The difference in driving speed between conventional hammering and a Vibratory Hammer - Saving significant installation time for OWF Monopiles
Increasing installation efficiency is a key component of LCOE reduction for the offshore wind industry. By reducing the installation time for key components such as Monopiles, significant savings on vessel hire can be made.
The 2018 average installation rate, where the vessel installed both monopiles and transition pieces, is 2.27 Days per Foundation (DpF). When using Vibratory Technology the DpF can drastically been reduced.
These video's were made during a comparison test in Germany and what you see is the actual speed. For the test we used the exact same Monopiles and exact same soil conditions. Besides the installation speed advantage, vibrating technology is less harmful to the sub-sea environment (Marine mammals, fish and other sealife) because of the much lower noise level during installation.
7 reasons to consider vibration technology for installing monopiles for Offshore Wind Farms
1. It shortens pile driving times. Tests show that under suitable soil conditions the vibratory hammer drives down the pile 10 times faster.* Complete the foundation work within short weather windows
2. It brings down installation cost by deploying fewer and more economical tools. The vibro, when fitted with an upending module, can lift a pile from its horizontal storage position, upend, and lift the pile into driving position. The pile is driven into the seabed without the use of a pile gripper or positioning frame. Verticality is maintained with sensors mounted on the vibratory hammer
3. Vibrating reduces pile fatigue and doubles design life to 50 years by introducing less energy into the pile during driving.* It would also allow for mono pile designs with thinner wall thickness, leading to significant material savings and handling cost.
4. Limit piling noise to improve working conditions on the Installation Vessel for the construction team.
5. Changing pile designs and increasing pile diameters call for modular equipment such as a GIANT vibro that can be easily reconfigured to drive piles from 3.5-8.4 meter in diameter.
6. The GIANT innovation is built up from time tested and mature components like the 500M, but in a novel set-up that reduces the complexity of synchronization, and the weight and height of the hammer, while increasing the structural rigidity and the dynamic range of pile diameter the hammer can handle.
7. Independent test results show end bearing and lateral bearing capacity of vibrated piles is within specification.
The offshore wind sector is a promising and challenging market to introduce new foundation techniques. Dieseko Group acknowledged potential of this market approximately 10 years ago and developed and supplied big vibratory hammers and tandems for driving offshore wind farm foundation piles. The foundations and production capabilities of monopiles have taken a lift and recent designs show diameters of 10 metres for future XXL monopiles. Jacket foundations and tripod/quinpod foundations are also being considered for several projects and Dieseko Group has a wide range of PVE vibratory hammers to serve the complete market.
Decommissioning of met mast. More and more projects need to decommission met masts, due to the start of commercial OWF and/or the decision to abandon potential wind farm projects. Our vibratory hammers can be used to extract the complete met mast foundation, without leaving debris on the sea bed as a result of the internal cutting of piles. This application is evolving and offers an economic and ecological solution for utilities.
To date we have vibrated monopiles, jacket foundations and tripod foundations around the world and we are ready for the future.
Benefits of PVE vibratory hammers:
Significant time saving (handling tool)
Noise reduction (< 140 dB)
Less fatigue - Cost efficient pile design - Longer life-time of structures
Accurate positioning - Option to extract piles
Multi-purpose hydraulic power packs - Possible to drive hydraulic impact hammers and other equipment e.g. winches