Royers lock – Rolling Gates
Renovation works on the Royers lock in the Port of Antwerp will start shortly. SBE provides the design of the new lock complex. This Blog item describes the concept of the gate and the lessons learnt during the design process. Both lock heads will be fitted with wheelbarrow type rolling gates. These gates have dimensions of 38m long and 10m wide and differ in height.
The gate on the Scheldt side of the lock has a traditional configuration and is quite like the existing gates in and around the Antwerp Harbour. In contrast, the gate on the port side of the lock (the upstream gate) has a more modern configuration.
A difference of the modern vs traditional configuration is that the modern lock gate is equipped with a minor buoyancy chamber. The main advantage is the use of less steel resulting in a lower overall weight. This weight reduction was the main driver behind this gate choice. The lower weight allowed for an alternative installation method involving the gate being installed in its chamber.
Another advantage of having a lighter gate type is that the gate can be moved into its maintenance position more efficiently. The method entails strand jacks on temporary steel gantry cranes. These gantry cranes are positioned over the gate and lifts it into the maintenance position. Once the gate is in this maintenance position it is fixed to the gantry crane. This lifting operation is more controlled and safer than the buoyancy method used on the other gates in the Port of Antwerp. The gantry cranes may also be used to lift the heavier Scheldt side gate. The Scheldt gate can, however, also be lifted (or lowered) making use of the traditional buoyancy-method.
This new maintenance method has led to other advantages in lock-gate design such as the elimination of the complex piping-system to fill and empty the compartments of the buoyancy chamber with ballast water. In the past buoyancy chambers were emptied using a relief valve. This relief valve is no longer required which allows the use of thinner steel plates and less stringent specification adherence requirements. The steel structure no longer needs to conform with the pressure-tanks specifications.
The new design involves the compartments being filled and emptied from the top level of the gate with the use of temporary pumps. This results in an easier, safer and more controlled handling of the ballast water. The top level is also easily accessible from the surrounding area. Additionally, a heavy central maintenance-tunnel is no longer needed in the inside of the buoyancy-chamber which adds to the reduction in the overall weight of the gate. The simplification of the filling-system also enhances the reliability of the gate and lock. Less (or no) mechanical components are present in the gate itself, so failure of one of these mechanical components is unlikely to occur.
To summarize. The new gate maintenance method resulted in a drastic reduction of the overall gate-weight which results in a safer and easier maintenance procedure. The simplification of the filling/emptying-system led to a more reliable gate with less need for maintenance.
For more information about the project, click here.