Offshore WindForce (OWF) has taken delivery of a subsea pre-piling template from LDD, UTEC and Menck to help pre-install foundation piles for the 350MW Wikinger offshore wind farm in the German Baltic Sea.
OWF, a joint venture between Boskalis and Volker Stevin International, will pre-install the piles into the seabed prior to the placement and grouting of the four-legged jacket foundation using Boskalis vessel Giant 7.
LDD said it was responsible for design, supply, installation and commissioning of the hydraulic, survey and control systems on the template, which has been manufactured by Volker Staal en Funderingen in Rotterdam,
The survey system was designed and supplied by UTEC, LDD said.
It added that a computer-controlled subsea hydraulic system will automatically level the PPT on the seabed and allow operators to adjust the pile position to within the required +/-50mm and 0.5 degree installation tolerances.
The metrology system on the template includes real-time survey data on the PPT position and orientation, plus pile location, verticality and depth monitoring.
OWF has also contracted Menck to provide a service package, including the supply of two MHU1200S hydraulic hammers to drive in the jacket piles.
Noise mitigation has been incorporated into the PPT and hammer deployment systems, said LDD.
It said the PPT has been fitted with a ‘small bubble curtain’ system that can be activated at each pile guide sleeve, while the piling hammer and pile are deployed within a HydroSound Damper system.
An OWF deployed ‘double big bubble curtain’ also surrounds the entire template, LDD said.
Commissioning and testing of the PPT has been completed and field operations started at the end of the first quarter of 2016.
Image: LDD
