Advanced sub-sea scour and cable protection
Ridgeway, established in 1969, is a major supplier to the construction and engineering sector in Northern Ireland. The Ridgeway Renewables division was created in 2009 to focus on the development of applications within Ridgeway’s fields of expertise (steel and glass reinforced plastic, or GRP, products) for the renewable energy market. At the same time, Ridgeway Renewables entered into a distribution agreement with Sumitomo of Japan and brought an advanced sub-sea scour and cable protection fi lter unit solution, developed by Sumitomo subsidiary Sumisho-Kyowa, to the UK and Irish markets.The Sumisho-Kyowa filter unit, which is supplied by Ridgeway Renewables for offshore wind farms, is highly durable and flexible. It can also be deployed for tidal devices and has the ability to protect sub-sea foundations from strong tidal currents.
The unit, which is designed specifically for scour protection, is an advanced alternative to traditional materials used for this purpose such as rock dumping and concrete mattresses. It protects sub-sea structures such as monopile – and it protects and stabilises export cables, the cables at the j-tube bell mouth, cable crossings and cable arrays.The Sumisho-Kyowa fi lter unit is manufactured from recycled synthetic materials and has a double-netted structure, ensuring that it is sufficiently durable to withstand the harshest marine environments. With a flexible structure which makes it ideal for irregular seabed conditions, the unit has a lifetime of at least 50 years in saline water. It is also environmentally friendly – actually creating new habitats for marine fauna.
The unit can be deployed easily and cheaply, using a one point lifting system, and requires no seabed preparation. It takes up less area per square metre on vessel decks than traditional methods and a single filter unit can be installed on the sea floor in just ten minutes – resulting in significant reductions in vessel times.
One unit was installed recently at the Sheringham Shoal offshore wind farm, to protect and stabilise the HDPE pipe extended from the j-tube bell mouth. The product was chosen by ISS (Integrated Subsea Services) as the most simple and cost effective cable protection solution. The Sheringham Shoal project has demonstrated the potential of the filter unit in the offshore wind market, and Ridgeway has the potential to become a key provider to this growing industry.