An approximately 1 km long pipeline string was pulled through the River Elbe from the river banks in Lower Saxony at Barförde to the other side at Boizenburg in Mecklenburg using horizontal directional drilling (HDD).

In order to cross the Elbe, Europe’s largest underground drill channel had to be built which was 1,080 m long with a 1.8 m diameter. The drill channel runs under the two embankments and the river, which is about 300 m wide at this point.

Senior Site Engineer Michael Muth said “We only needed about eight hours to pull the pipeline into the drill channel, which is a magnificent technical accomplishment. The pipeline string, which had to be pulled underneath the Elbe, has a diameter of 1.4 m and weighs more than 900 tonnes.”

The connecting pipeline for the Nord Stream Baltic Sea pipeline to the west runs 440 km from Lubmin through Mecklenburg-Vorpommern and Lower Saxony to Rehden south of Bremen.

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Mr Muth said that the use of HDD to complete the river crossing minimised the impact on the natural surroundings as the construction time was extremely short and deep excavation trenches were not necessary. Other benefits of using the technique included that fact that construction did not require shipping traffic on the Elbe to be halted, and the integrity of the embankments was not affected.

The North European Gas (NEL) pipeline will have a transport capacity of around 20 Bcm/a of natural gas, which is roughly equivalent to a fifth of Germany’s annual consumption of natural gas. Planned investments for the pipeline project are approximately $US1.35 billion.

So far, more than 230 km of the NEL pipeline have already been laid and about 300 km welded together. Overall, over 24,500 pipe segments about 18 m long and weighing 15 tonnes each have to be laid.

The natural gas pipeline is being built by the WINGAS Group and E.ON Ruhrgas. The shareholders of NEL include WINGAS (51 per cent), E.ON Ruhrgas (10 per cent), N.V. Nederlandse Gasunie (20 per cent) and the Fluxys G (19 per cent).