Pieter Schelte will be 382 m long and 117 m wide. Positioned at the bow is a slot, 122 m long and 52 m wide, where topsides are lifted using eight sets of horizontal lifting beams. Two tilting lift beams, for the installation or removal of jackets, are located at the vessel's stern. The tilting lift beams can also be used as regular crane lifts for the installation and/or removal of structures such as modules and bridges.
Her large ship size gives Pieter Schelte a very good wave response behaviour, superior to semi-submersible crane vessels in operational wave conditions; topsides and jackets can be installed and/or removed in significant wave heights of up to 3.5 m.
She will be equipped with eight main diesel generators, providing a total installed power of 95 MW, powering 12 azimuth thrusters for full dynamic positioning and propulsion. She will have a maximum speed of 14 knots and can accommodate up to 571 persons in two-berth cabins.
Pieter Schelte's primary area of focus is the removal (in accordance with OSPAR ’98 regulations) of large steel jacket based platforms in hostile areas such as the North Sea, as well as the less challenging areas of the world. She will target the decommissioning of topsides and jackets that are too heavy, or too large, to be lifted in a single section by existing crane barges. In particular, topsides heavier than 10,000 t and jackets over 70 m in height.
Allseas has analysed in detail a large number of contemporary platforms to verify the vessel's versatility and to develop viable solutions for lifting and lowering structures onto a cargo barge, transporting structures and skidding them ashore.
Gravity-based topsides, for which the leg spacing fits the slot on the vessel's bow, can be lifted with pods fitted in the clamps of the topsides lift system. Platforms with a leg spacing of up to 51 m can be accommodated. Only a few of the widest gravity structures and jackets currently found in the North Sea do not fit Pieter Schelte's bow slot; the topsides of these platforms can be removed modularly using the tilting lifting beams.
