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Reviewing your rigging

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Let’s face it, dismasting is one of the most dangerous accidents that can happen at sea. Not only do you lose your means of propulsion but there is the added risk of serious injury. We don’t always give it much thought, but the state of the standing rigging is essential to ensure safe sailing. Three types of cables used for stays and shrouds. Single-stranded wire such as 1x19; Dyform; and Rod. Single-stranded cable (fig. 1) is the most common type in use for shrouds on modern boats. Its construction consists of an assembly of 19 strands of stainless steel wire: one straight center wire, 6 wires on the inner ring in one direction and then an outer ring of 12 wires in the other direction. The characteristics of this type of cable are an average stretch, good reliability, moderate cost, medium tolerance of the problem of alignment of the terminals, and the option to use manually-fitted terminals. Dyform (fig 2) is an evolution of single-strand, with a better compactness thanks to the fact that the wires that make up the cable are not round but of a trapezoidal shape on the outer ring. For example a nominal 7 mm cable represents a theoretical cross-sectional area of 42.87 mm², but in a 1x19 single-stranded cable, there is only a 29.23 mm² section due to the spaces between the wires, as opposed to 34.16 mm² in Dyform. This better “stacking” of wires implies that for an equal diameter we have better resistance and, at equal effort, a lower stretch. Which is why it is used on boats requiring more sophisticated rigging, while maintaining good reliability due to the multi-strand construction and the least water retention. Rod rigging is reserved for very demanding boats in search of high performance. Its great qualities are its very low stretch and its consistent diameter compared to Dyform or Single-strand. Its main drawback is its relatively short lifespan. It is recommended to be changed at 5 years or 20,000 miles, whichever is sooner. And there must be no compromise here, because a break happens without warning. However, it is rarely used on cruising catamarans, while the previous two types are fitted to 90% of the fleet.

Even though the running rigging is considered as a consumable that must be replaced once it becomes worn, most people tend not to think in the same way regarding the cable stays whose longevity seems to them to be equal to that of the mast. Yet the stainless steel they are made of, despite being a strong material and resistant to the marine environment, is not eternal. It ages without this being noticed and crystallization phenomena can occur which end up causing the clean break of a cable. And this, all without the cable in question being over-loaded. It will occur regardless of the number of times you go out and how many times the rigging is strained, since it will age even when anchored or on the dock, with the wind that generates vibrations. Even with rigorous maintenance of all elements of the stays (turnbuckles, ...

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