Extraordinary dimensions on the Main-Danube canal: Bauer Spezialtiefbau executes retaining structure for replacement construction of Kriegenbrunn Lock

• Main excavation pit: 330 m long, nearly 30 m wide and 30 m deep – secured by a pile wall, sheet pile walls, ground anchors, and 8,000 t of steel pipe braces
• More than 85% of piles already installed
• Digital planning and close coordination ensure smooth construction progress

Erlangen-Kriegenbrunn, Germany – With an order volume of 447 million euros (net) and a total construction period of eight years, one of Germany’s most significant inland waterway infrastructure projects is taking shape in the southern part of Erlangen, Bavaria: the replacement of the Kriegenbrunn Lock. Commissioned by the Federal Waterways and Shipping Administration (WSV), the new lock is scheduled for completion by 2032 and will secure navigation on the Main-Danube Canal for generations to come. BAUER Spezialtiefbau GmbH, together with its joint venture partners Züblin Spezialtiefbau GmbH and Ed. Züblin AG, is responsible for constructing the retaining structure, among other tasks – an impressive project not only because of its massive scale, but also due to its technical complexity. 

A Lock Structure on a Grand Scale 

The centerpiece of the project is the main excavation pit with an impressive length of 330 m and a width and depth of nearly 30 m each. To secure the excavation pit, the specialist foundation engineers are constructing a secant pile wall. Using the Kelly drilling method, fully cased piles are installed with a diameter of up to 2 m and a length of up to 37 m. Sheet pile walls, ground anchors and roughly 8,000 t of steel pipe braces with diameters of up to 1.40 m are also executed as struts for the main excavation pit. “These dimensions are extraordinary even for specialist foundation engineering,” explains Bauer Project Manager Andreas Hertenberger. “Each pile needs to be installed with the utmost precision – this is the only way we can ensure the stability of the entire excavation pit.” Among other equipment, several Bauer drilling rigs are being used for the work, including the BG 55, BG 45, and BG 39. 

On the home stretch 

By the end of October, more than 85% of the piles for the retaining structure were already constructed. At the same time, excavation work has already begun on the main excavation pit, paving the way for the start of lock construction. “Close coordination between all trades involved is essential,” adds Bauer Site Manager Agnes Demharter. “The only way to successfully complete a project of this magnitude is with exact planning, digital assistance and a strong team on site.” 

An important step for ship traffic

The replacement of the Kriegenbrunn Lock is more than technical feat – it’s a milestone for the future of waterway infrastructure in Germany. “Here, we are building the foundation to ensure safe and sustainable ship traffic for decades to come,” emphasizes Hertenberger. What makes us particularly proud,” Demharter adds, “is that every single member of our team contributes their expertise and dedication to turning this once-in-a-century project into reality.”