Lankhorst Ropes supplied heavy lift slings to Seaway 7, the renewables and heavy lifting business unit of Subsea 7, for the accommodation upgrade project on Shell’s Dolphin platform offshore Trinidad and Tobago.
The project involves the provision of a permanent living quarter module (PLQ), which consists of a control room, living quarters, and helideck, designed and constructed to facilitate a single lift installation. The slings were manufactured to safely lift the 1110-t platform onto the Dolphin platform.
“With the slings for Seaway 7, we’ve shown that unprecedented levels of tolerance accuracy can now be achieved with fiber slings even where different diameter ropes are used to prepare the slings,” Lankhorst Ropes managing director Wilco Stroet said in a statement.
In total, Lankhorst supplied three of its Lankoforce slings with a different diameter rope for each sling. One 520-Mt MBL sling measured 104 m in length with a 64-mm rope diameter, another 520-Mt MBL was 47.2 m in length with a 76-mm rope diameter, and the third sling used 46.1 m of 108-mm diameter rope with a load capacity of 1300 Mt.
The slings had length tolerances of +/-1%. Lankhorst said that such tight tolerances are critical to heavy lift projects. Variations in sling lengths lead to uneven load distribution, or skew loading, in the object being lifted. As such, this can impact the structural integrity of the object. Where excessive tolerance deviation was observed during testing, Lankhorst re-spliced the slings to achieve the smallest possible tolerance.
Dolphin began producing in 1996. Shell acquired the field from Chevron in 2017 as part of a $250-million deal that included several assets.