CEN/TC 256

Date: 2024-11-01

WI 00256A0K

Secretariat: DIN

Railway applications — Railway rolling stock — Digital Freight Automatic Coupler — Performance requirements specific interface geometry and test method

Bahnanwendungen — Schienenfahrzeuge — Digitale automatische Kupplung für Güterwagen — Leistungsanforderungen, spezifische Schnittstellengeometrie und Prüfverfahren

Applications ferroviaires — Matériel roulant ferroviaire — Coupleur automatique numérique pour le fret — Exigences de performance, géométrie spécifique de l'interface et méthode d'essai

Contents Page

European foreword 3

Introduction 4

1 Scope 5

2 Normative references 5

3 Terms and definitions 6

3.1 General terms 6

3.2 Functional Levels (FL) 8

4 Product requirements 8

4.1 General 8

4.2 Digital automatic coupler main characteristics 9

4.3 Interfaces of digital automatic coupler to freight wagons 11

4.3.1 Interface for existing wagons 11

4.3.2 Pneumatic interface to the vehicle 11

4.3.3 Electrical and data connection to vehicles 11

4.3.4 Uncoupling / prevent recoupling from side of wagon 11

5 Mechanical Coupler head requirements 12

5.1 General 12

5.2 Coupling conditions 12

5.2.1 General 12

5.2.2 Geometric requirements 12

5.2.3 Mechanical coupling / coupled position 12

5.2.4 Prevent coupling - Buff position 13

5.2.5 Ready to couple 13

5.2.6 Uncoupled position 13

5.2.7 Pneumatic coupling 13

5.3 Uncoupling conditions 14

5.3.1 General 14

5.3.2 Manual uncoupling fallback solution 15

5.3.3 Manual uncoupling 15

5.3.4 Automatic uncoupling 15

5.4 Coupling status indicator 15

6 Draft gear 16

6.1 General 16

6.2 Main characteristics of draft gear 16

6.3 Force stroke characteristics 20

6.4 Mechanical stroke indicator 21

7 Shank and pivot point 21

7.1 General 21

7.2 Pivot point 22

7.2.1 General 22

7.2.2 Using UIC hook with pivot pin of DAC draft gear 22

7.3 Shank for freight wagons 23

8 Support and centering 23

9 Electrical coupler 23

10 Hybrid coupler Digital Automatic Coupler – Screw coupler 24

10.1 General 24

10.2 DAC mode 24

10.3 Screw coupler system mode 25

11 Test methods 25

11.1 Routine testing 25

11.2 Type test 26

11.2.1 General 26

11.2.2 Mechanical head and gathering range 26

11.2.3 Manual uncoupling system 26

11.2.4 Test of uncoupling under different temperature conditions 26

11.2.5 DAC level 5 Actuator device 27

11.2.6 Prevent coupling test 27

11.3 BP valve and hose connection – Measurement of the pressure fall time 27

11.4 Electrical coupler testing 27

11.5 Strength test 27

11.5.1 General 27

11.5.2 Test principle 27

11.5.3 Test procedure for static yield-strength test 28

11.5.4 Tension load 29

11.5.5 Compression load 29

11.5.6 Test principle 29

11.5.7 Fatigue test 30

11.5.8 Nominal breaking force 31

11.5.9 Vertical strength test 31

11.6 Static test of draft gear elastic element characteristic 32

11.7 Endurance test 33

11.8 Test on track / Vehicle 33

11.8.1 General 33

11.8.2 Installation on wagon 33

11.8.3 Operations 33

11.8.4 Interoperability test 33

11.8.5 Dynamic test of spring characteristic 33

11.8.6 Propelling Test 33

11.8.7 Examination of running safety under longitudinal compressive forces by driving tests in curves 34

Annex A (informative) Electrical coupler 35

Annex B (informative) Example of manual uncoupling handle from the side of the wagon 39

Annex C (informative) Support and centering 40

Annex D (informative) Mechanical stroke indicator 41

Annex E (informative) Test bench test for longitudinal compressive forces 42

Annex F (normative) Endurance testing under service load for elastic system 47

F.1 Aim of the test 47

F.2 Test principle 47

F.3 Test results to be obtained 47

Annex G (informative) Gathering range 48

Annex H (informative) Electrical Coupler (as defined at the state of Enquiry) 49

H.1 For information 49

H.2 Electrical Coupler General 49

H.3 Additional requirements for explosion protection 51

H.3.1 insulating materials 51

H.3.2 Avoidance of hot surfaces and uncontrollable surface overheating 51

Annex ZA (informative) Relationship between this European Standard and the Essential Requirements of EU Directive (EU) 2016/797 aimed to be covered 52

Bibliography 55

European foreword

This document (prEN 18171:2025) has been prepared by Technical Committee CEN/TC 256 “Railway applications”, the secretariat of which is held by DIN.

This document is currently submitted to the CEN Enquiry.

This document has been prepared under a standardization request addressed to CEN by the European Commission. The Standing Committee of the EFTA States subsequently approves these requests for its Member States.

For the relationship with EU Legislation, see informative Annex ZA, which is an integral part of this document.

This standardization request is based on the Technical Specification relating to the subsystem ‘rolling stock — freight wagons’ of the rail system in the European Union Commission Regulation (EU) No 321/2013 of 13 March 2013 and repealing Decision 2006/861/EC and EU regulation 2019/776.

Introduction

This document is presented to the public with the intention of obtaining validated knowledge and data during the CEN enquiry. With the knowledge gained, among other things, Annex H will be moved to Section 9 and a second CEN enquiry is planned.

This document specifies the requirements for the digital automatic coupler (DAC) for freight compliant with the Technical Specification relating to the subsystem ‘rolling stock — freight wagons’ of the rail system in the European Union Commission Regulation (EU) No 321/2013 of 13 March 2013 and repealing Decision 2006/861/EC and EU regulation 2019/776.

This document specifies the minimum interface requirements to allow automatic coupling (mechanical and pneumatic) of two digital automatic couplers. This document further specifies the mechanical interfaces needed for the interoperability of electrical couplers, it does not cover the electrical contacts needed.

This document covers the requirements for DACs integrated into locomotives.

The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

EN 1005‑3:2002+A1:2008, Safety of machinery — Human physical performance — Part 3: Recommended force limits for machinery operation

EN 10204:2004, Metallic products - Types of inspection documents

EN 10228‑1:2016, Non-destructive testing of steel forgings - Part 1: Magnetic particle inspection

EN 10228‑2:2016, Non-destructive testing of steel forgings - Part 2: Penetrant testing

EN 12663‑2:2024, Railway applications — Structural requirements of railway vehicle bodies — Part 2: Freight wagons

prEN 14198:2023, Railway applications — Braking — Requirements for the brake system of trains hauled by locomotives

EN 14601:2024, Railway applications — Straight and angled end cocks for brake pipe and main reservoir pipe

EN 15227:2020+A1:2024, Railway applications — Crashworthiness requirements for rail vehicles

EN 15085‑1:2023, Railway applications - Welding of railway vehicles and components - Part 1: General

EN 15085‑2:2020+A1:2023, Railway applications — Welding of railway vehicles and components — Part 2: Requirements for welding manufacturer

EN 15085‑3:2022+A1:2023, Railway applications — Welding of railway vehicles and components — Part 3: Design requirements

EN 15085‑4:2023, Railway applications - Welding of railway vehicles and components - Part 4: Production requirements

EN 15085‑5:2023, Railway applications - Welding of railway vehicles and components - Part 5: Inspection, testing and documentation

EN 15551:2022, Railway applications - Railway rolling stock - Buffers

EN 15566:2022, Railway applications - Railway Rolling stock - Draw gear and screw coupling

EN 15839:2024, Railway applications - Testing and simulation for the acceptance of running characteristics of railway vehicles - Running safety under longitudinal compressive force

EN 16019:2014, Railway applications - Automatic coupler - Performance requirements, specific interface geometry and test method

EN 16839:2022, Railway applications - Rolling stock - Head stock layout

EN 17976:2024, Railway applications - Bolting of rail vehicles and components

EN 50125‑1:2014, Railway applications — Environmental conditions for equipment — Part 1: Rolling stock and on-board equipment

EN 50124‑1:2017, Railway applications — Insulation coordination — Part 1: Basic requirements - Clearances and creepage distances for all electrical and electronic equipment

EN 60529:1991,^[1] Degrees of protection provided by enclosures (IPCode) (IEC 60529:1989/A2:2013/ COR1:2019)

EN ISO 228‑1:2003, Pipe threads where pressure-tight joints are not made on the threads — Part 1: Dimensions, tolerances and designation (ISO 228‑1:2003)

For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https://www.iso.org/obp/

— IEC Electropedia: available at https://www.electropedia.org/

3.1.1

Digital Automatic Coupler

DAC

central buffer end coupling system for freight applications that couples automatically

Note 1 to entry: The degree of automation is defined in functional levels 1 to 5 see 3.2.

Note 2 to entry: The requirements described in this standard are valid for digital automatic couplers for use in freight trains. For digital automatic couplers for use in passenger trains there exist different or additional requirements.

Note 3 to entry: The mechanical housing for the electrical coupler will be covered in this standard.

3.1.2

electrical coupler

system that is used for connecting or disconnecting the electrical lines automatically which transfer control signals or power supply / current from one railway vehicle to another within a train

Note 1 to entry: If relevant the Electrical coupler will also house data connections and lines. The electrical components of the electrical coupler are defined in prEN 50746 and prEN 50747.

Note 2 to entry: For clarity, the mechanical interfaces but not the transmission conduits (pins) and their configuration of the electrical coupler are covered in this standard.

3.1.3

horizontal and vertical support

system that moves or aids - in the uncoupled condition - the complete coupler back into the central position after being deflected

3.1.4

split collar

fastening element consisting of two metal half-shells that are joined by fasteners

Note 1 to entry this is not a standardized interface covered by this standard.

3.1.5

draft gear

element of the coupler that can transfer compressive and tensile forces into freight wagon or locomotive

Note 1 to entry the draft gear can handle regenerative and non-regenerative energy

3.1.6

crash element

non-regenerative energy absorption devices that absorb energy in the event of a collision

Note 1 to entry These devices are used to protect the main structure of the wagon, load or other rail device it is attached to. These elements may be sacrificial.

3.1.7

coupler shank

connection between the coupler head and the draft gear

3.1.8

pivot pin

pin used to connect the coupler shank to the draft gear

3.1.9

manual uncoupling mechanism

device which provides manual rotation of the locking mechanism from the coupled position in to the ready to couple position

Note 1 to entry It can be a lever, handle, rope or other tool which is connected to the coupling mechanism and is pulled until the ready to couple position is attained.

3.1.10

uncoupling actuator

device which provides automatic rotation of the locking mechanism from the coupled position in to the ready to couple position

3.1.11

prevent coupling

state when the mechanical mechanism of the coupler is retained in an uncoupled state preventing coupling of the couplers even if two couplers are put in contact (buffed) with each other – which normally would result in coupling

Note 1 to entry this enables buffing in hump and yard operations.

3.1.12

Berne or Berner rectangle

area between the vehicles ends defined in EN 16839:2022, 3.1 and 4.2

3.2.1

functional level 1

FL1

automated coupling of the mechanical connection; manual uncoupling possible

3.2.2

functional level 2

FL2

FL 1 plus automatic coupling of air pipe(s)

3.2.3

functional level 3

FL3

FL 2 plus automatic coupling of electrical power line(s)

3.2.4

functional level 4

FL4

FL 3 plus automatic coupling of data line(s)

3.2.5

functional level 5

FL5

FL 4 plus full automated uncoupling

Note 1 to entry The full automated can be by means of remote access

This document specifies the product requirements of a digital freight automatic coupler intended to be equipped into freight wagons and locomotives.

For the components of the digital freight automatic coupler which transfer forces in the draw and buff line (for example coupler head, shank, pin and draft gear) the:

— inspection documents of materials used for the manufacture shall be according to 3.1 or 3.2 in EN 10204:2004,

— bolted connections shall be in accordance to EN 17976:2024,

— welded parts shall be in accordance with EN 15085‑1:2023, EN 15085‑2:2020+A1:2023, EN 15085‑3:2022+A1:2023, EN 15085‑4:2023 and EN 15085‑5:2023.

The couplers shall be prepared for upgradability from a lower functional level to a higher functional level.

NOTE For example, from FL2 to FL4 without major reworks.

For the main components of a Digital Freight Automatic Coupler see Figure 1.

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Figure 1 — Main components of a Digital Freight Automatic Coupler

The digital automatic coupler shall be able to withstand the following static loads without any plastic deformations (Rp_0,2):

NOTE 1 see also EN 12663‑1:2010+A2:2023 or EN 12663‑2:2024.

— tensile load = 1 000 kN

— compressive load = 2 000 kN

A nominal breaking point for tensile loads of 1 500 kN shall be located in the draw line, located in the tensile chain between the pivot pin and the front plate of the coupler head.

NOTE 2 The couplers are not designed to withstand continues use at high forces (2 000 kN).

NOTE 3 Recommended max operational force in day use 850 kN.

For new designs the proof of the fatigue loading shall be carried out.

NOTE 4 The dynamic test procedures can be supported by the methods described in EN 15566:2022, Annex A, for tensile loads and in EN 15551:2022 for compressive loads.

The DAC shall fulfil a fatigue loading of at least ± 300 kN, with view to a lifetime of 30 years.

The proof of the fatigue loading shall be carried out by a dynamic test.

The load collective shall cover a damage equivalent load of at least 300 kN.

For an unwelded steel structure following load collective F shall be applied:

— ΔF1 =  ± 300 kN

— F = 0 kN ± 300 kN and N1 = 1 500 000 cycles

NOTE 5 In case of welding connections in the load path, adjustments of the load collective are required with regard to appropriate S-N diagrams (see EN 17149‑3 or FKM Guideline) depending on the weld type, in order to cover a damage equivalent load of at least 300 kN.

NOTE 6 The declared service life of the coupler is defined by an assumed distribution of loads. Real service life may be affected depending on real distribution of loads. Please see UIC B 51 RP 21 (ERRI B 51 RP 21) for an assumed load spectrum.

For evolved designs the proof of the fatigue load can alternatively be carried out by simulation with a validated FE-model.

The whole air connection system of the digital freight automatic coupler shall be suitable for a nominal 5 bar pressure on the brake pipe (BP).

For an optional main reservoir pipe (MRP) the air connection system of the digital automatic coupler shall be suitable for a nominal 10 bar pressure. If no mating MRP exists the valve of the MRP shall remain closed.

The digital automatic coupler shall work reliably under normal European operational conditions, e.g. rain, pollution, washing water, snow, ice and particularly in hot summers as well as in cold winters. The coupler shall follow the requirements set out EN 50125‑1:2014. The temperature shall at least match the temperature range of the vehicle.

Coupler (excluding the regenerative energy absorption components) should be designed to commensurate with the service life of a vehicle.

The service life of the digital freight automatic coupler is defined as 30 years under the premises that all necessary maintenance and overhaul have been carried out. Based on 70 000 km per years, three coupling cycles per day, 250 operation days per year.

The service life of digital Automatic hybrid couples or digital automatic couplers for mainline locomotives is based on 150 000 km per year, five coupling cycles per day, and 360 days per year .

The service life of digital Automatic hybrid couples or digital automatic couplers for shunting locomotives is based on 50 000 km per year, 80 coupling cycles per day, and 320 days per year .

The height of the coupler shall not lead to restrictions on the ability to drive over end boards on wagons. The distance between the centre line of the coupler and the top of the coupler shall not exceed 200 mm from the centre line of the coupler.

NOTE 7 The height of the coupler is including additional components (such as e-coupler, valves levers, etc).

The permissible longitudinal compressive forces of the wagons, equipped with automatic couplers, when passing a 150 m s-curve with 6 m intermediate straights, shall be above 500 kN according to EN 15839:2024. This can also be proven via calculation or similarity.

NOTE 8 Annex E test bench set up can be used to aid in calculations of endurable longitudinal compressive forces.

The coupler shall be designed so that greasing outside the planned minor and major overhauls shall be possible without removing any parts of the coupler.

DAC is intended for the installation on a freight wagon that meets the relevant requirements for centre buff freight wagons set out in 4.3.2.

NOTE For information on the height of the couple see EN 16839:2022, 6.2, Interface for existing wagons.

The installation space is decisive for the design of the coupling with cross beam support (see UIC 530-1:1982-04, Appendix 4a). For wagons with spring strut support (see UIC 530-1: 1982-04, Appendix 6a and 6b) are recommended. Contact point b is not required and can be neglected. It shall not be required to remove the contact point b to install a digital automatic coupler draft gear into the installation space.

Adaptations may be done for existing and new wagons that are not compatible and not conform to a standard such as UIC 530-1:1982-04. The characteristics defined for the draft gears and pivot point defined in this standard shall be maintained.

For information on force transmission into the underframe, see UIC 530-1:1982-04, Appendix 1 to the tension and compression stops according to Section 5 or Appendix 4 and 6 (UIC 530-1:1982-04).

For wagons with modified installation space a maximum height of 120 mm above the centre line of the coupler draft gear should be considered.

The vehicle shall be fitted with a pneumatic hose for the brake pipe (BP) which can be attached via a screw connection G 1 1/4 inches to the coupler according to EN ISO 228‑1:2003.

Optionally the vehicle can be fitted with a pneumatic hose for the main reservoir pipe (MRP) which can be attached via a screw connection G 1 inch to the coupler according to EN ISO 228‑1:2003.

The electrical and data connections to vehicles are defined in EN 16839:2022, Clause 9.

NOTE Future plug and connection box please refer to prEN 50746 and prEN 50747.

A manually operated device can be used to enable uncoupling and prevent recoupling position from both sides of the wagon. Annex B shows an example of such a lever mechanism.

Figure 2 shows the mechanical parts of a coupler head

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Figure 2 — Mechanical coupler head

For conflicting requirements, between this standard and EN 16019:2014 the DAC couplers shall comply to the values defined in this standard.

The coupler head shall have four positions: Coupled position, ready to couple position, prevent coupling position and uncoupled position.

The geometric requirements for the DAC coupler head are found in EN 16019:2014. Clause 5 of this standard specifies additional functional requirements.

On straight tracks the couplers shall couple automatically without manual intervention.

The digital automatic coupler shall be designed to ensure that coupling is possible when the height mismatch between the centre lines of the couplers to 125 mm on straight tracks. The horizontal gathering range of the coupler head shall be 220 mm minimum at each side. Use of guiding horn is not compulsory if this requirement is fulfilled.

To prevent an overriding of impacting wagons, the couplers shall be designed to withstand a vertical load of at least 150 kN in the centre of two mating couplers and shall safely connect at impact speeds up to 36 km/h in relation to conditions defined in EN 15227:2020+A1:2024. The vertical load can be proven with a semi static test (see 11.5) or calculations.

NOTE 1 This is related to the dangerous goods wagons safety requirements.

On straight tracks and in curves down to R150 m (in transition zones manual intervention might be necessary) the couplers shall be designed to be able to couple automatically without manual intervention.

Couplers shall be designed for the following operational procedures:

a) During normal coupling operations on straight tracks the minimum coupling speed shall be 0,6 km/h up to coupling speed of 5 km/h.

b) maximum coupling speed of 12 km /h shall not be exceeded.

c) In all other infrastructural conditions like curves, s-curves the couplers are designed for a maximum coupling speed of 5 km/h.

Coupling above 12 km/h is considered as an incident and above 18 km/h as a collision; in both cases appropriate steps shall be taken according to the user manual.

NOTE 2 Please consult the user’s manual.

It shall be possible to set the locking mechanism in a position in which the coupler heads remain uncoupled in the uncoupled position when mated with another coupler. This is, to prevent undesired coupling e.g. at the hump or during push off operations.

In manual operations, if two mated couplers are uncoupled to enable that both couplers are in prevent coupling, manual activation of prevent coupling the mated (opposite) coupler can be put into prevent coupling in a separate action.

For functional level 5 this shall be automated

It shall be possible by an external device to release the prevent coupling position.

NOTE For functional level 5 this can be an actuator.

It shall be possible, by means of a manual operation, to set the locking mechanism in a position in which the coupler head is ready to couple.

Is a position, after uncoupling operation, where the front face of the couplers is still in contact but not connected.

The pneumatic connection and disconnection of the brake pipe (BP) of the automatic coupler shall be done automatically synchronized with the mechanical coupling connection.

The coupler head shall be prepared for upgrading with a main air reservoir (MRP) (10 bar airpipe).

If the digital automatic coupler is unintentionally disconnected due to a failure, the brake pipe (BP) line shall remain open.

The diameter of the main brake pipe (BP) and the valves inside the automatic coupler shall be minimum 32 mm (≈1 1/4 inches).

The diameter of the main reservoir pipe (MRP) shall be 25 mm (≈1 inch).

The DACs’ brake pipe (BP) curves and volume shall not degrade the propagation speed of the emergency brake command signal according to prEN 14198:2023, Clause 5.

The venting capacity of the string of brake pipe components between two neighbouring vehicles shall be equal or better to the venting capacity of the following string of components: End cock (EN 14601:2024) – air hose – pneumatic half coupling (EN 15807:2021) – pneumatic half coupling (EN 15807:2021) – air hose – end cock (EN 14601:2024).

Figure 2 shows a brake pipe interface in the mechanical front plate.

Dimensions in millimetre

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Figure 3 — Brake pipe interface

Uncoupling can be performed manually or automatically by releasing the coupler lock of a mated automatic coupler. This means that under optimal conditions both couplers (mates) will be in the uncoupled position after the uncoupling has been performed.

NOTE 1 Optimal uncoupling results are achieved when there are no tensile forces on the coupler. The larger the tensile forces that are applied the higher the force will be needed for uncoupling (safety feature of design).

NOTE 2 Uncoupling under tension can lead to lower performance of the uncoupling device.

If the uncoupling device is a pneumatical device, it’s not allowed to take the pressure (air) from the brake pipe (BP).

Manual uncoupling fallback solution shall always be possible from at least one wagon side. For one time use a max value of 400 N is allowed.

For emergency uncoupling it is permitted to enter the safety zone between the wagons.

NOTE 1 The coupler is then in the state ready to couple.

NOTE 2 For level 5, surrounding equipment such as actuator and electrical coupler is allowed to be disconnected manually prior to manually decoupling.

For functional level 1 to functional level 4 a solution should be provided where the uncoupling can be done from the side of the wagon with forces according to EN 1005‑3:2002+A1:2008, when the couplers are free of tension load. If a lever mechanism is used the length of the lever is allowed to be adapted to ensure compliance with EN 1005‑3.

The uncoupling shall be possible without any part of the operator’s body to enter between the wagons.

NOTE 1 150 N is presumed to be compliant with EN 1005‑3.

NOTE 2 As in stated in 5.1.4 “It shall be possible by an external device to release the prevent coupling position”.

NOTE 3 Annex B shows a possible manual uncoupling device for uncoupling from the side of the wagon.

Interaction with the gauges should be considered with EN 15273.

For functional level 5 the automatic coupler shall be equipped with an automatically operated uncoupling device.

If the uncoupling device is not in action, it shall be in a neutral position (ready to couple position).

The coupling state for the DAC (coupled/uncoupled) shall be visible from the side of the wagon, even in different weather conditions (darkness, snow, ice, etc.). A lamp commonly used by operations may be used to detect the coupling state in the dark. See Figure 4.

The indicator, which show the coupling state shall be mechanically linked to the rotary movement of the hooked plate, or main pin. The dimension of the movable indicator is shown in the following picture. The indicator shall be orange and visible only in coupled position.

The colour of the coupled position indicator shall be Orange RAL 2005.

Dimensions in millimetre

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Figure 4 — Example of a status indicator

The indicator shall be mounted on the coupler head. The indicator shall be clearly visible without stepping between the wagons entering the Berne rectangle, under normal weather conditions as specified in EN 50125‑1:2014, T1.

The coupler draft gear contains an energy absorption element and represents the mechanical connection between the DAC and the freight wagon.

The standard coupler draft gears with a buff stroke of 110 mm are generally used for general freight wagons and category L rear parts are designed for impact-sensitive freight wagons and have therefore an increased buff stroke of 150 mm. The draw part of the energy absorption element is similar for all coupler draft gears. The stroke is limited to 70 mm to protect the wagon flaps during the service.

Figure 5 shows as an example a draft gear interface on the basis of UIC 530-1, Appendix 4b.

Dimensions in millimetre

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NOTE The drawing is based on a drawing of which the copyright is held by the International Union of Railways (UIC), Paris, France. All rights reserved. Source: UIC Ref.Nr 530-1. ed. 2 1.4.1982, Appendix 4b, Copyright © 2024 UIC, Paris, France.

Figure 5 — Example of draft gear interface

Installation spaces are shown in Figure 6.

Dimensions in Millimetre

a) bottom view

b) side view

Figure 6 — Installation spaces

Table 1 — Draft gear main characteristics

To keep the longitudinal force level occurring during braking as low as possible, the preload force should be between 20 kN to 100 kN. For buff characteristics Table 2 shall be used.

NOTE For more information see EN 15551.

For tensile characteristics EN 15566:2022, 7.1, shall be used.

Table 2 — Overview Draft Gear Categories force stroke parameters reversable compression
(see EN 15551:2022 for reference)

For a mechanical stroke indicator, see informatively Annex D.

Figure 7 shows a coupler intended for freight wagons.

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Figure 7 — Schematic drawing of coupler intended for freight wagon installation

The pivot is defined as the horizontal rotational point between coupling arm and draft gear. The pivot point shall be situated 380 mm behind the head stock (buffer fastening plane), This value is valid for a DAC equipped with draft gears category A, AX and C.

The diameter of the pivot pin for the DAC between the draft gear and coupler shank shall have a diameter of 79 mm (h11), see EN 15566:2022 for reference.

The pivot pin shall be removable from the bottom of the wagon without loosening the lower draft gear retaining plate under the draft gear.

NOTE This requirement can be adapted for special wagon types.

The DAC draft gears shall via the pivot pin be compatible with a EN 15566:2022 hook interface. Adapters on the pin are acceptable to ensure correct height, see Figure 8.

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Figure 8 — Spacer / adapters together with a EN 15566:2022 hook in a DAC draft gear

The coupling arm's articulated length (from the pivot up to the coupler level) shall be 1 000 mm for a DAC equipped with standard draft gear category A or C. For a DAC equipped with a long stroke draft gear category L the coupling arm's articulated length shall be 1 045 mm.

The length of the coupler from the head stock (buffer fastening plane) to the coupler plane shall be 620 mm for a DAC equipped with standard draft gear category A and C. For a DAC equipped with a long stroke draft gear category L the length of the coupler from the head stock to the coupler plane shall be 665 mm.

The coupler shall be equipped with a horizontal and vertical support. The support shall enable adjustment of the coupler front face to be perpendicular to the plane of top of rail. Tolerance ± 0,5°.

In event of failure of the vertical support the coupler head shall not fall and reach the track.

The support and centering shall ensure that the coupler returns to a centred position, thus when uncoupled and wagon is moved the DAC should horizontal self-centre to a neutral position (0° to ± 2°) on tracks without slope.

The centering does not have to be immediate and may be gravitational.

NOTE An acceptable readjustment to centre is within approximately 50 meters after moving the vehicle from standstill.

Manual deflection of the DAC to a maximum angle of 6° may be possible by overruling the self-centering functionality. The manual force to be applied for manual deflection shall not exceed 400 N.

Examples and common hole pattern are shown in Annex C.

Please see informative Annex H, and Annex A for the current status of information of this Clause 9. This possibility of publication was chosen for the first enquiry.

The hybrid couples are a special design, incorporating the functional features and interoperability requirements of the DAC but also accommodates the possibility to use a conventional UIC draw hook together with a side buffer system.

The hybrid coupler has two defined positions DAC and screw coupler mode.

If required, the draw gears and draw gear/pivot interfaces may be adapted to enable the different operational modes.

The hybrid DAC used in locomotives shall meet the crash worthiness requirements set out in EN 15227:2020+A1:2024 for centre buffer freight couplers.

The installation for locomotive can be done using a flange system.

The hybrid, coupler can be equipped with sensors indicating the position “DAC” or “Screw coupler/UIC mode” mode.

The DAC parts which will be subjected to 30 years life expectancy shall be tested according to 4.2 load spectrum.

NOTE 1 For exceptional special installation cases, if life expectancy of the locomotive is expected to be considerably lower than 30 years, exceptions to the load spectrum can be made.

NOTE 2 See 4.2 for service life.

The Berner Rectangle according EN 16839:2022 may be infringed for vehicles equipped with side buffers and DAC.

NOTE 3 For the coupled state all possible interference cases need to be investigated, in order to ensure a free horizontal and vertical deflection on both vehicle ends, also in relation to applicable longitudinal strokes of the draw gear. For a hybrid DAC, both coupler modes (DAC and Screw coupler) need to be analysed.

NOTE 4 The distribution between UIC and Hybrid mode is 1:2.

The coupler shall be compatible with and fulfil the relevant requirements of a DAC system in Clause 4 to Clause 9 of this document.

If external components are needed to switch from Screw coupler to DAC mode or from DAC to screw coupler mode the total mass of any hand handled component may not be more than 25 kg.

The maximum force needed to change modes manually shall not be more than 250 N, e.g. crank handle.

The coupler shall be designed for:

a) Smooth coupling between 0,6 km/h to 3 km/h ;

b) coupling speeds up to 5 km/h to be handled on frequent bases;

c) for 7 km/h the energy absorption system of the hybrid coupler shall be designed in the way that the deceleration (inside the driver’s cab) does not exceed a mean deceleration of 2 g for coupling up to 7 km/h or a maximum force of 2 000 kN.

NOTE As an accident scenario a speed of 7 km/h is defined for main line locomotives running against a braked wagon with a total weight of 80 tons which is equipped with a digital automatic coupling with a standard draft gear (category A). See EN 15227:2020+A1:2024, C.2, for definition of obstacle.

EN 15227 should be used to determine the mean deceleration.

When the UIC coupling function is not in service, the UIC coupling shall be secured against unintentional movement.

The fatigue load in 4.2 shall be adapted to 20 years life expectancy based on 67 % of usage in DAC mode.

The hybrid coupler shall be compatible with the screw coupling system (screw coupler, hook and side buffers) according to EN 15566:2022 and EN 15551:2022.

The DAC mode shall clearly be put out of use and the automatic coupling head shall not affect the function of the UIC coupling system.

When the automatic coupling function is not in service, the automatic coupling shall be secured against unintentional movement.

The connective element (mixed train coupler) as part of the hybrid coupler shall fulfil the strength requirements of 1,5 MN coupling system according to EN 15566:2022.

Fatigue loads shall be tested according to EN 15566:2022, Table A.3 for equivalent of 10 years to reflect a 33 % usage of this position for a 1,5 MN screw coupler.

The used buffers shall fulfil the requirements according to EN 15551:2022.

If the automatic coupling function is not in use, the spaces to be respected according to the clearance gauge of EN 16839:2022 shall not be restricted.

The Berner Rectangle according EN 16839:2022 may be infringed for vehicles equipped with side buffers and DAC.

If using the UIC coupling point the pneumatic connection between the vehicles shall be done manually.

The pneumatic connection between the vehicles with different coupling systems shall be made via a UIC/TSI compliant interface according EN 16839:2022.

If the screw coupling system is in use, and an the electrical and data connection is required between the vehicles this shall be connected manually.

Interaction of draw hook and side buffer in a 150 m curve shall follow the requirements in EN 16839:2022, 5.4.1.

The supplier of the coupler shall perform routine tests during manufacturing and after final assembly.

The following tests are recommended to be part of the routine test program for all digital automatic couplers that are manufactured in serial production:

— visual checks based on assembly drawings;

— testing of the automatic coupling system. The DAC interfaces mechanical, pneumatic, and electrical interfaces shall be tested against another DAC coupler. The test can be carried out against a dummy representing the Digital Automatic Coupler;

— testing of the automatic uncoupling system. Uncoupling performance of the Digital Automatic Coupler coupled to an automatic coupler according to this standard by releasing the coupler lock of the adjacent automatic coupler. This may be tested by using a dummy coupler;

— leakage test of air coupling system by pressurizing and checking for leakage at all connections.

NOTE Checks as specified in CENELEC can be carried out at the same time.

The dummy coupler does not have to include a draft gear.

Type tests are for approval only.

The type test shall be formed according to EN 16019:2014, 5.1.

Measuring of the manual operating force

The test shall be performed with the automatic couplers mounted on a test bench, see Figure 9.

— To determine the uncoupling forces, it shall be ensured that the manual actuated coupler locking mechanism transmits the needed unlocking movement/rotation to the inactive/passively operated coupler side. The mating coupler heads do not slide apart before both locking devices have reached the uncoupled position.

— The couplers are placed under a compressive force of 2 kN.

— The mechanical coupler heads are equipped with the BP valve or BP-line connectors and with an electric coupler system.

— The BP-line is pressurized to 5 bar.

— The measurement is carried out by applying uniformly manual uncoupling force and in a defined operating movement. Force peaks from a jerky movement and dynamic effects due to the stop limitation should be avoided.

— Uncoupling shall be carried out on one side of the mated coupler heads).

— To isolate the influence of the e-coupler on the uncoupling force, two tests shall be performed: one with; one without e-coupler.

Figure 9 —Example of setup

Appropriate coupler function shall be tested under extreme climate conditions in a climate chamber.

— Coupling and uncoupling test at −25 °C

— Coupling and uncoupling test at 40 °C

— Coupling and uncoupling test at −25 °C with 3 mm ice layer (to the top and front)

Coupling and uncoupling activate and de-activate prevent coupling position of all functions shall be achieved without manual intervention (except release of decoupling).

NOTE  For other environmental testing please refer to EN 50125‑1.

Functional test:

— actuator device opens the locking mechanism of both couplers simultaneously;

— check that the uncoupling is performed correctly.

Verify the prevent coupling function. This test shall be done without pressure in the brake pipe system on a test bench setup.

— Starting with two coupled couplers, uncouple and activate the prevent coupling position on both couplers;

— Show that the prevent coupling state can be activated and operated as intended.

To be tested for two coupled couplers .

Leakage test in reference to EN 14601:2024, 5.3.4.

For electrical test, see prEN 50746 and prEN 50747.

Measurements are the following:

— force;

— stroke;

— time;

— functionality of the coupler.

All the parameters shall be recorded. The temperature on the test area should be noted.

It shall be demonstrated by means of static tests that the automatic coupler withstands the loads stated in 4.2.

The test consists of the determination of the minimum static load of the coupler, or components of the coupler. It shall be demonstrated by means of static tests that the coupler head of the automatic coupler withstands the loads stated in EN 12663‑2:2024, 5.2.2. The tests shall in each case be performed on unstressed couplers which have not been tested before.

Two couplers (complete) shall be coupled in order to conduct the tensile/compression test. Resistance strain gauges shall be applied at appropriate positions, where calculation have shown the highest/critical strain positions, on coupler head, shank, draw gear and other critical components exposed to tensile and compressive forces. In the Figure 10 shows an example for the shank. For the coupler head the procedure outlined in EN 16019:2014, 5.1.2, shall be used for the placement of the strain gauges.

Key

Figure 10 — Example of strain gauge placement on shank

The loads shall be applied gradually up to the maximum value and held for 1 min.

The maximum tensile and compressive loads shall not cause permanent deformation of the coupler head.

It is recommended that:

— the couplers used for the type test are preloaded so as to stabilize the overall structure;

— the maximum force is applied incrementally at least twice;

— the measurement equipment shall be reset to 0 before the final test.

The results of the final test shall be taken into account in the validation. The strains measured under the maximum applied loads, shall be

where

Evaluation of local stress concentrations may be done according to EN 12663‑1:2010+A2:2023, 5.4.2.

After applying and removing the maximum tensile load, the coupler locks of the coupler heads and the draft gear shall move freely. This can for example be demonstrated by manually uncoupling the coupler heads.

Test procedure tension load

— Two couplers are coupled and aligned horizontally and vertically before being preloaded to approx. 30 kN to stabilize the overall structure.

— The measurement equipment shall be reset to 0.

— Increase the forces in 200 kN/or a minimum of three steps up to 1 000 kN and hold the force for 1 min. Repeat the procedure two times for a total of three cycles.

— The maximum tensile load shall not cause permanent deformation (≤Rp_0,2) of the coupler. For coupler head see EN 16019:2014.

— After applying and removing the maximum tensile load, the coupler locks of the coupler heads shall move freely.

— Two couplers are coupled and aligned horizontally and vertically before being preloaded to approx. 30 kN to stabilize the overall structure.

— The measurement equipment shall be reset to 0.

— Increase the forces in 200 kN/or a minimum of three steps up to 2 000 kN and hold the force for 1 min. Repeat the procedure two times for a total of three cycles.

— The maximum compression load shall not cause permanent deformation (≤R_p0,2) of the coupler. For coupler head see EN 16019:2014.

— The test consists of the determination of the minimum breaking at tensile load of the coupler, or components of the coupler.

— Pull the coupled couplers until breaking.

Static test procedure:

— Test temperature shall be between 15 °C and 25 °C;

— BP shall be pressurized to 5 bar at start of the test;

— Breaking load of coupler/coupler parts is stated in 4.2;

— The BP line shall remain open after breaking,

Measurements:

Measurements are the following:

— force;

— brake pipe pressure, on both sides;

— time.

All the parameters shall be recorded. The temperature on the test area should be noted.

The relevant components are connected either to a mating part or a dummy and subjected to load cycles according to 4.2 in an appropriate test setup. Relevant parameters shall be recorded during the whole test.

The procedure for the fatigue strength test of the DAC is based on the procedure for testing the screw coupler according to EN 15566:2022, Annex A. The following test steps, which are carried out one after the other, shall be observed during the dynamic testing of the DAC:

— The fatigue test shall be carried out on three samples of the DAC;

— Conditioning of the DAC with a tensile force of 1 125 kN (equivalent to approximately 75 % of the minimum breaking load);

— Non-destructive testing: Before the endurance test, the DAC shall pass a magnetic particle test or dye penetrant test according to EN 10228‑1:2016 and EN 10228‑2:2016. Any sign of a surface defect that appears shall be recorded in size and shape;

— Dynamic testing:

— ΔF1 =  ± 300 kN

— F = 0 kN + ΔF1 and N1 = 1,5 × 10⁶ cycles (in accordance to 4.2)

— The load frequency should not exceed 4 Hz.

— Non-destructive testing after the fatigue test.

— Analysis of the residual strength by carrying out a static test. 95 % of the minimum breaking load shall be withstood for three minutes.

— Macroscopic and microscopic tests according to the specifications in EN 15566:2022, Annex E.

Each individual test shall be performed in a single laboratory.

EXAMPLE Dynamic tests from start to finish shall be carried out in one laboratory.

Wear parts are to be exchanged during the test.

The coupler shall not lead to apply major damages on wagons due to excessive tension loads. A test shall determine the minimum breaking force at tensile loads to the coupler, or components of the coupler.

The test system elasticity shall be similar or equal to the elasticity of a complete coupler.

Static test procedure:

— apply tension load to two coupled coupler heads up to the breaking point.

— min. breaking load of coupler/coupler parts 1 500 kN .

— Test temperature shall be between 15 °C and 25 °C.

Static test

The coupler shall withstand a vertical load of min 150 kN without fracturing to prevent climbing of two impacting wagon. The test conditions shall be applied according to the Figure 11.

Key

NOTE The test is a simplification of a complex reality. It is assumed that the coupling plane is the weak part of the coupled coupler. The test focuses on the bending moment in the coupling plane. The simplification also considers the geometry of the headstock, the elastic stroke of 110 mm and the irreversible stroke of dangerous goods wagons. All these dimensions reduce the lever of a force of 150 kN acting on one end of the vehicle. The simple test induces approximately the same bending moment in the coupling plane.

Figure 11 — Test conditions of vertical strength test

Dynamic test

The test shall be complemented with a dynamic (physical) test at 36 km/h.

A wagon with draft gear category A (running wagon) is run into a stationary wagon of 80 t equipped with a draft gear category AX (referred to as dangerous goods wagon) at 36 km/h The weight of the accident wagon shall be adjusted such that at least 75 % of the total energy absorption is used in the test.

The running wagon shall be 40 mm higher than the dangerous goods wagon, to ensure that a vertical offset of 40 mm is achieved.

The couplers shall catch and stay together until both vehicles have the same speed.

The couplers are allowed to lift during the test.

The couplers may be deformed or damaged.

NOTE 1 The coupler does not replace the anti-climber.

NOTE 2 Refer EN 15227 for inspiration.

NOTE 3 Separation means that the coupler will not damage a dangerous goods wagon and could separate after the test.

NOTE 4 The couplers do not have to be coupled after the test.

Test principle:

— The test consists of the determination of the force-stroke diagram during the compression and tension of the complete draft gear.

Test procedure:

— The test shall be carried out at least 72 h after assembly, if rubber or another elastomer elastic are to be tested.

— Test temperature of the draft gear shall be between 15 °C and 25 °C.

— The compression and tension phase shall be followed immediately by the decompression phase. The maximum displacement speed of the press in both directions shall be less than or equal to 0,005 m/s. When fully released, the draft gear shall be found to be in the same condition as initially.

— Three cycles up to the maximum stroke according to Table 2 are made. The test shall be arranged in such a way that the draft gear system will not be exposed to unacceptable thermal loads. A break after two complete cycles is allowed if the break is less than 10 min.

— A force-stroke diagram is recorded during the three cycles, all curves shall be included in the tolerance defined in Table 2.

— Draft gear system with hydrodynamic or hydrostatic elements shall carry out an additional test that shows the draft gear reaction remains virtually constant within [±5 %] of the nominal value for 10 min with compression and tension values of 30 mm, 60 mm and 100 mm.

Measurements:

Measurements are the following:

— stroke;

— force;

— time.

All the parameters shall be recorded. The temperature should be noted. Additionally, the parameters stroke of the spring system and force are recorded on a force-stroke diagram. Stored energy W_es and absorbed energy W_as are calculated with the diagram.

Activation speed 2 mm/s.

Values are to be compared to Table 2.

Endurance testing under service load and impact type load for elastic system with reference to Annex F.

NOTE Draft, based on EN 15551:2022, Annex F and Annex G.

Field tests should be performed under real condition, coupler system shall be mounted in a test wagon / train and the following parts tested (11.8.2 to 11.8.7).

Check installation compatibility with draft gear space as defined 4.3.1.

Check that hook can be used as per 7.2.2.

Coupling at minimum coupling speed 0,6 km/h.

Coupling in curves to show manual deflection.

Test coupler to at least one competitor coupler which has to be tested for interoperability.

General

Requirements for elastic systems and testing of dynamic characteristics of the draft gear shall be done according to EN 15551:2022, Annex E; category B draft gear shall not be tested.

Dynamic test procedure for wagon DAC couplers

For category A couplers when pushing 90 t against 80 t with coupling either up to maximum force of 2 000 kN or a max. speed of 12 km/h no damage on the automatic coupler shall occur. Tests to be performed according to EN 15551:2022, Annex E.

Dynamic test procedure for locomotive DAC couplers

The DAC used in locomotives shall meet the crashworthiness requirements derived from the collision scenarios of EN 15227:2020+A1:2024 for locomotives equipped with centre buffer freight couplers.

Requirements concerning the derailment safety of wagons with automatic couplings.

Testing of running safety under longitudinal compressive forces.

The Proof of the endurable longitudinal compressive force that can be borne is provided by driving tests in curves. The test conditions for the performance and evaluation of driving tests on freight wagons with side buffers according to EN 15839:2024 is apply to freight wagons with automatic coupling.

NOTE For similarity design qualification lab tests or simulations can replace full scale derailment tests.

The test conditions are described in EN 15839:2024, Clause 7. The freight wagons used have automatic couplers instead of side buffers and screw couplers.

1. 
   (informative)
   
   Electrical coupler

Figure A.1 shows the interface of the centering elements of the electrical coupler.

Dimensions in millimetre

Figure A.1 — Electrical coupler housing view from below centering elements

Figure A.2 shows the geometry of the seal.

Dimensions in millimetre

Figure A.2 —The sealing lips of the electrical coupler

The hardness of the sealing lip shall result in sufficient contact pressure and flexibility to ensure the sealing effect.

Figure A.3 shows an example of the layout of the contacts and the layout of the centering elements.

Dimensions in millimetre

Figure A.3 — Example of the layout of the contacts and the layout of the centering elements

NOTE 1 The dimensions and the positions of the contacts are defined prEN 50746 and prEN 50747.

The centering elements (pin and bushing) align the two electrical couplers with each other.

The play between the mechanical couplings is compensated by the play of the plain bearings on the guide rods. The electrical couplings have no relative movements and can therefore remain rigidly connected to each other.

NOTE 2 The play of the plain bearings on the guide rods is ideal when plain bearing diameter is 2 mm wider than guide rod diameter.

Without a counter coupler, the electrical coupler shall move (2 to3) mm beyond the coupler front plate, so that movements of the coupler heads can be compensated in the coupled state. The electrical couplers shall always be pressed against each other e.g. by compression springs.

NOTE 3 Reliable coupling movement is performed at higher than 50 N coupling force of electrical couplers.

The flap shall fully open during the stroke and shall not protrude beyond the coupling plane.

The front plates of the mechanical couplers may stay in an “A-position” to each other. And therefore, the electrical couplers, too. To prevent collision of the electrical couplers, they shall be mounted retracted from the front of the front plate (see grey marked area in Figure A.4).

NOTE 4 “V-position” of the front plates of the mechanical couplers is uncritical for electrical couplers.

The height limitation and free space for impacts with vertical angular offset are shown in Figure A.4.

Dimensions in millimetre

a) ready-to-couple position	b) coupled position

Figure A.4 — Side view of height limitation and free space for impacts with vertical angular offset

As defined in Annex H, a locking device shall be used to prevent flap opening.

An example of the locking device for the housing which prevents the electrical coupler from opening is shown in Figure A.5.

The inactive locking device is shown in Figure A.5a). It shows the ready-to-couple position of the electrical coupler.

The active locking device is shown in Figure A.5b). It shows the ready-to-couple position but with the locked electrical coupler.

a) open position

b) closed position

Key

Figure A.5 — Locking device

1. 
   (informative)
   
   Example of manual uncoupling handle from the side of the wagon

Figure B.1 is an example of an uncoupling handle system from the side of the wagon.

Dimensions in millimetre

Key

Figure B.1 — Manual uncoupling handle from the side of the Wagon

1. 
   (informative)
   
   Support and centering

Figure C.1 shows as an example the support and centering devices.

Key

Figure C.1 — Examples of support and centering devices

The hole placements for vertical support is shown in Figure C.2.

Dimensions in millimetre

Figure C.2 — Hole placements for vertical support

See UIC 530-05, Appendix 2 cut E, for reference.

1. 
   (informative)
   
   Mechanical stroke indicator

If the automatic coupler has been exposed to unacceptable loads that may have caused damage to the draw gear.

The stroke indicator shall be visible from the bottom of the wagon and is in the area based on Figure D.1 Full Stroke Indicator placement.

To simplify the wagon inspections the stroke indicator shall be red (RAL 3001).

For functional level 5 systems optionally, an electrical device can be used to indicate a full stroke.

Dimensions in millimetre

Key

Figure D.1 — Full stroke indicator placement Example side view

1. 
   (informative)
   
   Test bench test for longitudinal compressive forces

Before driving tests in curves, tests can be carried out on the test bench to characterize the stabilizing function of the coupler joint and the guidance of the pressure plate under compressive force and angular displacement.

Before executing propelling tests (see EN 15839:2024), tests can be carried out on the test bench to characterize the stabilizing function of the coupler joint and the guidance of the thrust plate under compressive force and angular displacement.

The bench test can be used to assess the efficiency of the stabilizing function of the coupler.

This can be done by following steps:

a) Control of the defined geometric properties of the joint, the pressure plate and pressure stops. Tolerances should be observed.

1) Examination of the dimensions of the joint consisting of the thrust plate, the main pin and the coupler shank;

2) Examination of the position of the stops influencing the position of the draft gear in the installation space.

b) Checking the guidance of the pressure plate under compressive force and eccentricity. This is also described in UIC 524:1978-01. This Annex describes the setup and execution of a suitable test.

1) Setup of test bench

— The test bench consists of the following main components:

— Test frame to accommodate the draft gear under test;

— Plunger to apply force to the thrust plate;

— Measurement devices to measure tilting of thrust plate and applied force.

The test frame is simulating the installation situation in the wagon, however dimensions are different on purpose to simulate worst case installation situation. The draft gear under test is mounted into the test frame according to supplier specification for mounting into wagon installation space.

The installation situation on the test bench shall correspond to the test frame specified in Figure E.1.

Dimensions in millimetre

Key

Figure E.1 — Test frame

The plunger is designed in a way that it does not undergo plastic deformation during test. This can be achieved by a linear contact area between plunger and thrust plate.

Following measurement parameters shall be recorded:

— applied force F [kN];

— angular deflection of thrust plate vs test frame β (horizontal) [°];

— angular deflection of thrust plate vs test frame γ (vertical) [°].

2) Execution of test

Loading of the thrust plate takes place by the plunger eccentrically as shown in Figures E.2 and E.3. The test procedure can be described as follows:

— Force application 5 kN/s;

— 0 kN – 800 kN – 0 kN in steps of 100 kN;

— 1 min holding time at each 100 kN step.

This test is repeated for each configuration of horizontal and vertical offset of force application:

— eccentricity 55 mm vertical;

— eccentricity 95 mm horizontal.

Horizontal eccentricity may be reduced to 85 mm due to practical reasons (e.g. undefined force application at edge of thrust plate).

The angular deviation of thrust plate β (horizontal) and γ (vertical) perpendicular to the centre line of the test frame is one important parameter to judge the overall stabilization function of the joint. UIC 524:1978-01 describes limit values of β = γ = ±1,25° (at vertical/horizontal eccentricity of 55 mm/95 mm).

Dimensions in millimetre

Key

Figure E.2 — horizontal eccentricity

Dimensions in millimetre

Key

Figure E.3 — Vertical eccentricity

Key

Figure E.4 — Example of a curve showing horizontal and vertical angel displacement vs force

1. 
   (normative)
   
   Endurance testing under service load for elastic system
   1. Aim of the test

The aim of this test is to verify the fatigue performance of the product when functioning under short stroke conditions (behaviour during braking).

• 1. Test principle

Test the elastic system with 10 000 compressive cycles between heights (H₁ – 0,25 a) and (H₁ – 0,60 a) (see Figure F.1).

For the centre buff coupler the test can be performed with a complete coupler coupling against a dummy.

Key

Figure F.1 — Definition of heights/Test setup

At the end of this test, a new stroke-force diagram is plotted.

• 1. Test results to be obtained

The functioning of the draft gear is considered to be acceptable if the deviations relative to the initial static characteristics measured between (H₁ – 0,25 a) and (H₁ – 0,60 a) do not exceed: ± 20 % for the force.

1. 
   (informative)
   
   Gathering range

Figure G.1 shows the typical gathering range of the coupler.

Dimensions in millimetre

Figure G.1 — Minimum gathering range of the coupler

1. 
   (informative)
   
   Electrical Coupler (as defined at the state of Enquiry)
   1. For information

This informative Annex contains the current status of information – second enquiry document to be updated following test results in Spring 2025.

• 1. Electrical Coupler General

The Electrical coupler houses electrical and digital contacts used for the transmission of electrical power and data signals.

Figure H.1 shows as an example a sketch of the electrical coupler defined by this standard. It shows the overall position of the electrical coupler on top of the mechanical coupler.

Key

Figure H.1 — Example of a principle sketch of the electrical coupler

The electrical coupler is mounted on top of the mechanical coupler. It works in conjunction with the mechanical coupling of the couplers. The electrical coupler has two positions, the ready-to-couple position and the coupled position, shown in Figure A.4. The electrical coupler is located behind the mechanical coupler front plate in ready-to-couple position. The forward movement of the electrical coupler starts after the coupling mechanism rotation has been released (unlocking of the trigger bar). The forward movement of the electrical coupler is performed linear (in x-axis) to avoid a bending moment on the contacts.

The vertical distance between the centre line of the mechanical coupling and the top edge of the electrical coupling don’t exceed 200 mm in the coupled or in the uncoupled state and during transition between these states, as defined in 4.2.

The connection and separation of the mechanical and electrical connection is done automatically (without additional activities by the operating personnel).

Parts protruding in front of the coupler front face (e.g. centering devices) does not negatively affect the components of the mating coupler. During the movement forward of one electrical coupler the electrical coupler lid does not exceed the coupler front plate to avoid collision between contacts and lid of opposite electrical coupler.

If the coupling mechanism is in coupled position before coupling against an opposite coupler, the electrical couplers move back before the mechanical coupling mechanisms are engaged.

NOTE 1 When coupling the electric couplers, both electrical couplers are activated in such a way that the forward movement takes place almost simultaneously. This is necessary so that the space required for forward movement by one electrical coupler is not blocked by the engaging electrical coupler.

The electrical coupler stays in backward position when prevent coupling mode is active.

The electrical coupler is protected against environmental influences (ingress of water and dirt) with a degree of protection of minimum IP55 when coupled and minimum IP54 when uncoupled according to EN 60529:1991.

NOTE 2 See 4.2 for climate requirements.

The electrical coupler is designed in such a way that water accumulation is avoided. The electrical coupler fulfils the requirements according to EN 50124‑1:2023 regarding clearances and creepage distances for equipment.

The electrical coupler does not reduce the gathering range of the coupler as defined in 5.1.1.

Live parts are protected from physical contact when the mechanical coupler is in ready to couple position.

The electrical couplers casing meets the mechanical interfaces shown in Annex A.

A DAC equipped with electrical coupler (FL3 or FL4 or FL5) does not prevent coupling mechanically when coupling to a DAC of FL1 or FL2 or further mechanical coupler according to EN 16019:2014 with other electrical coupler designs (e.g. passenger train applications). A locking device is used to prevent flap opening, see Figure A.5.

For maintenance purposes of the electrical coupler, it is possible by simple means to test, access and exchange components (pins, blocks, and gaskets). For this purpose, the electrical coupler can be put in an open position.

The electrical connection between the electrical coupler and the wagon body is established via cables, e.g. hybrid cables (combination of data and power cables).

NOTE 3 The Electrical and data connections to vehicles are specified in prEN 50746 and prEN 50747.

NOTE 4 The electrical connection and at the transfer point to the vehicle body is defined prEN 50746 and prEN 50747.

Single contact wear parts of the electrical coupler are replaceable from the front without removing or replacing the complete electrical coupler.

The design considers the risk of falling objects on the electrical coupler and adequate protection is included in design. The requirements in EN 14601:2024, 5.3.11.1, are used to prove the design. For the falling objects test the falling objects onto the electric coupling falls onto at least two places, selected randomly, on one of the mating electrical couplers, one in the middle and the other in the rear area relative to the front plate. Both places are at least 50 mm apart.

The test includes a sequence of coupling and uncoupling after the drop of the object. The design considers a resistance against static load up to 120 kg. The test is performed with a load area which has the size of 120 mm x 280 mm with a random position on the electrical coupler cover.

A non-step sign on the electrical coupler top is placed.

The movable parts of the electrical coupler operate satisfactory in winter conditions. To test operational capability in winter applications a minimum 3 mm thick ice layer is created on all movable parts by using a water mist. The ice is to settle for at least 1 h at max −20 C. Two tests are to be performed: one straight coupling test at low speed approx. 1 km/h (one cycle) and one test at mid speed approx. 5 km/h (one cycle). Both are performed successfully.

The couplers are re-iced before each test.

The minimum ice thickness is always noted.

• 1. Additional requirements for explosion protection
     1. insulating materials

Size restrictions for insulating materials are stated in the prEN 50746.

Minimum cross section areas of bending wires are specified in the EN IEC 60079‑0:2018, 15.4.

To avoid brush discharges, the layer's thickness of insulating coating of earthed surfaces shall not exceed a value of 0,2 mm for usage in areas for gases and vapors of the group IIC in CLC/TR 60079‑32‑1:2018 (6.3.4).

Equipment dust ignition protection by enclosure.

The ingress protection class of enclosures and housings for equipment exposed to the presence of hazardous dust atmospheres shall guarantee complete dust tightness, namely shall be of ingress protection class IP5x.

Due to the constructive presence of the movable protective flap at the front side of the DAC E-coupler, the ingress protection IP-Class for the e-coupler shall be implemented as follows:

— front/outer side (pins-side) of the E-coupler under the protective flap: minimum IP54 in uncoupled state and IP55 when coupled;

— back/inner- side (cables-termination-side) of the E-coupler: minimum IP55 (complete dust tightness).

• • 1. Avoidance of hot surfaces and uncontrollable surface overheating

The colour of the surfaces of enclosures and other parts of installed electrical equipment with internal heat generation exposed to the direct sun-light should be light-reflecting (bright colours with bright shades).

1. 
   (informative)
   
   Relationship between this European Standard and the Essential Requirements of EU Directive (EU) 2016/797 aimed to be covered

This European Standard has been prepared under Commission implementing decision C(2023)1057 of 20.02.2023 on a standardization request to the European Committee for Standardization and the European Committee for Electrotechnical Standardization as regards products in support of Directive (EU) 2016/797 of the European Parliament and of the Council (M/591) to provide one voluntary means of conforming to (parts of) Essential Requirements of Directive (EU) 2016/797 of the European Parliament and of the Council of 11 May 2016 on interoperability of the rail system (recast) as specified in the relevant technical specifications for interoperability (TSI).

Once this standard is cited in the Official Journal of the European Union under that Directive, compliance with the normative clauses of this standard given in Table ZA.1 for freight wagons, and Table ZA.2 for locomotive and passenger RST and confers, within the limits of the scope of this standard, a presumption of conformity with the corresponding Essential Requirements of that Directive as specified in the technical specifications for interoperability (TSI), and associated EFTA regulations.

Table ZA.1 — Correspondence between this European Standard, Commission Regulation (EU) N° 321/2013 concerning the Technical Specification for Interoperability (TSI) relating to to the subsystem ‘rolling stock – freight wagons’ and Directive (EU) 2016/797

Table ZA.2 — Correspondence between this European Standard, Commission Regulation (EU) N° 1302/2014 concerning the Technical Specification for Interoperability (TSI) relating to rolling stock — locomotives and passenger rolling stock’ and Directive (EU) 2016/797

WARNING 1 — Presumption of conformity stays valid only as long as a reference to this European Standard is maintained in the list published in the Official Journal of the European Union. Users of this standard should consult frequently the latest list published in the Official Journal of the European Union.

WARNING 2 — Other Union legislation may be applicable to the products falling within the scope of this standard.

Bibliography

[1] UIC 522:1990-01, Technical conditions to be fulfilled by the digital automatic coupler of the UIC and OSJD Member Railways (4th edition) ^[2]

[2] UIC 523:1981-07, Technical conditions with which automatic couplers of the UIC and OSJD member railways shall comply in order to ensure compatibility of couplers (1st edition)²

[3] UIC 530-1:1982-04, Design measures on freight wagons with regard to the introduction of automatic coupling (2nd edition)²

[4] UIC 530-2:2011-12, Wagons — running safety (6th edition)²

[5] EN 12663‑1, Railway applications — Structural requirements of railway vehicle bodies — Part 1: Locomotives and passenger rolling stock (and alternative method for freight wagons)

[6] EN 13803, Railway applications - Track - Track alignment design parameters - Track gauges 1 435 mm and wider

[7] EN 16116‑1:2022, Railway applications — Design requirements for steps, handrails and associated access for staff — Part 1: Passenger vehicles, luggage vans and locomotives

[8] EN 16116‑2:2014, Railway applications — Design requirements for steps, handrails and associated access for staff — Part 2: Freight wagons

[9] EN 14478, Railway applications — Railway rolling stock — Brake pipes

[10] EN 10168:2004, Steel products - Inspection documents - List of information and description

[11] EN 12663‑1:2010+A2:2023, Railway applications - Structural requirements of railway vehicle bodies - Part 1: Locomotives and passenger rolling stock (and alternative method for freight wagons)

[11] EN 15273 (series), Railway applications - Gauges

[12] EN 15380‑1:2006, Railway applications - Designation system for railway vehicles - Part 1: General principles

[13] EN 15380‑4:2013, Railway applications - Classification system for railway vehicles - Part 4: Function groups

[14] EN 50124‑1, Railway applications - Insulation coordination - Part 1: Basic requirements - Clearances and creepage distances for all electrical and electronic equipment

[15] EN 50124‑1, Railway applications - Insulation coordination - Part 1: Basic requirements - Clearances and creepage distances for all electrical and electronic equipment

[16] prEN 50746,^[3] Railway applications – Rolling stock - Electrotechnical requirements and test methods for DAC (DAC - Digital automatic coupler for freight)

[17] prEN 50747,³ Railway applications – Rolling stock - Requirements and test methods for electrotechnical equipment for digital freight train operation

[18] EN 61373:2010, Railway applications - Rolling stock equipment - Shock and vibration tests

[19] CLC/TR 60079‑32‑1:2018, Explosive atmospheres — Part 32-1: Electrostatic hazards — Guidance (IEC/TS 60079-32-1:2013)

[20] EN IEC 60079‑0:2018, Explosive atmospheres — Part 0: Equipment — General requirements (IEC 60079‑0:2017)

[21] EN ISO 5817:2023, Welding - Fusion-welded joints in steel, nickel, titanium and their alloys (beam welding excluded) - Quality levels for imperfections (ISO 5817:2023)

[22] INSTA 851:2023, Railway applications — Environmental conditions — Design guidance for rolling stock for severe winter conditions

[23] UIC 827-1:1990-01, Technical Specification for the supply of elastomer components for buffers (2nd edition, January 1990)²

[24] UIC 827-2:1987-01, Technical Specification for the supply of steel rings for buffer springs (3rd edition, January 1987)²

[25] PN-H-83160:1988, Abrasive wear resistant cast steel — Grades

[26] UIC B 51 RP 21 (ERRI B 51 RP 21), BUFFING AND DRAWGEAR — Strength studies with the coupler body of the basic variant of the automatic coupler 1969 for wagons²

[27] TSI WAG, COMMISSION REGULATION (EU) No 321/2013 of 13 March 2013 concerning the technical specification for interoperability relating to the subsystem ‘rolling stock — freight wagons’ of the rail system in the European Union and repealing Decision 2006/861/EC

[28] Guideline F.K.M. Analytical Strength Assessment 7th. Ed. 2020, Published by: FKM Forschungskuratorium Maschinenbau e.V., ISBN 978‑3‑8163-0745-7, To order from: VDMA Services GmbH, Lyoner Str. 18, 60528 Frankfurt am Main, GERMANY; Internet: https://www.vdmashop.de/fkm-richtlinien/483/analytical-strength-assessment-7th.-ed.-2020-en

1. Document impacted by EN 60529:2019/A1:2000, /A2:2013 and /AC:2019. ↑

2. See list of web shops in shopping basket. ↑

3. In preparation. Being worked on in CENELEC/SC 9/XB/WG44. ↑