Faster, bigger, more efficient

Monday, 22 June, 2015 - 14:00
One boat, two modes: the Cat-SWATH combines the advantages of two ship types in one CTV. (Photo: Danish Yachts)
One boat, two modes: the Cat-SWATH combines the advantages of two ship types in one CTV. (Photo: Danish Yachts)

One vessel for a hundred wind turbines. With this claim and a new tool, Siemens Wind Power intends to revolutionise the servicing of wind farms far from shore. The first ­service ­operation vessel will be christened in Rostock in late June. ­Better times might also be ahead again for the German flag, because there is good news for transporting passengers.

Service operation vessels (SOVs) have long been said to be an option for more effectively ser­vicing and maintaining large-scale wind farms far from shore. Now, Siemens intends to be the first manufacturer to prove this. “We need floating solutions to make maintenance more ­efficient. To this end, we use SOVs that are positioned in the wind farm and serve as a base for the ­technicians, who are taken by crew transfer vessels, helicopters or the base vessel’s access system to the turbines from there,” explains Michael Hannibal, CEO of Siemens Offshore.

The market leader for offshore wind intends to revolutionise maintenance – or, in other words, to lower the costs significantly. To achieve this, the job will have to be done faster, safer and more reliably in future; after all, by now Siemens, too, is installing large wind farms quite far from shore. For this purpose, crew transfer ­vessels (CTVs) with a limited deployable range that depend greatly on weather conditions are far from optimal tools. “We plan on using one SOV for every hundred wind ­turbines. Although the vessels are rather costly, they can be used in many different situations,” says Hannibal.

The first two units come from Norwegian shipyard Havyard and were commissioned by Danish shipping company Esvagt, which has signed a long-term ­charter agreement with Siemens for refinancing the floating workshops with hotel facilities. The two vessels are earmarked for the German Baltic 2 and Butendiek wind farms. The units, each 83 m long with a top speed of just under 14 knots, have enough room for 60 people on board, including 40 technicians, who rotate with new personnel in regular intervals. Moreover, the decks have a payload capacity of 3,200 tonnes and provide ample space for tools, consumables and spare parts.

Photo gallery from the christening of SOV Esvagt Froude

This vessel type can be used in many more types of weather. While a CTV with a maximum significant wave height of 1.5 m statistically can only be used on 219 days a year, an SOV with a maximum significant wave height of 2.5 m boosts availability up to 278 days and is therefore available for 78 % of the year, when periods spent in shipyards are deducted. Because technicians’ jobs are executed just outside the “door” of their floating home, according to estimates by Siemens, effective work time should grow from seven to ten hours per day, based on calculations with regular work shifts of 12 hours.

Business is flourishing

German Windea Offshore GmbH & Co. KG is the lucky charterer of another two vessels. The company’s partners are SSC Wind GmbH, EMS Maritime Offshore GmbH and the Bernhard Schulte Group. Windea has ordered two SOVs from Ulstein Verft, a shipyard in ­Norway. The vessels, each 88 m long with a speed of 13.5 knots fast, will be put into operation in 2016 and 2017 and also have room on board for 60 persons. “These are the dimensions requested by the market. The vessels are envisaged for the Gemini wind farm in the Netherlands and Sandbank 24 in Germany,” explains Christian Brozinski, business developer at Windea. Refinancing is facilitated by an agreement with Siemens and the company’s strong ­financing partners.

The two new acquisitions are unique in some ways thanks to the more than 100 technicians who ­assemble turbines on land and at sea for Windea. “We asked them what a vessel should look like that is optimally adapted to the day-to-day work out at sea and integrated these ideas into the design,” says Brozinski. The equipment therefore includes, for example, an access system.  ­However, they opted not for an Ampelmann system as Esvagt did but for a solution from Uptime International that is used in the oil and gas industry. The reason is that the Ampelmann system, including operating personnel and training measures, can only be leased in a package and not bought. “At the end of the day, that makes a difference of several million euros,” Brozinski points out. Nevertheless, the medium-sized Windea has committed itself considerably in terms of finances, thereby taking a major step in continuing to develop itself as a maritime service provider.

Over the last one and a half years, the ­consortium has bought three Twin Axe boats from Damen ­Shipyards. The Damen CTVs, which are very popular on the ­market, are in use at the Nordsee Ost, Borkum West 2 and ­Meerwind wind farms. Windea is the first company to have a ­vessel that is allowed to take 24 passengers on board, twice the previous standard of 12. Windea thus benefits from changes to the Code for Offshore ­Service Craft that were approved in late 2014 and state that ­offshore workers are no longer classified as ­passengers, but as ­technical personnel – on the condition that the vessels sail under the German flag and meet the required safety codes. “The German flag is, of course, a real advantage for us, ­because we are permitted to transport more personnel and operators don’t have to lease a second boat. ­Moreover, higher safety standards are of major importance for customers,” says Brozinski.

New options

The German Shipowners’ Association (VDR) hopes to see a boost in ship construction as a result of these changes. It has long called for the “Code for construction, equipment and operation of offshore service craft” to be amended. Now, internationally comparable safety stan­dards apply to vessels that sail under the German flag in the Exclusive Economic Zone (EEZ). They are authorised to take up to 60 people on board, as long as they meet the mandatory safety requirements. As a result, the competitive disadvantages that had been prompted by the internationally varying standards have been formally abolished. “There was strong pressure from the industry. Previously, vessels under the German flag had to fulfil the requirements for passenger ships when more than 12 passengers were on board. Now it has been made clear that service technicians are not passengers,” explains Christof Schwaner, spokesman for the VDR.

Word has already spread as far as the UK, the biggest market for CTVs. “The amendments to the German code are a very interesting option. We are giving serious consideration to constructing our vessels according to the standards of the German flag,” confirms Andy Page, Design Manager at Alicat Workboats...

You can read the complete article written by Torsten Thomas


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