Mooring line performance in Warm Climate and Dynamic Conditions

Aug 19, 2020



The maritime sector is progressing as fast as ever. New regulatory requirements, higher safety standards, cost pressure, and larger vessels are just some of the challenges operators are facing today. The combination of larger vessels, exposed terminals and rapid climate change means that mooring lines are increasingly subjected to extreme conditions both in terms of load and temperature.

Summary:

  • DSM and Samson Rope Technologies have co-developed
    a model to predict rope temperature in any condition where a rope is subjected to dynamic loading conditions.
  • Based on first principles, the model has been validated with experimental data and has shown to give accurate predictions in a wide range of conditions.
  • Combining the temperature model with DSM’s Performance Model, the lifetime of a mooring line can be predicted more accurately than ever before.
  • Even in challenging conditions with severe loading and high load amplitudes, rope temperatures stay well below Dyneema® SK78’s continuous safe use limit
    of 70 °C.
  • In a typical case study, the lifetime for a mooring line with SK78 on an LNG vessel traveling back and forth between Middle-East and Northern Europe is calculated to be in excess of 15 years based on 480 mooring hours per year.
  • In the same case study, calculations for an equivalent rope with generic HMPE yield lifetimes between 5-8 years.

Read the full Technical Paper
In this document, we present a co-development by DSM and Samson Rope Technologies: a tool to predict lifetime of mooring lines with Dyneema® SK78 subjected to tension-tension fatigue in any environmental temperature.