One of the largest and most visible landmarks of Styria’s industrial and mining history is now history itself. The 145-meter-high industrial chimney known as the “Long Ernst,” built in 1975 at the former RHI Magnesite Works in Trieben, Upper Styria, was demolished in a controlled explosion at midday on Saturday. Before the blast, houses were evacuated, and traffic was halted along the Schoberpass federal highway (B113) and the ÖBB railway line through the Palten-Liesing Valley.
According to the municipality, the B113 was closed from 9:00 a.m. to 1:30 p.m. between the Bahnhofstraße intersection and the town exit toward Gaishorn. Four public viewing zones were set up for residents and spectators, while restricted areas were cordoned off with tape. Fire department sirens served as detonation signals and to mark the start and end of the blast. In a curious side note, unknown individuals had painted rainbow colors above the five red-and-white stripes at the top of the tower in September, according to the Kleine Zeitung.
Train Passed Before Explosion
At 11:10 a.m., a train still passed through the area before ÖBB suspended rail traffic until 12:50 p.m. Fritz Hanisch, construction manager at demolition company Zöchling from Haindorf in Lower Austria, said preparations for the explosion took up to five months. The actual detonation was carried out by a subcontractor. For Hanisch, it was the first time demolishing a structure of such height. The challenge was to ensure the chimney fell precisely between the B113 and the railway line, within the old plant site. “It fell exactly as we wanted,” Hanisch told APA after the successful demolition.
A “hinge” of concrete was built to make the chimney fall in the correct direction, similar to felling a tree with a wedge. A “fall bed” was also prepared and thoroughly soaked to minimize vibrations, Hanisch explained. No major issues were expected, though a thunderstorm would have caused a delay due to the electrical ignition system.
Four water-operated dust-suppression cannons—similar to snow cannons—were used to keep dust levels as low as possible. “Water walls” created by the fire department also shielded nearby houses. Around 27 kilograms of gelatinous explosives were installed in 150 drilled holes and connected by cables. The charges were detonated in three stages within milliseconds. Clearing the debris will take about three weeks, Hanisch said, noting that the material will be crushed and recycled.
A Landmark With A Long History
Zöchling, the demolition and disposal company based in Hainfeld, Lower Austria, had already demolished another building at the former magnesite processing plant in Trieben: in July 2025, the 70-meter-high factory building was blown up and dismantled.
The site has a storied past. In April 2004, it served as a disaster response training site for the major “Schutz 04” military and emergency exercise, simulating a terrorist attack at the magnesite plant. The magnesite once came partly from the nearby mine in Hohentauern, west of Trieben, known as “Sunk.” Magnesite was also mined in Radenthein (Carinthia), Veitsch and Breitenau (Styria), and Hochfilzen (Tyrol).
The Sunk mine was closed in the early 1990s. The Trieben plant—initially owned by Veitscher Magnesitwerke, later Veitsch-Radex, and finally RHI or RHI Magnesita—was one of the region’s largest employers, with about 1,000 workers in the refractory industry. By the end, only 20 remained. The site’s current owner, a German company, plans to redevelop it for business use.
One Of Styria’s Tallest Structures
At about 145 meters tall, the “Long Ernst” was one of the tallest structures in Styria. For comparison, the tallest church tower in the state, the Herz-Jesu Church in Graz, stands at roughly 110 meters.
A similar demolition had already taken place in Styria: the 180-meter chimney of the Voitsberg coal power plant was also brought down in a controlled explosion in 2015. The first attempt failed, and a second blast was required to topple the structure. The Voitsberg tower, once the tallest in Styria, was demolished after the Verbund company shut down the unprofitable brown coal-fired plant.
