A month and a half have passed since TRAKO 2025 in Gdańsk, where the achievements and plans for the implementation of Digital Automatic Coupler (DAC) were presented prominently. The programme of events regarding DAC was rich, the speakers’ speeches meaningful.
Borys Ganaylyuk, from Ukraine, is a physicist by training, with a career spanning research, economics, and industrial management. After starting out in a research institute, he transitioned into economic consulting and later led major automotive enterprises in Lviv. Since 2018, his focus has shifted to research on the Lviv railway junction, bringing his multidisciplinary expertise to the rail sector.
Almost all speakers who were critical of DAC, and there were a few of them, agree on one thing: the price. It was not said outright, and numerous other arguments were given, but in reality the price was the only significant reason against DAC.
Today, the implementation of DAC would increase the average price of a wagon by at least 30%. And so far, the market does not see clear economic advantages that will allow wagon owners to compensate for these costs.
Automatic coupling certainly reduces the number of manual operations when forming and breaking up trains. However, in modern railway logistics – where direct trains without rail yard sorting are increasingly used – the potential of this advantage seems limited.
For intermodal transportation, where trains are formed on the route “from terminal to terminal”, the need for constant uncoupling of wagons almost disappears. In such conditions, it is enough to equip only the main wagons in the composition of permanent trains with DAC – that would be sufficient for changing locomotives or operations where networks intersect.
For other types of transportation, where sorting yards and the recomposition of trains are still used, the economic effect of DAC is also questionable. The average annual mileage of wagons and the number of coupling-uncoupling operations simply do not give a chance for a return on investment.
Rolling stock’s long life cycle as a hindering factor
Railway rolling stock has an extremely long life cycle – up to 30 years, while in the road industry it is only 10. So, even if DAC is recognized as the technology of the future, replacing the entire fleet will take a decade. And this turns any attempt at mass implementation into a process with an extremely slow return.
The general “aftertaste” of TRAKO 2025 regarding DAC is thus uncertainty and skepticism – carriers do not accept this innovation, developers act by inertia.
A month later, during scheduled working meetings in Brussels, this impression was confirmed. Walking through the city center, I saw an electric-powered carriage that takes tourists along historic streets.
This carriage, as a strange hybrid of ultra-modern solutions implemented in a traditional rolling stock from the 19th century, best symbolises the problem of implementing DAC – a story that has occurred more than once when changing technological eras.
We take the technology of the 21st century – an electric drive, digital control, a modern battery – and install it on a 19th-century structure. Yes, it moves. It can even be convenient and comfortable for leisurely movements through the historical part of the city and attractive for photos. But this is an attraction, not a transport system.
We observe the same thing with DAC: we are trying to install the technology of the future on the rolling stock of the past. And this modern DAC technology, being implemented in the existing rolling stock that works without it, in fact does not bring something so good that it is impossible to work without it – because we have been doing without it for decades.
Moreover, it would not work to its full potential, would not reveal its potential, because the old basic design, infrastructure and transportation technologies are not adapted to this new technology and new conditions. As long as we try to “attach” DAC to existing wagons, to existing transportation technologies, we will repeat the path that wagons have taken from motorised carriages to modern cars.
Every revolutionary technology brings revolutionary changes. And only after the implementation of all changes is the real effect of the introduction of this revolutionary technology achieved.
Is it now, after the experience of numerous revolutionary changes, worth spending public funds and efforts on many years of DAC implementation in outdated transport?
Why railways are losing to trucks
The implementation of DAC can and should be a chance to truly renew rail transport and return the railways to their lost leadership. History proves that the winner is not the one who has the best idea, but the one who evolves faster. Railway transport systematically loses to automobile transport. The reason is obvious – railways are updated three times slower than the road sector. And as evolutionary logic shows, the ecosystem that updates faster always wins. This simple conclusion is the whole essence of the problem.
Yes, railways have an undeniable physical advantage – minimal energy costs when moving horizontally. However, this advantage is not enough if there is no ecosystem that provides quick access, quick loading, quick shipment of cargo and quick route passage.
Fear of extraordinary events (the prevention of which is important and unconditional), excessive regulation, standards that are not updated, tolerances, procedures, institutional complexity – all this creates an environment that limits the possibility of introducing innovations due to the cost and time of implementation, which are several times higher than in automobile logistics.
As a result, the railway is modernising too slowly, losing market share, and therefore leadership, forced not to lead, but to catch up.
There are attempts at change – technologies for combined transportation are being developed, with swap bodies and piggyback transportation – automobile trucks on specialised platforms, and even various technologies for horizontal loading of trucks.
But since the theoretical useful mass of goods transported by such a train does not exceed 35-40% of its total mass, this is a pseudo-innovation, a mutation that distracts from the development of effective transportation systems rather than a step towards a new type of transport.
This state of affairs is not just a technical problem. It is evidence of systemic stagnation. And the introduction of DAC in this context can and should be an impetus for the evolution of rail and combined transport technologies.
DAC is a major breakthrough, but not in that context
DAC is, without exaggeration, one of the key technologies of the future of rail transport. It is the basis for the digitalisation of the industry: it provides automatic coupling, energy and data transmission, synchronisation of wagons in a train, increases safety and reduces the human factor.
But most importantly, DAC changes the logic of railway operation. This is not just a new coupling, it is an element of a system that can combine all processes: train formation, container operations, load control, locomotive interaction and sorting automation.
However, this system cannot function effectively if the basis is old rolling stock designed for a different era, other speeds, other loads and even other ideas about the railway.
Why implementing DAC on old wagons is economically and technically irrational
Today, the average cost of a DAC set is comparable to the price of a modern electric car, although it is tens of times simpler in terms of mass and complexity. Such a cost can be justified only when the system provides a qualitative effect – reducing time, energy, increasing productivity.
This will not happen on the old fleet:
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- The structural geometry of existing wagons that were designed for the current train coupling system and the behavior of wagons in the train does not correspond to the dynamic loads that arise when using DAC.
- And even if the wagons can work with the new coupling, they will not be able to fully use the advantages of driving trains (dynamics, speed).
- The height and angle of attachment of autocouplers vary, so DAC will not be able to fully realise its advantage in stability and safety.
- There is no digital infrastructure for data transmission, which DAC provides in the basic architecture.
Returning to the analogy with a carriage, it is impossible to use the power and capabilities of the engine on the carriage – it was designed for a pair of horses from the front pulling the drawbar and is simply not able to move with the parameters that the engine can provide.
DAC as the basis of a new generation of trains
DAC makes sense to implement only as part of a specially designed rolling stock – a new generation of wagons created for the requirements of the 21st century.
Such wagons should have:
- Balanced mass-dimensional parameters, where the wagon and container is no more than 20–25% of the total mass permissible for transportation;
- Optimised useful volume for transporting freight per linear metre of train;
- Energy efficiency, which allows reducing energy costs for transporting one tonne-kilometre by at least half;
- Other equally important parameters.
That is, it is proposed to use DAC only on modern wagons that will enter the market and not to be afraid that there will be two coupling systems for some transitional period.
Certain organisational solutions will be required for that – such as a gradual determination of stations that will work with the new coupling.
DAC as a tool for multimodal integration
The potential of DAC lies not only in technology, but also in the organisation of traffic and logistics. It can become a universal interface between rail and road transport to end competition and jointly develop mutually beneficially, contributing to the achievement of the goal of the Green Deal and modal shift through synergy.
This is precisely the key to a new model of European transport integration – when different types of land transport, operators, standards and networks are able to interact through a common technological language. However, this requires fully designed rolling stock and transportation technologies of the future.
Instead of a conclusion
DAC is not an overestimated innovation and not an overly expensive project. It is a powerful tool for the evolution of rail transport. But for it to work, the implementation process must be accompanied by the development and implementation of appropriate rolling stock and appropriate transportation technologies.