Operators respond to wind farm demand

Owners making the bold decision to invest considerable sums of money in WTIVs are responding to the demands of the emerging global offshore wind farm industry, particularly within the burgeoning European market.

Wind farm projects either complete, or at various stages of development in UK waters alone, give an indication of the scale of the requirement for installation vessels. Round 1 involved 14 leasing options totalling just over 1GW. Fifteen projects totalling 7.2GW are currently in progress under Round 2, and there is a target capacity of around 30GW for the forthcoming Round 3.

Currently, most European offshore wind farms are in water depths up to around 30m, and the majority of turbines up to 3.6MW capacity. Future projects, particularly UK Round 3, will see turbines of up to 6MW or more, installed in water depths of 50m or more.

Installation work has, thus far, largely been carried out by a variety of vessels adapted for the specific requirement (not including the MPI Resolution). Conventional multi-purpose jack-up barges, often non-propelled, have also been fitted with cranes of sufficient capacity and height to carry out the task. Crane vessels, more commonly seen operating in the offshore oil and gas industry, have also played a part, particularly for heavier components such as offshore sub-stations.

The world’s first dedicated WTIV, MPI Resolution, was considered ahead of its time when it entered service in 2003. Experience however indicates the basic concept to be sound, and is evident in the emerging next generation designs.

Orders covering 18 vessels from 11 owners were considered here by A2SEA A/S, Beluga Hochtief Offshore, Fred. Olsen Windcarrier, Gaoh Offshore Ltd, Inwind AS, MPI Offshore, RWE Innogy, Seafox Contractors BV, Seajacks Ltd, Swire Blue Ocean and Van Oord BV. At the time of writing it was unclear what effect, if any, Beluga Shipping’s recent filing for insolvency would have on their WTIV, ordered jointly with Hochtief Offshore.

A number of factors are behind the current state of the WTIV order book. With the sheer scale of projects planned within Europe alone, existing installation capacity will not be sufficient to keep pace with demand. The move into deeper waters also puts future projects beyond the ‘reach’ of the legs of many existing vessels. Importantly, there is the urgent demand for greater efficiencies throughout the whole installation process, including greater payloads and transit speed between load-out port and the site.

First question, conventional ship or barge shaped hull? The 18 under consideration are all self-propelled and all except one being to DP2 standards, financing being a capital expenditure item rather than operational expenditure with a towed vessel. Payload, jacking speed and deck area have to be considered, along with the ability to cope with the more inclement weather conditions of locations further offshore than currently experienced. Both ship and barge designs have the advantage of increased speed over non-propelled examples, an important financial consideration with greater distances between loading port and the site of deepwater projects.

Five of those considered have ‘barge shaped’ hulls, 13 have conventional ship shaped hulls. The speed of the barge hulls range from 7.5 to 10 knots, while the conventional ship hulls range from 10 to 13 knots. Average overall lengths are 113m and 135m respectively for the barge and ship hulls.

Specialist vessels are often described as multi-purpose, and literature for a number of those considered indicates the ability to also operate in the oil and gas industry. This is mentioned as it will influence the ship or barge question, together with other specification decisions including length, beam, deck area and variable load capacity.

Careful consideration has to be given to carrying capacity. Operators have to balance maximising the number of turbines carried at one time, against the increased capital expenditure of the consequential extra power demand on jacking and propulsion systems. Selecting higher jacking speeds also demands increased power generation. A range of information is provided by owners and designers on loading options, and one source recently reported current new designs ranging from 5,500t to 21,000t elevated weight.

The deepwater element of future projects, previously mentioned, is reflected in the operating depth capabilities of the vessels on order. All 18 reviewed are able to operate in water depths of 40m or more, with the newbuilds for Seafox Group and Swire Blue Ocean capable of working in depths of 70m and 75m respectively.

Larger turbines, weighing in excess of 450t, and heavier foundation designs over 700t, require crane capacities greater than previously considered adequate. The MPI Resolution recently had its original 300t crane replaced with one capable of lifting 600t. The 18 newbuilds reviewed will have cranes capable of lifting between 800t and 1,200t. Sufficient outreach to handle tripod and other next generation foundations will also be a consideration. Several feature the so called ‘wrap around’ crane, built around one of the legs, maximising available deck space, and improving accessibility.

A decision with obvious cost implications is the number of legs. The example for Inwind AS will have three legs, 13 of the remainder have four legs. The MPI Resolution has six jackable legs and MPI Offshore, together with Swire Blue Ocean, which each have orders with yards in south-east Asia, have selected the six leg option.

The Netherlands based GustoMSC traces its history back to 1862, and is now a major force in the field of offshore engineering and design. Its SEA series of self-elevating platforms is regularly seen installing offshore wind farms. To keep pace with demands of heavier loads, greater depths and increased flexibility, the NG series of self-propelled offshore construction vessels was developed, examples of which are also employed in turbine installation work. GustoMSC has continued to develop this marque, including conventional ship hull designs of which the MPI Resolution is an example.

At least five owners have selected GustoMSC designs, covering eight firm orders and options, including a further two upgraded, but similar examples for MPI Offshore. GustoMSC also designs and manufactures jacking systems, offshore cranes and load handling equipment. Designs from Beluga Hochtief/Overdick GmbH/Wärtsilä Ship Design, JJ Sietas KG and Keppel FELS are also among those on order.

Only two owners have chosen European shipyards for their orders. Hamburg based JJ Sietas KG beat off competition from China and the UAE to secure a one vessel order plus option from Van Oord BV while Beluga Hochtief Offshore has returned to Crist Shipyard in Gdansk for a single vessel.

Of the remainder, six owners have selected yards in south-east Asia, while two have ordered vessels from UAE based Lamprell plc, which recently announced that one of two options for Fred. Olsen Windcarrier, and a single option for Seajacks Ltd, had been allowed to lapse for what they described as ‘ongoing delays in the development of the offshore wind sector driven by a number of factors’. Around the same time, it was reported that Swire Pacific Offshore had converted an option for a second vessel with Samsung Heavy Industries into a firm order.

The first of two newbuildings for MPI Offshore, MPI Adventure, is due to commence construction work at London Array wind farm in May of this year. Deliveries of the remaining 14 firm orders are due in 2011 and 2012.

It is appropriate to mention seven vessels for four owners recently delivered and involved in offshore wind farm construction. Delivered in 2009 to Seajacks Ltd, two GustoMSC NG-2500-X self-propelled jack-ups, Seajacks Leviathan and Seajacks Kraken, are at the time of writing installing turbines at the Greater Gabbard wind farm in UK waters. Seajacks has an upgraded GustoMSC design, to be named Seajacks Zaratan, on order with Lamprell and due in 2012.

The GustoMSC CJ50 jack-up Haven was delivered to Norwegian company Master Marine in June 2010 by Drydocks World Indonesia, with a second example, to be named Nora, also under construction at the yard. Designed for both the offshore oil and gas and wind farm markets, the Haven has been outfitted as an accommodation unit for ConocoPhillips.

The Nora was due to install turbines at the UK’s Sheringham Shoal wind farm but late in 2010 Master Marine reported they had ‘reached an amicable agreement’ with Statoil, representing Scira Offshore Energy Ltd, for the cancellation of the contract due to the delayed delivery of the Nora.

GMS Endurance and GMS Endeavour, built to the same GustoMSC design as the two Seajacks vessels, were delivered to Gulf Marine Services in 2010. The latter vessel is scheduled to carry out construction work this year at the Sheringham Shoal wind farm.

Emden based BARD Engineering is involved in several areas of the offshore wind industry, including operating the 80 turbine BARD Offshore 1 wind farm. They produced and installed the turbines themselves, using their 2010 delivered DP1 self-propelled jack-up vessel Wind Lift 1.

In addition to the above, a number of ship design companies have unveiled interesting concept ideas and specific design proposals that are yet to translate into firm orders. Ulstein Sea of Solutions, together with IDEA Heavy Equipment BV, are proposing a WTIV based on the Ulstein X-bow series of offshore vessels. Meanwhile, Wärtsilä and Aker Solutions recently unveiled a WTIV concept idea based on a jack-up vessel, with dual-fuel engines able to operate on LNG and including a 24/7 global support service for maintenance, repairs and component supply to the vessels.

By Peter Barker