One Lift Decommissioning Drydock
Seaways Engineering International are introducing Nessie, the Novel Extended Semi-Submersible for Installation and Decommissioning (NESSI/D). Designed to remove the Brent Alpha, she will, however, adapt to any rig. A vessel like this can lift even the largest rigs in the North Sea. Using a semi-submersible as the base, Seaways has adapted their original semi-submersible design into a massive dry dock, with a gate at one end.
Getting around and under the topside makes it possible to remove the whole topside in one lift. For the jacket, lift winches are added to allow Nessie to be customised to fit any situation. Traditional cranes operate at a perceived safe limit. Nessie’s lifting capacity is far beyond any required lift. Her topside connections are solid and over-engineered. Her jacket “sling” has more connections than needed. These features make her a very safe option. Nessie is a zero-heave vessel; motion compensation is, therefore, an unnecessary and expensive process.