Germany: ‘Pieter Schelte’ Special Vessel Lifts Offshore Platforms in One Piece

As the major engineering partner to the Allseas Group, Bosch Rexroth has developed and engineered the drive and control system solution for the world’s largest mobile lifting mechanism for offshore installations.

The special vessel equipped with this topside lifting system (TLS), “Pieter Schelte”, can lift and transport topsides of offshore platforms with a weight of up to 48,000 tons in one piece. Allseas thus considerably lowers the costs and risks for offshore assembly and disassembly. Pieter Schelte is currently being built in South Korea and will be ready for use in early 2014.

To disassemble topsides of offshore platforms, workers used to have to manually disassemble the structure into transportable individual parts on the high seas – work that is both time consuming and hazardous. In the future, the new special vessel from the Allseas Group will completely lift the platforms from their steel “jacket” and transport them onto land, making disassembly considerably safer and more cost-effective. The prerequisite for that decisive simplification is a topside lifting system (TLS), an innovation never before seen in such dimensions. The TLS can lift 48,000 tons, which is equivalent to 80 fully-loaded das Airbus A380s.

As engineering partner to the Allseas Group, Bosch Rexroth developed and engineered the drive and control system solution and the major components for the TLS. For Allseas Group Owner Edward Heerema, the engineering is the heart of the project: “We had to lay the foundation for all of the ship’s functions here. That’s why nothing could be forgotten: all technical requirements have to be precisely met and all possible scenarios had to be run through.”

To make that happen, Allseas brought a long-term partner on board: Bosch Rexroth. Rexroth possesses comprehensive experience in designing and realizing challenging drive and control solutions for offshore installations and maritime applications. An international team made of industry specialists and technology experts developed a TLS drive and control system, based on the principles as provided by Allseas. “No comparable system has ever been created before, making this an exciting task, even for our experienced engineers,” as Project Manager Ron van den Oetelaar explains the challenge for Bosch Rexroth.

In complex co-simulations, Rexroth reviewed the design and dimensioning of major components with a continuous focus on adhering to high safety standards. The company-owned software takes both mechanic strengths as well as specific hydraulic characteristics into consideration. In addition to engineering products and services, Rexroth also supplies the five-megawatt central hydraulic power unit as well as numerous key components and subassemblies for the TLS. The new special vessel is currently being built in a South Korean shipyard and is set to begin disassembling the first offshore platforms in early 2014.