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Sea trials demonstrate workability of jack-up vessels under extreme tidal conditions

RAZ BLANCHARD, FRANCE | GeoSea (DEME Group) announces a major break-through in the tidal energy sector. As a specialist in complex offshore marine engineering projects, the company has successfully completed trials of a jack-up vessel in extreme current flows. The results of the trials confute industry reluctance to deploy jack-up vessels on tidal sites.  The demonstrated workability and reliability create confidence for tidal project developers and open the market for all types of tidal energy applications. 

GeoSea has chosen French Raz Blanchard as operational area, which is a renowned site for strong tidal currents and is located between Alderney (UK) and Cap de la Hague (FR). The campaign was held during the Autumnal Equinox of September 2015 with currents during spring peaks. GeoSea’s jack-up vessel Goliath operated in currents of up to 10 knots (approx. 5 m/s) and water depths, under hull, of 56 meters.  

The demonstrated utilisation of GeoSea’s jack-up platform under those extreme tidal conditions are the direct result and the practical implementation of a two year in-house study analysing and researching the behaviour of jack-up platforms while jacked-up in strong currents. On that basis, specific operating models as well as procedural and technical improvements have been developed that enable the use of the GeoSea’s respective jack-up platforms and vessels in strong tidal race areas.

The real life trials at Raz Blanchard validated and calibrated those models and procedures with a successful result: GeoSea’s jack-ups are able to position accurately and to operate safely in tidal sites, even in those sites that are recognised as one the most extreme and energetic with significant depths.

This is an important milestone in the tidal energy sector which will accelerate the construction of tidal turbines and all related operations such as maintenance and decommissioning. GeoSea’s practical experiences under those demonstrated extreme conditions should give confidence to developers and project owners alike to use cost effective jack-up platforms and vessels for the realization of their tidal projects.

More information
Marleen Vanhecke
Head of Communication at DEME Group
M + 32 486 49 01 09

About DEME
The Belgian dredging, marine engineering and environmental group DEME has attained a prominent position in several extremely specialised and complex marine engineering disciplines worldwide. The group has diversified from dredging work and land reclamation, to marine engineering projects in international waters, supplying services to oil- and gas companies, the installation of offshore wind farms, and environmental activities such as soil remediation, sludge recycling and reassessment of brown fields and wreck clearance.

Thanks to its multidisciplinary expertise and experience, project synergies and its integrated corporate structure, DEME has expanded to become a ‘global solutions provider’. The group has one of the most modern, high-tech and versatile fleets for dredging- and marine engineering work. DEME has 4,600 employees. In 2014, the group achieved a turnover of 2.59 billion euro.

About GeoSea
GeoSea (DEME GROUP) is a fast growing company specialising in complex offshore marine engineering projects. GeoSea has participated in the construction of large-scale European offshore wind farms including the Alpha Ventus, EnBW Baltic 2 wind farm, Trianel West Brokum II and the Godewind wind farms in German waters, Westermost Rough, Kentish Flats and West of Duddon Sand wind farms in the UK, Walney and the Ormonde farms in the Irish Sea and the C-Power and the Northwind wind farms off the Belgian Coast. GeoSea’s business also covers more traditional activities such as soil investigation, drilling of large diameter piles and high-tech directional drilling. GeoSea relies on its ability to provide innovative techniques and high operational reliability through high-tech equipment. GeoSea’s jack-up platforms include Innovation, Neptune, Thor, Goliath, Vagant, Buzzard and Zeebouwer. The new jack-up Apollo is under construction.

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