Here at Jimmy Green Marine, we love to race boats. Whether it’s a yacht, sports boat or dinghy, we enjoy the competition and the thrill of the boat to boat combat. Coming out on top often comes down to a matter of feet on the water so we drive hard looking for those gains. Extracting top performance places a significant strain on the rigging in all but the lightest of conditions. For most people, the enjoyment of Regatta racing has been tainted by a breakage at some point in their history, resulting in a perfectly good series punctuated with a DNF or two. Only a strength test will definitively inform you how much strength is left in your lines, but a good line inspection and replacement policy will help mitigate the risk of breakage.
Racing Rope Construction and Fibre considerations
It is important to consider the construction and material of your lines when deciding if they are still fit for purpose. 12-strand Dyneema/Vectran with or without a braided cover should make up the majority of lines on board. This type of line provides high strength to weight ratio and minimal stretch under load which is exactly what is required to keep a rig light and responsive, but also super stiff for translating all the energy of the wind into speed across the water.
12-strand ‘core only’ lines featuring Dyneema or Vectran are excellent for high load applications such as running backstays, kicker cascades, sail and pole control lines. The working load of these lines should generally not exceed 20% of the breaking strain of the line. Any degradation of the strands has a direct effect on the residual strength of the rope, so deterioration of a quarter of the overall diameter or 2 cut strands, should be the benchmark for retiring an individual line.
12-strand high strength cores with a hard wearing, heat resistant cover are excellent for sheets, halyards and all other control lines that terminate in a cleat or through a clutch. The cover will usually be polyester and occasionally have Technora or even Vectran fibres blended in for additional wear resistance. Degradation of the cover does not affect the overall strength of the line, therefore the integrity of the line will remain even with 50% cover degradation. Line retirement should be considered at 50% because if the cover parts completely, the line will not run smoothly.
Occasionally, braid on braid 100% polyester line is used for low load applications. These lines share the load equally between the cover and the core. Covers on this type of line commonly have between 16 and 20 plaits (strands), this smooth construction improves wear resistance by maximising the contact surface area of the line. However, all degradation of the outer cover has a direct effect on the strength of the line.
Image - Racing Rope Construction and Fibre considerations
Dynamic line friction and heat generation on racing ropes
Multiple manoeuvres on short courses with high levels of course traffic often require rapid-fire hoists, drops and sheeting as the point of sail continuously changes. All this action results in an enormous amount of friction as lines turn through multiple angles and run through blocks at speed. Even when care is taken to ensure that all lines travel with minimal resistance, it is virtually impossible to remove all the friction and resulting heat generation from the system.
All free-running lines need to be inspected along their entire length looking for pulled strands, abrasion and heat damage. A serviceable line will have a consistent, flexibility and softness along the line. The outer cover will have a slightly matted or furry outer layer which is entirely normal. The key is to check for consistency in the look and feel of the jacket. Particular attention must be paid to areas used in winches, especially the final metre or so to come in when trimming upwind. The frictional forces generated in this area are quite destructive.
Image - Dynamic line friction and heat generation on racing ropes
High static load strain on racing ropes
Lines such as halyards and control lines are typically set for longer periods of time than sheets and other lines with dynamic loads. Once set, the line is exposed to high static forces while contorted around many turns from the masthead to the cleat. The fibres unfortunate enough to be located on a turning point are exposed to more force than those acting in a straight line. This is because some of the fibres will be stretched further round the outer most radius of the turn than those on the inside which are being compressed. Even with modern braided high strength cores, the increased loading over time will steadily reduce the strength of the line in that spot.
It is worth making a note of the points in the middle of these lines that turn corners or hold in cleats. These areas need special attention and can be marked so they are easily found when the rope is not in service. The bitter end of these lines should also be monitored. Spliced loops should be used to preserve the breaking strain of the line wherever possible. Inconsistent line diameter, stiffness and/or cut strands will indicate a weakening of the line. This is especially important with covered lines where visual inspection is not possible.
Image - High static load strain on racing ropes
Additional factors and considerations
Occasionally, some of the lines on board may be subjected to shock loads through incidents such as crash gybes or flogging spinnakers in bigger breeze. Shock loads are especially dangerous for racing ropes because they are designed for minimal stretch. The shock load is therefore decelerated swiftly which in turn produces load spikes in excess of the working load limits. Shock load damage remains in the memory of the fibres and can cause incremental weakening of the line. Check for line stiffness and diameter changes regularly and retire the line if in doubt.
To prolong the life of your lines, make sure that they are hidden away from UV rays while not in use. Preferably dry them out prior to storage and ensure that any coil of a braided line is made in the figure of 8 configurations to prevent any kinks forming.
Finally, inspect your lines daily to build up a picture of the working life of your lines. Any unusual acceleration in the degradation of your lines will help you spot problems on deck with your hardware, and vice versa. If in doubt about the integrity of any line on board, ask for a second opinion and/or replace your line for peace of mind.