15 The Europipe landfall Project
159
further optimization of the selected alternative, final construction permission was given
on 27 October 1993.
Having been through this difficult planning permission process, it seemed logical to
anticipate the need for future additional pipeline capacity by utilizing the spare space
in the pipeline trench and the tunnel. Therefore, it was decided to apply for permission
to lay 12 km of pipeline with tie-in connections in both ends parallel to Europipe through
the landfall area of the National Park, thereby avoiding future construction work in
this environmentally sensitive area. This permission was given in early 1994.
15.4
Europipe Project Facilities
The total Europipe project can be subdivided into:
1. Off-shore facilities consisting of: a) A new riser platform, bridge - connected to an
existing platform in the Sleipner field in the Norwegian sector of the North Sea b) A
630-km, 40-in.-diameter pipeline from the new riser platform to the German North
Sea 3-mile zone.
2. Landfall facilities and/or construction activities consisting of:
a Dredging of a 12-km, 2-m-deep, 12-m-wide trench from the 3-mile zone through
the Accumer Ee tidal inlet
b Laying of two paralleI40-in. pipelines in the trench
c A 2.6-km,3.8-m-diameter concrete tunnel through which the pipeline was brought
on-shore under the tidal flats and the mainland dike
d A 12-m-diameter, 20-m-high cylindrical tie-in chamber, connected to the tunnel,
and enabling recovery of the tunnel boring machine and installation of the tie-in
connections between the land and the off-shore pipeline
e Laying of two paralleI40-in. pipelines through the tunnel
f Backfilling of the dredged material.
3. On-shore facilities consisting of:
a A 50-km, 42-in. diameter on-shore pipeline
b A gas receiving station at Dornum, some 5 km from the tunnel
c A gas metering station at the contractual delivery point in Emden.
15.5
Europipe Landfall Facilities/Activities
15.5.1
Dredging
The pipeline landfall section is about 12 km long, extending from the 3-mile zone outside the islands of Baltrum and Langeoog, crossing a sandbank, following the Accumer
Ee tidal inlet between the islands, continuing into the shallow Accumersieler Balje before reaching the tidal flats. The pipeline route crosses a dynamic morphological area,
where the tidal channel is found to shift sideways with a cycle time of about 45 years.
Hence, a morphological design basis had to be established, taking the dynamics into
account, as well as observed long-term rise of the water level in the area. The design
159
further optimization of the selected alternative, final construction permission was given
on 27 October 1993.
Having been through this difficult planning permission process, it seemed logical to
anticipate the need for future additional pipeline capacity by utilizing the spare space
in the pipeline trench and the tunnel. Therefore, it was decided to apply for permission
to lay 12 km of pipeline with tie-in connections in both ends parallel to Europipe through
the landfall area of the National Park, thereby avoiding future construction work in
this environmentally sensitive area. This permission was given in early 1994.
15.4
Europipe Project Facilities
The total Europipe project can be subdivided into:
1. Off-shore facilities consisting of: a) A new riser platform, bridge - connected to an
existing platform in the Sleipner field in the Norwegian sector of the North Sea b) A
630-km, 40-in.-diameter pipeline from the new riser platform to the German North
Sea 3-mile zone.
2. Landfall facilities and/or construction activities consisting of:
a Dredging of a 12-km, 2-m-deep, 12-m-wide trench from the 3-mile zone through
the Accumer Ee tidal inlet
b Laying of two paralleI40-in. pipelines in the trench
c A 2.6-km,3.8-m-diameter concrete tunnel through which the pipeline was brought
on-shore under the tidal flats and the mainland dike
d A 12-m-diameter, 20-m-high cylindrical tie-in chamber, connected to the tunnel,
and enabling recovery of the tunnel boring machine and installation of the tie-in
connections between the land and the off-shore pipeline
e Laying of two paralleI40-in. pipelines through the tunnel
f Backfilling of the dredged material.
3. On-shore facilities consisting of:
a A 50-km, 42-in. diameter on-shore pipeline
b A gas receiving station at Dornum, some 5 km from the tunnel
c A gas metering station at the contractual delivery point in Emden.
15.5
Europipe Landfall Facilities/Activities
15.5.1
Dredging
The pipeline landfall section is about 12 km long, extending from the 3-mile zone outside the islands of Baltrum and Langeoog, crossing a sandbank, following the Accumer
Ee tidal inlet between the islands, continuing into the shallow Accumersieler Balje before reaching the tidal flats. The pipeline route crosses a dynamic morphological area,
where the tidal channel is found to shift sideways with a cycle time of about 45 years.
Hence, a morphological design basis had to be established, taking the dynamics into
account, as well as observed long-term rise of the water level in the area. The design