Renovation of the Radar Station on Koralpe

Giant of the Sky: Comprehensive Renovation of the Radar Station on Koralpe

The radar station on Koralpe has undergone extensive renovation. Vasko+Partner was responsible for the local construction supervision, while architect Reinhold Wetschko closely monitored the architecture and adaptation work at this high-alpine construction site.

Austro Control, the Austrian Society for Civil Aviation, is responsible for the safe and efficient management of air traffic in Austrian airspace. To achieve this, three major radar stations are strategically placed. One of them is situated on Koralpe, specifically on the majestic Speikkogel at an altitude of 2,140 meters. This mountain straddles the border between Carinthia and Styria. In this high-alpine terrain, a secondary radar antenna with a range of 500 kilometers is operated. Austro Control constantly tracks the position of each aircraft in the airspace. A secondary radar emits signals at 1030 MHz, which aircraft receive and respond with information about their altitude and identification number.

The Koralpe radar station dates back to the 1970s and is one of the three medium-range radar stations, MBR, along with those on Buschberg in Lower Austria and Feichtberg in Upper Austria. Access to the radar station leads right through the ski resort. The building houses not only garages, workshops, and offices but also a kitchen, operational rooms, and emergency accommodations. Autonomous power supply is ensured by batteries and diesel generators. Due to changes in operational conditions, a renovation of the project, as well as all the related systems, was necessary. All electrical installations, ventilation, heating, as well as drainage and rainwater pipes were renewed. The interior spaces were also renovated – a challenge summarized by Alois Schnabl: "All renovation works were carried out during ongoing operations, as continuous radar surveillance had to be ensured." Additionally, the long and snowy winter on Koralpe kept the team busy from April to October for two consecutive years. During the winter months, work was suspended. All systems were replaced, including the emergency power system with the use of a backup unit. About 800 boreholes for cable passages and provisions were required. Two secure rooms were dismantled, as well as two air calming rooms. The renewal of the floors was also interesting: "The raised floors were completely replaced – the new raised floor was exchanged step by step with the old one," explains Schnabl. Simultaneously, the systems needed cooling. Schnabl is impressed with the overall construction process – a top team, consisting of Austro Control's personnel and the remodeling team, worked together seamlessly like gears. A five-meter-wide rolling door with RC4 intrusion protection was installed, capable of withstanding wind speeds of up to 150 km/h. The entire building is equipped with the highest possible security level.

Under the recognizable dome, known as the "Goldhaube," and visible from afar on clear days, lies the heart of the facility – a 14-ton heavy antenna, a giant of the sky, guaranteeing the safety of civilian air traffic even during the renovation process.