Digital Coupler or Electric Carriage? Ukrainian Expert Warns DAC Faces "Systemic Stagnation" in Europe’s Rail Modernisation

Ukrainian expert Borys Hanailiuk took part in this year’s TRAKO fair in Poland, contributing to profile discussions on the future of the Digital Automatic Coupler (DAC). The magazine RailFreight has now published his comprehensive analysis of the future of coupling digitalisation.

Borys Hanailiuk is a physicist by education who has worked across research, industrial economics, and management. His career included roles in a research institute, economic consultancy, and management of automotive companies in Lviv. Since 2018, his focus has shifted to the study of the Lviv railway hub, bringing multidisciplinary expertise and an external perspective from outside the EU, where DAC is viewed as a prestigious project tied to the future competitiveness of rail freight.

🚄 #SIFER2025: showed the Digital Automatic Coupler (DAC) with RLE, @IRT_Railenium & @UNIFE. 🎯 €95 m FP5-TRANS4M-R, 76 partners, targets EU 30 % rail-freight by 2030. #DAC cuts coupling to <3 min, provides 400 V power + data, boosts safety. French pilot coming. #RailFreight pic.twitter.com/N1EsWgotTW

— Antoine Belleguie (@ABelleguie) June 25, 2025

DAC Costs Raise Prices by up to 30%, Return on Investment Remains Unclear

According to Hanailiuk, experts largely agree on a critical assessment of DAC’s price. In fact, he says, cost is the only serious argument against DAC. If DAC were introduced today, it would raise the average price of a freight wagon by at least 30%. Meanwhile, the market does not yet see clear economic benefits that would allow wagon owners to offset these expenses.

While DAC certainly reduces manual work in train formation, its potential seems limited in modern rail logistics, where complete block trains are increasingly used without the need for wagon sorting. In intermodal transport, where trains operate on "terminal-to-terminal" routes, decoupling is almost unnecessary. In such cases, DAC would only need to be installed on wagons at the front and rear of the train, sufficient for locomotive changes or operations at junction terminals.

However, in traditional freight operations, which still rely on marshalling yards and variable train compositions, the economic effect of DAC is questionable. The average annual mileage of wagons and the frequency of coupling operations simply do not justify the investment.

Hanailiuk: "We’re Installing 21st-Century Technology on 20th-Century Vehicles"

Another obstacle, Hanailiuk points out, is the long lifecycle of rolling stock. Railway vehicles last up to 30 years, while road vehicles average about 10 years. Even if DAC is declared the technology of the future, replacing the entire fleet would take at least a decade, making any mass implementation a slow and costly process. According to him, the project is surrounded by uncertainty and scepticism, as operators remain unconvinced and developers remain inert.

During a working trip to Brussels, Hanailiuk saw an electric carriage carrying tourists through the old town. The hybrid vehicle — modern electric drive on a 19th-century chassis — became a metaphor for DAC implementation: "If you put 21st-century technology with electric propulsion, digital control, and modern batteries on a 19th-century carriage, it will move — maybe even comfortably — but it’s a tourist attraction, not a transport system."

The same, he argues, applies to DAC: installing a future technology on outdated vehicles cannot deliver real transformation. The old design, infrastructure, and operational systems aren’t built for it, so DAC would never reach its full potential. "As long as we try to ‘plug in’ DAC to existing wagons and outdated technologies, we’ll be repeating the transition path from motorised wagons to modern cars," he says.

DAC Only Makes Sense if the Entire Railway is Renewed

"Every revolutionary technology requires revolutionary change," Hanailiuk emphasises. "But only after full implementation can its benefits be realised." He questions whether it is worth spending public funds on a decade-long DAC rollout in an outdated transport system, noting that costs will likely exceed public financing.

Instead, DAC should be a trigger for real rail renewal and a return to industry leadership. History shows that success favours those who adapt faster, not those with the best ideas. Railways, he warns, lose systematically to road transport because they innovate three times slower. And in any ecosystem, the faster one always wins.

Old Railways, New Technology: DAC Meets Systemic Stagnation

Rail has undeniable physical advantages (aka minimal energy costs for horizontal movement), but that’s not enough without an ecosystem of speed: quick access, loading, transit, and delivery. Fear of incidents, overregulation, outdated standards, institutional complexity, and slow procedures create an environment where innovation is too expensive and slow, far behind the automotive sector.

As a result, the railway modernises too slowly, loses market share, and follows rather than leads. Some hybrid innovations are emerging, such as piggyback transport or horizontal truck loading, but since these trains carry only 35–40% of their total weight in actual goods, Hanailiuk calls them pseudo-innovations, diversions from real efficiency.

This, he argues, is not merely a technical problem but proof of systemic stagnation. The introduction of DAC could and should act as a catalyst for innovation in rail and combined transport, but only as part of a broader renewal strategy.

DAC is the Key to a Modern Railway, but Not for Old Wagons

DAC is undeniably one of the key technologies of future rail transport. It enables automatic coupling, data and power transfer, wagon synchronisation, enhances safety, and reduces human error. More importantly, it redefines the logic of rail operations, integrating train assembly, container handling, freight management, and locomotive communication into a single digital system.

However, such a system cannot function efficiently if it is based on obsolete rolling stock designed for slower speeds, lower loads, and outdated operational assumptions.

Why Implementing DAC on Old Wagons is Economically and Technically Irrational

Today, the average cost of a DAC set is comparable to a modern electric car, even though it’s ten times simpler in mass and complexity. Such an investment only makes sense if the system significantly cuts time, energy, and costs, which it doesn’t for old wagons.

Existing wagon geometry, designed for legacy couplers, cannot handle DAC’s dynamic loads, and while technically operational, DAC-equipped wagons wouldn’t reach full performance. Even the height and angle of coupling differ, limiting the promised stability and safety. Moreover, there’s no digital infrastructure to transmit the data DAC enables. Returning to his analogy: "You can’t use a car engine’s full power on a horse carriage — it was built for horses."

DAC Should Be the Basis of a New Generation of Trains

DAC only makes sense as part of a new generation of wagons, designed for 21st-century requirements. Such wagons should have:

• Optimised weight-to-volume ratios, where the wagon and container make up only 20–25% of the total load capacity.
• Maximised usable cargo space per train length.
• High energy efficiency, cutting transport energy costs per tonne-kilometre by at least half.

Hanailiuk proposes introducing DAC only on modern wagons as they enter the market, accepting a temporary coexistence of two coupling systems. This would require organisational measures — for instance, designating specific stations for DAC operations during the transition period.

DAC as a Tool for Multimodal Integration

DAC’s potential lies not only in technology but also in transport organisation. It could become a universal interface between rail and road transport, ending competition between modes and fostering synergetic development aligned with the EU Green Deal.

Different transport modes, operators, standards, and networks could interact through a shared technological language. However, this requires fully redesigned rolling stock and logistics systems for the future.

Thus, DAC is neither an overrated innovation nor an overly expensive project. It is a powerful tool for rail development. But to make it work, its implementation must go hand in hand with the creation of new-generation vehicles and technologies.