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DAC: Topic for European Carriers. See the Project Analysis

DAC: Topic for European Carriers. See the Project Analysis
photo: Archive/DAC: Topic for European Carriers. See the Project Analysis
30 / 11 / 2022

On Wednesday, 23 November 2022, another seminar on Digital Automatic Coupling was held in Bratislava, at the new headquarters of ZSSK Cargo. The DAC Ambassador for Central and South-Eastern Europe Libor Lochman, the Director of the European Railways Joint Undertaking (ER JU) Carlo Mário Borghini and the Technical Director of ÖBB Holding, and also the Project Manager of the European Digital Coupling Development Programme (EDDP) Mark Topal-Gökceli.

The presentation was given by Andreas Lipka from DB Cargo, Christian Kuhn from CK Rail & Logistics, and Oliver Martin from OakTree Management Consultants GmbH. The presentation, for the first time, gave concrete scenarios and roadmaps for the DAC transition, which will result in different costs for individual carriers over time. Plans for the transition to DAC must be centrally managed and coordinated between Member States, including the provision of public support. There are still vague ideas about financial support from the European Union. Partly based on knowledge of existing instruments in countries that use European funds for the modernization or acquisition of rolling stock (the Czech Republic is traditionally not one of them), a certain angle is offered by how some Member States are dealing with the introduction of mobile ETCS units. C.M. Borgini suggested that the financing would have to be multi-sourced, based on a subsidy pillar, but with a pillar made up of loans (guarantees), while some opinions suggest that the European Union, and not the carriers, should take out the loan for this project. 

The European Railways Joint Undertaking (ER JU) and the EDDP - European Digital Coupling Programme followed up on 28 and 29 November with a videoconference on various aspects of the transition (migration) process from conventional to digital coupling. EDDP cooperated in the migration discussion with DB Cargo, Rail Cargo Austria, ČD Cargo, GATX, Wascosa, On Rail, PKP Cargo, SBB Cargo, Fret SNCF, VDV Verkehrsunternehmen, Netzwerk Europäische Eisenbahnen, VTG, Touax, Green Cargo, Lineas, and TWA.

It is now clear that the original deadline for the TSIs will not be met this year. As the EU has historically committed to the rail transport sector that TSI revisions would only take place once every seven years, it can be expected that the TSI revision will wait until the digital coupling TSIs are ready.

In terms of timing, there are now several migration strategies on the table, distinguishing between the transition to DAC for wagons and locomotives; another divide in the approaches has been between integral trains in relatively stable configurations and mixed traffic wagons used in trains with variable wagon mixes. In terms of time, there are three scenarios spread over the years. All involved at some point in time (1-2 weeks) a 'Big Bang' when the entire fleet will need to be equipped for DAC operation. The objections to the unrealistic and costly nature of the Big Bang have been addressed by EDDP with two new proposals: cars and locomotives, especially shunting locomotives, will be able to be equipped with adapters to allow conversion at a later date or to run with the adapter until the end of the car's useful life. The second, important for the hauler, is that for a certain number of cars, the hauler will create a fixed twin, and it can be fixed with a conventional coupler for an interim period after the Big Bang. It spreads the need to acquire a certain, economically significant number of retrofits over time for individual carriers. It was also mentioned in the discussion that it would be possible to install a hybrid coupling on a substantial number of locomotives (about 21,000 in Europe). For locomotives, probably due to the diversity (high number of types), EDDP cautiously proposes to create a Task Force to explore the market and technical possibilities. It estimates that 70% of electric locomotives will be able to be equipped with DAC, but on the other hand, only 25% of locomotives intended for shunting can technically integrate DAC. Shunting locomotives, in particular, will have to be equipped for DAC by the time of the 'big bang' due to the traffic management of terminals. EDDP recognizes that the bottleneck is retrofit, so it wants to allow a sufficient lead time of several years for the carriers and give the market room to adjust production capacity. DB envisages that DACs can be installed in mobile workshops, and tents right on the tracks. Inspired by the apparent mass vaccination against Covid, they have started calling these facilities DACcination Centers.

The phases of the DAC deployment process are illustrated here:

There are three scenarios in play: 

1. Four years of pre-big bang preparation for equipment to DAC-ready level, followed by a Big Bang and a two-year post-big bang phase for digitalization to definitive conversion to DAC


The cost of DAC is estimated at €5,000 per unit, i.e., double for each car and locomotive. The cost of fitting the couplers will vary according to the car or locomotive design. For new vehicles, an extra cost for the DAC (compared to the cost of acquiring wagons and locomotives equipped with screw couplers) of €3 500/ wagon and €8 000/ locomotive is foreseen. It is also estimated that the complication of managing wagons not equipped with DAC will require an additional cost of €5 000/vehicle. It includes their limited availability on the rail network.

Table of additional costs

Communication component costs


Wagon communication unit incl. power management and battery


2nd wagon communication unit (redundant)


Cloud communication unit


Apps management unit (calculation power for all use cases)


2nd apps management unit (calculation power for all use cases), redundant


Retrofit costs




Other Cost


Automated venting device


Automated venting device-retrofit costs


Automatic braking test device


Automatic braking test device-retrofit costs


Automatic uncoupling (type 5) actuator (per wagon)


Automatic uncoupling (type 5) actuator-retrofit costs (per wagon)


Automated parking brake system


Automated parking brake system-retrofit costs


Train integrity function & train composition determination


Train integrity function & train composition determination-retrofit costs


Wagon telematics


Wagon telematics-retrofit costs


Video gate – counts


Video gate – cost

150 000


























It is not envisaged that the entire fleet will be equipped with DAC because it would be too complex or because some wagons and locomotives are too old and their remaining useful life is the determining parameter for not being equipped with DAC. EDDP acknowledges that these wagons and locomotives will have to be taken out of service before the end of their useful life, and the owner will have to write them off. They calculate an average cost of EUR 25 000/car and EUR 50 000/locomotive.

The ultimate parameter is the speed of the 'big bang' operation. A very rough assumption is that if a single carload system is out of service for more than four weeks, the whole business chain will come to a standstill and customers will permanently switch to road transport, for example. Furthermore, EDDP analyses the costs/losses (for rail transport) if a parallel operation were to operate in the JVZ for a longer period. It also recognizes the complexity of customers returning to rail but is optimistic that the DAC implementation strategy will avoid such a situation.


  • Capacity in terminals
  • Capacity - trips saved
  • Capacity - infrastructure
  • Capacity - car savings
  • Savings on track
  • Safety

The fact that a carrier saves 1 hour with DAC does not mean that it will be able to use shunting locomotive capacity elsewhere or gain additional capacity for a locomotive in deployment on the line. In a marshaling yard with three people per shift (8 hours) and one shunting locomotive, DAC saves nothing. Likewise, the 1-2 hours saved by DAC in train making may not be enough to form another train.

Nevertheless, the DAC Program has attempted to quantify the benefits as follows: it has divided rail operations into different categories of employees and resources - operating employees, shunting locomotives, mainline locomotives, mainline engineers, and railcars. For each category of employees/means, he determined a conversion factor for time savings that would express productivity and multiplied this by the average cost per hour. Several countries (Hungary, Italy, Germany, France, and Portugal - the Czech Republic did not report). that there may be a benefit in freeing up the road, terminal, and siding capacity and, thus, a benefit in wagon capacity. The authors of the DAC program acknowledge that the capacity benefits for rail cannot be attributed solely to the introduction of DAC. Concurrent projects such as the completion of the TEN-T network, high-speed rail in Central Europe, and ETCS are also aiming to increase capacity for rail freight. ÖBB and RINA are preparing a capacity utilization study on the Brenner line Pass in the Alps, taking into account the introduction of DAC and ETSC. They are testing the hypothesis that the increase in infrastructure capacity could be up to 30%. The DAC program considers the hypothesis to be very optimistic, and for the overall rail network, its authors work with a realistic assumption of a 15% saving of the network and a conservative (pessimistic) assumption that the benefit in additional rail infrastructure capacity gain will be only 5%.

The DAC should lead to an increase in railcar capacity utilization, which is currently very low. If the EU aims to double rail freight transport by 2050, more wagons will be needed. Capacity utilization by gaining time in train building should lead to a modeled reduction in fleet growth of 2 to 6 percentage points of the projected need for a 33% increase in the number of wagons and thus savings in investment in new wagons. Further savings will result from the cost of wear and tear on the railway infrastructure (investment costs of 30.000 €/km of track and a 5% reduction in track maintenance costs. Finally, the DAC is expected to bring about an increase in the safety of railway staff during shunting and train operations. The modeling of the benefits does not, of course, omit energy savings and declares DAC as an integral part of the shift of a substantial part of transport capacity from road to rail.

2. Realistic 6 + 3

3. Conservative 4 + 8 (a version of 6 + 6 is also being considered)

Based on the Swiss experience with EDDP, DB Cargo empirically verified the labor requirements associated with converting a wagon from a standard coupler to a DAC. The dismantling, assembly to brake test requires 26 hours, the big unknown is the process of digitizing the coupler, where the number of hours required to get it up and running is estimated at an additional 30 hours for an average of 66 hours. EDDP recognizes that the process will require labor with typically non-railroad qualifications - electricians, and IT mechanics.