Milestone for the Secure Power Supply in East Tyrol: Transformer for New APG Substation in Matrei Successfully Delivered

The 380/110 kV transformer, the most important component for a substation, was successfully transported from its original site, APG’s Südburgenland substation to its new “workplace”, the substation in Matrei, where it arrived on April 1^st by means of an impressive heavy load transport. As of the summer of 2025, the transformer, which has a capacity of 200 megavolt amperes (MVA), will connect the Austria-wide APG grid with the regional distribution grid of TINETZ and help to make the electricity supply in East Tyrol much more secure. In addition, it will facilitate the transport and distribution throughout Austria of locally generated electricity from renewable sources that is not fully consumed.

Relocation from Burgenland to East Tyrol: a transport that had to be meticulously planned

"APG's transformers have a long service life of 40 to 50 years. This means that the 'giants' sometimes change location," says Wolfgang Ranninger, who has been managing substation projects for Austria's electricity grid operator APG (Austrian Power Grid) for 10 years. This is exactly what happened in this case: In the summer of 2024, a 380/110 kV transformer with a higher capacity of 300 MVA was installed in Burgenland, where wind turbines produce enormous amounts of electricity every day. The 200 MVA transformer that was previously in operation at the Burgenland site up until then had the technical specifications that made it perfectly suitable for the new site at Matrei – obviously, it was most cost-effective and sustainable to relocate the transformer.

"The first considerations regarding the transport started back in 2021," recalls Ranninger, remembering the beginnings of the heavy load transport, which had to be planned with military precision. From March 28 to 30, 2025, the transformer was initially transported by rail from Oberwart (Burgenland) via St. Veit a der Glan (Carinthia) and Dölsach (Tyrol) to the Lienz substation in Nußdorf/Debant, which is directly connected to the rail network of the Austrian Federal Railways (ÖBB). The final stretch to the new 380/110 kV substation in Matrei, which is a joint project of APG and TINETZ and is currently under construction, had to be covered by road. "A transport like this cannot adhere to the normally applicable traffic regulations. It requires years of planning in advance and thorough coordination with various local authorities. The route was meticulously scrutinized, transport route analyses were carried out, curve radii and bridge crossings were measured and in some cases even digitally simulated," reports Ranninger

489 tons on their way through the Isel Valley

The transformer is a true giant: 12 meters long, 4 meters wide, 5 meters high, and weighing 236 tons. At 489 tons, the total weight of the transport train was even more than twice as heavy. Two trucks, each with 630 HP, were needed to overcome the inclines along the route: one to pull and one to push.

The exit from the Lienz substation took around 20 minutes.  "The logistics team guided the vehicle out of its 'parking space' with the utmost precision: With a total length of 80 meters, 42 m of which are rigid, every bend is a challenge - but the experienced technicians and especially the drivers from the transport company know how to carry out such extreme manoeuvres," emphasizes Ranninger, who has plenty of experience himself with numerous transformer transports throughout his career at APG. Beforehand, various fences and installations had to be temporarily dismantled along the B100 (Drautalstrasse), and a bend had to be fortified. At 7 p.m., the gigantic transport unit, escorted by 5 special cars, drove at walking pace onto the B100 and on towards Lienz, where adaptations to the traffic infrastructure were also necessary, for example, the removal of some traffic signs. Hundreds of interested spectators enthusiastically followed the spectacle along the route.

Finally, uphill through the Isel Valley, the team had to manoeuvre safely over 7 bridges on the B108. Ranninger: "Three bridges had to be crossed using so-called 'flyovers’, mobile bridge constructions that help to deal with the huge weight. This is a real tightrope act in which the driver has to cross the temporary bridges very slowly and evenly, without braking or accelerating - this is the only way to distribute the weight evenly. Abrupt braking manoeuvres or immediate acceleration would lead to adverse loading of the bridge." The installation and crossing of all flyovers took around 3 hours. Thus, traffic had to be temporarily diverted onto the L 393 (Kienburger Landesstraße) between St. Johann am Walde and Huben. Apart from this, three other bridges had to be structurally reinforced in close coordination with the Tyrolean provincial government and TINETZ.

Permanent coordination from start to finish

To stick to the schedule and keep traffic disruption to a minimum, the well-rehearsed team stayed in constant contact via radio and coordinated every move. "The approximately 29-kilometre journey from Lienz to Matrei at a maximum speed of 20 km/h took 7 hours. The transformer finally arrived at the substation at 1:30 a.m.," says the APG project manager, and he adds: "The next day, it took another 4 hours to place the giant on its watertight foundation." This also requires precision work: "First, the necessary equipment is brought into position to lower the transformer from the transporter and place it on the train tracks. Then it is pulled centimetre by centimetre to its destination by two hydraulically driven cable hoists."

From the Isel Valley to everywhere in Austria

"The transformer is the heart of every substation. From the summer of 2025, East Tyrol will be supplied with electricity from APG's Austria-wide grid from the Matrei substation. Or vice versa: electricity from hydropower and photovoltaic systems that cannot be fully consumed locally will be fed into the system, transformed at the substation, and from there transported to wherever it is needed or to the large storage power plants," says Ranninger, highlighting the importance of the substation. The new transformer is the link between the regional 110 kV grid of TINETZ on the one side and the 380 kV APG high-voltage lines on the other. "The ability to transport electricity generated from renewable energies over long distances within Austria reduces our dependence on imports from abroad. We are thus making another step towards a secure power supply for the Isel Valley, East Tyrol, and Austria as a whole," says Ranninger. The Matrei substation is being planned and built in close cooperation by the specialists from TINETZ and APG; the total investment for the new Matrei substation amounts to 46.5 million euros. 

APG plans to build another 65 transformers across Austria by 2034

Projects like this are the key to a secure decarbonization of the electricity supply. The APG grid development plan envisages the construction of another 65 transformers by 2034. Over this period, Austria’s TSO will invest a total of nine billion euros in the expansion and conversion of the grid infrastructure and its digitalization to make all players in the energy system available for operational purposes (including flexibilities) in the future. This will increase the security of supply for businesses, industry, and society in Austria and facilitate the electrification of all areas of life as well as the energy transition.