Civils contractor in project first with tensioner

Consisting of a TTS-4/140 series tensioner, an adjustable radius controller, a reel drive system and an overboarding chute, the spread was mobilised onboard a locally-available construction support vessel (CSV).

“Another fantastic project for MDL where our fresh approach to overcoming project challenges delivered a successful campaign,” said Chris Reid, vice president-sales at MDL.

“The application of MDL’s lay spread, with our market-leading tensioner as the master item, delivered a safe and lean mooring solution, allowing for the wire rope to be installed in a single offshore trip, using a vessel of opportunity – that is, one that was readily available in the region.”

Eliminating risk

During the project, more than 6.4km of the 149mm OD sheathed Spiral Strand Wire Rope (SSWR) was transpooled at the mobilisation port in Singapore from storage reels onto five transportation reels. The SSWR was then deployed to moor in an FPSO in 310-500m water depths.

This was the first time an MDL tensioner was used for the installation of a wire rope off a CSV, allowing 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 product.

Eliminating the risk associated with hose or other grip-related failure, this unique system removes the single point failure risk associated with other standard tensioners on the market. It provides a directly mounted manifold and accumulator on each individual active grip cylinder, ensuring that the required grip force is maintained in the event of any unforeseen system failure or black out.

Also used on the project was MDL’s adjustable radius controller, which optimised the handling of the wire rope as it was deployed from the double-drum transportation reels, by hydraulically moving in and out to maintain the product in the firing line.

The project followed other mooring projects in the Gulf of Mexico and offshore Brazil, where a similarly innovative approach was taken using an RDS-based spread mobilised onboard a heavy load carrier.