Straightpoint Load Cells Integral to Onboard Crane Load Tests
Anchor Industries used water bags in addition to a variety of force measurement and rigging equipment to complete load tests on a Liebherr crane aboard a vessel in Cape Town Harbour, South Africa recently.
The 500t capacity Liebherr, model BOS 14000-500D, is the main crane on the deck of Van Oord’s pipe-laying vessel, DLB Stingray. The prime focus for Stingray is S-lay pipe-lay work; when performing S-lay pipeline installation, joints of pipe are welded into a pipe string aboard the vessel. The crane required five-yearly testing.
Anchor accepted a scope of work from Dormac Marine & Engineering to complete an overload test of the crane, constituting a 550t load being applied to the main hoist. Additionally, Anchor was required to complete a 55t load test of the auxiliary hoist as well as a 50t calibration test of the main hoist after the 550t overload test was complete.
Four 75t capacity Radiolink plus wireless load cells and four 30t capacity wireless low headroom links, all manufactured by Straightpoint and sourced from Anchor stock, provided data to handheld devices throughout the project. Another four 120t load cells from a different manufacturer completed the force measurement fleet for the job.
For the main overload test, a dozen water bags were used in a near-40m, three-tier cascading rig. At the top and middle were two 100t and two 40t bags, while three 20t and a 30t bag combined at the bottom.