Intense activity in the power plants: diver, floating cranes, stop-logs

The VERBUND power plants on the Danube in Upper Austria are beginning first inspections in autumn

Intense activity in the power plants: diver, floating cranes, stop-logs

VERBUND, Austria’s leading electricity company and operator of the Danube power plants, has started the inspections on its Danube power plants in Upper Austria. The autumn and winter months from September until March are most suitable for such inspection work on account of the low flow conditions.

In the VERBUND power plants of Aschach, Ottensheim-Wilhering, Abwinden-Asten and Wallsee-Mitterkirchen, weir fields, hydroelectric generating sets and sluices are this year being examined for possible damage and renovated. Also being employed in the process are divers and floating cranes, without which no inspection is possible in large power plants.

Every year VERBUND calls in the services of local and regional companies and is thus a reliable client and economic partner, as well as employer in Upper Austria.

VERBUND employees, specialist companies, divers, floating cranes and lively activity on the power plant sites of the Danube power plants in Upper Austria indicate the start of inspection work on the hydroelectric generating sets, sluices and weir fields.

"The hydroelectric generating sets have a very high running time during the six-year inspection interval and, just like the weir fields, are exposed to a high water pressure and vibrations during operation," advised plant group manager Reinhard Kremslehner. "The sluice systems are under a great deal of strain due to the large number of sluicing operations – sluicing can be carried out up to 60 times a day during the summer."

Diving down to depths of 15 metres

The three-member diving team from the VERBUND subsidiary of Lestin are the first to be on-site. Work on the settling of the stop-logs is necessary during the inspection. The diving team comprises the diver and two colleagues, who are entrusted with the diver’s security and air supply. They remain in constant contact via a radio link during the entire diving operation. The diver makes his way down to the bottom of the Danube at a depth of 15 metres. In the process, the spotlights on his diving helmet offer a small amount of visual aid. Below water he feels along the structure, controls the weir inlet and cleans the sealing surfaces, ensuring that the affected power plant section can be sealed against the stop-log.

50 tons on the floating crane

Once the diver has completed his work, it’s the turn of the floating crane. It places 50-tonne stop-logs on top of each other in the tailrace. The floating crane is mainly employed for damming work on the weir fields and sluices. Autumn and winter of this year will again see the diver being deployed in order to perform the damming work on the hydropower plants. No inspection is possible without a diver and cranes.