Allseas, a global contractor in the offshore energy market, is expanding its fleet versatility with the addition of a purpose-built semi-submersible Heavy Transport Vessel, to be named Grand Tour. The new vessel reinforces the company’s commitment to delivering projects smarter, strategically, and with the future in mind.
A construction contract has been signed with Guangzhou Shipyard International (GSI) in China, with delivery scheduled for Q1 2028. The new Heavy Transport Vessel, will feature a 40,000-tonne load capacity, designed to transport the world’s largest offshore structures across oceans and seamlessly transfer them to Pioneering Spirit for installation.
The new vessel is designed to fit exactly inside the bow slot of Pioneering Spirit. This integration will streamline the offshore installation process, and offer clients a one-stop-shop for transport and installation of large structures fabricated far away from the installation location.
The solution reinforces Allseas’ role as a key player in the expansion of the European offshore electricity grid and the wider energy transition.
True to Allseas’ track record of innovation, Grand Tour is engineered for operational flexibility and sustainability:
- Semi-submersible hull with 57-metre beam for enhanced stability and shallow-draft access at global yards.
- 40,000-tonne load capacity
- Advanced ballast system pumping 24,000 cubic metres per hour – equivalent to 10 Olympic swimming pools – enabling safe, precise load transfers.
- Methanol-ready 24 MW propulsion system, with capability to transition to e-Methanol, securing competitiveness in a changing energy market.
- Air lubrication system under the hull and podded propulsion to reduce drag, improve transit efficiency, and cut fuel use.
- 180 x 57 m cargo deck designed for direct skidding, roll-on/roll-off, and float-on/float-off operations.
Grand Tour will play a key role in Allseas’ execution of TenneT’s landmark 2GW offshore wind programme, which will deliver 28 gigawatts of clean offshore wind power to European homes and businesses by 2032.
The vessel will transport very large converter stations from fabrication yards in Asia and Europe to installation sites in the Dutch and German North Sea, where Pioneering Spirit takes over for single-lift installation.
“This addition to our fleet is more than an expansion – it’s a strategic investment that enhances our ability to deliver fully integrated Transport & Installation (T&I) solutions for some of the world’s most ambitious offshore energy projects,” says Project Director Pieter Kambier. “By keeping transport and installation in-house, Allseas can reduce risk, streamline schedules, and offer clients unmatched reliability in delivering complex offshore infrastructure.”
Beyond offshore wind, Grand Tour will enable Allseas to relocate its own fleet assets, and enter new floating cargo markets – opening new long-term opportunities across sectors.
