Ground-breaking ceremony for major overhaul of the double-chamber lock at Kachlet

The official ground-breaking ceremony for this 86 million Euro project took place in Passau on 10th October 2011 in the presence of State Secretary Dr. Scheuer, Mayor of Passau Mr. Dupper, president of the waterways authority in Southern Germany Mr. Aster und head of the Bavarian waterways authority Mr. Schillinger.

As part of a consortium, KREBS+KIEFER was responsible for the planning and tender procedure for the concrete construction and in part for construction supervision.

History: The entire barrage (lock, weir and power plant) was built in the period from 1922 to 1927. The first ships passed through the completed southern lock as early as 1925. At that time, the Kachlet lock was the largest inland waterway lock in Europe.

Following a number of repair measures to remedy stability problems that arose over the years, a major overhaul of the lock is now required.

Advance measures: The first measures to be taken consist of major repairs to the middle wall. The main tasks involved are:

• Partial demolition of the existing chamber walls along the middle wall and construction of the new chamber walls as an anchored shell
• Extensive dismantling and replacement of the lock equipment (including floating bollards) in the area of the middle wall

Main measure: The next measure consists of major alterations to the upper and lower pounds and the external walls including the lock gates and the seals. The main tasks involved are:

• Demolition of the existing external chamber walls and construction of new external walls including anchoring in the same way as the middle wall
• Dismantling of the existing lock equipment on the external walls and installation of new lock equipment
• Extension of the central mole into the upper pound to achieve a usable length that meets the recommendations of the Danube commission and to create space for optimization of the new circulation and filling system.

Information: The overhaul of the double-chamber lock at Kachlet was the subject of a presentation at the conference of the Federal Waterways Engineering and Research Institute in Karlsruhe on 25^th and 26^th October in Karls­ruhe.

Data on the existing lock:

• Double-chamber lock
• Maximum water level 9,80 m
• Width of each chamber 24 m
• Usable length 230 m
• Maximum volume of chamber: 55.000 m³