Seven Waves
3Pages

SEUEN UUAUESEUERY SEUENTH UUftUE IS HIGHER Seven Waves, a 'flex-lay' pipe laying vessel, is the latest addition to the Subsea 7 fleet. The vessel is designed and built by IHC Merwede, whilst the pipe-laying equipment and cranes were developed and installed by Huisman. It will initially be used in the Brazilian territorial waters to support the development of significant oil fields in the Santos Basin. Supporting Petrobras during a five-year contract, the 'flex-lay' vessel will mainly be installing flexible flow lines and risers in water depths up to 2,500 metres, off the coast of Brazil. Builder IHC Merwede BU, Krimpen aan den IJssel, The Netherlands Owner Subsea7, London, United Kingdom Principal particulars Length o.a. Beam mld. Depth to main deck Draught, operational Draught, max. Air draught, ramp upright Air draught, ramp inclined speed, service Cargo capacities Deadweight, operational Deadweight, max. Displacement, max. Gross tonnage Net Tonnage 5,185 Complement single berth cabins/dayroom single berth cabins Double berth cabins Crew, total Hospital capacity (excl.) Tank capacities Marine Gas Oil 2,197 m3 Anti-heel ballast water 1,525 m3 Technical fresh water 633 m3 MARITIME BY HOLLAND MAGAZINE APRIL / MAY 2014 PAGE 045 The helicopter deck, on deck ten forward of the superstructure, is an approved and certified platform Seven Waves, the fifth vessel contracted by Subsea 7 to IHC Merwede's Offshore division, will mark the next chapter in Subsea's Brazilian operations as the first of a new generation of high tension pipe layers contracted to Petrobras. Seven Waves was preceded by the delivery of Seven Oceans (pipe laying), Seven Seas (pipe laying and construction), Seven Atlantic (diving support) and Seven Pacific (pipe laying). Subsea 7 selected IHC Merwede and Huisman for this latest vessel, primarily for their efficiency and reliability in delivering the four previous orders on time, whilst at the same time meeting the required level of quality. With the contract between the Subsea 7 and IHC Merwede signed in November 2011, the keel-laying ceremony was held one month ahead of schedule in August 2012. The naming ceremony was performed on 3 May 2013 by Lucia Andrade, the ship's godmother. Although originally planned at the end of the first quarter of 2014, the vessel was delivered in two weeks early in March 2014. The synergy, concept studies and basic design IHC Offshore & Marine designed the ship in close cooperation with Subsea 7. The overall construction and all associated shipbuilding aspects were handled by the IHC Merwede yard in Krimpen aan den IJssel, while the development of the ship's cranes, pipe handling plant and pipe lay tower was done by Huisman Equipment. For installation of all Huisman equipment, the vessel was sailed to their local facilities in Schiedam, the Netherlands. Whilst developing deepwater oil resources is becoming increasingly economically viable, this has implications for the design of the vessel with respect to their ability to stay at sea for longer periods. The Santos Basin is such a remote deepwater project and to fulfil the project requirements, the vessel is equipped for transporting and installing flexible flow lines and umbilicals in water depths of up to 2,500 metres. The vessel is designed to operate fully autonomously, with all facilities on board for loading and laying flexible pipes. The vessel itself is a DP2 mono-hull, built to Lloyd's Class requirements, with an overall length of 146 metres. The beam of 30 metres is determined as a result of the stability and port access requirements. Considering the effect the amount of deck equipment has on the vessel centre of gravity, meeting the stability requirements whilst also having a width restriction was a challenge. The vessel is equipped with a vertical lay system, a mast crane, a knuckle-boom crane and twin ROV systems. The hull features two underdeck storage carousels for flexible pipe and a moonpool. Accommodation and wheelhouse The superstructure of the Seven Waves is located forward and has accommodation for 120 persons in four single berth 'staterooms' with separate day-room, 40 single berth cabins and 38 double berth cabins. To facilitate the required hospital capacity another three berths are provided in a separate 'sick bay'. In addition to the necessary staircases, the superstructure features an elevator, running from deck four up to deck ten, with the shaft extended into deck three to house the dedicated machinery and equipment. This technically advanced ship will also exploit IHC Merwede's "A new generation of high tension pipe layers'

knowledge and experience in offshore dredging vessels, to provide a comfortable and quiet accommodation. These include low noise and vibration levels and further features to provide the personnel with a high level of comfort. The second largest crane on board is a knuckle boom, which is on starboard side behind the carousels Deck ten is the helicopter deck and has the helicopter reception area with adjoining changing room and on starboard side an airconditioning room. The helideck itself is an approved and certified platform, suitable for Sikorsky S92 and Super Puma operations. Deck nine is...

an emergency/harbour generator set installed above main deck. Should a situation arise like a weather change, such that operations have to stop and the ship has to abandon the site, the pipe end is terminated, lowered to the seabed and released. Once back on site, the end of the pipe is recovered and manipulated back into to the moonpool. For this, Seven Waves is equipped with an A&R (Abandon & Recovery) system, featuring two winches of 600 tons and 200 tons, with 3,500 and 2,000 metres of wire respectively. Main propulsion is provided by three fixed pitch/ variable speed azimuthing...