Expertise in the service of moorings

Nodusfactory-Sail mooring lines are designed to combine:

• Strength: They are made from high-tenacity fibers, such as High Tenacity (HT) Polyester or specific blends. They guarantee a high breaking load for maximum safety, even in strong wind and current conditions.
• Controlled elongation: Unlike pure polyamide ropes, which can be too elastic and make the boat unstable, Nodusfactory-Sail uses materials with optimal elongation to absorb shocks (particularly significant in port) without creating excessive movement.
• Durability: The mooring lines are treated to resist abrasion and UV rays, which are the main factors in rope aging and breakage.
• Ergonomics: A mooring line must be easy to handle. Nodusfactory-Sail offers mooring lines that remain soft and flexible even after prolonged use, making mooring maneuvers more comfortable and faster. Choosing the perfect mooring line will depend on your boat type and usage. It is always recommended to consult product specifications to ensure their breaking load characteristics match the tonnage of your sailboat or catamaran, and to always oversize your mooring lines for safety.
Factors to Consider
The load that mooring lines must support depends on several factors:
• Boat tonnage (displacement): This is the weight of the boat in running order. The heavier it is, the greater the force required to hold it.
• Boat length and type: A catamaran offers greater wind resistance (windage) than a monohull of the same tonnage, requiring stronger mooring lines.
• Weather conditions: Wind is the main source of tension on mooring lines. Wind force increases exponentially. A strong swell or current also adds stress. • Rope type: Materials such as polyamide (nylon) and polyester have different characteristics in terms of elasticity and strength. Polyamide is very elastic and absorbs shocks well, while polyester is more rigid.
• Mooring: The way the boat is moored (along a quay, on a finger, on a mooring line, etc.) and the use of mooring springs or shock absorbers influence the load on the ropes.
Basic rule and recommendations
Although there is no single universal formula, a commonly cited rule of thumb for the diameter of polyamide mooring lines is to take a diameter in millimeters that corresponds to the length of the boat in meters plus 4. For example, for a 12-meter boat, you could choose 16 mm mooring lines. It is also generally recommended that the breaking load of the mooring lines be at least two to three times the maximum anticipated load (which can be estimated based on displacement and wind conditions).
Examples of strength (for guidance only)
Here is a table of recommendations based on tonnage, which gives an idea of ​​common diameters for a monohull. For a catamaran, the diameter would probably need to be increased by one notch.

Important: These values ​​are guidelines. It is essential to always check the rope manufacturers' technical data sheets, which provide the breaking load (expressed in daN or kg) for each diameter.

Other important points:

• The mooring knot: A knot can reduce the strength of a rope by up to 50%. Splices are much more reliable and only reduce strength by 10 to 20%.
• Chafing: The friction of the rope against the dock, a cleat, or other elements can significantly weaken the mooring line. The use of chafing protection is strongly recommended.
• Doubling mooring lines: In severe weather conditions, it is prudent to double the mooring lines to distribute the load and provide redundancy in case of breakage.
In summary, the best approach is to oversize your mooring lines for most situations. It is better to have a rope that is stronger than necessary than the opposite.

In summary, the best approach is to oversize your mooring lines for most situations. It's better to have a rope that's stronger than necessary than the other way around.