The Single-Lift Vessel "Pieter Schelte": Honoring the Past, Shaping the Future

Abstract This paper describes the building of a ship for single-lifting of very large topsides of offshore platforms. The ship's layout and functioning was described in an earlier OTC paper (Heerema, E.P. 2012). The paper covered in detail the significance of a motion compensation system for rough seas, and the benefits of single-lifting by removing the need to build up or remove topsides module by module. The paper also described the installation and removal methods for jackets, as well as the vessel's pipelay system for application in the periods when there is insufficient heavy lifting work. This paper deals with the next step, the actual building of the vessel and her equipment, taking place largely over the past two and a half years; the commissioning is planned to be completed by the end of 2014. The concept behind Pieter Schelte is entirely novel, and such is the scale of the ship and her equipment that the building is a major challenge, but one that the shipyard and suppliers are presently coping with well. Proven equipment is used in all elements, but the method of functioning is unprecedented. Pieter Schelte will have a topsides lifting capacity of 53,000 short tons (48,000 metric tons) and a jacket lifting capacity of 27,500 short tons (25,000 metric tons) (see figures 1 and 2). Her length will be 1253 feet (382 m) excluding lifting equipment protruding overboard, and her width will be 406 feet (124 m). For moving in around platform substructures, the width of the bow slot will be 193 feet (59 m) (see figure 3). She will also be a pipelayer with a tensioner capacity of 2200 short tons (2000 metric tons), enabling her to lay heavy pipelines in shallow and deep water (see figure 4).