Polyspace™
There is often a requirement to maintain a positive clearance between cables and existing pipelines at crossing points. Methods such as pre-lay rock dumping, concrete matressing and steel structures are expensive, time consuming and difficult to place accurately.
As a solution, we have developed Polyspace™, a product that generates a 350mm clearance between the cable and the pipeline. This system is flexible and comprises of interlocking hollow half-shells fastened around a cable by a combination of corrosion resistant metallic banding and sacrificial banding. The half-shells are manufactured from UV stable, marine grade, high density polyethylene which has good impact strength and abrasion resistance. Each moulding is free flooding and can be supplied with a ballast system to provide up to 90kg/m of additional submerged weight to suit the application.
Polyspace™ is installed onto the cable as it is deployed from the cableship at the crossing location. Internal cable clamps are used to lock the Polyspace™ mouldings onto the cable at regular intervals. 'Leading' and 'trailing' bending stiffeners can also be included with the system to prevent the cable exceeding the recommended minimum bend radius at any time during installation or retrieval.
Polyspace™ offers an innovative, cost-effective solution at pipeline crossings where clearance is required. As this system becomes an integral part of the cable, additional problems associated with installing over a pre-laid bridge or separator are negated. This is in addition to the obvious benefits of no pre lay operations and the associated costs this would entail.