TWS invests in series pull-in systems

Tension Winding Solutions, originally a subsidiary specializing in rentals at DROMEC, is investing in a new series of pull-in systems.

Gerrit Drost says,
“With TWS, we aim to continue innovating and distinguishing ourselves in equipment for offshore applications. Having successfully completed two projects, the pull-in operation at the Luchterduinen wind farm in the North Sea and Windplan Blauw in Urk, in collaboration with a reputable offshore contractor, we now aim to contribute to a sustainable future with these new systems!”

Pull-In System

TWS intends to rent out pull-in systems for various operations at wind farms and provide coaching for operators. The pull-in system is used to pull power and data cables from the vessel into the wind turbine. It’s a complex tool specifically developed by DROMEC Winches for this purpose. Specific variations have been designed for different continental regions. For instance, additional safety standards such as Loler and Puwer are required in the waters of the United Kingdom.

Constant Tension

Before installing the wind turbine on the platform, the pull-in operation takes place. The cables are pulled from the vessel through the seabed onto the platform using the pull-in system under constant tension. This means the cable is always kept at a predetermined tension, even in the event of unexpected increases or decreases in cable force, preventing cable overload. This special tool has a nominal pulling force of 10 tons. The force is applied through friction between the rope and a special capstan head. By adjusting the number of windings in combination with a tensioner, the pulling force is ensured up to a holding force of 12 tons.

TWS plans to deploy the pull-in systems in sets of 4 to 10.

Gerrit Drost adds,
“With DROMEC, we can strengthen each other in collaboration. If a system fails during the pull-in operation, as a rental company, we can immediately arrange a backup. We also assess on-site whether any improvements can be made. With DROMEC, we can quickly adapt and create innovative solutions for each other. From TWS’s perspective, once the market experiences these pull-in systems, they become indispensable. Since the operation can only be performed during certain times of the year due to weather conditions, we also aim to focus more on operator training. The right expertise benefits both ways. Equipment remains in better condition, ensuring continuity in operations, which is crucial. Our focus is more on the service and maintenance of the product. Eventually, we’d like to build a test tower to simulate real-life pull-in operations, enabling us to expand rentals to Germany, Denmark, Belgium, and France!”

Automatic Tensioning

The system operates with automatic tensioning. A tensioner synchronized with the capstan head ensures there is always sufficient tension between the tensioner and the capstan. This guarantees the pulling force through the capstan without requiring a person to continuously hold the slack end. The system is electrically powered, very compact, with a low weight of 550 kg. Without the detachable tensioner, it weighs 475 kg. Once the operation is complete, the system is moved to the next wind turbine platform, making it highly suitable for rental by TWS.

Pieter, engineer at DROMEC, comments,
“This compact pull-in system is a user-friendly tool that can be installed on any platform for pull-in operations. The combination of low weight with high force, using advanced control software, is a real time-saver for the customer. The system can be used both in a standing and hanging position. Several improvements have been made for the new series, such as the nominal pulling force and the hard-anodized capstan head, which is more resistant to corrosion. The frame is also more user-friendly, with an integrated lifting eye and additional guide bracket, allowing the cable to be wound on and off at a 70-degree angle.”