SBB Cargo freight train travels through Swiss mountains
Your connection to success

Digital automatic coupler

Greener freight transport engineered

    The digital automatic coupler connects and disconnects freight cars, air pipes, data- and powerlines automatically.

    In this way it forms the basis for shifting freight traffic to the rails. And it contributes significantly to combating the ever-increasing carbon emissions and achieving the goals of the European Green Deal.

    Reliable and on-time delivery are the keys to the success of attractive and competitive rail freight services, and Voith’s digital automatic coupler, the CargoFlex, forms the basis for ensuring that these are both the case.

    Contact us Are you ready? FAQ
    To achieve the European climate targets, the share of rail in freight transport needs to be increased to 30%.

    Rail freight transport accelerated to the max with CargoFlex

    Strong system partner found

      Voith combines proven mechanical systems with digital intelligence to offer you a complete, compatible system. As a reliable partner, we also provide support during the entire service life, starting with the installation

      Are you ready for the future? We’ll take you there.

      A data network emanates from a fast-moving freight train.
      System partner
      System partner for DAC migration: mechanical system, service, and digital add-ons from a single source
      Reliable couplers proven in commercial operations
      A data network emanates from a fast-moving freight train.
      Years of experience
      Partner for the entire fleet: freight car expertise and many years of experience as a locomotive system integrator
      Pioneer in automation and digital features
      A data network emanates from a fast-moving freight train.

      System speed accelerated

        To achieve a massive shift in freight traffic from the road to the rails, freight trains need to become more efficient and more competitive. More goods need to be transported faster and on time. Our digital automatic coupler, the CargoFlex, is the basis for ensuring just this. It is a key component in guaranteeing that freight trains can start their journey and reach their destination faster.

        Voith's digital automatic coupler

        Speed up train preparation

        How long does it take for a train to get on its way? Many manual and time-consuming steps mean that freight trains sometimes only leave for their destination when a truck would have already reached it.
        The CargoFlex automates and significantly speeds up operations:

        • Automatic coupling
        • Electrical, automatic uncoupling
        • Automatic brake testing
        • Automatic load monitoring

        Furthermore, we are working on implementing additional functionalities to further optimize train preparation:

        • Train set up check
        • Train inauguration
        • Remote uncoupling
        • Brake lever: position detection, remote control, adjustment

        Increase travel speed

        How long does it take for a freight car to reach its destination? Today, various restrictions prevent freight trains and goods from reaching their destination as quickly as possible.

        In conjunction with the latest train protection systems (ETCS 3), the digital automatic coupler enables higher speeds thanks to faster line clear authorization. This requires information on train integrity to be communicated, among other data, which is achieved by means of permanent communication between the train’s front and rear ends. The DAC makes the necessary data communication along the length of the train possible. This is also critical to precisely controlling the brakes and keeping braking distances short. These, in turn, play a key role in increasing speed and route frequency.

        Today, Voith is already working on enabling data communications over the entire train and dependent functions to accelerate the speed of the system:

        • Constant train integrity control
        • Selective braking of each car


        Digital revolution launched

          The future of rail freight transport is digital, intelligent, and connected. This is the only way that available resources can be used in the best possible way and the freight carrier can survive in the competitive logistics market. Voith already offers a significant increase in efficiency in train preparation with automatic brake testing, automatic load monitoring and other digital solutions.

          Contact our experts

          Our robust solution seamlessly combines real-time monitoring and automation and is designed specifically for rail freight operators to make operations more efficient and safer.

          Automatic brake testing

          Automated brake tests replace time-consuming manual tests. For a 500 m freight train, this results in a time saving of 30 minutes. The results of the automatic brake test are shown on the display of the train driver or the employee responsible for the brake test. 

          VT Automatic Brake Testing 22 KL

          Automatic load monitoring

          All relevant information about the load is provided in real time on the wagon and in the web portal. This opens up new avenues in terms of safety and optimum loading capacity. 

          Automatic load monitoring
          Matheus Habets
          Besides improved train preparation times, we are already able to solve another major rail cargo problem: We enable one man operation. Cancelled trains due to lacking personnel are history.
          Matheus Habets, VP Product Management Digitalization Mobility, Voith

          Proven mechanics adapted

            Scharfenberg® couplers have been used reliably in passenger rail services for more than 100 years. Voith’s freight couplers for locomotives and freight cars are based on this proven technology and have already been used in commercial operations by SBB Cargo since 2019.

            Digital automatic couplers for freight trains

            The CargoFlex reliably connects and disconnects freight cars even under extreme weather conditions. The freight car coupler is optimized to always securely connect the mechanical system as well as the power, air, and data lines.

            Digital automatic couplers for locomotives
            CargoFlex Hybrid

            The CargoFlex Hybrid gives operators the ability to gradually convert to DAC. With it, coupling via a draw hook and via automatic coupling is possible, as the head can be placed in the automatic and manual position as required.

            Scharfenberg® couplers have been proving their worth in passenger rail services for more than 100 years. By making advancements to this technology for freight trains, we are playing a major role in the modernization of European rail freight transport.
            Christian Radewagen, SVP Strategic Projects Mobility, Voith
            Portrait of Christian Radewagen
            Scharfenberg® couplers have been proving their worth in passenger rail services for more than 100 years. By making advancements to this technology for freight trains, we are playing a major role in the modernization of European rail freight transport.
            Christian Radewagen, SVP Strategic Projects Mobility, Voith

            Migration and maintenance settled

              The digital revolution in rail freight transport offers great potential but is also an enormous challenge. To help wagon keepers as well as operators master new requirements and realize maximum availability and smooth operation, Voith Service offers a wide range of services for the digital automatic coupler from migration to maintenance.


              Upgrading the entire fleet to DAC is a major challenge for wagon keepers. For a smooth migration process, Voith Service provides support from fleet preparation to installation.

              • Support with fleet preparation and assisting with modifications (wagons and locomotives)
              • Support with coupler installation (on-site support as well as take-over)
              • Consultation for approvals and certification


              Are you ready?

              Service packages

              To enable rail freight experts to focus fully on their core business, Voith Service offers a wide range of needs-oriented service packages especially for DAC.

              Service packages
              • Maintenance support perfectly matched to operators’ needs
              • Wide range of service packages with matching scope (small - medium - large)
              • Planning security thanks to contractual safeguarding



              The Europe-wide DAC migration also poses new challenges for maintenance personnel. The experts from Voith Service are happy to pass on their knowledge, because only trained, certified personnel can ensure optimum maintenance.

              • Various training programs covering mechanics, hard- and software
              • Coordinated theoretical and practical training
              • Experienced trainers with in-depth DAC know-how


              Technical support

              Solution-oriented consulting from experienced DAC experts. With the competitive edge in experience and know-how, Voith is the right partner for any technical questions.

              Technical support
              • Individual consulting by experienced experts
              • Immediate technical assistance via different communication channels
              • Worldwide access to Voith expertise via web-based video collaboration platform OnCall.Video


              MRO & field service

              When wagon keepers and operators need maintenance support, Voith Service is ready with experienced specialists - fast, flexible, at any location.

              MRO & field service
              • Fast repair and overhaul thanks in one of our many workshops Europe-wide
              • Instant on-site support by Voith Service experts located all over Europe


              Exchange units

              Even the most robust coupler can be damaged by extreme impact. In the worst case, a complete freight train is then at a standstill until the problem is solved. With the Voith Service exchange program, this takes less than a day.

              Exchange units
              • High-quality exchange units (e.g., coupler head) and complete exchange couplers
              • Zero-day delivery
              • Minimum downtime of freight cars


              Spare parts

              Because safety has top priority and there is no time for downtime, Voith Service supplies rail freight operators with high-quality DAC spare parts and kits - at any time, Europe-wide.

              Spare parts
              • Optimally designed original spare parts ensure maximum safety and reliability
              • Spare parts availability throughout the entire life cycle
              • Short delivery times thanks to Europe-wide network and spare parts stocking


              Fast maintenance in the field with CargoFlex

              Swiss freight transport automated

                SBB Cargo and Voith have been working together since 2017 to speed up processes at freight hubs and shunting yards in Switzerland. Following extensive testing, the company has been using the CargoFlex and the CargoFlex Hybrid in commercial operations since 2019. Since 2021, all of Switzerland’s combined domestic transport has been coupling automatically.

                Every day, more than 400 freight car couplers and 50 hybrid couplers from Voith reliably couple during commercial operations in Switzerland.

                Cooperating closely for a strong rail system

                Frequent questions answered

                  Are you ready to take that decisive step toward the rail freight transport of the future, but still have questions about how to implement it? You will find the answers to the most frequently asked questions here.

                  Isn’t an automatic freight car coupler much heavier than the existing buffers and chain coupler?

                  The weight of Voith’s automatic coupler for freight cars equals that of the buffers and chain system.

                  Is it possible to gradually convert to DAC?

                  The CargoFlex Hybrid allows coupling with both an automatic coupler (AC) and a screw coupler.In this respect, gradually retrofitting your fleet is possible without any impact on your operations.

                  In addition, it is possible to prepare your cars for the upgrade and continue to operate with buffers and screw coupler – you can integrate the buffer and draw gear and continue to operate with the buffers and screw coupler until the final upgrade. The dimensions of your freight car remain the same after preparing it for DAC.

                  How did the CargoFlex perform in the DAC4EU tests?

                  In the selection tests for a future European standard for rail freight transport, the CargoFlex was the only one to receive the full number of possible points and thus played a major role in securing the decision of the European DAC Delivery Program (EDDP) in favor of a Scharfenberg type coupler.

                  Is Voith’s coupler a prototype or is the CargoFlex already being used in commercial operations?

                  The CargoFlex and the CargoFlex Hybrid were developed in close collaboration with our partner SBB Cargo with a focus on real-world use. They have been used with success in commercial operations in Switzerland since May 2019. Every day, more than 400 CargoFlex and 50 hybrid couplers reliably couple freight cars there.

                  What forces are the CargoFlex and CargoFlex Hybrid designed to withstand?

                  The forces are designed for the freight car structure (EN 12663, UIC 522, UIC 530).

                  With a maximum tensile force of 1000 kN and a compressive force of 2000 kN (toward the yield point), the forces for which the CargoFlex is designed clearly exceed those of the existing buffers and screw coupler system. The design against component failure is verified with 1.5 times the resistance to fracture.

                  The CargoFlex Hybrid is designed for a maximum tensile force of 1000 kN and compressive force of 2000 kN (yield strength) (EN 12663, UIC 522). Due to the central application of force, however, the locomotive must be tested in advance. We’d be happy to help you with this process. Simply send us a message.

                  Do the CargoFlex and CargoFlex Hybrid already conform to DAC level 5?

                  At the current time, the CargoFlex and CargoFlex Hybrid comply with the DAC level 4 requirements. They are, however, already DAC5-ready and take future specifications into account.

                  Is it possible to transmit power and data with the CargoFlex system?

                  To increase automation in terms of upgrading from automatic coupler (AC) to digital automatic coupler (DAC), the CargoFlex and CargoFlex Hybrid can be equipped with an electric head/ e-coupler. It is already integrated into the DAC version.

                  Can an electric head/ e-coupler be retrofitted and upgraded to DAC at any time?

                  Due to the modular design of the coupler, an electric head/ e-coupler can be quickly and easily retrofitted at any time and thus upgraded to DAC. It is mounted to the coupler head with two bolts, with wiring subsequently carried out by the customer. The ECU works purely mechanically, so it does not need any power.

                  Can Voith couplers be customized?

                  Generally speaking, customizations are possible, but are not usually required. The couplers were developed in close collaboration with the market and are therefore perfectly adapted to operators’ needs.

                  In addition, the CargoFlex is intended as a mass product for the European market and has been intensively tested in its existing design.

                  Does Voith offer any assistance in retrofitting the freight car fleet?

                  Voith provides support during the inspection of your rolling stock. From drawings to 3D data to on-site inspections, we provide the help you need.

                  We also support with installation. We offer on-site support or can handle the entire installation process for you. How can we help you? Simply send us a message.

                  What preparations must be made in advance prior to installing the couplers?

                  Before installing the CargoFlex, you must determine whether the freight car is suitable for installation and capable of handling transmission of the forces. In the future, the forces will be applied centrally and no longer via the buffers. All of the components that are no longer needed are then removed and plates for the transmission of forces are installed. 

                  Preparing locomotives for the installation of the CargoFlex Hybrid is a process highly unique to each locomotive. You need to determine whether the vehicle is designed for the hybrid coupler’s central application of force (longitudinal compressive force of 2000 kN). Minor technical changes may be necessary and must therefore be assessed in advance. Depending on how the elevating device is actuated, adjustments may also have to be made to the locomotive in terms of the control system (pneumatic and electrical systems).

                  We have already carried out successful installation tests with most leading OEMs. Our locomotive experts will also be happy to assist you with any custom testing you may need to conduct. Simply send us a message.

                  Can the DAC be installed and brought into service quickly and easily?

                  The CargoFlex is designed for the installation space required by UIC 530-1, which 95% of all freight cars meet. This design and the modular structure of the coupler make it possible to install and bring the freight car coupler into operation in the shortest possible time with a minimum of personnel and labor. In fact, the coupler can be installed on a prepared freight car in 45 minutes. In addition, Voith maintains a constant dialog with the industry to further optimize the installation process.

                  Is the CargoFlex delivered fully assembled?

                  The CargoFlex and CargoFlex Hybrid are supplied in three parts, which are mounted one after the other:

                  • Front section with rod and, if necessary, electric head/ e-coupler
                  • Support
                  • Draw gear

                  How do the CargoFlex and CargoFlex Hybrid perform during winter operations?

                  The CargoFlex and CargoFlex Hybrid are designed with winter optimization in mind, ensuring that they can be reliably coupled in winter even without being heated. This is demonstrated by the excellent results after two winters in commercial operation in Switzerland.

                  In addition, the CargoFlex has been extensively examined by independent testers. The suitability of Voith’s DAC for winter use was confirmed both under real-life conditions in the Swedish winter and in DB’s climatic chamber.

                  What is to be expected in terms of maintenance work and does Voith provide support in this regard?

                  The CargoFlex has been designed to be low-maintenance. Standard maintenance intervals may need to be adjusted depending on use and operating conditions. The aim is to carry out a functional test and preventive measures after three years at the earliest. Our experts will be happy to support you with this as part of a personalized service agreement. Simply send us a message.

                  Is it easy to perform maintenance and repairs in the field?

                  Thanks to the coupler’s modular design, even internal components are easily accessible. This means that maintenance and repair work can also be carried out quickly and easily in the field.

                  See for yourself here

                  Do you have further questions? Not a problem! Our CargoFlex experts look forward to assisting you. Simply send us a message.

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