articulation shall be 
possible with the coupling not fitted to  a vehicle but assembled, and in the 
same normal position as when fitted to a vehicle; 
11.6.1. ±90° horizontally about the vertical axis; 11.6.2. ±8° vertically about th e horizontal transverse axis; 
11.6.3. ±3° axial rotation about the horizontal longitudinal axis. 
12. DEVICES FOR REMOTE INDICATION AND REMOTE 
CONTROL  
12.1. General requirements 
Devices for remote indication and remote control are permitted only on 
automatic coupling devices of Classes C50-X and G50-X. 
Devices for remote indication and remo te control shall not interfere with 
the minimum free movement of the coupled drawbar eye or coupled 
semitrailer. They shall be permanently fitted to the vehicle. 
All the devices for remote indication or remote control fall within the 
scope of testing and approval of the c oupling device together with all parts 
of the operating devices and transmission devices. 
12.2. Remote indication 12.2.1. For an automatic coupling proced ure, remote indication devices shall 
indicate the closed and doubly locked  position of the coupling in an 
L 373/106 EN Official Journal of the European Union 27.12.2006 
 optical manner according to paragraph 12.2.2. Additionally the open 
position may be indicated as in paragraph 12.2.3. 
The remote indication device shall be  automatically activated and reset 
during every opening and cl osing of the coupling. 
12.2.2. The change from the open to the closed and doubly locked position shall 
be indicated by a gr een optical signal. 
12.2.3. If the open and/or unlocked positio n is indicated, a red optical signal shall 
be used. 
12.2.4. In the case of indicating the completion of the automatic coupling 
procedure, the remote indicator sha ll ensure that th e coupling pin has 
reached the doubly locked end position. 
12.2.5. The appearance of any fault in the remote indication system shall not 
indicate a closed and locked positio n during the coupling procedure if the 
end position has not been reached. 
12.2.6. The disengagement of one of th e two locking devices shall cause the 
green optical signal to extinguish and the red optic al signal (if fitted) to 
show. 
12.2.7. The mechanical indicators fitted directly to the coup ling device shall be 
retained. 
12.2.8. In order to avoid di stracting the driver during no rmal driving, there shall 
be a provision for switching off the remo te indication device but this shall 
be automatically re activated when the coupling is next opened and closed 
- see paragraph 12.2.1. 
12.2.9. The operating controls and indica tors of the remote indication devices 
shall be mounted within the driver's  field of vision and be permanently 
and clearly identified. 
12.3. Remote control 12.3.1. If a remote control device, as defi ned in paragraph 2.8 of this Regulation, 
is employed, there shall also be a re mote indication device as described in 
paragraph 12.2 which shall at leas t indicate the open condition of the 
coupling. 
12.3.2. There shall be a dedi cated switch (i. e. master switch, lever or valve) to 
enable the coupling to be opened or cl osed by means of the remote control 
device. If this master switc h is not located in the dr iving cab it shall not be 
in a position where it is freely accessible to unauthorized persons or it shall be lockable. The actual operati on of the coupling from the driving 
cab may only be possible when inadve rtent operation has been precluded, 
for example by an operation requ iring the use of two hands. 
It shall be possible to ascertain whether opening of the coupling under 
remote control has been completed or not. 
27.12.2006 EN Official Journal of the European Union L 373/107 
 12.3.3. If remote control involves the coupling being opened by external force, 
the condition under which the external force acts on the coupling shall be 
indicated appropriately to the driver. This is not necessary if the external force is only operative while th e remote control is operating. 
12.3.4. If the actuating device for opening the coupling under remote control is 
mounted externally on the vehicle it shall be possible to oversee the area 
between the coupled vehicles, but it shall not be necessary, however, to 
enter this area in order to operate it. 
12.3.5. Any single error in operation or th e occurrence of any single fault in the 
system shall not result  in accidental opening of the coupling during 
normal road use. Any faults in the system shall be indicated directly or be immediately obvious at the next operation e.g. by a malfunction. 
12.3.6. In the event of a failure of the re mote control it shall be possible, in an 
emergency, to open the coupling in at least one other way. If this requires 
the use of a tool then this shall be included in vehicle's tool kit. The 
requirements of paragraph 3.6 of this  annex are not applicable to hand 
levers used exclusively for openi ng the coupling in an emergency. 
12.3.7. The operating controls and indicator s for the remote c ontrol devices shall 
be permanently and clearly identified. 
 
L 373/108 EN Official Journal of the European Union 27.12.2006 
 Annex 6  
TESTING OF MECHANICAL COUPLING DEVICES OR 
COMPONENTS  
1. GENERAL TESTING REQUIREMENTS  
1.1. Samples of coupling devices shall be  tested for both stre ngth and function. 
Physical testing shall be carried ou t wherever possible but unless stated 
otherwise the type approval authorit y or technical service may waive a 
physical strength test if the simple  design of a component makes a 
theoretical check possibl e. Theoretical checks may be carried out to 
determine worst case conditions. In al l cases, theoretical checks shall 
ensure the same quality of results as with dynamic or static testing. In cases of doubt it is the results of physical tes ting that are overriding. 
 See also paragraph 4.8 of this Regulation. 1.2. With coupling devices the strength shall be verified by a dynamic test 
(endurance test). In certain cases additional static tests may be necessary (see paragraph 3 of this annex). 
1.3. The dynamic test shall be performe d with approximately sinusoidal load 
(alternating and/or pulsati ng) with a number of stre ss cycles appropriate to 
the material. No cracks or fractures shall occur. 
1.4. Only slight permanent deformation is permitted with the static tests 
prescribed. Unless stated otherwise the permanent, plastic, deformation after releasing shall not be more  than 10 per cent of the maximum 
deformation measured during the test. In the case where measurement of deformation during the test puts the test er at risk then, provided that the 
same parameter is checked during other tests, such as the dynamic test, then this part of the static test may be omitted. 
1.5. The loading assumptions in the dynamic tests are based on the horizontal 
force component in the longitudinal ax is of the vehicle and the vertical 
force component. Horizontal force components transverse to the 
longitudinal axis of the vehicle, an d moments, are not taken into account 
provided they are of only minor significance. 
If the design of the coup ling device or its attachment to the vehicle or the 
attachment of additional systems (s uch as stabilizers, close coupling 
devices, etc.) generate additional forces or moments, additional tests may be required by the type approval au thority or technical service. 
The horizontal force component in the longitudinal axis of the vehicle is 
represented by a theoretically determined reference force, the D or D
c 
value. The vertical force component, where applicable, is represented by 
the static vertical bearing load, S, at  the point of coup ling and the assumed 
vertical load, V, or by the static vertical bearing load, U, in the case of fifth wheel couplings. 
27.12.2006 EN Official Journal of the European Union L 373/109 
 1.6. The characteristic values D, Dc, S, V and U, on which the tests are based 
and which are defined in paragraph 2.11.  of this Regulation, shall be taken 
from the manufacturer's information given in the application for type 
approval - see communication form shown in annexes 1 and 2. 
1.7. Any positive locking device, which is retained in position by spring force, 
shall remain in its secured position wh en subjected to a force applied in 
the least favourable direction and equiva lent to three times the mass of the 
locking mechanism. 
2. TEST PROCEDURES  
2.1. For the dynamic tests and static te sts, the sample shall be placed in a 
suitable rig with a means of force applic ation, such that it is not subjected 
to any additional forces or moments apart from the specified test force. In the case of alternating tests, the dir ection of force application shall not 
deviate by more than ±1° from the specified direction. In the case of 
pulsating and static tests, the angle shall be set for the maximum test 
force. This will normally require a joint at the point of force application (i.e. the point of coupling) and a se cond joint an adequate distance away. 
2.2. The test frequency shall not exceed 35 Hz. The selected frequency shall be 
well separated from resonance frequenc ies of the test set up including the 
tested device. With asynchronous testi ng the frequencies of the two force 
components shall be between approximately 1 per cent and a maximum of 3 per cent apart. For coupling devi ces made from steel the number of 
stress cycles is 2 x 10
6. For devices made from materials other than steel a 
higher number of cycles may be nece ssary. The dye-penetration method of 
crack testing or an  equivalent method shall be  used to determine any 
cracking during test. 
2.3. With pulsating tests, the test for ce varies between the maximum test force 
and a lower, minimum, test force, which may not be greater than 5 per 
cent of the maximum test force unless otherwise stated in the specific testing procedure. 
2.4. With static tests, other than the special tests required by paragraph 3.2.3 of 
this annex, the test force shall be applied smoothly and quickly and be 
maintained for at least 60 seconds. 
2.5. The coupling devices or component  on test should normally be mounted 
as rigidly as possible on a test rig in  the actual position in which they will 
be used on the vehicle. The fixing de vices should be those specified by the 
manufacturer or applicant and should be those intended for the attachment 
of the coupling device or component to the vehicle an d/or shall have 
identical mechanical characteristics. 
2.6. Coupling devices or components sha ll be tested in the form used on the 
road. However, at the discretion of  the manufacturer, and in agreement 
with the technical service, flexible components may be neutralized if this 
L 373/110 EN Official Journal of the European Union 27.12.2006 
 is necessary for the test procedure and if this wi ll not have a ny unrealistic 
influence on the test result. 
Flexible components which are overheated during these accelerated test 
procedures may be replaced during the test. The test loads may be applied 
by means of special slack-free devices. 
3. SPECIFIC TESTING REQUIREMENTS  
3.1. Coupling balls and towing brackets 
3.1.1.  Mechanical coupling devices with  coupling balls may be of the following 
types: 
(i) one-piece coupling balls including devices with non- interchangeable 
detachable balls (see Figures 20a and 20b), 
(ii) coupling balls, comprising a num ber of parts which can be dismantled 
(see Figures 20c, 20d and 20e), 
 (iii) towing brackets without ba ll fitted (see Figure 20f). 
27.12.2006 EN Official Journal of the European Union L 373/111 
 Figure 20 - Arrangements of ball type towing brackets 
a One piece towing bracket and coupling ball
b In this model the ball can be removed by hand : for
example, an assembly with a bayonet-type fixture
c Bracket with ball which can be removed using tools
d Bracket with ball and ball support, fastened using class
A50 bolts, for example
e Bracket with ball and integral support, assembled using
tools
f Bracket without ball
L 373/112 EN Official Journal of the European Union 27.12.2006 
 3.1.2. The basic test is a dynamic endurance test. The test sample comprises the 
coupling ball, the ball neck and the mountings necessary for attaching the 
assembly to the vehicle. The coupling ball and towing bracket shall be rigidly mounted to a test rig, capable of producing an alte rnating force, in 
the actual position in which it is intended for use. 
3.1.3. The positions of the fixing point s for attaching the coupling ball and 
towing bracket are specified by the vehicle manufacturer (see paragraph 
5.3.2. of this Regulation). 
3.1.4. The devices submitted for test shal l be provided with all parts and design 
details which may have an influence on the strength criteria (for example 
electrical socket plate, any marking, et c.). The test sample shall include all 
parts up to the anchorage points or fitting points to the vehicle. The 
geometric location of the coupling ba ll and the fixing points of the 
coupling device related to the reference line shall be provided by the vehicle manufacturer and shall be show n in the test report. All relative 
positions of the anchorage points with respect to the reference line, for 
which the towing vehicle manufacture r shall provide all the necessary 
information to the towing device ma nufacturer, shall be repeated on the 
test bed. 
3.1.5. The sample mounted on the test ri g shall be subjected to an alternating 
stress test applied at an angle to the ball as shown in Figure 21 or 22. 
The direction of the angl e of test shall be determined by the vertical 
relationship between a horizontal re ference line passing through the centre 
of the ball and a horizontal line pa ssing through the fixing point of the 
coupling device which is the highest of  the nearest, when measured in a 
horizontal plane, to a transverse ve rtical plane passing through the centre 
of the ball. If the fixing  point line is above the horizontal reference line, 
the test shall be carrie d out at an angle of 
α  = +15°±1° and if it is below 
then the test shall be carried out at an angle of α  = -15°±1° (see Figure 
21). The fixing points to be considered  in determining the angle of test 
shall be those declared by the vehi cle manufacturer and which transmit the 
major towing forces to the structure of the towing vehicle. 
This angle is chosen in order to ta ke account of the vertical static and 
dynamic load and is only applicable for a permitted static vertical load not 
exceeding: 
S = 120 x D [N] Where the static vertical load exceed s that calculated above, the angle 
shall, in both conditions, be increased to 20°. 
The dynamic test shall be performed with the following test force: 
F
hs res = ±0.6 D 
3.1.6. The test procedure is applicable to the different types of coupling devices 
(see paragraph 3.1.1 of this annex) as follows: 
27.12.2006 EN Official Journal of the European Union L 373/113 
 3.1.6.1. one piece coupling balls incl uding devices with non-interchangeable 
detachable balls (see Figures 20a and 20b). 
3.1.6.1.1. the strength test for the devi ces shown in Figures 20a and 20b shall be 
carried out according to the re quirements of paragraph 3.1.5; 
 
Note: The line parallel to the reference li ne passes through the ce ntre of the highest 
and nearest point for mounting the towing bracket to the vehicle - see annex 6, 
paragraph 3.1.5. 
Figure 21 - Angles of application of test force 
 
 

L 373/114 EN Official Journal of the European Union 27.12.2006 
 Note: 
Direction of alternating test force, Fhs res, depending on the location of the ball centre 
horizontal reference line in relation to th e line parallel to this reference line -  
see Figure 21 
Figure 22 - Angles of application of test force 
 
3.1.6.2. coupling balls, comprising parts which can be dismantled. 
The following categories are defined: 
(a) towing bracket and ball (see Figure 20c), (b) towing bracket and ball on in tegral support (see Figure 20d), 
(c) towing bracket with detachable ball (see Figure 20e), (d) towing bracket without ball (see Figure 20f). 
3.1.6.2.1. The strength test for the devi ces shown in Figures 20c to 20f shall be 
carried out according to the requirement s of paragraph 3.1.5. Dimensions 
e and f, shall have a manufacturing tolerance of ±5 mm, and shall be 
stated in the test report. 
The test of the towing bracket (see Fi gure 20f) shall be carried out with a 
mounted ball (on support). Account will be taken only of the result of the 
test on the towing bracket between the fixing points and the mounting 
surface of the ball support. 
The dimensions e and f shall have a manufacturing tolerance of ±5 mm 
and shall be specified by th e coupling device manufacturer. 

27.12.2006 EN Official Journal of the European Union L 373/115 
 3.1.6.3. Coupling devices with variable dimensions e and f for demountable and 
interchangeable coupling balls - see Figure 22. 
3.1.6.3.1. The strength tests for such to wing brackets shall be carried out to the 
requirements of paragraph 3.1.5. 
3.1.6.3.2. If a worst case configuration can be defined by agreement between the 
manufacturer and the type approval au thority or technical service, then 
testing of this one configurat ion alone shall be sufficient. 
Otherwise, several ball positions shall be tested in a simplified test 
programme according to paragraph 3.1.6.3.3. 
3.1.6.3.3. In a simplified test programme, the value for f shall be between a defined 
value of fmin and a value of fmax which does not exceed 100 mm. The ball 
shall be at a distance, emax, of 130 mm from the support. To cover all 
possible positions of the ball, in the field given by the horizontal distance 
from the mounting surface and the vertical range of f (fmin to fmax), two 
devices are to be tested: 
 (i) one with a ball in the upper (fmax) position, and 
 (ii) one with a ball in the lower (fmin) position. 
The angle of application of the test force will vary, positive or negative, 
depending on the relationship of the ball centre horizontal reference line to 
the parallel line passing through the highest and nearest coupling device 
fixing point. The angles to be used are shown in Figure 22. 
3.1.7. In the case where detachable ball units are retained using fixing 
arrangements other than screwed fit tings, for example, spring clips, and 
where the positive mechanical engagement aspect of the arrangement is not tested during the dynamic test, then the arrangement shall be subject to a static test applied to the ball or to the positive mechanical engagement 
arrangement in an appropr iate direction. Where the positive mechanical 
engagement arrangement retains the ball unit vertically, the static test shall 
be to apply an upwards vertical for ce to the ball equivalent to the "D" 
value. Where the positive mechanical engagement arrangement retains the ball unit by means of a transv erse horizontal design, the static test shall be 
to apply a force in this direction equivalent to 0. 25 D. There shall not be 
any failure of the positive mechanical engagement device or any distortion 
likely to have an adverse effect on its function. 
3.1.8. The attachment points for the seco ndary coupling referred to in annex 5, 
paragraph 1.5 shall withstand a horizont al static force equivalent to 2D 
with a maximum of 15 kN. Where there is a separate attachment point for 
a breakaway cable this shall withstand a horizontal static force equivalent to D. 
3.2. Coupling heads 
L 373/116 EN Official Journal of the European Union 27.12.2006 
 3.2.1. The basic test is an endurance test  using an alternating test force followed 
by a static test (lifting test) on the same test sample. 
3.2.2. The dynamic test shall be perf ormed with a Class A coupling ball of 
appropriate strength. On the test ri g the coupling ball and coupling head 
shall be arranged as instructed by th e manufacturer and orientated in a 
way corresponding to the relative positio ns in normal use. There should be 
no possibility of extra forces in addition to the test force acting on the specimen. The test force shall be applied along a line passing through the 
centre of the ball and inclined downwar ds to the rear at 15° (see Figure 
23). An endurance test must be performed on a test specimen with the following test force: 
 F
hs res w = ±0.6 D 
Where the maximum permissible static  vertical mass, S, exceeds 120 D, 
then the angle of test shall be increased to 20°. 
 
Figure 23 - Dynamic test 
 
3.2.3. A static separation test shall also  be performed. The coupling ball used for 
the test shall have a diameter of 49. 00 to 49.13 mm in order to represent a 
worn coupling ball. The separation force, Fa, shall be applied 
perpendicular to both the transverse and longitudinal cen tre line axes of 
the coupling head and shall be increa sed smoothly and quickly to a value 
of: 
 F a  =  g(C+ S/1000)          kN 

27.12.2006 EN Official Journal of the European Union L 373/117 
  and be held for 10 seconds. 
The coupling head shall not separa te from the ball nor shall any 
component of the coupling head exhi bit any permanent distortion which 
could have an adverse effect  on its functional capability. 
3.3. Drawbar couplings and drawbeams 3.3.1. An endurance test shall be performed on a test sample. The coupling 
device shall be equipped with all the fixings needed to attach it to the vehicle. Any intermediate devices fitted between the drawbar couplings 
and the vehicle frame (i. e. drawbeams) shall be tested with the same 
forces as the coupling. When tes ting drawbeams inte nded for standard 
drawbar couplings, the vert ical load shall be a pplied at a longitudinal 
distance from the vertical plane of th e fixing points that is equal to the 
position of the correspondi ng standard coupling. 
3.3.2. Drawbar couplings for hinged drawbars (S=0) 
The dynamic test shall be performed w ith a horizontal alternating force of 
F
hw= ±0.6 D acting in a line parallel to the ground and in the longitudinal 
median plane of the towing vehicle passing through th e centre of the 
coupling pin. 
3.3.3. Drawbar couplings for use with centre-axle trailers (S>0). 3.3.3.1. Centre axle trailer masses up to and including 3.5 tonnes: 
Drawbar couplings for use with centre axle trailers up to and including a 
mass of 3.5 tonnes shall be tested in the same way as coupling balls and towing brackets described in 3.1 of this annex. 
3.3.3.2. Centre axle trailer masses exceeding 3.5 tonnes: 
The test forces are applied to the sp ecimen in both horizontal and vertical 
directions in an asynchronous enduran ce test. The horizontal line of action 
shall be equivalent to being parallel to the ground and along the 
longitudinal median plane of the towing vehicle and pass through the 
centre of the coupling pin. The ve rtical line of action shall be 
perpendicular to the horizontal line  of action and shall act along the 
longitudinal centre line of the coupling pin. 
The fixing arrangements for the draw bar coupling and the drawbar eye on 
the test rig shall be those intended fo r its attachment to the vehicle in 
accordance with the manufactur er's fitting instructions. 
 The following test forces shall be applied:  
L 373/118 EN Official Journal of the European Union 27.12.2006 
 TABLE 14 - Test forces 
Test force Mean Value (kN) Amplitude (kN) 
Horizontal force 0 ±0.6Dc (See Note) 
Vertical force S x g/1000 ±0.6V (See Note) 
 
Note: In the case of Class T dedicated dr awbar couplings these values shall be 
reduced to ±0.5Dc and ±0.5V. 
The vertical and the horizontal components sh all be sinusoidal in shape and shall be 
applied asynchronously, where the difference of their frequencies shall be between 1 per cent and 3 per cent. 
3.3.4. Static test on coupling pin locking device 
With drawbar couplings it is also n ecessary to test the closure and any 
locking devices by means of a static fo rce of 0.25 D acting in the direction 
of opening. The test shall not cause the closure to open and it shall not 
cause any damage. A test force of 0.1 D is sufficient in the case of cylindrical coupling pins. 
3.4. Drawbar eyes 3.4.1. Drawbar eyes shall be subjected to the same dynamic testing as drawbar 
couplings. Drawbar eyes used solely for trailers having hinged drawbars 
allowing free vertical movement shall be subjected to an alternating force as described in paragraph 3.3.2. Dr awbar eyes also intended for use on 
centre axle trailers shall be tested in the same way as ball coupling heads 
(paragraph 3.2) for trailer masses C up to and including 3.5 tonnes and in 
the same way as drawbar couplings (paragraph 3.3.3.2.) for centre axle 
trailers with a mass, C, exceeding 3.5 tonnes. 
3.4.2. Toroidal eyes of Class L shall be tested in the same manner as standard 
drawbar eyes. 
3.4.3. The testing of drawbar eyes sha ll be conducted in such a manner that the 
alternating force also acts on the part s used for attaching the drawbar eye 
to the drawbar. All flexible intermediate components shall be clamped. 
3.5. Hook type couplings 3.5.1. Class K hook type couplings sh all satisfy the dynami c test given in 
paragraph 3.5.2 of this annex. 
3.5.2. Dynamic test: 3.5.2.1. The dynamic test shall be a pulsati ng test using a Class L toroidal eye and 
with the coupling mounted as it would be on a vehicle and with all of the 
27.12.2006 EN Official Journal of the European Union L 373/119 
 necessary parts for vehicle installati on. However, any flexible components 
may be neutralized with the agreemen t of the type approval authority or 
technical service; 
3.5.2.2. For hook type couplings intended for use with hinged drawbar trailers, 
where the imposed vertical load on the coupling, S, is zero, the test force shall be applied in a hor izontal direction simulati ng a tensile force on the 
hook and varying between 0.05 D and 1.00 D; 
3.5.2.3. For hook type couplings intended for use with centre axle trailers the test 
force shall represent the resultant of the horizontal and vertical forces on 
the coupling and shall be applied along an angle, -
α , that is, from top 
front to bottom rear (see Figure 21), a nd equivalent to the calculated angle 
of the resultant between the horizontal and vertical forces on the coupling. 
The force, Fhs res shall be calculated as: 
 F hs res = s hF F2 2+  where  F h  = D c and F s = 100081.9S.+ 0.8 V 
3.5.2.4. The applied force shall vary between 0.05 Fhs res and 1.00 Fhs res. 
3.5.3. Static test on coupling locking device 
With hook type couplings it is also n ecessary to test the closure and any 
locking devices by means of a static fo rce of 0.25 D acting in the direction 
of opening. The test shall not cause the closure to open and it shall not 
cause any damage. 
3.6. Drawbars 3.6.1. Drawbars shall be tested in the same way as drawbar eyes (see paragraph 
3.4.). The type approval authority or technical service may waive an 
endurance test if the simple design of a component makes a theoretical 
check of its strength possible. The design forces for the theoretical 
verification of the drawbar of centre axle trailers with a mass, C, of up to 
and including 3.5 tonnes shall be ta ken from ISO 7641/1:1983. The design 
forces for the theoretical verification of drawbars for centre axle trailers 
having a mass, C, over 3.5 tonnes sh all be calculated as follows: 
 F
sp = (g x S/1000) + V 
where the force amplitude V is that  given in paragraph 2.11.4. of 
this Regulation. 
The permissible stresses based on the design masses for trailers having a 
total mass, C, over 3.5 tonnes shall be in accordance with paragraph 5.3. of ISO 7641/1:1983. For bent drawbars  (e. g. swan n eck) and for the 
drawbars of full trailers, th e horizontal force component F
hp = 1.0 x D 
shall be taken into consideration. 
L 373/120 EN Official Journal of the European Union 27.12.2006 
 3.6.2. For drawbars for full trailers with free movement in the vertical plane, in 
addition to the endurance te st or theoretical verifi cation of strength, the 
resistance to buckling shall be verified either by a theoretical calculation with a design force of 3.0 x D or by a buckling test with a force of 3.0 x D. The permissible stresses in the case of calculation shall be in accordance with paragraph 5.3. of ISO 7641/1:1983. 
3.6.3. In the case of steered axles, the resistance to bending shall be verified by 
theoretical calculations or by a bending test. A horizontal, lateral static 
force shall be applied in the centre  of the coupling point. The magnitude 
of this force shall be chosen so that a moment of 0.6 x A
v x g (kNm) is 
exerted about the front axle centre. Th e permissible stresses shall be in 
accordance with paragraph 5.3. of ISO 7641/1:1983. 
However, in the case where the steered axles form a twin, tandem, axle 
front carriage (steered  bogie) the moment sh all be increased to 
0.95 x Av x g (kNm) 
3.7. Fifth wheel couplings 
3.7.1. The basic strength test s are a dynamic test and a static test (lifting test). 
Fifth wheel couplings intended for th e positive steering of semitrailers 
shall be subject to an additional sta tic test (bending test). For the purpose 
of the tests the fifth wheel coupling sh all be equipped with all the fixings 
needed to attach it to the vehicl e. The method of mounting shall be 
identical to that employed on the vehicle itself. It is not permissible to use 
a calculation method as an alte rnative to physical testing. 
3.7.2. Static tests 3.7.2.1. Standard fifth wheel couplings designed for a steering wedge or similar 
device for the positive steering of sem itrailers (see paragraph 2.7 of this 
Regulation) shall be tested for ade quate strength by means of a static 
bending test within the working range  of the steering device with the 
simultaneous application of fifth wheel load. The maximum permitted 
imposed vertical load, U, for the fifth wheel shall be applied vertically to the coupling in its operating posi tion by means of a rigid plate of 
sufficient size to cover the coupling completely. 
The resultant of the applied load shall pass through the center of the 
horizontal joint of the fifth wheel coupling. 
Simultaneously, a horizontal lateral force, representing the force needed 
for positive steering of the semitrailer, shall be applied to the flanks of the 
guide for the coupling pin. The magnit ude of this force and the direction 
in which it acts shall be chosen so that a moment of 0.75m x D is exerted 
about the center of the coupling pin by means of a force acting on a lever 
arm 0.5 m ± 0.1 m long. Permanent, pl astic deformation up to 0.5 per cent 
of all nominal dimensions is permitt ed. There shall not be any cracking. 
27.12.2006 EN Official Journal of the European Union L 373/121 
 3.7.2.2. A static lifting test shall be pe rformed on all fifth wheel  couplings. Up to a 
lifting force of Fa = g.U there shall not be any major permanent bending 
of the coupling plate over more than 0.2 per cent of its width. 
In the case of Class G50 standard fi fth wheel couplings and comparable 
couplings for the same coupling pin diameter, there shall not be any 
separation of the coupling pin from th e coupling with a lifting force of Fa 
= g x 2.5 U. In the case of non-stan dard couplings using a pin diameter 
greater than 50 mm, for example 90 mm pin diameter couplings, the 
lifting force shall be: Fa = g x  1.6 U with a minimum value of 500 kN. 
The force shall be applied by means of a lever bearin g on the coupling 
plate at one end and being raised at the other end at a distance of 1.0 to 1.5 
m from the center of the coupling pin - see Figure 24. 
The lever arm shall be at 90° to the direction of entry of the coupling pin 
into the coupling. If the worst case is obvious, this worst case has to be 
tested. If the worst case is not easy  to determine, the type approval 
authority or technical service shall deci de which side to test. Only one test 
is necessary. 
 
Figure 24 - Lifting test on fifth wheel couplings 
 3.7.3. Dynamic test 
The fifth wheel coupling shall be subj ected to alternati ng stress on a test 
rig (asynchronous dynamic test) with hor izontal alternating and vertical 
pulsating forces acting simultaneously. 
Rear view
L 373/122 EN Official Journal of the European Union 27.12.2006 
 3.7.3.1. In the case of fifth wheel couplings not intended for the positive steering 
of semitrailers, the following forces shall be used: 
 Horizontal: Fhw = ±0.6 x D 
 Vertical: FsO = g x 1.2 U 
 FsU = g x 0.4 U 
These two forces shall be applied in the longitudinal median plane of the 
vehicle with the lines of  action of both forces FsO and FsU passing through 
the centre of the joint of the coupling. 
The vertical force Fs alternates between the limits +g x 1.2 U and 
+g x 0.4 U and the horizontal force between ±0.6 D. 
3.7.3.2. In the case of fifth wheel coupli ngs intended for the positive steering of 
semitrailers the following forces shall be used : 
 Horizontal: Fhw = ±0.675 D 
 Vertical: FsO and FsU as in paragraph 3.7.3.1. 
 The lines of action of the forces are as given in paragraph 3.7.3.1. 
3.7.3.3. For the dynamic test of fifth wheel couplings, a suitable lubricating 
material shall be placed between the coupling plate and the trailer plate so 
that the maximum coefficient of friction, F, is 0.15. 
3.8. Mounting plates for fifth wheel couplings 
The dynamic test for fifth wheel coupli ngs described in paragraph 3.7.3. 
and the static tests described in paragraph 3.7.2. shall also be applied to mounting plates. With mounting plates , it is sufficient to perform the 
lifting test on one side only. The te st shall be based on the maximum 
designated installation height for th e coupling, the maximum designated 
width and the minimum designated lengt h of the mounting plate design. It 
is not necessary to carry out this test  if the mounting plate in question is 
identical to one which has already under gone this test except that it is 
narrower and/or longer and the total height is lower. It is not permissible 
to use a calculation method as an alternative to ph ysical testing. 
3.9. Fifth wheel coupling pins of semitrailers 3.9.1. A dynamic test with alternating stress shall be performed on a sample 
mounted on a test rig.  The testing of the c oupling pin shall not be 
combined with the testing of the fifth wheel coupling. The test shall be conducted so that the force is also applied to the fixings needed for attaching the coupling pin to  the semitrailer. It is not permissible to use a 
calculation method as an altern ative to physical testing. 
27.12.2006 EN Official Journal of the European Union L 373/123 
 3.9.2. A dynamic test with an a lternating horizontal force of Fhw = ±0.6 D shall 
be applied to the coupling pin in the operating position. 
The line of action of the force shall pa ss through the centre of the smallest 
diameter of the cylindrical part of the coupling pin having a diameter of 
50.8 mm for Class H50 (s ee annex 5, Figure 18). 
L 373/124 EN Official Journal of the European Union 27.12.2006 
 Annex 7  
INSTALLATION AND SPECIAL REQUIREMENTS  
1. Installation and special requirements  
1.1. Attachment of coupli ng balls and towing brackets 
1.1.1. Coupling balls and towing brackets shall be attached to vehicles of 
categories M1, M2 (below 3.5t ma ximum permissible mass) and N1 1 in a 
manner which conforms to the clearan ce and height dimensions given in 
Figure 25. The height shall be measur ed at the vehicle loading conditions 
given in appendix 1 to this annex. 
The height requirement shall not apply in the case of category G off-road 
vehicles as defined in annex 7 of  the Consolidated Resolution on the 
Construction of Vehicles (R.E.3)(document TRANS/WP.29/78/Rev.1/Amend.2). 
1.1.1.1. The clearance space shown in Figures 25a and 25b may be occupied by 
non-demountable equipment, such as a spare wheel, prov ided that the 
distance from the centre of the ball to a vertical plane at the extreme 
rearmost point of the equipment does not exceed 300 mm. The equipment shall be mounted to allow adequate access for coupling and uncoupling without risk of injury to the user a nd without affecting articulation of the 
coupling. 
1.1.2. For coupling balls and towing br ackets the vehicle manufacturer shall 
supply mounting instructions and stat e whether any reinforcement of the 
fixing area is necessary. 
1.1.3. It shall be possi ble to couple and uncouple ba ll couplings when the 
longitudinal axis of the ball coupling in relation to the centre line of the 
coupling ball and mounting: 
is rotated horizontally 60° to right or left, (
β = 60°, see Figure 25); 
is rotated vertically 10° up or down ( α = 10°, see Figure 25); 
is rotated axially 10°  to right or left. 
 
 
                                                 
1 See definitions in Regulation N°. 13 annexed to the 1958 Agreement concerning the Adoption of 
Uniform Technical Prescriptions for wheeled vehicl es, Equipment and Parts which can be Fitted and/ 
or be Used on Vehicles and Conditions for Reciprocal Recognition of Approvals granted on the Basis 
of these Prescriptions. The definition is also contained in annex 7 of Consolidated Resolution on the 
Construction vehicles (R. E. 3) (document TRANS/ WP. 29/ 78/ Rev. 1/ Amend. 2).  
27.12.2006 EN Official Journal of the European Union L 373/125 
  
 
Figure 25 (a) - Clearance space for, and height of, coupling ball - side view 
 
L 373/126 EN Official Journal of the European Union 27.12.2006 
  
       
 
               
Figure 25 (b) - Clearance space for coupling ball - plan view 
 
27.12.2006 EN Official Journal of the European Union L 373/127 
 1.1.4. When the trailer is not coupled to the towing vehicle, th e mounted towing 
bracket and coupling ball shall not  obscure the mounting space provided 
for the rear registration plate or affect the visibili ty of the rear 
registration/licence plate of the towing vehicle. If the coupling ball or 
other items do obscure the rear regist ration plate they shall be removable 
or repositionable without the use of tools except, for example, an easily operated (i.e. an effort not exceedin g 20 Nm) release key which is carried 
in the vehicle. 
1.2. Attachment of coupling heads 
1.2.1. Class B coupling heads are permitted for trailers of maximum mass up to 
and including 3.5 tonnes. With the tr ailer horizontal and carrying the 
maximum permitted axle load, coupling heads shall be fitted so that the centre line of the spherical area into  which the ball fits is 430 ±35 mm 
above the horizontal plane on whic h the wheels of the trailer rest. 
In the case of caravans and goods tr ailers, the horizon tal position is 
regarded as when the floor or loading surface is horizontal. In the case of 
trailers without such a reference surf ace (e.g. boat trailers or similar) the 
trailer manufacturer shall give an appropriate refe rence line defining the 
horizontal position. The height requirement shall apply only to trailers intended to be attached to vehicles me ntioned in paragraph 1.1.1. of this 
annex. 
 In all cases the horizontal position shall be determined to within ±1°. 1.2.2. It shall be possible to operate the coupling heads safely within the free 
space of the coupling ball given in Figures 25a and 25b, up to angles of 
α 
= 25° and β = 60°. 
1.3. Attachment of drawbar couplings and mounting blocks 
1.3.1. Mounting dimensions for standard drawbar couplings: 
In the case of types of standa rd drawbar couplings the mounting 
dimensions on the vehicle given in Figure 15 and Table 10 must be met. 
1.3.2. Need for remote controlled couplings 
If one or more of the following re quirements regarding easy and safe 
operation (paragraph 1.3.3.), accessibility (paragraph 1.3.5.) or clearance for the hand lever (paragraph 1.3.6. ) cannot be met, a coupling with a 
remote control device as described in  annex 5, paragraph 12.3. shall be 
used. 
1.3.3. Easy and safe coupling operation 
Drawbar couplings shall be mounted on the vehicle in such a manner that 
they are easy and safe to operate. 
L 373/128 EN Official Journal of the European Union 27.12.2006 
 In addition to the functions of opening (a nd closing, if applicable) this also 
includes checking the position of the i ndicator for the closed and locked 
positions of the coupling pin (by sight and touch). 
In the area in which the person operating the coupling has to stand, there 
shall not be any points of possible danger such as sharp edges, corners, 
etc. inherent in the de sign unless these are protected so that injury is 
unlikely. 
The way of escape from this area shall not be restricted or barred on either 
side by any objects attached to eith er the coupling or the vehicles. 
Any underrun protection device shall not prevent the person adopting a 
suitable position to op erate the coupling. 
1.3.4. Minimum angle for coupling up and uncoupling 
Coupling and uncoupling of the drawbar eye shall be possible when the 
longitudinal axis of the drawbar eye in  relation to the centre line of the 
jaw is simultaneously rotated: 
50° horizontally to right or left; 6° vertically up or down. 6° axially to right or left. This requirement shall also appl y to Class K hook type couplings. 
1.3.5. Accessibility 
The distance between the center of the coupling pin and the edge of the 
bodywork of the vehicle shall not exceed 550 mm. Where the distance exceeds 420 mm, the coupling shall be fitted with an actuation mechanism 
which will allow safe operation at  a maximum distance of 420 mm from 
the outer board of the bodywork. 
The distance of 550 mm may be ex ceeded as follows, provided that 
technical necessity can be demonstrat ed and that easy and safe actuation 
of the drawbar coupling is not adversely affected: 
(i) to a distance of up to 650 mm for ve hicles with tipping bodies or rear-
mounted equipment; 
(ii) to a distance of up to 1320 mm if the unobstructed height  is at least  
1150 mm; 
(iii) in the case of car transporters with at least two loading levels when 
the trailer vehicle is not separated from the towing vehicle in normal transport operation. 
1.3.6. Clearance for the hand lever 
27.12.2006 EN Official Journal of the European Union L 373/129 
 In order to permit safe operation of  drawbar couplings there shall be 
adequate free space around the hand lever. 
The clearance illustrated in Figure 26 is  regarded as sufficient. If different 
types of standard drawbar couplings are intended to be fitted to the 
vehicle, the clearance shall be such that the conditions are also satisfied 
for the largest size of coupling of the appropriate class given in annex 5, 
paragraph 3. 
Figure 26 - Hand lever clearance 
 
The clearance dimensions are also applicab le as appropriate for drawbar couplings 
having hand levers pointing downwar ds or of a different design. 
The clearance shall also be maintained within the specified minimum angle for 
coupling up and uncoupling given in pa ragraph 1.3.4. of this annex. 
1.3.7. Clearance for free movement of drawbar coupling 
The drawbar coupling attached to the vehicle shall have a minimum clear 
gap of 10 mm from every other part of  the vehicle taking into account all 
possible geometrical positions give n in annex 5, paragraph 3. 
If different types of standa rd drawbar couplings  are intended to be fitted to 
the vehicle type, the clearance shall be  such that the conditions are also 
satisfied for the largest possible coupling of the appropriate class stated in annex 5, paragraph 3. 
1.3.8. Acceptability of drawbar couplings with a special joint for vertical 
rotation - see annex 5, paragraph 3.4. 

L 373/130 EN Official Journal of the European Union 27.12.2006 
 Couplings having a cylindrical pin and which achieve vertical rotation for 
the coupled drawbar eye by means of a special joint will only be permitted 
when technical necessity can be dem onstrated. This may be the case, for 
example, on rear tippers when the c oupling head shall be hinged, or with 
the couplings of heavy transporters wh en for strength reasons the use of a 
cylindrical coupling pin is necessary. 
1.4. Attachment of drawbar ey es and drawbars on trailers. 
1.4.1. Drawbars for centre axle trailers  shall have a suppor t device which is 
adjustable in height if vertical bearing mass at the drawbar eye on the 
trailer exceeds 50 kg, when the trai ler is uniformly loaded to its 
technically permissible maximum mass. 
1.4.2. When attaching drawbar eyes and drawbar to centre-axle trailers with a 
maximum mass, C, of more than 3.5 tonnes and more than one axle, the 
trailers shall be equipped with device for axle load sharing. 
1.4.3. Hinged drawbars shall be clear of  the ground. They shall not fall below a 
height of 200 mm from the ground when  released from the horizontal 
position. See also annex 5, paragraphs 5.3. and 5.4. 
1.5. Attachment of fifth wheel couplin gs, mounting plates and coupling pins 
on vehicles. 
1.5.1. Class G50 fifth wheel couplings shall not be mounted directly on the 
vehicle frame unless permitted by the vehicle manufacturer. They shall be fixed to the frame by means of a mounting plate and the installation 
instructions provided by the ve hicle manufacturer and coupling 
manufacturer shall be followed. 
1.5.2. Semitrailers shall be equipped wi th landing gear or any other equipment 
which allows uncoupling and parking of the semitraile r. If semitrailers are 
equipped so that the connection of the coupling devices, the electrical 
systems and braking systems can be effected automatically, the trailer shall have landing gear which retracts  from the ground automatically after 
the semitrailer has been coupled up. 
These requirements shall not apply in the case of semitrailers designed for 
special operations where they are nor mally only separated in a workshop 
or when loading and unloading in specifically designed operating areas. 
1.5.3. The fixing of the fifth wheel c oupling pin to the mounting plate on the 
semitrailer shall be as instructed  by the vehicle manufacturer or the 
manufacturer of the fi fth wheel coupling pin. 
1.5.4. If a semitrailer is equipped w ith a steering wedge it shall meet the 
requirements as described in annex 5, paragraph 7.8. 
27.12.2006 EN Official Journal of the European Union L 373/131 
 2. REMOTE INDICATI ON AND CONTROL  
2.1. When installing remote indicatio n and control devices any relevant 
requirements given in annex 5, paragr aph 12 shall be taken into account. 
L 373/132 EN Official Journal of the European Union 27.12.2006 
 Annex 7 - Appendix 1  
LOADING CONDITIONS FOR ME ASUREMENT OF  COUPLING 
BALL HEIGHT  
1. The height shall be as specified  in annex 7, paragraph 1.1.1.  
2. In the case of M1 category vehicles  1/ the vehicle mass at which this 
height shall be measured shall be declared by the vehi cle manufacturer 
and shall be given in the Communica tion form (annex 2). The mass shall 
be either the maximum permissible ma ss, distributed between the axles as 
declared by the vehicle manufacturer  or the mass given by loading the 
vehicle in accordance with paragraph 2.1. of this appendix. 
2.1. The maximum figure for the mass in running order as declared by the 
towing vehicle manufacturer (see pa ragraph 6. of the Communication 
form, annex 2); plus 
2.1.1. two masses, each of 68 kg, positioned in the outer seating position of each 
row of seats, with the seats in the rearmost adjustable position for normal 
driving and travel, and w ith the masses located: 
2.1.1.1. for original equipment coup ling devices and components submitted for 
approval by the vehicle manufacturer, approximately at a point located at 
100mm in front of the "R" point for ad justable seats and 50 mm in front of 
the "R" point for other seats, the "R " point being determined according to 
Regulation No. 14 paragraph 5.1.1.2.; or 
2.1.1.2. for coupling devices and components submitted for approval by an 
independent manufacturer and inte nded for replacement market fitting, 
approximately at the pos ition of a seated person;   
2.1.2. In addition, for each mass of 68 kg, an additional mass of 7 kg allowance 
for personal luggage shall be distribute d evenly in the l uggage area of the 
vehicle; 
3. In the case of N1 category vehicles 1/, the vehicle mass at which this 
height shall be measured shall be: 
3.1. The maximum permissible mass, distributed between the axles as declared 
by the towing vehicle manufacturer (see paragraph 6. of the Communication form, annex 2).