Service provider can handle new-generation turbines

Having seen a 250 per cent increase in the number of its offshore crew and a similar increase in the number of personnel ashore since private equity fund Odin Equity Partners invested in the company in 2012, DBB Jack-Up Services is preparing to take delivery of two more jack-up vessels that it believes will provide it with an edge in an increasingly competitive market.

DBB Jack-Up Services was established in 2008 as a sister company to Dansk Bjergning og Bugsering. The company has a head office in Aarhus, Denmark, along with the other companies in the DBB Group, and focuses on providing vessels and services for operation and maintenance (O&M) work on offshore windfarms. Both new vessels are considerably more advanced than many other vessels in the market and will be able to work in much worse weather conditions. Both will be used to transport and lift main components for wind turbines and transport technicians who repair, service and maintain offshore wind turbines. DBB Jack-Up already owns what is one of a very few vessels tailored to service offshore wind turbines.

Apart from operating in worse weather conditions than other units, the new vessels will also be able to do so in greater water depths, lift components to greater heights and carry more equipment than earlier vessels. The contracts for the new units include options for more vessels and the company’s ambition is to acquire four to five vessels in the next 2–3 years – if conditions in the industry warrant further investment.

The first newbuild, Wind Pioneer (the former Hyundai Pioneer, a jack-up unit completed in 2010 that is being modified to meet DBB Jack-Up’s requirements), is due to be delivered to the company in January 2014; the second, a purpose-designed and built vessel, Wind Server, is currently under construction at Nordic Yards in Germany, with delivery anticipated in mid-2014.

Wind Pioneer, which is being completed at the Orskov Yard in Frederikshavn in Denmark, will have a Liebherr BOS 7500 crane installed, along with new thrusters and accommodation facilities. The design of Wind Server draws on DBB’s extensive experience in the offshore wind industry and hundreds of projects the company has already completed. It will also have a Liebherr crane, but a somewhat larger, more capable BOS 14000 unit with a lifting capacity of 500 tonnes which will be capable of lifting a load up to 96m above the deck of the vessel. This will enable it to work on the new generation of larger, 5-8 megawatt turbines.

Speaking to OWJ at EWEA Offshore 2013 in Frankfurt, Thorsten Jalk, the company’s chief executive officer, explained that all of DBB Jack-Up’s units are fitted with Liebherr cranes for easy maintenance and spares management across its fleet. “Using the cranes on the new units, we will be able to replace any component on a turbine”, he explained, noting that, in addition to drawing on its own experience in offshore O&M operations, DBB Jack-Up also drew on input from its customers and turbine manufacturers in the design process for the new units.

“Our business is all about reducing costs,” he told OWJ. “When a turbine isn’t working, it isn’t generating electricity. That’s where we come in, changing blades or gearboxes or whatever component needs work done on it. With our new vessels we like to say that we are ‘challenging the weather’ because they will enable us to carry O&M projects in much more challenging conditions than would otherwise be the case.

“Because we can work when other vessels can’t, we can minimise turbine downtime,” he explained, noting that in order to maximise the availability of its new vessels, they were designed with what Mr Jalk described as “a very high level of redundancy”.

“At DBB Jack-Up we say that we specialise in order to optimise. Although our vessels could work in the installation market, we don’t intend to use them there. By specialising in O&M work, we think we are gaining an edge over multipurpose units that weren’t designed to work in this way.”

A keel-laying ceremony for the Nordic Yards-built unit took place in September when a 390-tonne section of the wind turbine service vessel was laid down in dock at Wismar. Wind Server will have dynamic positioning to DP2 standard, a leg length of 80m and breadth of 32m. In keeping with the high level of redundancy built into the unit, Mr Jalk said the capability of the new unit comfortably exceeds what is required for DP2 classification and describes it as almost a DP3 unit. The dynamic positioning capability will mean that the sophisticated newbuild will not need to make use of anchors to be positioned prior to being jacked up.

Apart from the crane, one of the most important features of the vessel is its jacking system, which will enable its legs to be lowered and raised quickly and efficiently in water depths of up to 45m. The rack and pinion-type jacking system – which will be the first example of its type – was developed by DBB Jack-Up working closely with naval architects OSK Ship Tech. It was supplied by SH Group and has been approved by classification society DNV GL. Mr Jalk told OWJ that what the company particularly wanted from the jacking system was technology that would enable the new unit to jack up and down quickly, with a high level of redundancy. “The system we have ordered from SH Group will enable us to jack up and down again twice a day so that we can move quickly and efficiently between turbines,” he said. “It incorporates a lot of small jacking engines that give it a lot of redundancy – even if 25 per cent of them were to fail for any reason we can still jack up and down and complete the job.” The new unit may be larger and more capable than the company’s existing vessels, but because it has a relatively shallow draught – just 2.6m – it will also be capable of working in shallow water too.

Wind Pioneer is a less capable but still sophisticated unit. It will require the assistance of a tug in transit but, having been fitted with five swing-up thrusters, it will be capable of operating in DP1 mode once it has arrived at an offshore windfarm. The vessel has a length of 50m and breadth of 28m, and the crane on board will have a lifting capacity of up to 300 tonnes. The new unit is designed to operate in water depths of up to 40m.

Asked what he sees as the main challenges facing the company and the offshore wind industry as a whole, Mr Jalk noted that political uncertainty surrounding the industry was undoubtedly having an effect, but said he believed that companies operating expensive assets such as turbine installation vessels would be worse hit than companies such as DBB, for whom turbines already installed represent potential long-term business. OWJ