Offshore energy chain for strong cable guidance on a wind farm drilling rig

Profile

• What was needed: OSC offshore chain
• Requirements: Safe cable guidance from the ship to the drill was to be ensured under high tensile forces, in corrosive environments, and with long travels.
• Industry: Offshore
• Success for the customer: Thanks to an integrated pull rope in the two chain links, the energy chain ensures safe cable guidance even when high forces are applied. The corrosive environment is no problem for the plastic chain, nor is the high volume of dirt, strong vibrations, or impacts.

Problem

Herrenknecht Offshore Foundation Drilling is currently the largest offshore drilling rig and is being used by DEME, a world leader in dredging and land reclamation, solutions for the offshore energy market, and environmental and infrastructure work, to install monopile foundations in Saint-Nazaire. The first offshore wind farm in France is being built here. A total of 73 monopiles with a diameter of 7,700mm must be drilled at depths between 6 and 24m. It is also the first offshore wind farm in the world where rock drilling for XL monopiles is one of the essential installation techniques. The new offshore foundation drilling machine used for this purpose offers significant environmental and economic advantages over conventional methods. But it also presents a major challenge, since the huge machine must be safely supplied with electricity from the ship. In establishing safe cable guidance, it was not only the corrosive environment that was a problem. The long travels of the drill, which works deep in rock, also required a robust, reliable solution.

Solution

To guarantee a high level of planning security for drilling monopile foundations, DEME today uses our OSC offshore energy chain. The cable guidance system, which is also used for shore power supply for ships at ports, can also be used in particularly harsh conditions thanks to a high-strength integrated pull rope in its two chain links. The plastic energy chain is suitable not only for the corrosive environment, but also for strong vibrations, impacts, and high levels of dirt. The modular energy chain design ensures a flexible internal cable and hose design. Overall, the system thus ensures long-term protection of the cables and hoses and the most user-friendly handling possible for rapid project planning and commissioning. And to accommodate the long offshore pipeline in a compact manner and to safely unwind it gradually as the drill is lowered, it was wound up on a huge cable drum installed on a ship.