The construction of shore approaches and landfalls for offshore pipelines are among the most delicate and complex of hydraulic engineering works, requiring precision and close cooperation among all partners.

They are performed in both exposed areas and the nearshore surf zone, requiring heavy seaworthy plant that is simultaneously shallow draught.

At the Libyan site, Sidra and Tideway are dredging a 1.9km trench in which three pipelines will come ashore. One of these is the 32in trunk line which is the umbilical cord linking the continents and will be laid in depths up to 1.114m.

Sidra/Tideway started works on the Mellitah landfall in August of this year. A cutter suction dredger was mobilised for cutting through hard rock material at the site. Two rock causeways were constructed for crossing the coastline. In addition to trench dredging, Sidra/Tideway were also in charge of backfilling and rock dumping over the trench as well as foundation works and anchoring for the winches that pulled the pipelines ashore in October.

Sidra and Tideway have completed the 700m landfall at the European end of the project at Gela. A small trailing suction hopper dredger was able to execute trenching on this site as a sandy sea bottom made for much easier working conditions.

A cofferdam was built at Gela for crossing the coastline.

MJ Information No: 18926