Doublebraid to D2 Racing: A high performance upgrade
by Marlow Ropes 11 Jun 2018 12:00 BST
Twisted Core & Parallel core v Doublebraid
"I'd like to know more about twisted core and parallel core constructions, and why these would be used over Doublebraid?"
Parallel core fibre is theoretically the strongest and lowest elongation as the fibres are all aligned along the load path, however there is little or no sharing of load between the fibres, they are hard or impossible to splice and they tend to be very prone to 'knuckling' when bent. For these reasons this construction isn't common. Twisted cores solve some of these issues; multiple twisted cores are the norm in climbing ropes as they give a good balance of flexibility, strength and knot efficiency. Overall they are less common in sailing ropes as they can be hard to splice.
A single twisted core, like that used in Marlowbraid, gives a good balance between the benefits of the parallel core and the multiple cores, it's also relatively easily to splice. The core carries most of the load and the cover is protective allowing these elements to be designed differently to suit each requirement, i.e. aligned fibres in the core and tight abrasion resistant covers for greater performance. Overall, the twisted core construction is very well suited to smaller ropes used in our Excel Dinghy range such as the Excel Pro.
In comparison, a Doublebraid rope is normally 50/50 core and cover and both components have to work together if the rope is to have good performance, this means the cover has to both protect the core and carry 50% of the strength. When engineered correctly, this can give very high strength and is easy to splice. It tends to result in softer covers that are less abrasion resistant.
In summary, each construction has particular benefits and therefore no one construction is better, which is why Marlow engineers ropes in all these types.
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