Crucial design choices for a monopile upending tool

Bigger & Slender
As monopiles increase in size, we can install larger wind turbines and generate more energy. To increase the size of the foundations and at the same time keep the weight of these foundations within reason, monopiles tend to become slender. This is a great achievement by monopile designers and fabricators. But what is needed on the equipment side to lift and handle these huge foundations?

Impact on upending tools
The design of a monopile upending tool is depending on the integrity of the monopile. A slender monopile demands more connection points from the upending tool to divide the load. At the same time, the weight of the upending tool cannot increase as the crane capacity of offshore installation vessels is easily reached with the heavy structures we see nowadays. We saw the same challenges with the design of a floating monopile tool (also called wet tow plug). Although it’s a floating application, it has the same principles as an upending tool. The challenge here was to add strength and redundancy to the floating monopile tool, but without adding more weight to it.

Secure pile installation
Reducing risk and ensuring safe operation is a continuous process for offshore projects. With the casing lift adapter – an upend tool for pin piles – we achieved this with two things. On the equipment side, we choose to handle our casing lift adapter with a Balltec tool. An easy interface tool that could also handle other equipment during the same project. Less rigging was needed and immediate uptime was achieved. Secondly the design. To install the casing lift adapter into the pin pile, we designed the casing lift adapter in such a way that the position of the COG was optimized for easy installation into the pin pile. To lock the casing lift adapter into the pin pile, we choose robust pins. The locking mechanism is designed in such a way that a secure connection is maintained even during a unexpected loss of hydraulic power.