Accommodation far at sea

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With wind farms getting bigger and bigger it means that the need for materials and personnel is also growing. The previous article described this growth in the need for support vessels sailing to and from wind farms under construction, or needing maintenance, transferring materials and personnel. But when do the support vessels stop being the only solution for transferring personnel from the coast to the wind farm?

We have seen that support vessels are getting bigger, and some are able to transfer more people, and that their design is much more adjusted to operate in higher wave heights, but the fact remains that wind farms are getting further out at sea making personnel transfers to and from the wind farms a time consuming activity. Let us not think too much about the exhausting, ‘bumpy rides’ for which not all personnel have the sea legs!

Some of the support vessels are already including some accommodation facilities for a few persons to stay a bit longer at a wind farm. Vestas has been using the Esvagt Supporter, a former rescue vessel, as a hotel service vessel for 12 O&M personnel on the Belgian wind farm Bligh Bank since 2010. In general, support vessels though are still designed for fast and safe transfers.

Accommodation units

At the same time the number of wind farm installation vessels (WTIVs) is also growing and becoming more and more able to carry more and heavier loads. With more loads these vessels can now remain for longer periods on location on the wind farm for their installation or maintenance work. These vessels have either accommodation space already for personnel on board, as in the case of new vessels, or are adapted for this purpose by placing modular accommodation units on board. This applies also to jack-up platforms.

Such was the case with the Jumbo Javelin which was used by Jumbo Offshore for installing TP’s at Greater Gabbard and will be doing the same at Anholt Offshore Wind Farm in the next few months. As the Jumbo Javelin is normally used for the long distance transport of heavy lift cargo, with only a few crew members on board, it was not fitted to accommodate the larger installation team that was needed for the far shorter trips to a wind farm. Jumbo Offshore used in this case accommodation units provided by Ferguson Modulars which were installed on deck to solve this problem. Other companies are H2M, ELA-units, Workfox, Edda accomodations, just to name a few. In a future edition of Offshore WIND we will have a closer look at these. But even installation vessels will have to go back to port to reload after a few days.


Another initiative has been to charter a vessel for the sole purpose of providing an accommodation base for engineers and construction workers that need to work on wind farms for longer periods such as during the construction and commissioning phase, but also during planned maintenance projects. These floating hotel vessels, or so-called floatels, can provide a long-stay comfortable residence for the crew, rather than ferrying passengers up and down to the distant wind farm every day.

This alternative is already known in the oil & gas industry for decades, ever since discoveries were made in deeper waters, further at sea. With the offshore wind industry following the same route they have become more in demand which is reflected in the announcements made in the news lately.

The current floatels are usually former cruise ferries. They are adapted to the health and safety standards for the offshore wind industry and to the comfort needs of the work crew. The floatel concept has been used for a few years now.

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C-bed is the marketplayer at the moment. The company started getting involved in the offshore wind industry in 2008 after talks with a major turbine manufacturer who expressed the need for the concept.

They have 2 floatels which have been chartered for several wind farms. The 122.71m Wind Solution, was chartered first at the Lynn & Inner Dowsing in 2008, followed by Horns Rev II and has now finished work at Greater Gabbard only to continue at Lincs. Their second, the 153m Wind Ambition, was first used at Walney I in 2010, followed by Sheringham Shoal, and is this year chartered by Siemens Wind Power for the London Array I project. Both vessels have 137 cabins.

At the time of writing C-bed’s Shipping- & Project Manager Michael Rix told Offshore WIND that the company had just signed the contract for a third floatel to be added to their fleet. The Wind Perfection, previously known as Julia or Christian IV, will be used on Anholt Offshore Wind Farm. C-bed manages their fleet themselves, with the help of external Technical Management.

At the Sheringham Shoal Offshore Wind Farm the 145m Regina Baltica, owned by Estonian company AS Tallink Grupp, was contracted to accommodate the crew responsible for the installation and commissioning of the remaining turbines and electrical infrastructure.

For their technicians to work on the Walney Offshore Wind Farm Siemens ordered the 90.60m Sea Spirit, with a passenger capacity of 120, from Comfort at Sea, a joint venture set up in 2010 between Blue Water Shipping and ISP. The Sea Spirit is just one of their fleet of ferries, accommodation vessels and cruise vessels.


There are also new and existing names entering the offshore wind market for the first time. Below we mention a few. Well-known P&O Ferries is one of the newcomers. They recently announced that one of their large freight ships, the 180m European Seaway, will be used for a few months, starting in April, as an accommodation vessel for technicians doing maintenance and operations work at the Lynn and Inner Dowsing Wind Farm Array.

Offshore specialists Svitzer and floating accommodation providers Sanderson Maritime came up last year with the accommodation concept SEATEL. The SEATEL is a 25,000m2 North Sea barge fixed to an offshore barge with a 70 bedroom hotel module from where personnel can be transferred by transfer vessel or helicopter to the work site.

Also a newcomer to this specific market is Dutch company Chevalier Floatels. Managing Director Marcel Roelofs told Offshore WIND that they are currently laying the last hands on the redesign of the former passenger vessel Galyna. Once having received the go-ahead by Lloyds they will start with the refurbishment at Holland Shipyards. The Galyna could be ready in the winter or in early spring, depending on the wishes of its future client. The Galyna will have 55 cabins, 30t load space for spare tools and will be able to spend 30 days at sea before calling port again. He is looking forward to see the Galyna on its first assignment. If this turns out well, there will be a second vessel waiting to be upgraded to the class of floatels… the Gezina. Atlas Ship Delivery will be managing the vessels.


Especially far out at sea and on larger wind farms the floatel could offer many advantages. Mr Roelofs: “Most of the support vessels currently in the market can mainly operate in 1,5m Hs. Floatels can operate in waters with 3m Hs. This enlarges the weather window in which we can operate from around 55% to even 85%.” With wind farms getting further out at sea support vessels could easily take 2 hours each way “and that doesn’t even include the time that is needed for the crew to get from the hotel to the port before even getting onboard of the support vessel”. Being close to the wind farm therefore allows a swift response to weather changes.

Mr Rix explains that the time saved in transfer of personnel could lead up to over 6,000 hours a month. But, he adds, just as important is the fact that the entire site is being moved offshore, including storage and offices. The floatel would not only take personnel but also spare parts and enough provision on board to stay at the wind farm for a minimum of 30 days before going back to port to refuel. This means that one does not need to look at shore-based accommodation possibilities which might at some places not always be available for the large number of crew that will sometimes be needed.

With the personnel normally being used to staying in comfortable hotels with all the necessary comfort facilities on hand onshore, the floatels will have to make sure they provide a comparable standard onboard. Some of the floatels will include bars, a gym or even a swimming pool, everything to help the engineers and construction workers to relax after a day ‘out at sea’ and keep them highly motivated. The larger the floatel, the less discomfort is caused by sea movements, something C-bed strongly believe in.

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So far this all makes sense. But how do the personnel get to the actual turbine then? Currently most floatels will moor at the wind farm where they would still need transfer vessels to bring the personnel from the floatel to the turbine where they will perform their work.

The vessel then either moors at the floatel or, which is more common, goes back to port. Even though the transfer vessel still needs to do the traveling up and down to shore, at least it is not ‘wasting’ time of the personnel. It does mean though that when the sea is rough there will still be no work done. But at least the personnel will be near the wind farm and able to respond quickly when the weather changes.

This is where Chevalier Floatels think they can make a difference. Mr Roelofs, “The Galyna will have an Ampelmann heave compensated gangway on board which will enable transfer of personnel to the turbines even at a rough sea with a 3m Hs.” In the meantime the floatel can be used for survey and cable repair work at the wind farm.

Floatels versus Support vessels

So, when does one alternative becomes more desirable than the other? Of course it is difficult to state exactly where to find the break even point between time efficiency and cost reduction. It depends on the project and on the wishes of the operator.

According to Mr Roelofs one could say that the floatel already becomes a good alternative with wind farms far out at sea that will have at least 80 turbines.

Mr Rix: “It’s a combination of several things, of which some are not possible to price before the project is over, for example a significant decrease in sick days. But time is the most important thing we sell.” That there is a market for floatels Mr Rix is clear on, “our clients have been using us for four years, and just signed for a third vessel, it must be worth the money.”

When asked whether the floatels could become a market on its own Mr Roelofs is optimistic, “If the industry is developing as it is there will be a market big enough for new vessels to be built specifically for this sole purpose. Unfortunately these vessels are not the cheapest – a floatel could easily cost over €30m – and banks and investors are still a bit weary to invest in new builds.” Offshore WIND will keep an eye on the developments in this market.

Sabine Lankhorst