The renovation of the Nesserlander lock in Germany was a specialist job that was executed by our German sister company Sterk Spezial Tiefbau.

The work consisted of the demolition/deconstruction of the old lock foundation. This was done under water. The old lock foundation was made up out of wooden piles that were fitted with wooden constructions (so-called ‘kespen’) and ‘tras’-concrete in between. The addition of this so-called ‘tras’ improved the strength and density of the concrete and made it more watertight.

On top of this construction the base of the lock was poured and the lock heads, made out of masonry, were build. Due to the presence of piping in the soil that wasn’t allowed to set too much, the water levels could not be lowered more than just a few metres.

The 1700 wooden piles could not be removed in their entirety. Instead they had to partially removed. This meant they had to be ‘cut’ at about 7 metres below the old lock floor so the bottom part of the pile could remain in the sealing layer of clay.

Sterk also placed over 70 metres of combined wall consisting of steel tube and sheet piles and restored parts of the sealing clay layer. We also removed over 1300m3 of masonry and dredged more than 10.000 m3 of soil.

All and all a nice challenge for our people at Sterk Spezial Tiefbau.

Project details

  • Client: Arbeitsgemeinschaft Nesserlander Schleuse
  • Location: Emden, Germany
  • Contract value: € 1.000.000 +
  • Start date: 11-11-2013
  • End date: 05-06-2014

Used techniques

(Pre-)drilling, Combi sheet pile walls, Fluidisation, High-frequency vibration/extraction, Removal of foundation piles, Specialist techniques, Underwater demolition work