Using Motion Compensate Pile Gripper during installation of super-sized monopiles in deeper waters can lead to cost reductions of up to 40%, according to the tool’s developers – Temporary Works Design (TWD) and Barge Master.
Nowadays, most monopiles are installed using purpose built jack-up vessels, however, for XL monopiles, these jack-ups have too little lifting and jacking capacity.
Alternatively, monopiles are being installed with floating heavy lift vessels. These vessels have sufficient crane and payload capacity, however, they are sensible to wave motions and have rather limited workability as you cannot keep a monopile still on a moving vessel.
The principle function of the Motion Compensated Pile Gripper is to hold a monopile perfectly vertical by counteracting the wave motions of the vessel on which it is fixed.
The impact of this technology on the installation cycle has been investigated for different vessel types, both for existing assets as for new-built floating heavy lift vessels, the companies said.
The cost reductions are achieved through a higher pay-load, reduced vessel day-rate and time savings related to the jacking process, according to the developers.
Together with certifying bodies, installation contractors and wind farm developers, TWD and Barge Master are currently working on refining this solution, aiming for a full scale demonstration of the technology in 2018.
Photos: TWD