September 2022

MDL spread installs mooring rope offshore India

MDL has carried out transpooling and installation of mooring wire rope off the coast of India using an MDL flex-lay spread.

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).

Over 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. The Failsafe Grip System 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.

Prior to the project, MDL performed a pull test on a product sample at its Peterhead facility up to 45-tonne WLL, to prove the squeeze and pull capacity of the tensioner-based approach.

Chris Reid, Vice President-Sales at MDL said:

“Another fantastic project for MDL where our fresh approach to overcoming project challenges delivered a successful campaign.

“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. Our tensioner, with its unique Failsafe Grip System, gave the field operator the additional reassurance in taking this alternative approach.

“This scope followed our other mooring projects in the Gulf of Mexico and offshore Brazil, where a similarly innovative approach was taken: an RDS-based spread mobilised onboard a Heavy Load Carrier.

“This project allowed us to offer a package of support to the offshore contractor on top of the work we had already completed with them in the North Sea – demonstrating our commitment to assist our clients wherever they need us in the world and across multiple energy sectors. I look forward to strengthening this successful relationship on future projects.”