Lankhorst Ropes has supplied heavy lift slings to Subsea 7's heavy lifting arm Seaway 7 for the Dolphin Accommodation Upgrade Project (DAUP) on the East Coast Marine Area (ECMA), offshore Trinidad and Tobago. The project comprises provision of a Permanent Living Quarter Module (PLQ), consisting of a control room, living quarters and helideck, designed and constructed to facilitate a single lift installation.
Shell Trinidad & Tobago contracted the transportation and installation of the PLQ Module to Seaway 7. Manufactured to unprecedented sling length tolerances, the slings were used to safely lift the module with a total weight of 1,110 tons, onto the Dolphin platform.
In total, Lankhorst supplied three Lankoforce slings with a different diameter rope for each sling. One 520-metric-ton MBL sling measured 104 meters in length with rope diameter 64 millimeters, another 520-metric-ton MBL slings was 47.2 meters in length with rope diameter 76 millimeters, and the third sling used 108 millimeters diameter rope, measured 46.1 meters, and had a load capacity of 1,300 metric tons MBL. Length tolerances of +/-1% of nominal length were required by the customer. Working with Precision Tension Solutions (PTS), Lankhorst achieved +/- 0.1% tolerance.
Tight tolerances are critical to heavy lift projects. Variations in sling lengths lead to uneven load distribution, called skew loading, in the object to be lifted and as such can impact the structural integrity of that object. “With the slings for Seaway 7, we’ve shown that unprecedented levels of tolerance accuracy can now be achieved with fibre slings even where different diameter ropes are used to prepare the slings,” said Wilco Stroet, managing director, Lankhorst Ropes. Where excessive tolerance deviation was observed during testing, slings were re-spliced to achieve the smallest possible tolerance
Manufactured in Brazil, tested in Houston and project managed from the Netherlands, the slings were delivered on-site within a six-week timeframe. The Lankoforce endless rope slings (grommet) features a polyester protective braided jacket and hard wearing, low-friction Dyneema HMPE sleeves at the lift points and crane hook prongs to ensure proper load distribution.