Vesconite Bearings has manufactured its largest and most technically complex rope diverter.
A South African-based company ordered a Vesconite Hilube liner designed to guide a 150 mm diameter, 36-ton steel rope weighing 112 kg/m from the quayside onto a spooler drum aboard a vessel. Vesconite Hilube, a bearing and wear material with a low coefficient of friction, protected the costly steel rope from damage, ensuring operational reliability.
The steel rope’s limited bending radius was a critical factor in the design to prevent permanent deformation or damage. Several solutions were evaluated, including a sheave wheel. Ultimately, a static sheave lined with Vesconite Hilube was selected due to its compact size, ease of handling, and simplified maintenance.
Vesconite Hilube was incorporated as a low-friction lining material within a metallic housing for structural support. The housing was manufactured by a third-party supplier to meet the required specifications.
The spooler drum operated at speeds of 4–6 metres per minute, and the static sheave experienced loads of 45 tons in the upper region and 35 tons in the lower region, resulting in an approximate force of 261 kN on the sheave. This translates to a pressure of 1.5 MPa on the Vesconite Hilube, well below its design limit of 30 MPa, ensuring durability under operational conditions.
The Vesconite Hilube lining was designed in two halves—an upper and a lower section, with flared sections on both sides. The upper and lower halves, each with a thickness of 137 mm, were laminated together using thinner Vesconite Hilube plates. The combined section view of the two halves measured 400 mm in width and 274 mm in height. The flared sections, measuring 500 mm x 443 mm x 140 mm, were similarly laminated. The upper and lower sections, as well as the two flared sections, were mechanically fastened, incorporating M10 threaded rods inserted into drilled holes, secured with nuts for high torque. To maintain a clean aesthetic and protect the fasteners, Vesconite Hilube plugs were used to cover the drilled holes, rendering the threaded rods and nuts invisible. The parts were initially machined to a semi-finished state, then laminated, fastened, and machined to precise final dimensions for optimal fit.
The mechanical fastening eliminated the need for epoxy, which can degrade over time and become brittle. Such degradation could reduce clearances between the laminated plates, loosen fasteners, and lead to stress concentrations.
This design leveraged Vesconite Hilube’s low-friction and wear-resistant properties, ensuring smooth rope guidance and extended service life. The mechanical fastening system provided a robust, maintenance-friendly solution. The sheave design simplified assembly and potential repairs, while the metallic housing ensured structural integrity.
