Offshore Deep Sea Mooring

Deep Rope is the industry standard in safe and secure offshore mooring solutions. It is Class certified product and the entire production process has been type-approved and certified according to latest DNV -OS-E303 and ISO 9001 standards. With its Deep Rope constructions Bexco is capable of achieving breaking loads of up to 2500 tonnes and more. It is also capable of producing lengths of up to 2800 metres and diameters of up to 300 millemetres. For the most critical part of production, Bexco its SPLICE-RIGHT procedure – this is based on the definition of a good splice, which should lock perfectly, avoiding sub rope length differences and reaching maximum compactness and stabilization. These factors contribute to high efficiency and strong, sturdy rope.

For more information on our Deep Sea Mooring solutions, please send an e-mail to offshore@bexco.be

Taut-leg moorings

As water depth increases conventional, catenary systems become less and less economical. For permanent systems a cost-effective, synthetic alternative has been developed: Taut Leg Mooring. In this system each line is strung out directly to the seabed typically at an angle of 45°. As the platform drifts horizontally with wind or current, the lines stretch and this sets up an opposing force. Our DeepRope® Polyester mooring lines have the right restoring characteristics and thus are the preferred choice for this application. Because of the angle at which the rope arrives at the seabed the anchor will be loaded vertically. Suction piles or special anchors, so-called VLAs (Vertically Loaded Anchors) have to be used.

Insert catanary mooring

For temporary systems either a polyester taut-leg or a catenary mooring with insert lines made of Dyneema® are a cost effective alternative for dynamically positioned rigs. The choice between these two alternatives is driven by cost of the mooring versus operational limitations. A DeepRope® insert made with Dyneema® will transfer mooring forces without changing the catenary. In shallow waters, an all chains system works well but as the water depth increases the weight of the chain becomes excessive and it tends to hang directly down from the rig. By inserting a line made of Dyneema® the mooring stiffness increases, without a weight penalty. Thus no modifications to the riser system are necessary when going to deeper water. Depending on the exact design it is even possible to improve the restoring characteristics. This will extend the weather window for drilling time. As the DeepRope® lines made of Dyneema® are neutrally buoyant they can be pre-installed with only a small surface buoy, thus reducing hook-up time. More information can be found in our OFFSHORE leaflet with focus on our DeepRope Mooring lines.