Scaffolding for service port in final design phase

The service port at the New Lock in Terneuzen obviously needs to be equipped with the necessary scaffolding. A nice assignment that fell to Van der Zalm Metaalindustrie BV. They do the design and realization, Simon Knaap tells more about it.

"The port is located in the outer harbor on the Western Scheldt and has a usable length of 375 meters, by a width of about 88 meters. Completely rectangular, with an inlet in the embankment. All floating objects and bridges within the harbor fall within our scope," Knaap begins. "Then we are talking about a service jetty, mooring jetties walking jetties, some finger jetties, a heavy vehicle bridge and about three footbridges. All of that is designed, produced and installed by us."

Floating pontoon

"The service jetty is intended for loading and unloading goods, as well as facilitating emergency services. The jetty measures about 100 meters long by a width of 12 meters and consists of three sections. These will be floating pontoons attached to a number of piles. This jetty will soon be accessible via the service bridge measuring 43 meters by 4 meters, which is hinged on one side of the retaining structure. The other side is rolling on the service jetty because of the large differences in water level," Knaap explains.

About the mooring jetty East: "This pontoon structure is 280 meters long and will be cut into 45-meter modules. This jetty floats up and down along piles and is provided with plastic purlins at the mooring line for mooring. Via two walkways this jetty is accessible, we are talking about the same hinge and roller construction as with the service jetty."

Design issues

Everything is still in the design phase, taking into account the considerable forces that can occur in the service port. Knaap: "In the right corner of the service port there is a lot of wave action, more than in the rest of the port. For the jetty this means bouncing off, colliding and falling back. We take into account occurring wave heights of 2.8 meters with an interval of 4 seconds that could occur (once every 100 years according to studies by Svasek). These are moments when the whole thing is lifted into the air, which presents a tough engineering issue for us. This is why we work closely with VNSC and external specialists on this for analyses and calculations. It takes good dynamic studies to design a safe scaffold."

Walking jetty and mooring jetty East

On the northwest side in the service port, a walking jetty is planned. "A floating tube with a platform, attached to tube piles. This jetty is intended to allow access to the wave baffles but also for mooring small fleets." The wave baffles serve to reduce the incoming wave energy by some 80%.  

The planned mooring jetty East, like the service jetty, will be heavy-duty. This is necessary to allow heavier boats to moor and to take a hit in case of calamities. In conclusion, Knaap says, "We are busy designing and are out of the preliminary design phase. Now the final design is being worked out and it is expected to be completed in September. We also expect to have the implementation design ready this year."