Good progress at Rotterdam’s Maasvlakte 2

Quay walls are emerging from recently reclaimed land, sea defences are growing by the day, and infrastructure, including railway tracks, is under construction.

Aerial pictures, released regularly by PRA, illustrate graphically the scale of Maasvlakte 2. Vital statistics include a 20% expansion of the existing port, covering an area of 2,000ha (half of which industrial sites), 11km of hard and soft seawall, 8.5m TEU capacity at the first two terminals, and construction costs of €2.9bn. The possible effects on nature from construction or future use are being compensated through a 25,000ha seabed protection area and creation of a new 35ha dune area.

With around 200m of the 240 million m³ of sand required for Maasvlakte 2 delivered, the foundations for Rotterdam’s new port extension are now in place. This latest review examines progress with the three main areas of construction activity: the quays, the seawall, and the associated infrastructure.

The Quays

Sub-contractor BAVO Kademuren, a consortium of BAM Civiel and Van Hattum & Blankenvoort, are making steady progress constructing the quays for Rotterdam World Gateway (RWG) in the Prinses Amaliahaven.

Adopting the same principles used at the Euromax Terminal, construction involves a ‘train’ with a trench for the quay wall dug at one end, and the bollards installed at the other end. In between, and over the 1,150m length, 200 55m long MV piles and over 900 35m long vibro piles support the 1.2m wide concrete quay wall which has a depth of 38m, twice the depth of the basin itself to withstand pressures from sand on one side and container ships on the other. On the landward side of the wall, a horizontal concrete superstructure is built resulting in an L-shaped structure providing the required stiffness. The sand on the seaward side is then removed, exposing the completed quay wall to the water in the basin. This sand is used to raise further the level of the land behind the wall and at other sites at Maasvlakte 2. Cutter suction dredgers are now busy achieving the required depth in the basin itself.

Construction of the quay for RWG commenced early in 2010 and water is now lapping against parts of the wall. At the head of the basin, work is continuing with the 550m long barge/feeder quay, due for handing over towards the end of 2011.

The same construction method is being used on the opposite side of the Prinses Amaliahaven for APM Terminals. Work commenced here at the start of 2011 and progress is reported to be going well, partly thanks to the experience at RWG. Work on APM Terminals’ 1,000m long deep-sea quay and 500m barge/feeder quay, along with construction of the terminal by the user is due to continue to 2013, with container handling commencing in 2014.

At the peak of activity, around 15 suction hopper dredgers worked around the clock reclaiming land for Maasvlakte 2. With most of the sand now delivered, the number of these vessels has reduced, however, cutter suction dredgers are now busy deepening the harbours and dredging the new quays.

Seawall

The 11km perimeter of the outer seawall is the main defence against the weather, comprising a 7.5km soft seawall along the southern and western edges and a 3.5km hard seawall protecting the more exposed north-western edge to a height of 14m +NAP. The design of the hard seawall was influenced by the reduced available area, due to its proximity to the main fairway into Rotterdam

The hard seawall consists of a complex mix of material known as a ‘stony dune and block dam’ design. Various grades of sand form the base of the actual wall, onto which a 4m thick layer of cobblestones is laid. As this layer can be expected to move with the current and waves, a gentle gradient is incorporated in the wall, resembling the slope that can be expected to develop during storms. This model should also require only minimal maintenance.

To provide a firm base, a layer of gravel has been laid between the sand and cobblestones beneath the area of the block dam. The gravel is one of several interlocking layers intended to support the block dam, the main protection against the elements. Next are layers of quarrystone varying from 5kg to70kg pieces at the base, above which are pieces of 150kg to 180kg.

The main breakwater is provided by the block dam. Consisting of concrete blocks, mostly recycled from the existing Maasvlakte block dam, now several kilometres inland, the blocks each weigh around 40 tons and around 20,000 are currently being placed both above and below water by the purpose built crane Blockbuster. The block dam would be susceptible to collapsing in extreme storm conditions and to prevent this, a ‘buffer’ of stones varying from one to ten tons is being laid both above and below the main block dam. Around one million tons of basanite is also being recycled from the old to the new block dam while the landward side of the seawall will be covered with grass on a layer of clay.

Around 1,000m of the eventual 3,500m of the dam has been completed, the highest blocks now visible 3m above the water. In an operation due to last two years, a self-discharging bulk carrier arrives every two weeks from Norway carrying 90,000 tons of quarrystone rock, unloaded at a specially built berth in the Yangtzehaven. Around 5m tons has so far been delivered to the sifting installation and subsequently transferred by a never-ending convoy of dumper trucks to the seawall site.

Careful consideration has been given by the PUMA building consortium to achieving a sustainable approach to costs, including those of construction and 50 years of maintenance. The seawall is designed to withstand a 10,000 year super-storm. The storms that caused widespread destruction across Europe in 1953 were in the 100 to 250 year category.

Infrastructure

Maasvlakte 2 is, understandably, currently a ‘building site’, separated from the existing port by fences and security. On the first day that the first berth opens for business however, it will be essential for tenants of the two Maasvlaktes to dovetail their operations without interruption. Roadways, rail tracks, cycle tracks and utility services will need to be in place and PRA report good progress with construction of this part of the project.

Ronald Paul, managing director project organisation for Maasvlakte 2 said, “If we don’t ensure the infrastructure that connects the new port to the existing port, we will come up against angry tenants of Port of Rotterdam sites who will, quite rightly, knock at our doors. To prevent this, and at the same time to allow the PUMA Consortium to continue its work undisturbed, the RPA made detailed plans to join the sites together seamlessly.”

Along with roads and railways; nautical services, pilotage and safety and environmental measures will all have to be ready when business starts for real.

With the aim of increasing rail freight leaving the port in the future from 9% to 20%, and an eventual capacity for 480 freight trains daily, assessing the potential effects of sand drift on the open tracks from the sand flats were essential. The first rail traffic is just a year away now and a 100m test track was constructed in January. An evaluation in June concluding that anti-sand-drift measures would be required and the PUMA Consortium is currently investigating available options.

A gap left in the outer seawall of Maasvlakte 2 allows access for the construction vessels, and dredgers will soon be busy filling this gap in. This will allow progress to continue with construction of the infrastructure of what will become the access route to Maasvlakte 2 and the existing businesses to the north of the Yangtzehaven including Euromax Terminal, Maasvlakte Olie Terminal, and Gate LNG Terminal.

The dredged sand that will fill the gap has to settle before roads and railways can be built, at which point in time the new harbours within would become land-locked until the Yangtzehaven is cut through, becoming the main navigational access route to the new port.

Access for dredgers and other service vessels will of course still be required, so making the sea connection via the Yangtzehaven is also a priority. The potential dilemma however, would be that the new perimeter road will not be completed, while the Europaweg access route to existing businesses will be cut off at the Yangtzehaven. To satisfy the requirement of maintaining land access, while allowing sea access to Maasvlakte 2, a temporary viaduct is to be constructed over the Yangtzehaven, to be removed once the outer perimeter road is complete.

Other infrastructure work includes developing what will become the new road entrance to Maasvlakte at the head of the Mississippihaven and construction of a dune viaduct, a grade separated junction that will lead to the main access routes to the coast, the port, and the existing Distripark.

By Peter Barker