Synthetic line deal allows faster, safer mooring for the world’s biggest ships

Since the first installation of mooring ropes made with Dyneema® fiber completed back in 2008, the COSPEARL LAKE has been a familiar sight on shipping lanes from China to the Middle East, logging 11,200 mooring hours in the process. In all this time and in every port, the COSPEARL LAKE has moored using the same original 22 mooring lines made with Dyneema® fiber. With the expected lifetime of steel wire ropes limited to five years on average, the lines have far exceeded lifetime expectations and proved to be a game changer for COSCO.

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At the time of inspection in October 2018, the COSPEARL LAKE’s mooring lines had been in operation for over a decade, with very limited loss of performance over this time. Breaking tests on the spring lines showed a residual strength of 114 tons, retaining 87% of its original 130-ton strength.

“During these ten years, lines made with Dyneema® fiber have exceeded our expectations by the clear performance over lifetime, efficiency and safety benefits they bring,” said Zhao Jin Wen, Vice President of COSCO Shipping Energy. “We are delighted to extend our relationship with long-term partner Avient and will apply lines made with Dyneema® fiber on further oil tankers.”

“With our experience with Dyneema® spanning over 20 years, and the potentially rapid deterioration of this casualty’s situation, it was clear that in addition to the salvage team, a line made with Dyneema® would make the difference.”

Zhao Jin Wen, Vice President of COSCO Shipping Energy.

Delivering performance since 2007

After many years spent mooring 300,000-ton VLCCs (Very Large Crude Carrier) using steel wire ropes, COSCO Dalian changed their way of working in 2006.

Although steel wire ropes had been the industry standard for decades, simply because they did the job and there had been no other viable alternatives, COSCO Dalian (a subsidiary of China Ocean Shipping Group) evaluated two mooring lines made with Dyneema® fiber, the world’s strongest fiber™, on an eight-month sea trial period.

The trial was such a success that in Sep 2007, COSCO decided to equip its newest VLCC vessel, the COSPEARL LAKE, with a complete set of mooring lines made with Dyneema® fiber. The vessel was equipped with a full set of 22 mooring lines, becoming the world’s first VLCC vessel to be 100% equipped with mooring lines made with Dyneema® fiber.

Maintaining faster and more profitable operations

With the trend for larger VLCCs over recent years, there has been a corresponding need for stronger mooring lines. This means there will be more weight and in larger quantities. Using conventional steel lines, each single line would reach 2.46 tons, with a unit weight of 8.8kg/m. More weight means more man hours required for mooring and difficulties when it comes to handling. This is where the lines installed on the COSPEARL LAKE came into their own. A mooring line made with Dyneema® fiber only weighs 0.35 tons, 1/7th as much as a steel line of the same strength.

Thanks to the exceptional strength-to-weight ratio of mooring lines made with Dyneema® fiber, the average docking time for the COSPEARL LAKE has been a mere 70 minutes – much less than the average four hours that would have been required had steel wire rope been used. The lines have also saved a huge number of docking hours over the last ten years, helping COSCO achieve much faster docking operations. Faster docking also means more profitable operations thanks to a reduction turnaround time. Handling heavy, greasy steel lines is much more time consuming for crew and involved much more preparation time before mooring. Using lines made with Dyneema® simplifies this process – allowing crew to simply pull them out from the winch and start docking straight away.

Keeping crew safe

As well as freeing up valuable time – allowing the COSPEARL LAKE more time on the high seas than stuck in port – the lightweight mooring lines made with Dyneema® fiber are safer to use for the various ship and port personnel involved in mooring.

With the COSPEARL LAKE plying seaways and oil loading terminals in the Middle East, efficiency is important for crew health. “Working in extreme weather conditions with heavy and cumbersome mooring lines can be challenging for even the most experienced crew, making fast and efficient docking absolutely essential,” says Jorn Boesten, segment manager maritime for Avient. 

And because they are lightweight, soft and flexible, mooring lines made with
Dyneema® fiber are very safe for crew to handle. To date, there has not been a single case of hand, wrist or back injury due to handling new mooring lines on the COSPEARL LAKE.

“Working in extreme weather conditions with heavy and cumbersome mooring lines can be challenging for even the most experienced crew, making fast and efficient docking absolutely essential”

Jorn Boesten, segment manager maritime for DSM.

Contributing to cleaner seas

Unlike steel wire alternatives, mooring lines made with Dyneema® fiber require no grease or other lubrication, eliminating the need for crew to clean the decks and other polluted parts of the vessel, but also reducing the chances of slips and injury on slippery decks.

As well as making life on deck safer for the ship’s crew, eliminating the
need for grease or lubricants, and associated cleaning products, limits the
pollutants entering the ocean and ensures that the COSPEARL LAKE complies with strict environmental pollution regulations.

Bastiaan de Koning, Global Segment Director of DSM, says about the COSPEARL LAKE milestone: “We are very proud of our partnership with COSCO Shipping Energy over the past decade. The relationship was forged with the success of the original trial and the installation of mooring ropes onboard the COSPEARL LAKE back in 2008 and it is testament to both Dyneema® technology – and COSCO’s application of it – that the mooring ropes are still going strong today. We hope to continue delivering outstanding performance to COSCO vessels for many more years.”

The case for choosing mooring ropes made with Dyneema® fiber

  • Minimal loss of performance: After ten years in action, breaking tests on the spring lines showed a residual strength of 114 tons, 87% of its original 130-ton strength.     
  • Seven times lighter: Mooring ropes made with Dyneema® fiber are seven times lighter than steel-wire ropes of the same strength and diameter.      
  • Much faster docking: Ropes made with Dyneema® fiber cut docking times from an average of four hours to just 70 minutes. 
  • Improved health and safety: Because they are lightweight, soft and flexible, there has not been a single reported case of hand, wrist or back injury due to handling new mooring lines on the COSPEARL LAKE.
  • Better for the environment: Unlike steel wire alternatives, ropes made with Dyneema® fiber do not require the use of grease, lubricants and associated cleaning products, which helps to limit pollutants entering the ocean.

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