The best way to reduce noise emissions is not to generate noise in the first place, which is exactly why vibro driving can be a good alternative installation method. Add to this the much faster penetration (up to 10 times faster in sand) compared to hydraulic impact hammers and further savings can be made. By then integrating a certified lifting and upending function to the vibro hammer (VLT-U), suddenly the tool can contribute greatly in speeding up the installation process by negating the need for tool changes between the installation steps.
The VLT-U is able to pick up a stored pile, upend it to vertical position, place it overboard, lift it to installation position. It can then drive it down, measuring and adjusting verticality while driving, all in a single operation without the need of an ILT or trunnions, a gripper system or seabed frame. Further developments to enlarge the workability and reduce costs are the installation with VLT-U from a floating vessel using Dynamic Positioning and combining vibration and drilling technology to tackle any seabed quietly. The overall savings in time and money can be substantial. CAPE Holland has already proved the vibro technology works during the installation of Monopiles at the Riffgat OWF in German waters. Now with the next generation vibro’s in the form of the VLT and VLT-U’s also successfully tested, CAPE Holland is ready to serve the Offshore Wind Industry with its cost saving installation methods and tools.
All that is needed now, is to convince the governing and certifying bodies to certify the vibro installation method. To achieve this, the joint industry Cuxhaven Vibro Test, where lateral loading resistance of vibro driven piles were compared against impact hammer driven piles has been initiated by RWE. The official outcome is expected soon and once the certification is in place all benefits of using a vibro can be used to its full extend.
The advantages of the Vibro Lifting Tool for offshore wind:
- Low noise emissions
- Low fatigue levels
- Fast installation speed
- Upending, Lifting and handling tool
- Verticality measuring during installation
- No need for an installation frame or pile gripper
- Free pile run due to soft soils is mitigated
- Extraction possible in case of misalignment or de-commissioning.
- Ability to link multiple hammers to be able to install large piles (up to 1600t)
- Monopiles (XXL)
- Jacket piles
- Anchor piles