Terminal construction under difficult conditions

CT 4 was no ordinary building site: poor subsoil, turning tides, the power of the elements, storms and rough seas - difficult conditions that posed problems for the planning engineers and construction companies. As the riverside quay replaced the dyke, the structure had to satisfy particularly stringent demands.

There was an obstacle in the way of the quay extension. Grauwall Canal carries rainwater from the city of Bremerhaven and the surrounding area in Lower Saxony into the Weser. The outer reach of the canal cut through the location of the new terminal, so that excavators had to dig a new bed for the outfall at the north and east of CT 4. After the former mouth had been filled in, the old and new terminal areas could be joined up.

The subsoil, too, was problematic: it consisted of unstable marsh soil at depths of up to 17 metres under mean sea level. That layer had to be removed over a width of more than 60 metres and replaced by sand with better bearing capacity. The marsh soil was then dumped in the Outer Weser. The sand was taken from the Weser navigation channel by a hopper dredger and distributed in the foundation pit.

A heavy-duty sheet pile wall was the crucial element for the new quay. It consists of bearing piles which were driven into the subsoil at intervals of approx. 2.35 metres, and intermediate piles which fill in the gaps between the bearing piles. The bearing piles are 36 to 40 metres long and weigh up to 25 tonnes.

This called for precision work: the pile driver had to be securely mounted on a jack-up platform to ensured that the bearing piles could be driven into the foundation absolutely exactly, thus providing the best possible connection with the filler piles. The sheet piling was anchored with batter piles, which are also placed at intervals of 2.35 metres. Each of these 45-metre long piles bears a load of around 180 tonnes. Sand was deposited behind the sheet piling so that the landside work on the quay could began.

But Bremerhaven's new quay extension does not rest on this heavy sheet piling alone. Extra stability is provided by some 1700 piles, each between 22 and 32 metres long, which are driven into the bearing soil by pile drivers on land.

The wave absorber of Container Terminal 4 and the pier slab which protects the sheet piling from the pressure of the soil were made of cast-in-place concrete. These structures required 55,000 cubic metres of concrete, reinforced with 10,000 tonnes of steel. A special formula ensured that these huge concrete sections can withstand the aggressive salt water. The reinforced concrete was produced without any expansion joints - 1681 metres of concrete like a single cast structure.

Sand as far as the eye can see: roughly ten million cubic metres was required for CT 4, to guarantee the necessary stability of the terminal area behind the sheet piling, on the pier slab and in the hinterland. The material was obtained from the navigation channel of the Outer Weser and extraction sites in the German Bight.

New dykes were built in the north and east of the terminal extension. These 8.50-metre high structures will provide reliable protection from the vagaries of the North Sea.

Six loading sidings, each 1100 metres long, were also constructed to permit fast transport of containers to and from the terminal - after all, Bremerhaven is and will remain a railway terminal.

Finally, huge fenders were inserted to protect vessel walls and quay during docking manoeuvres. Bollards, each designed to withstand 200 tonnes of tension, were bolted in place to hold the heavy hawsers. Electricity, telephone and water connections were also provided.

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Planning permission - design and location approval

Expansion of a federal waterway - WSD examines objections and statements

The project to expand the riverside quay on the Weser involved a federal waterway. This was the responsibility of the North-West Directorate of Waterways and Shipping (WSD) in Aurich, which organises the design and location approval process. The application documents compiled by bremenports fill a total of eight files. The WSD examines all objections and statements submitted on the project. These were taken into account in the design and approval location decision, which ultimately constitutes building permission.

On 15 June 2004, official design and location approval was issued, including the ecological compensation measures on Luneplate and the dyke foreland along the Wursten coastline.

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