International maintenance project
August 11, 2025 | Moritz Glück
From May 10 to July 12, 2025, production in Pirdop came to a standstill — every single day meant losses of around one million euros. “The pressure was correspondingly high to meet the tight schedule. In the past, a single filter could be replaced in 45 days; in Pirdop, two 450 ton colossi had to be replaced in just 62 days,” explains Yordan Georgiev, General Manager Felbermayr Bulgaria, and shows the dimensions of the project. The scheduled maintenance shutdown thus marks the largest maintenance project at the site in the past three decades. For Southeast Europe, this is a milestone in copper production
Impressive lifting technology
The overall responsibility for lifting technology lay with Felbermayr Bulgaria, with active support from Felbermayr colleagues from Romania. The main protagonist of this blockbuster project was a 750-ton crawler crane — powerful enough to lift around 190 elephants in one go and at the same time sensitive to the millimetre to precisely position the new filters. The crawler crane was accompanied by a 650-ton truck-mounted crane, which, among other things, made it possible to build a bridge crane and thus secured further heavy-duty manoeuvres. The parallel use of two 600-ton crawler cranes was also required. When it became apparent shortly before the start of the project that one of them was not available, a replacement from Poland could be arranged within a few days — coordinated by the Felbermayr headquarters in Wels. For client Aurubis, this made it clear that a partner like Felbermayr impresses with flexibility and reliability — and is not just a requirement, but almost a guarantee of successful implementation.
120 individual projects
In addition to the replacement of the electrical filters, six heat exchangers weighing between 100 and 150 tons were replaced in sulfuric acid production. The complete renovation of the melting furnace was also a particular challenge: More than 100 truckloads of 1,500 tons of fireproof bricks, 300 tons of steel structures and 15 kilometers of copper pipes had to be installed for this purpose. During the two-month shutdown, a total of more than 120 individual projects with a total volume of 115 million euros were implemented — a dimension that is exceptional even by international standards.
Precision under time pressure
“A tight schedule and the enormous loads made this project a particular test. Every move had to be right, every work step was meticulously planned. “Each additional day of use would have caused production losses amounting to millions of euros. The pressure was enormous — that motivated us to work even more precisely and efficiently,” says Georgiev, describing the challenging situation.
A total of 19 cranes and more than a dozen work platforms were in use on the factory premises. Even at the start of the project, it was clear that ten cranes had to be in use around the clock — including operating personnel. Another test was therefore the provision of our own employees in order to secure “24/7 operations” in the long term. Despite the extensive amount of work involving hundreds of specialists, the project went without significant incidents — the result of over a year of preparation involving around 2,000 specialists from twelve countries. For Georgiev, it was impressive to see: “How quickly our departments from Bulgaria and Romania formed a single unit and then worked at full speed around the clock in shifts for a month. A logistical, technical and, above all, human masterpiece that you don't experience every day. ”
Modernization with a signal effect
For Aurubis, the modernization in Pirdop marks an important step towards the future. The new plants are more efficient, safer and have a significantly better energy balance. For Felbermayr, too, the project was a reference achievement of international standing. “The project in Pirdop is a strong sign: With our technology and know-how, we can secure even the largest industrial projects — and coordinate this internationally,” underlines Georgiev.
After 62 labor-intensive days, the Pirdop plant was able to resume production — with modernized technology and assured sustainability. For Felbermayr, the commitment was further proof of how international teams, using the latest technology, supported by high precision standards, can achieve great things even under demanding conditions.
