But back to the foundations: the monopiles were driven by the
□utch company Ballast Nedam Offshore. In the process, they
were transported horizontally from the port of Esbjerg to the
construction site, capped at both ends. The gigantic Steel
pipe was then moved to an upright position and hoisted to the
required height by the starboard crâne hook on the heavy lift
crâne vessel, Svanen, which had been positioned and moored
inch-perfect prior to the start of piling works. After the crew of
the Svanen had placed and secured the sound absorber on the
sea bed, the monopile was lowered into the sound absorber using
the pile guiding tool.
This so-called Noise Mitigation Screen reduces noise émissions considerably. And it does in two ways: on the one hand, the
double-walled Steel screen is fîlled with air which reduces sound
propagation. On the other hand, the screen is fitted with an
bubble injector System, providing an additional noise barrier.
After the first hammer blows in the night of April 1, 2014, it quickly
became clear that further measures would be required.
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