Boskalis Awarded Nord Stream Post-lay Rock Protection Project
Royal Boskalis Westminster N.V. has been awarded a LoI (Letter of Intent) to install rock on the 1,220km ‘Nord Stream‘ gas pipelines running through the Baltic Sea, connecting Russia to Northern Germany. The contract value will amount to approximately EUR 100 million, with the share of Boskalis amounting approximately EUR 50 million. Image courtesy of Nord Stream AG.
Earlier, in January 2009 Boskalis already acquired the contract for seabed preparation prior to the installation of the two 48″ gas pipelines. This subsequent contract requires Boskalis to install rock berms at critical sections of the installed pipelines after the pipeline is laid. This single contract will represent one of the largest pipeline rock protection contracts ever awarded.
The rock – coarse gravel with a diameter of typically less than 10 cm – will be sourced from countries on the Baltic Sea coast. The rock material has to meet certain engineering and environmental criteria. Material has to be free from clay, silt, chalk, vegetation, or other deleterious substances. It will behave as any existing inert material on the seabed and will be re-colonised within a few years. In shallow waters, algae will soon populate exposed surfaces and in deeper water where oxygen and light are scarce, the surface of the rocks will be colonised by micro-organisms.
Boskalis Offshore worked closely with the main contractor Saipem in the preliminary project phase. The project will be executed in a 50/50 partnership and at least two, potentially three fall pipe vessels will be deployed, depending on the pipeline installation sequence chosen. The project is scheduled to start in 2011 and will be completed in 2012.