Royers lock – Outer harbour
Renovation works on the Royers lock in the Port of Antwerp is due to start shortly. SBE is responsible for the design of the new lock complex. This blog discusses the design of the maritime infrastructure in the outer harbour and approach channel.
A navigation lock is like a crossroads for vessels and is often a nervous activity for the skippers as there are many factors to consider when passing through. To safely navigate through the lock, any help is welcomed. Along with control systems (lighting, radio communication, tug boat assistance), properly designed infrastructure is also key to safe navigation. The Royers lock connects the inland waterways of the Port of Antwerp with the river Scheldt, a tidal river that discharges into the North Sea.
Various challenging boundary conditions are present on the Scheldt side of the lock such as strong tides and the required draft of the navigation channel. These issues not only lead to large differences in water levels, but also a considerable bottom depth requirement and difficult manoeuvrability for the ships entering the channel. For these reasons a continuous guide wall was selected, similar to the existing palisade guide wall that is in terrible condition due to severe degradation. The layout of the new guide wall and the loads due to vessel impact has been carefully examined in the Flanders Hydraulics Research laboratory. The results from these investigations informed SBE’s design, and a continuous floating guide wall consisting of various structures was developed.
Air tight tubes are horizontally placed on the water so they can rise and fall with the water level. They are held in place with piles and fitted with protective panels and bollards. They serve a dual purpose; vessels are visually guided at all water levels and protected from scraping the embankments and they can berth when they can’t enter the lock.
In corners or in parts where the alignment of the guide walls changes in radius, a pile with a donut fender was provided in order to smoothen the curve or transition. Single piles with protective beams were placed at the entrances. Two different types of single piles were used at the northern and southern sides respectively, since some are more subject to impact by vessels than others. An easily replaceable single pile design was used in case any damage by vessels would occur.
To summarize, a combination of different types of known mooring and berthing structures has led to an optimal design in which the approach channel to the lock is as safe as possible for both the vessels and the lock heads in relation to a reasonable cost.
For more information about the project, click here.