Underwater Tie-Ins (Nord Stream)

Each of the two Nord Stream Pipelines is built in three sections. Once completed, the sections are welded together. This "tie-in" process takes place on the seabed in an underwater welding habitat. Welding activities are remotely controlled from a support vessel, and divers assist and monitor the subsea construction work. 

For more information, visit their website at ‪http://www.nord-stream.com