Lanaye Lock – Hanging-rolling gates
SBE is involved in the renovation of the Lanaye lock complex situated at the entrance of the Albert Canal in Belgium. Wear and tear over the years necessitated the restoration of the third lock which was constructed in 1958. The opportunity was also taken to replace several other components. The Lanaye locks overcomes an impressive height difference of 14m between the upstream and downstream water level. This blog describes the concept of the hanging-rolling gates which were renovated during the project.
The original design of the lock is somewhat unconventional, especially the uncommon gate types selected – both hanging-rolling gates. These uncommon steel structure hangs from a supporting steel structures and has a movable carriage on top. What characterizes this type of gate is the absence of any support along the bottom of the gate.
The supporting structure at the upper gate is a steel beam stretching the overall length of the lock and gate. A rolling system on the supporting beam is used to open and close the gate horizontally. The gate is connected to the rolling system with steel cables on the front and back of the gate. A sequence of pullies on both steel elements guides the two cables. The steel frame is high enough to allow vessels to easily sail under it. Consequently, the cables are quite long, and the gate runs a little bit behind the rolling system.
The downstream gate has a similar configuration but with minor differences. Due to the much greater head difference at the downstream gate, the gate needs to be much heavier and therefore steel cables are not adequate. A welded steel frame connects the gate to the rolling system. Another difference is that no steel structure is required for the supporting beam as the concrete structure of the lock complex itself can be used. The beam is supported by the upper level of the upstream lock platform.
The major advantage of a hanging-rolling gate is that very few mechanical parts are required beneath the water level. No rails or under carriage is required. A major benefit for the reliability and maintenance of the lock. Most mechanical components are located on the supporting structure and beam and are easily reached for inspection and maintenance purposes. This is a real advantage in ensuring the lock operates without much delays.
A disadvantage is the flexibility of the suspension system with steel cables. The gate tends to run behind the upper carriage which causes issues ensuring the gate is firmly closed. Therefore, a very reliable system which detects whether the gate is closed properly is required.