Precision above water – getting started with DSD

Lock Gates for the 5th NOK Lock Chamber in Brunsbüttel

For the new 5th lock chamber of the Kiel Canal (NOK) in Brunsbüttel, three identical lock gates were manufactured: two for regular use in the inner and outer heads, and one spare gate for maintenance and emergencies. The steel segments were produced in Plauen, with final assembly taking place in Emden.

Before the newly built lock gates VII, VIII, and IX could leave the Emden shipyard, they were precisely weighed using our specially developed, high-precision weighing method. This measurement was crucial for several key calculations, including:

• Buoyancy calculation during water transport to Brunsbüttel
• Load and force analysis for future operation
• Optimal ballasting to ensure floating stability

Precision Weighing for Maximum Safety 

Each sliding gate, weighing approximately 2'200 tons, measuring 24 meters high, 10 meters wide, and 47 meters long, was weighed in its fully assembled state including steel structure, coating, drives, and electrical and hydraulic equipment. Components not yet installed, such as flood protection elements, were measured separately and added to the total weight.

To eliminate external influences like wind, ground vibrations, or temperature fluctuations, the weighing was conducted under controlled conditions inside the production hall.

For optimal weight distribution during transport, special hollow chambers in the gates were filled with precisely calculated amounts of ballast concrete to ensure a stable center of gravity.

Modern Measuring Technology: 128 Hydraulic Presses in Action

The weight of the three Brunsbüttel lock gates was determined using pressure sensors from 128 hydraulic presses. Each gate rested on 32 support beams, with each beam placed on a group of four hydraulic presses that lifted the gate synchronously by just a few millimeters during the weighing process.

The weight measured by each pressure sensor was recorded separately and adjusted for the weight of the support beams, ensuring an exact total weight calculation. This high-precision method allowed even the smallest weight variations to be detected and factored into the final result.

Triple Verification for Maximum Accuracy

To guarantee the exact weight, each lock gate was weighed three times. The official weight was determined as the average of all measurements, with a strict tolerance of just 1%. Our weighing work extended from January 2024 to January 2025.

With this precise weighing method, we ensure the safe and efficient commissioning of the new Brunsbüttel lock gates - an outstanding achievement in heavy load technology.

"Precision is not just a skill, but a commitment – to safety, stability, and progress." Lukas Abbühl, Technical Manager