Ecosse Subsea Systems (ESS) has been awarded its largest boulder clearing and multi-pass trenching contract to date by Siem Offshore Contractors.
ESS will deploy its SCAR plough system for clearing and pre-lay trenching operations on a 90km route on the EnBW owned Baltic 2 offshore wind farm project.
Baltic 2 is an 80 turbine development located 32km north of Rügen island in the Baltic Sea. The 27km2 site spans water depths ranging from 20m to 45m LAT and has a wide array of soil conditions from fine sands to gravels and cobbles.
This 80 cable inter-array workscope follows on from two highly successful projects on behalf of Total in Shetland and on E.ON’s Humber Gateway wind farm project in the North Sea.
The Baltic 2 workscope includes providing a trench design for each array cluster and all pre-engineering including the provision of plough tips for variant soils conditions and plough cut depth configuration.
Boulder clearance and multi-pass trenching to 1.5m depths is scheduled to take place over a 90km long route. ESS will use its own ROV system to monitor, survey and record operations and a vessel mounted multi-beam will determine the quality of trenching achieved.
Rapid deployment from a range of vessels, including anchor handlers, and smaller operational crews make SCAR much more cost effective compared to traditional subsea plough solutions. It can work in varying soil conditions and speedy conversion to different plough types offer versatility and greater efficiency.
Ecosse Subsea Systems managing director, Mike Wilson , said: “Our SCAR ploughing system is proven on diverse oil and gas and renewables projects as a rugged and reliable low risk option for cable trenching and burial.”
He added SCAR was becoming a preferred option by cable manufacturers and product warranty holders and that clients were requesting ESS adapt their tools for their specification requirements.
He said: “One of SCAR’s great advantages is that it can work in shallow and very deep waters and handle diverse soil types and this flexibility, as well as SCAR’s ability to dig deep trenches (5m+), is generating a great deal of interest in both the renewables and traditional oil and gas sectors.
“Its multi-functional capacity allied to being able to work from almost any type of vessel with smaller crews is a real game changer for contractors and operators who want to control costs while obtaining consistent results which offer optimum subsea cable protection.”
ESS have mobilised from Aberdeen to Gdansk enroute to the Baltic 2 site and expect the project to be completed within 10 weeks.
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Press release, March 13, 2013; Image: ocosse subsea