Page 35: of Offshore Engineer Magazine (Mar/Apr 2026)

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1 mooring line featuring large diameter chains and f- projects will also require smaller support MSVs and ber ropes, generally bigger than those seen on oil & gas AHTSs, where supply is greater.

projects, which constrain the number of vessels that can technically lay these mooring lines; (2) a 3 x 2 mooring

IS ANYONE BUILDING?

line, featuring smaller diameter chain and rope than the Whereas there is new building in the 250t AHC crane 3 x 1 scenario, opening up the number of vessels that can MSV segment, there are no 400t AHC conventional lay the mooring line; and a 3 x 3 mooring line featur- MSVs under construction. The same goes for large AHTS. ing even smaller diameter chain and rope and making Without a specifc long-term charter to back an invest- more vessels technically capable of laying the mooring ment, the economics required to build such vessels are line. The anchor handlers required to lay these moorings generally missing. Without investment, as foating wind are also those involved in deepwater oil& gas projects. demand grows, vessel supply will become tighter, which

Another engineering decision is whether to anchor will push rates up.

each mooring line with an individual anchor or share/ However, there are some moves to build new large an- mutualize anchors, as has been demonstrated at the Hy- chor handlers.

wind Tampen project in Norway, currently the world In Brazil’s deep waters, the world’s largest foating pro- largest foating wind array. duction system market, Petrobras was considering long-

Anchor choice is another variable, with the focus to term chartering two new build 140m 300t bollard pull date on suction anchors installed by MSVs or AHTSs mooring pre-lay vessels with larger capabilities than its equipped with large subsea cranes and drag embedment current 120t torpedo anchors connected by 120mm chain anchors installed by anchor handlers. and fber rope systems. There was talk that the vessels were being specifed with both oil & gas and foating projects in

Floating wind projects will rely on vessels built predomi- mind. The original specifcation called for vessels capable nantly for oil & gas projects. of carrying 8x160t torpedo anchors (1,500sqm deck) with

As noted above, foating wind projects will rely on large 150t AHC crane and =2,500cbm chain lockers. After in-

AHTSs and MSVs to pre-lay moorings, tow & hook-up dustry feedback, the design has now been revised to 4x120t the foating turbines and lay array cables. torpedo anchors (840sqm back deck), 4 chain lockers that

The large MSV segment is relatively simple to group can store =142mm chain, and a 20t crane. The revised in terms of AHC crane size and back deck. To meet the specifcation is suited to oil & gas projects but sub-optimal offshore construction schedules of commercial foating for commercial scale foating wind projects.

projects, Vessels with large back decks, of 2,000 square In an interesting move, South Korea’s Hana Shipping re- meters and more, equipped with AHC cranes with ca- cently announced that it is building the world’s frst pur- pacities of 400 tonnes or more will be required to ensure pose built foating wind installation vessel at China’s Jiangsu offshore productivity. Dajin Heavy Industry Co., Ltd. The 127m vessel features a

Large AHTSs are more complicated. Not only are high Kongsberg deck machinery package, including a 500t tow- bollard pull vessels required (those with 300 tonnes and ing/anchor handling winch with three drums and chain more bollard pull) but vessels with large back decks, large handling equipment for 220mm chain, and a MacGregor chain lockers, large capacity fber rope winches and high- 400t AHC crane. The vessel will be delivered in 2028 and capacity chain handling equipment. The latter point is is intended to be deployed for mooring and cable laying for often under-looked, but many of today’s anchor handlers foating wind projects offshore Ulsan in South Korea.

are equipped with chain haulers, gypsies, etc. that can It is to be seen whether more owners will follow Ha- handle 76-165mm chain seen in most oil & gas proj- na’s example. However, without new vessel investment ects, but not the 175-220mm chain anticipated for many (and the conditions to support an investment), suitable foating wind projects. large AHTS and MSV supply will become an increas-

In addition to large MSVs and AHTSs, foating wind ingly rare commodity.

MARCH/APRIL 2026 OFFSHORE ENGINEER 35