In 2020, Savske Elektrarne Ljubljana entrusted us with their largest project in the field of hydromechanical equipment renewal, namely the replacement of overflow fields 1 and 2 at HPP Medvode. The hydroelectric power plant, located in the centre of Medvode above the confluence of the Sava and Sora rivers, was built in 1954. After almost 70 years of operation, the renovation of the sluices was necessary. These are double hook locks, which were the standard designs for that time of construction and were manufactured by our predecessor Metalna from Maribor.

Every project begins with the creation of documentation (project documentation for construction). Due to the barrier, the new lock had to remain the same dimensions as the old one, but with a touch of new technologies. Our design office, Montavar Projekt LJ, met the challenge perfectly and the documentation was prepared in a quick time without any practical errors that could have occurred during production and assembly.

After the documentation was prepared, the equipment was manufactured in the premises of Metalna. A big challenge was the size of the gates, so the assembly, welding and machining had to be at a very high level. Our employees made sure that it was carried out within all the prescribed tolerances and made with high quality. All in all, she constantly monitored the control with various inspections and tests.

The special feature of the sluice gates for HPP Medvode is that all equipment is fully metallized and then painted on the basis of epoxy coatings. The last covering layer is made with a polyurethane coating that offers good UV protection. We entrusted the entire ACP corrosion protection to the company Tekol.

The biggest challenge was the installation of the sluice gates. Basically, the elevators at the hydroelectric power plant are not designed for lifting the sluice gates from the niche, so it was necessary to foresee the complete dismantling of the old sluice gates and the installation of new ones down to the last detail. All the guides embedded in the concrete and along which the rubber of the sluice gates slide were also renewed. The chain, which is used to lift the gates via drives, was also replaced.

The peculiarity of the work on the project was that we had a very narrow window from the closure of the overflow field to the completion of all the work and its reopening, since there are only 2 fields at the electric plant (for comparison, on the Drava, there are 4 fields at all power plants). There could also be problems in case of high water. We have to thank nature, because it was very dry during the two-year period when the work was carried out in this way.

The project was completed at the end of 2022. This was the second largest project  for our company, right after the construction of the hydromechanical equipment of HPP Brežice. We cooperated good with the client’s supervisors and all involved contractors. Implementation of such a large-scale project was of high quality and completed within the stipulated time.