Leading deepwater rope manufacturer, Lankhorst Ropes Offshore Division has invested Euro 2M in a synthetic fibre rope test machine that, for the first time, will enable naval architects to run ‘what if’ scenarios to simulate the effects of storms and hurricanes on deepwater mooring lines.
Located at Lankhorst Ropes’ fibre rope production facility in Portugal, the rope test machine will be used to test the mechanical performance and fatigue behaviour for a range of new materials and rope constructions for deepwater mooring and single point mooring (SPM) systems.
The machine can test 20m ropes with loads up to 1,200 tonnes. It has a primary cylinder rated at 1,200 tonnes x 3m stroke and a secondary cylinder of 1.5m length coupled to a power pack of 350kW. In addition, the machine features a precise mechanical control system designed to maintain peak load such that target loads can be maintained within 10kN during testing.
Optimised Mooring Line Installation
Given industry concerns about the rising cost of performing deepwater installations, the test machine is expected to have wider benefits in optimising installation scenarios. Deepwater ropes are routinely loaded to approx. 40% of MBL to pre-stretch the rope during installation. More accurate information on the degree of pre-loading required will avoid the high cost and safety issues surrounding excessive pre-loading during offshore installation.
“Until now the lack of specialised rope test equipment, and the very high cost of testing, has led to a shortage of authoritative data on rope properties for a variety of fibre types and rope constructions. The Lankhorst fibre rope test machine will fill this knowledge gap, enabling ‘what if scenarios that show the effects of storms, hurricanes and loop current events with associated vortex induced vibrations on deepwater mooring lines,” says Chris Johnson, sales director, Lankhorst Ropes Offshore Division.
The rope test machine is currently being used to provide test data for a Joint Industry Project (JIP) on Polyester Rope Stiffness Modelling, Testing and Analysis.
Source: lankhorstropes, March 21, 2011;