Roman Stone has partnered with Subsea Protection Systems Ltd, out of Yarmouth in the United Kingdom to provide proven engineered designs for scour protection and cable protection specific to the offshore wind industry. Roman Stone is the US based manufacturer under license to SPS. Further information about SPS and other products they can provide can be found at www.subseaprotectionsystems.co.uk
CONCRETE MATTRESSES
Concrete mattresses provide a recognized engineering solution for several of the challenges faced in Offshore Wind subsea cable protection. They are cost effective and may be readily deployed using standard handling systems.
Typically, concrete mattresses may be used to provide :
• Protection from dropped objects
• Added weight and stabilization
• Protection from Trawl Boards
• Scour prevention
• Crossover support and separation for pipelines and umbilicals
• Supports or foundations for other subsea activities
• Riverbank erosion control
Roman Stone/SPS manufacture a range of standard mattresses but will also design and manufacture mattresses to a client’s specific requirement. Quality and safety are the key issues in all SPS designs and appropriate safety factors are applied to address lifting and handling in an offshore environment.
The Concrete Mattresses shown below are being loaded on to a ship for the South Fork Wind project in Falls River MA.
Concrete Mattress Options
Concrete Density
The density of concrete used in the manufacture of standard mattresses, is generally between 145 – 150 pounds per cubic foot. Under certain conditions where there may be a requirement for additional, or less weight in a mattress, Roman Stone /SPS can design and supply a concrete mix with a higher or lower density than the standard.
Protection Pads
Under certain operating conditions clients require a low friction or anti abrasion material between the concrete mattress and the asset, that it may be stabilizing or protecting. SPS can provide this by affixing a range of materials to its mattress segments.
Fronded Concrete Mattresses
The Anti Scour Frond Mattress (above) may be deployed directly into its location, or alternatively attached to and deployed together with a concrete mattress. This latter method simplifies deployment and provides additional protection and stabilization.
General Options
SPS engineering and experience is available to address any requirements that clients may have for special mattress designs and modifications.
Fleximats
The Fleximat is a standard Roman Stone/SPS product. It provides a high degree of flexibility, allowing it to closely follow the contours of a pipeline/umbilical cable and seabed. It is constructed using high strength concrete profiled blocks and U.V. stabilized polypropylene rope. The Fleximat brick pattern matrix, reduces the open line effect, thus offering additional protection and stability. Once installed the Fleximat may scour into the seabed to increase the stability and overtrawlability.
Tapered (Wedged) Fleximats
Revetment mats
The Revetment mattress is a fleximat used for protection against river and sea embankment erosion. Its flexible construction ensures that it can be laid to cope with variations in the embankment profile, maintaining maximum protection against erosion.
Revetment mats are suitable for various environments including:
- Harbors, Docks, Lakes, Riverbanks, Break waters, Weirs, Sea defenses, Slipways, Outfalls, Reclamation applications, Environmental applications, Slope stabilization, Roads