Carbon Composite Fiber as Rigging Material, PBO, Dyneema, Carbon EC6 and Kevlar

Traditionally, there was little variance between rod rigging suppliers, but in today’s composite rigging world with a suite of composites, there are more options available in material selection and style of construction. The basic facts on composite fibers used in the rigging industry are discussed in the article.

Composite Fibers for Rigging

PBO and Carbon EC6 are the two main fibers used for side shrouds. PBO fiber is intrinsically lighter and stronger when compared to carbon. The properties and specifications of the two fibers are listed in Table 1.

Table 1.

* mid section of a cable with equal braided cover

Carbon rigging cables are made of bundles of pultruded carbon fiber rods that contain carbon strands which are hold together with an epoxy resin. The combination of this resin and the heavier base fiber makes carbon fiber rigging much heavier when compared to PBO, without any performance benefit. The weight advantage of PBO over Carbon EC6 is shown in Figure 1.

Figure 1. Forestay on a current Volvo70 – shows a weight advantage to PBO of 21.5%

PBO, Dyneema and Kevlar are the three key contenders for aft rigging cables. The properties of PBO, Dyneema and Kevlar are listed in Table 2. PBO is roughly double the strength Kevlar and Dyneema.

Table 2.

Since aft rigging is typically constructed to break strength instead of stretch, more Kevlar and Dyneem fibers are required to make cables of the same strength when compared to PBO. This, in turn, results in increased weight and diameter as shown in Table 3 and in Figures 2 and 3.

Table 3.

Figure 2.

Figure 3.

PBO fibers are smaller, stiffer, stronger and lighter when compared to any other suitable material, making it the optimum solution for aft rigging.

This information has been sourced, reviewed and adapted from materials provided by Future Fibres.

For more information on this source, please visit Future Fibres.