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A service operation vessel concept to be proud of

A trusted shipping company with an enviable safety record and a far-reaching reputation for reliability, ESVAGT is a shining star in the offshore wind sector. We analysed the company in depth and found an operation that’s committed to safety and quality in equal measure…

ESVAGT is a ship-owning company founded in Esbjerg, Denmark, in 1981 by a group of local investors, with the aim of providing standby and rescue services to the accelerating oil and gas activities in the Danish sector of the North Sea. Over the years, the fleet of vessels has grown from a few rebuilt fishing vessels to a total of 38 vessels plus additional five new vessels scheduled for delivery over the next year.

Today, ESVAGT is a subsidiary company of the A.P. Moller – Maersk Group with the original founders remaining minority shareholders.

The majority of the ESVAGT vessels are still engaged in standby and rescue services and some also carry supplies, do anchor handling, personnel transfers, tanker assists, oil pollution response cover, etc. Over the years there has been an increasing interest for the company’s vessels from the offshore wind industry for standby and guard jobs but also for offshore accommodation with possibility of transferring personnel from mother vessel to various installations during the construction as well as operational phase.

Most of ESVAGT’s vessels are operating in and around the North Sea but the company is also active in Arctic regions such as the Barents Sea, and have several vessels specifically designed for operation in cold and harsh weather.

ESVAGT boat operations

The operation of Fast Rescue Boats (FRBs) is the backbone of ESVAGT as these boats are to be used in rescue operations which have always been, and still is, the company’s prime functions on the seas. In 2013, the ESVAGT vessels launched FRBs 25,000 times for a variety of purposes. ESVAGT have so far rescued a total of 124 persons (in several cases under extreme conditions such as darkness and 10-12 metre seas). 

Such operations require top class equipment and excellent boat handling skills from the boat crews.

The experience gained over the years has given the company a unique opportunity to develop its own rescue boats and launch/recovery equipment with a top priority on safety, reliability, redundancy and manoeuvrability based on direct feedback from the people using these boats on a daily basis. The development and maintenance of the boats is all done by ESVAGT’s own personnel in Esbjerg, Denmark.

ESVAGT has been transferring personnel to and from normally unmanned offshore oil and gas installations in the North Sea since 1994, and now that offshore wind farms are moving further offshore, the company has found that operators of offshore wind are facing many of the same challenges moving people around as has been seen in the oil and gas industry. 

Based on the company’s experience from the oil and gas industry, it has proven that it can also provide a safe and valued service to the offshore wind parks. ESVAGT has had a healthy growth over the years and the company believes that offshore wind is an opportunity to grow even more in the future.

The company has transferred nearly 100,000 of its clients’ personnel to and from offshore installation by boats over the years. In 2014 alone ESVAGT will complete in excess of 15,000 such transfers with more than half of these in the offshore wind sector. These numbers are due to increase significantly over the coming years when two new purpose built Service Operation Vessels (SOVs) will start operation in 2015. 

Experience in offshore wind 

The company’s first experience with offshore wind dates back to 2002 where Esvagt Alpha acted as an accommodation vessel and transferred maintenance personnel to the Horns Rev 1 wind farm in Denmark. In recent years Esvagt Beta has been on several jobs in similar functions using traditional open rescue boats as well as larger closed boats to transfer people. Besides that, ESVAGT provides man overboard cover when people need to work on the outside of offshore wind installations.

Since 2010 the company has had one vessel, Esvagt Supporter, working as Service Operation Vessel (SOV) in Belgium where it has been accommodating and transferring technicians and spare parts to the turbines for MHI Vestas Offshore Wind. This job, with an uptime of more than 98% and no incidents, has proven that the SOV concept is working.

ESVAGT is now in the process of constructing two large Service Operation Vessels due to start long term charters for Siemens in first half of 2015. The vessels are based on design from the Norwegian yard Havyard but with many additional features to ensure high fuel efficiency and a great level of comfort for the technicians and crew who will have their daily lives on-board. 

ESVAGT and Siemens have worked closely together on the design of the accommodation to ensure an efficient flow of people and spare parts around the vessel. These vessels are expected to be on location at the wind farms for several weeks at the time enabling technicians to spend more time working in the turbines rather and less time in transit between shore and wind farm.

Based on experience from the first SOV at Bligh Bank and in connection with building the two new SOVs, ESVAGT has developed two types of Safe Transfer Boats (STBs) specifically designed for swift and comfortable personnel transfers rather than rescue operations in rough seas. 

The STB7 is for transfer of just a few technicians and minor spare parts and the larger STB12 closed daughter craft for up to eight technicians, cargo and spare parts with more comfort than traditional daughter crafts of this size.

ESVAGT has proven that boat transfers are safe and efficient in moderate weather conditions. But if charterers like to have “walk-to-work”, the vessels are prepared for that. The two new buildings going on charter to Siemens will be equipped with a gangway system and the company is looking forward to seeing how much added value this feature will give customers compared to boat only operations.

Service Operation Vessel versus shore-based operation

Over the years, ESVAGT has considered entering the market for Crew Transfer Vessels (CTV) but has so far decided to focus on the far offshore market where they have decades of proven track record and see more synergies with their existing operation. With the mother vessel concept, company technicians can spend much more time working on turbines compared to the shore-based crews who tend to spend much time in transit or waiting for weather in port. 

With a mother vessel always near, the wind farm technicians can respond to trouble on a turbine within minutes day or night and even short weather windows can be used for scheduled maintenance. Conversely, the shore based crews often choose to stay in port rather than facing a long and tiresome journey out to the wind farm and back maybe just to discover that they cannot work there anyway. 

Also, when a service technician is facing unforeseen challenges on a turbine, then spare parts and tools can quickly be dispatched from the mother vessel nearby enabling him to complete his task quickly rather than postponing it until next time there is an opportunity to sail out from shore.

The short transit times from mother vessel to turbines also significantly reduces the risk of sea sickness which is likely to ruin a full working day for a technician and, more importantly, pose a safety risk if trying to climb onto a turbine anyway. 

A mother vessel can also be used for many other purposes than just accommodation for maintenance personnel. A mother vessel can also be a platform for under water surveys, blade inspections and other tasks that might otherwise require separate vessels to be chartered in.


Considering that the offshore wind industry is relatively young, and with many players and employees entering the market, safety and quality varies greatly. The companies ESVAGT has been working for so far have all had a strong focus on safety, and with 30 years of experience from the offshore oil and gas industry, it has been easy for ESVAGT to provide an organisation able to deliver high quality in design, development, ship building and execution of the work offshore. 

At the time of writing ESVAGT has passed more the 500 days of operation without a Lost Time Incident involving any of its 38 vessels and 800 marine crew.

The company is now and then faced with concerns from the industry about the safety aspects of its SOV concept with boat transfers which, by some, are perceived as high risk operations. It is especially the launch and recovery of the boats and access to the WTG’s boat landings ESVAGT needs to explain and demonstrate to operators who are used to crew transfer vessels sailing out from shore. But with well established procedures, special equipment, carefully selected crew and extensive training in place ESVAGT has proven over the years that it can be done. 

More companies are showing interest in ESVAGT’s concept and realise that the efficiency of SOVs for far offshore wind farms does not need to compromise safety. This is essential in order to develop wind farms further and further from shore. 

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