VERBUND’s Kaprun 2029 Project Reaches Major Milestone with Tunnel Boring Machine Launch

VERBUND’s Kaprun 2029 Project Reaches Major Milestone with Tunnel Boring Machine Launch

(IN BRIEF) On February 18, 2025, the tunnel boring machine (TBM) for VERBUND’s Kaprun 2029 project began its 5.6-kilometre journey from the Limberg valve chamber to the surge tank beneath Maiskogel, marking a key milestone in the project’s modernization efforts. The tunnel’s launch was celebrated with the traditional miner’s greeting “Glück Auf” by approximately 200 guests, including VERBUND hydropower leaders, project managers, and tunnel patron Kathrin Aberger-Dick. The goal of the Kaprun 2029 project is to build a new headrace, ensuring the continued safe flow of water from the Wasserfallboden reservoir to the Kaprun power plant. The tunnel boring machine used in this project, which has previously worked on Limberg II and Limberg III, weighs 1,200 tonnes and is designed to excavate the pressure tunnel at a rate of 15 metres per day. With an investment of 370 million euros, this project will modernize the infrastructure to meet Austria’s green energy needs for decades.

(PRESS RELEASE) VIENNA, 20-Feb-2025 — /EuropaWire/ — On February 18, 2025, VERBUND’s Kaprun 2029 project reached a significant milestone as its tunnel boring machine (TBM) began its 5.6-kilometre journey from the Limberg valve chamber to the surge tank beneath the Maiskogel. The machine’s launch was celebrated with the traditional miner’s greeting, “Glück Auf,” marking the commencement of an essential phase of the modernization of the Kaprun-Hauptstufe power plant, scheduled for completion by the end of 2027.

The event, known as the “turning ceremony,” was attended by around 200 guests, including VERBUND’s hydropower management team, Michael Amerer and Karl Heinz Gruber, tunnel patron Kathrin Aberger-Dick, and key project representatives from ARGE, including Jürgen Raschendorfer (COO, Porr AG) and Bernd Raderbauer (Marti Tunnel AG). Together, they pressed the button to start the TBM’s drill head, setting the project in motion.

The goal of the Kaprun 2029 project is to build a new headrace, ensuring a continued, safe, and efficient flow of water from the Wasserfallboden reservoir to the power plant, enabling VERBUND to provide green electricity and flexibility to Austria for decades. The new pressure tunnel will serve as the heart of the project, which is part of an extensive upgrade to the power plant’s infrastructure.

The tunnel boring machine used in this project is a familiar piece of technology, having been previously employed in the Limberg II and Limberg III projects. While the TBM’s essential components, including the cutting head, were replaced and adapted, the machine remains a proven tool for excavating headwater channels. With a 6.90-metre diameter cutterhead and 42 cutting rollers, the TBM weighs an impressive 1,200 tonnes and spans around 190 metres in length. The various components of the TBM were transported to the assembly cavern in 90 challenging journeys and assembled on-site in just eight weeks.

Michael Amerer, Managing Director of VERBUND Hydro Power, commented: “We are building on the legacy of those who reconstructed Austria after the Second World War. The launch of the first metres of the new pressure tunnel is an important step for VERBUND. This tunnel is central to our project, which will modernize the power plant by 2029, ensuring that we can continue providing sustainable energy to Austria.”

VERBUND project manager Maria Leo added: “The start of the tunnel boring work is always a special moment, and we are thrilled that the preparations have gone so smoothly. With the geology well understood, we are confident that the TBM will progress as planned. Much of the work will take place underground, minimizing the environmental impact of the construction.”

Kathrin Aberger-Dick, the tunnel patron, expressed her personal connection to the project: “Having grown up with the high-altitude reservoirs in Kaprun, it is an honor to serve as the earthly representative of Saint Barbara, the patron saint of tunnel builders. I hope the work progresses without incident and that the TBM reaches its destination smoothly.”

Over the next year, the TBM will cut through rock at an average rate of 15 metres per day, reaching the new surge tank in about 12 months. The pressure tunnel will be around 5,600 metres long, with an average incline of 0.50% and an excavation diameter of 6.90 metres.

A unique aspect of the project is the rail system used to supply the TBM. Rails are installed along the tunnel to transport the machine, while approximately 200,000 cubic metres of excavated material will be removed via a conveyor belt system. This innovative approach helps alleviate regional traffic congestion and reduces the overall environmental impact of the construction.

With an investment of approximately 370 million euros, the Kaprun 2029 project is a key part of VERBUND’s commitment to ensuring the future of sustainable energy generation in Austria.

Media Contact:

Rainer Tschopp
Spokesperson Region West
+43 (0) 664 882 613 32
rainer.tschopp@verbund.com

SOURCE: VERBUND AG