Moorings Case Study
Installing SSWR offshore India
Transpooling and installation of mooring wire rope
An offshore contractor was looking to install sheathed Spiral Strand Wire Rope (SSWR) off the coast of India, to moor in an FPSO in 310-500m water depths. They were looking to perform the installation using one of the offshore support vessels from their own fleet.
Prior to the project, MDL performed a pull test on a product sample at its Peterhead facility up to a Working Load Limit (WLL) of 45 tonnes, to prove the squeeze and pull capacity of a tensioner-based approach. For the execution of this operation, MDL utilised a lay spread consisting of a TTS-4/140 Series Tensioner, an Adjustable Radius Controller, spooler and an overboarding chute, all of which were mobilised onboard the client’s construction support vessel (CSV). Prior to the offshore installation, over 6.4km of the 149mm OD sheated SSWR was transpooled at the mobilisation port in Singapore from storage reels onto five transportation reels, using the MDL tensioner.
In keeping with its innovative approach, MDL pursued a creative solution: for the first time an MDL tensioner was used for the installation of a wire rope off a construction support vessel (CSV). This allowed the project team to maintain consistent line tension and squeeze on the product while benefitting from MDL’s Failsafe Grip technology preventing unexpected loss of the product and offering peace of mind to the field operator. MDL's Adjustable Radius Controller also came into play and optimised the handling of the wire rope as it was deployed from the double-drum transportation reels, by moving in and out to maintain the product in the firing line. On top of that, MDL was able to safely and efficiently execute the installation of this wire rope in just a single offshore trip using a vessel of opportunity.