Seafox and their main subcontractor Ardent successfully executed the decommissioning of the two Forewind Dogger Bank Meteorological Masts.
The meteorological masts were composed of an 80-meter lattice tower on a 16 m2 platform, which was mounted on a single pile, secured by a 15-meter diameter wide and 7-meter tall suction bucket.
The two masts were installed four years ago to gather climate data to assess the feasibility of one of the UK’s largest potential offshore wind farm developments. In light of minimising the environmental impact of the now decommissioned offshore structures, Forewind opted for the efficient installation and removal operation due to the suction bucket concept.
In preparation of the removal operations Seafox and Ardent performed a pre-removal survey to reduce any uncertainties and to confirm the proposed removal procedure of the weather data measuring equipment, lattice towers, platforms and suction bucket monopiles.
All project engineering, fabrication and execution were carried out by Seafox and Ardent. As the foundations, platforms and lattice towers lend themselves for re-use, options for re-using are being explored although nothing has been confirmed at this stage. The offshore operations were executed in September more quickly than originally planned, which given the weather of the North Sea was of huge benefit to the project. The engineering, fabrication, testing and deploying together with SPT Offshore of a project specific interface frame to control the original suction bucket pump system contributed to the successful removal. The heaviest lift, of the suction bucket and monopile, with potentially clay-sticking, was calculated at 768t.