Interview with Klaus Schneider, Project Manager of the Koralm Tunnel

Innotrans Report:
Mr. Schneider, you’ve been involved with the project for 28 years. It went into operation in December. How does it feel now that it’s over?

Klaus Schneider: Of course, there is great joy in having successfully completed such a long and difficult project, one that has moved and occupied us for so long. It wasn’t just the launch itself that was a success. The enthusiasm and joy with which people are embracing this new connection is a huge thank you. At the same time, there is also a touch of wistfulness, but that’s only natural when letting go of something that has been with you for so long.

There were ups and downs throughout the whole time. What do you remember most?

Klaus Schneider: The centerpiece of this 130-kilometer new section is the 33-kilometer-long Koralm Tunnel, the sixth-longest tunnel in the world.

The challenges we faced in this tunnel were immense. We conducted extensive surveys beforehand, but tunnel construction remains one of the last great adventures. We enter a space that no one has ever entered before, because we create it ourselves. Geologically, it was challenging, especially when it came to mechanical tunneling and the very thick overburden. We have 1,200 meters of overburden there; it’s warm there, and there’s a lot of pressure.

These geological conditions kept us quite busy, for example with cyclic counter-excavation. Anyone involved in tunnel construction knows that a one-year delay isn’t just a one-year delay in construction, but also costs an immense amount of money.

In the end, in 2020, the pandemic hit us with full force, just a few weeks before we were set to break through the final section of the tunnel. Construction was temporarily halted to ensure everything was under control from a safety standpoint. We were able to make up for the tunnel breakthrough three months later, but we couldn’t celebrate it the way one would normally celebrate after twelve years in the tunnel and already 20 years of construction. That was emotionally very challenging.

The third factor is the duration itself. The biggest challenge is actually the long timeframe involved in planning and implementing such a project. Everyone knows that technological lifespans are getting shorter and shorter. We already know this from cell phones alone.

In the early 2000s, we completed the planning for a project that was supposed to go live in 2025 and represent the cutting edge of technology—and even look toward the future. Transport infrastructure projects have an extremely long service life of 150 to 200 years.

We don’t know what kinds of vehicles will be traveling on the Koralmbahn infrastructure in 100 years, but the infrastructure itself must remain stable and durable. This discrepancy in time horizons poses a major challenge.

Constantly weighing how much change and innovation to allow, and which fundamental aspects of the project must remain stable, is a major challenge. Ultimately, we had to obtain an operating license based on the approval granted 20 years ago. We are proud that, following a six-month extensive trial operation, we received confirmation last year that everything we built meets the requirements and that we actually obtained a legally valid operating permit before December 14, 2025.

One was the timeline, another was the technical challenges of the Koralm Tunnel, and the third was the emotional toll of the COVID-19 pandemic. We really didn’t leave out a single risk you could possibly imagine—and yet we pulled it off.

A lot has changed over the years—new materials, new technologies. How have you dealt with the new technical possibilities that have emerged over time?

Klaus Schneider: One last thing on that—which brings me to your question about developments.

The final, fourth point is that we must continually scrutinize guidelines, standards, and procedural instructions. It is important to grasp the spirit of a rule—what I call the “ratio legis”—and not just the wording. Especially in times when bureaucracy is a burden, this offers an alternative approach. This allowed us to integrate innovations without altering the character of the project.

When it came to tunnel doors, for example, we looked beyond our borders: In Switzerland, sliding doors were the state of the art, while in Austria and Germany we tended to use swing doors. Due to the extreme pressure conditions in the Koralm Tunnel, we developed, tested, and introduced a new generation of tunnel doors.

Another example is drainage. Typically, there are two secondary drains and one main drain; these systems require a great deal of maintenance because they must be protected against silting and flushed regularly. We wanted a tunnel that required as little maintenance as possible, so we replaced two-thirds of the traditional drainage pipes with a surface filter system. Water flows maintenance-free into the main drainage line via a dimpled membrane without causing silting. This works very well and significantly reduces operating costs.

Then BIM (Building Information Modeling) came into play. We planned and modeled the entire tunnel—structural work, railway equipment, control systems, trackwork, and ventilation—using BIM. At the time, this was a novel approach on this scale, and it allowed us to simulate construction processes early on, optimize material quantities, and clarify interfaces.

So we allowed for a great deal of innovation, as long as it didn't alter the spirit of the project and fit within the cost and risk framework.

Are the innovations and inventions from the Koralm Tunnel now being used elsewhere?

Klaus Schneider: Yes, there are quite a few. The new tunnel doors are now standard in all tunnels in Austria. As for the surface filter system in the drainage system, some are still waiting to see how it performs over the long term. BIM is now state of the art for projects of this scale.

Another fascinating topic was life-cycle costs and the climate control of the equipment rooms. In the Koralm Tunnel, these rooms are located in the cross-passages, in areas with high geothermal heat exceeding 30 degrees. Added to this is the waste heat generated by the equipment. We simulated the temperature distribution for each individual room and arranged the equipment so that each unit is located in the appropriate temperature zone.

At the same time, we have accepted that for certain technologies—such as telematics—the technological half-life is only a few years anyway. In those cases, we have deliberately accepted that the technical service life is slightly shorter due to higher temperatures, because the devices will become technologically obsolete sooner anyway. This has allowed us to significantly reduce the costs associated with air conditioning and ongoing operations.

I would like to follow up on that right away: How do you keep costs stable over such a long period of time?

Klaus Schneider: Our Koralmbahn is a project costing around 5.9 billion euros, and we have managed to keep costs stable over the past 20 years or so. This is remarkable, even in an international context.

One might say that we simply set the initial costs very high. But that is not the case. Compared to other major tunnel projects, we are in an impressively low cost range when benchmarked against such megaprojects.
Instead of asking, “How much will it cost?” we asked ourselves, “How much will it have cost by the time it’s finished?” That’s the real crux of the matter. And in the end, after 20 years, we were off by just a fraction of a percent.

With a project of this duration, it’s essential to factor in cost escalation—that is, inflation and cost trends over decades. This involves risks, but there are average figures that can serve as a basis.

In a project like this, risks must be identified at the outset—ranging from geology and site conditions to evolving technological issues, guidelines, standards, and changes in specifications.

These risk categories must be identified and quantified in terms of probabilities and cost estimates. Some people complete this initial step and then—just to give a rough estimate—quantify the risks at 20 percent of the total. However, identifying risks and documenting unknowns is merely the groundwork. The real challenge begins with the ongoing quarterly management of these risk assessments within the project team. Actively intervening in the project when deviations occur—that is, implementing active project management—is the second key to success.

When a risk escalates, countermeasures must be taken in other areas and the project must be adjusted accordingly. This requires courage and a team that embraces this approach.

The Koralmbahn consists of many individual construction projects and a very diverse group of people. The mindset of keeping costs under control must be reaffirmed at every stage. Instilling cost awareness throughout the entire team is an ongoing task. One thing must never be forgotten: behind all these superlatives are people. Every single screw has been tightened by a person. If it has been implemented incorrectly, even a very complex project cannot succeed, even though it may seem like a trivial task.

We have consistently carried out cost management on a quarterly basis with the lead team members in all sub-sections. This has a great deal to do with culture and people and is one of the key factors for success. It is important to instill this sense of appreciation and responsibility in each individual within the team—to foster responsibility, personal accountability, and trust. This is a mindset and is part of the toolkit of project management.

The project was put out to tender across Europe, yet about 97 percent of the participating companies were Austrian contractors. Are the Austrians the best at this?

Klaus Schneider: That’s obviously a leading question—I’d have to say “yes” to that. The fact is: We put all major contracts out to bid across the EU, as is standard practice. In this international competition, Austrian companies came out on top in the majority of cases. Austria is a powerhouse in the rail industry and has a long-standing reputation in tunnel construction—just think of the new Austrian tunnel-boring method. We are in a very strong position globally in the railway export sector, and this is also reflected in this project.

The Koralmbahn project is now complete. What are you working on now?

Klaus Schneider: The Koralm Railway isn’t quite finished yet—some construction contracts and final invoices are still pending. At the same time, there is a major follow-up project on the same Baltic-Adriatic axis from Gdańsk via Vienna to the Adriatic region: the connection north of Graz between Bruck an der Mur and Graz. There, the line is to be upgraded to 250 kilometers per hour and include another long tunnel of about 20 to 25 kilometers. We will begin planning this year.

I myself will not be able to see this project through to completion—my professional career is too short for that—but I am delighted to get it off the ground. We have a very good team—young yet experienced—and I hope that the spirit of project management will live on there.

Mr. Schneider, thank you for this interesting conversation.