Danube power plant Jochenstein: Turbine and ship lock under maintenance

24.02.2022Engelhartszell, Untergriesbach

VERBUND uses the dry winter period for power station maintenance

VERBUND - the largest hydropower generator in Bavaria and Austria, carries out annual maintenance work on the Kaplan turbines and the ship locks at the Jochenstein Danube power plant. The continuous care and maintenance ensures availability.

The five Kaplan turbines and the ship locks of the Jochenstein run-of-river power plant have been operating since the 1950s. It undergoes maintenance every nine years. At the moment, Turbine 1 is being subjected to a vital intervention. The locks are put through their paces every two years. Divers cleaned the rail to the seal at the bottom of the dam beam in the middle of October already and have thus completed initial preparations for draining the impeller of Turbine 1. The central piece of the electricity generation is undergoing extensive maintenance at the moment. A new intake screen will also be installed. The entire hydraulic steel structure of the southern ship lock will be renovated as well. 

Kaplan Turbine 1 being serviced

In this period of low precipitation, the turbines together with the generator and rotor are checked for proper functioning and for “traces of use”. That means the impellers and their seals, the control equipment, electrohydraulic plant components and the generator in the powerhouse will be inspected and refurbished by the power plant employees. 

The young deputy head of operations Andreas Bauer has been in office since June 2021. He is in charge of the inspection activities and says: “During this inspection, we will also replace the right-hand inlet screen, which has been protecting Turbine 1 against coarse sediment, logs and stones since 1956.”
A giant undertaking, given that this inlet screen is 17 metres tall and 12 metres wide. The screen is divided into upper and lower screen fields. The individual fields are 1.20 metres wide, 9 metres tall and supported on and bolted to 3 cross-members (fish beams). The screen is lifted out and inserted again with the aid of a gantry crane.  

The work is progressing rapidly. “In these times of Omicron, a lot of coordination effort is required with regard to compliance with the 3G rule and separating the team and external companies,” says Bauer. But the extensive maintenance works should be completed by end of March at the latest and the turbine handed back to its actual task again.

Heavy labour under water

“In order to even start the maintenance works,” Bauer continues, “we need our divers.” Because no divers, no inspection. “Cleaning the channel bed in front of the inlet screen is essential for the optimal placing of the dam beam, which weighs several tons. A clean bed means the dam beam can create an optimal seal. The turbine can then be drained and the inspection works can commence.”
In the middle of October, the divers of the VERBUND subsidiary Lestin spent a whole week removing sand, gravel and wood from in front of the inlet screen, 18 metres down on the bottom of the Danube. The work under water is very dangerous and involves dirty work that requires a sensitive touch. Details on the work of the divers at the Danube power plant Jochenstein can be read on our blog With the VERBUND diver under water and viewed in our diving video Divers at VERBUND.

Southern ship lock - a giant bathtub

The inspection of the South ship lock took place parallel to the maintenance works on Turbine 1. With its length of 230 meters, width of 24 m and depth of 13 m, when it’s dry it resembles a giant bathtub. 

“Both ship locks in the Jochenstein power plant on the Danube are inspected every two years,” says Bauer. “Currently it’s the turn of the South lock, where we are inspecting the entire hydraulic steel structure, examining it for damage and repairing it where necessary. We also check the underwater stemming gate bearing for sufficient grease supply. You can compare this with a car service.” The work will take around 26 weeks. The southern lock should be functioning properly again at the beginning of April.
The role of hydropower in a sustainable energy system
Electricity from hydropower has many functions in the energy system The VERBUND run-of-river power plants in Bavaria and on the border between Bavaria and Austria are in operation 24 hours a day and supply electricity to the grids for around 1.8 million households. Hydropower is CO2-neutral, protects resources, reduces dependency on imported fossil fuels and thus makes a key contribution to the energy transition.


Eveline Fitzinger

Project Communication

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Visitor with 3D glasses

Use of VR glasses to take a look behind the scenes of hydropower generation in the Jochenstein power plant on the Danube.