Accurate Rope Length Measurement

The accuracy of the polyester rope mooring line lengths is critical to the smooth installation of the mooring lines. Ropes for deepwater tethers are manufactured under a machine tension of approximately 1 tonne back tension. Lankhorst Ropes has installed a unique Length Measuring System (LMS) for length measurement under a controlled tension at its Porto factory. The rope is pre-tensioned to 1% MBL (maximum 20 tonnes) for length measurement in 75m increments.

Prototype testing always starts from the same reference tension of 1% MBL.

Rope measuring machine capstan

Length accuracy is achieved with a laser gun and mirror which is calibrated to 75m ±3mm. The rope is marked at each 75m increment and the marks, numbered sequentially (1=75m; 2=150m; etc), are recorded by digital camera, thus minimizing the risk of human error.

Rope Splicing and Terminations

The GAMA 98® rope construction is suitable for either hand spliced terminations or with socket terminations. The eye splice is engineered for high efficiency strength realisation. To achieve this, each sub-rope is allocated a preset position around the eye so that the load is shared equally by all the sub-ropes.

Spliced deepwater mooring rope

Sub-ropes are colour coded for identification purposes so they have the same position throughout the rope, within each eye and are spliced to themselves. The eyes and splice area are protected with polyurethane. Digital photos at 15 stages of each splice are taken for Quality Control checks as well as recording the individual splicer’s name. These records form part of the final documentation pack.

Moduline® ropes for mobile drilling unit (MODU) operations are terminated with hand spliced eyes. Likewise the eyes and splice area are protected with polyurethane.

Lankhorst Ropes provide a wide range of connection solutions for integration of mooring line components including:

• Polyester to Polyester
• Polyester to Chain
• Polyester to Steel Wire.