Wire rope alternative
22 May 2008
At first glance, replacing steel wire rope and chain, and even conventional synthetic fibres, such as nylon and polyester, with high-performance polyethylene (HPPE), does not appear to be a radical change. In reality, however, this ultra-strong yet soft and lightweight material can have a major, positive impact across the board – improving safety, reducing potential for damage, speeding up the lifting process, requiring fewer workers, consolidating sling inventories, and increasing the flexibility of operations says Jorn Boesten.
HPPE offers many advantages over steel wire and conventional synthetics for heavy lifting operations. A migration from steel and conventional synthetics to high-performance polyethylene in lifting slings is gaining momentum. Another potential application for HPPE fibre in heavy lifting is replacing steel wire running rigging on cranes to increase the net load capacity. Crane hoisting lines could potentially be replaced by (non-rotating) braided rope made from Dyneema fibre, saving more than 80% of the weight of the line.
This would pay off quickly with, for example, tall tower cranes constructing high-rise buildings, for example, in Asia and the Middle East, as the weight of the steel wire hoisting line begins to reduce the net pay load of the crane when these reach a few hundred metres height. Replacing steel wire with rope made from Dyneema could more than double the payload on the taller cranes.