When the test was carried out at Cosalt's Lowestoft branch, which has a test bed capacity of 250 tons, the rope was found to have retained over 60% of its rated new strength of 205 tons.

The test involved taking a 15m section of the rope considered to be in the worst condition.

This was then cut and re-spliced to form a 10m test piece. The test piece was broken as a full rope and not by the yarn realisation method to give a more accurate residual breaking strength result.

Nick Dennison, Cosalt's National Rope Sales Manager said the test demonstrated how improvements to the rope's design in recent years was now paying dividends for its customers. He said Adsteam was particularly pleased to hear that based on the bollard pull of the tug at 44 tons, and maintaining a preferred safety margin of 3:1, the rope was still within its designed operational limits.

Dennison said, 'We have increased the performance of Ultraline polyester rope for towing applications in several ways. This includes changing the composition of the outer jacket.

A special marine finish is now applied to the fibres during manufacture that significantly improves abrasion resistance, helping to enhance the fatigue life and prevent damage to the core of the rope, which is the strength member. We have also re-engineered the product itself to maximise breaking load efficiency for a given diameter.

'This particular test has provided Adsteam with a better understanding of how our Ultraline ropes stand up to the rigours of operational use and their expected service life.

Of course each situation is different and wear and tear will vary depending on the shock loads a rope has suffered in use.'

MJ Information No: 20210