3 CRITERIA TO KEEP IN MIND FOR YOUR NEXT PRE-PILING TEMPLATE
When installing an offshore wind turbine in 50-80 meter water depth, using a jacket foundation is an obvious choice. To install the pin-piles for the jacket, a pre-piling template is an excellent structure to ensure precise installation. Moving to new areas with different circumstances brings along new operational challenges. A few examples:
In 2015 the average water depth of offshore wind farms was 27 meters. The current wind farms under construction see water depths of 40 up to 50 meters. Deeper water means longer piles, which has a direct impact on the equipment involved.
Piling frames for these water depths need to handle longer and heavier piles and need to withstand stronger swell. Another crucial factor is the significant wave height. Recent projects show that a pre-piling template nowadays has to survive significant wave heights up to 3.5 meters.
With XXL monopiles, also pre-piling templates see new dimensions. The centre-to-centre distance of a piling frame can easily reach 45 meters. Covering so much ground – also taking into account that WTG’s need to be placed further apart from each other – chances are you meet a variety of soil conditions within one wind farm. For instance, in Taiwan, we see extreme conditions. From very rough and rocky ground to soft and muddy soil conditions. For the latter, you need to equip your piling template with large mud mats to avoid sinking into the bottom.
Even though the pre-piling template has become a large structure, it is still crucial to make it heavy enough to keep it from turning over. KENC has developed a calculation tool to easily determine the required stability of the piling template for different project parameters. We are happy to share our tool and provide you with valuable insight for your upcoming project. Just give us a call or send us an e-mail!