As one might expect from a vessel named after the eight-legged steed of Odin in Norse mythology, Heerema Offshore Services’ forthcoming, self-propelled semisubmersible crane vessel Sleipnir is intended to deliver serious kick when it comes to horsepower.
Measuring 220m in length by 102m in width, and featuring a displacement of 273,700tonnes at maximum operational draught, the vessel is reported to be the largest of its type built to date. She is currently being built for Dutch operator Heerema at SembCorp Marine, Singapore, with delivery scheduled for the second half of 2018, and will commence operations at the beginning of 2019. The building contract has an estimated value of US$1 billion.
Despite the offshore marine’s sectors ongoing woes, Heerema has been consistently optimistic regarding the production of Sleipnir.
According to Jan-Pieter Klaver, CEO of Heerema Marine Contractors (HMC): “The fact that we decided to press on with our plans in these times of low oil prices shows our belief in the offshore oil and gas industry and demonstrates our continued commitment to offer unparalleled installation services to the industry.” He has added that Sleipnir has been developed to serve a number of territories worldwide.
HMC’s current fleet includes the 201.6m x 88.4m semisubmersible crane vessel SSCV Thialf, the 211.5m loa deep water construction vessel DCV Aegir and the 260m loa H-851, the latter hailed as being the world’s largest barge, amongst other vessels.
Twin cranes Sleipnir will be equipped with a pair of revolving cranes, supplied by Huisman Equipment. Each crane will feature a boom length of 145m; with the boom up, the crane will be able to reach a height of 210m above the waterline. Each crane has a lifting capacity of 10,000tonnes, enabling Sleipnir to install and remove offshore facilities and to install subsea structures, foundations and moorings, and floating structures in deep water.
Also notable, especially for a vessel of this size, has been Heerema’s decision to power Sleipnir courtesy of a dual-fuel arrangement. The vessel will be fitted with 12 Tier III-compliant MAN Diesel & Turbo 8L51/60DF four-stroke engines, featuring selective catalytic reduction, or ‘scrubber’, technology, and enabling the operator to switch between marine gas oil (MGO) and LNG.
These engines will be spread across four engine rooms, and the set-up will grant Sleipnir a combined output in the region of 96MW and a transit speed of 10knots.
Moorings and safety
Meanwhile, Rolls-Royce has been awarded a US$11.3 million contract to supply Sleipnir’s mooring system. This will comprise a tailor-made package, featuring a 12-point mooring system with a control system, electrically driven winches, fairleads and wire sheaves. The newbuild will also be fitted with a dynamic positioning 2 (DP2) system.
Life-saving equipment manufacturer Harding will provide Sleipnir with nine FF1200 freefall lifeboat systems, complete with LA1200H and LA1200HO skid launch davits. Manufactured in accordance with DNV OS E-406 standards, each lifeboat has the capacity to carry 70 persons.
Harding claims to share Heerema’s commitment to the offshore oil and gas sector; CEO Styrk Bekkenes has commented: “On this project…we enlisted a high degree of participation from our offices in the Netherlands, Singapore and Norway. Access to this overall expertise allowed us to provide the most value for money. We are not in and out [of the offshore oil and gas sector]...Harding is in to stay.”