Officially, it’s called the “Microtunnel,” but to us, it’s the biggest one. That’s because it will house the 220-kV lifeline for greentec steel’s electric steel production starting in 2027.
The tunnel carries the high-voltage cable from the connection point in the southern part of the Linz plant site to the new electric arc furnace in the LD3 steelworks
The space required for the towers and the necessary clearances between cables, structures, and people ruled out an above-ground option. In the microtunnel, with its two-meter diameter, the cable runs safely and securely.
The supply of sustainably generated electricity is a cornerstone of green steel production. That is why we worked intensively and swiftly on tunneling beneath our plant site. In the spring of 2024, four shafts were excavated (“sunk”), from which the actual tunnel was driven in three construction phases. As early as July 2025, the boring machine was lifted out of the tunnel, making room for cable installation. The lifeline for greentec steel now stretches over more than 1,700 meters.
Once underground, we take advantage of another benefit of our microtunnel’s location during ongoing operations. At a depth of 25 meters, we ensure low-loss energy transport by carefully regulating the inflow of groundwater: We allow water from one of our deep wells to flow into the tunnel via the first shaft. At the end shaft near the electric arc furnace, we pump it back out, thereby ensuring water flow for efficient cooling of the cables.
Tunnel construction also brings a variety of names. Not only do tunnel godparents lend their names to the new underground structure, but tunnel boring machines are also traditionally given names. Thus, the tunnel boring machine “Andrea” ensured the timely commissioning of our microtunnel. On October 22, it was officially christened “Miriam.” And of course, a hearty “Good luck!” rang out to mark this special occasion for greentec steel.
Within the framework of our focus greentec steel, we provide an overview of our concrete steps on the way towards long-term green steel production and the innovative processes we are using on this way. We provide information about the challenges we face and the breakthrough technologies we are already researching today in order to achieve our goal of steel production with net zero CO2 emissions by 2050. funded by the BMK’s environmental support program.
Die voestalpine ist ein weltweit führender Stahl- und Technologiekonzern mit kombinierter Werkstoff- und Verarbeitungskompetenz. Die global tätige Unternehmensgruppe verfügt über rund 500 Konzerngesellschaften und -standorte in mehr als 50 Ländern auf allen fünf Kontinenten. Sie notiert seit 1995 an der Wiener Börse. Mit ihren Premium-Produkt- und Systemlösungen zählt sie zu den führenden Partnern der Automobil- und Hausgeräteindustrie sowie der Luftfahrt- und Öl- & Gasindustrie und ist darüber hinaus Weltmarktführer bei Bahninfrastruktursystemen, bei Werkzeugstahl und Spezialprofilen. Die voestalpine bekennt sich zu den globalen Klimazielen und verfolgt mit greentec steel einen klaren Plan zur Dekarbonisierung der Stahlproduktion.