Mooring ropes, mooring lines

In this category, you can order mooring lines and ropes. This type of rope is particularly suitable for securing a boat at a dock, pier, or another boat. The goal is to keep your boat securely moored and stable at the berth. Therefore, every motorboat and sailboat needs reliable mooring lines! Here are some tips to consider when choosing the right mooring lines for your boat in order to achieve this goal:

An ideal mooring line would have six different characteristics:

  • Elasticity / Stretch: A good mooring line is highly stretchable to keep the boat as stable as possible. A mooring line with high stretchability (indicated in %) can partially compensate for the boat's movements caused by waves. The more elastic the mooring lines, the better they absorb the energy generated by wind and waves, resulting in a dampened effect on the boat. This not only makes staying on the moored boat more comfortable but also helps prevent damage to the boat. The stretch of the mooring line depends on the material used and the construction method. The ideal mooring line is very elastic, providing excellent damping effect.
  • Breaking strength: The breaking strength is the maximum force that a mooring line can withstand before breaking. The breaking strength is usually indicated in deca-Newtons (daN) or kilo-Newtons (kN). The breaking strength of the mooring line should match the boat's weight to ensure secure mooring even during storms and rough seas. The breaking strength of a mooring line can be reduced by abrasion, friction, exposure to sunlight or UV radiation, water absorption, and knots. Therefore, it is advisable to always include a safety margin when considering the breaking strength of the mooring line.
  • Abrasion resistance: Moored boats often encounter potential areas where mooring lines can chafe or rub. Even small areas of chafing significantly reduce the breaking strength of a mooring line. Therefore, it is important to choose mooring lines that are highly resistant to chafing. Ideal mooring lines are robust and have high resistance to abrasion.
  • UV resistance: Mooring lines are typically exposed to sunlight for extended periods. UV radiation accelerates the aging process of ropes and can cause them to become brittle, porous, or prone to breakage. Additionally, UV radiation tends to reduce the elasticity of mooring lines, which negatively affects their damping effect.
  • Handling / Flexibility: A good mooring line should also have excellent handling characteristics. A flexible and easily manageable mooring line does not kink. It is supple, allowing for easy knot tying, such as a cleat hitch. Moreover, coiling and splicing a flexible line is generally easier and faster.
  • Floatability: Mooring lines can accidentally fall into the water. In such cases, it is helpful if the material is buoyant and the line does not get entangled in the boat's propeller or someone else's propeller. However, floatability is considered a secondary characteristic compared to other properties. Ideally, one or two buoyant mooring lines should be kept on board as backups, but they should not be used for permanent mooring.

Since the available materials do not fulfill all these requirements simultaneously, it is important to consider the construction, material, and price-performance ratio when selecting the most suitable mooring line.

Laid or twisted ropes: The individual strands or yarns that make up the rope are twisted around each other. The main advantage of twisted construction for use as mooring lines is their high elasticity and resulting excellent damping effect. Additionally, twisted ropes are very suitable for splicing. The main disadvantage is their lower dimensional stability and flexibility: Care must be taken to prevent twisted ropes from untwisting or opening up. Especially during winding and unwinding, the direction of twist must be considered to avoid kinks.

Square braided ropes / Squareline: For better handling, square braided mooring lines can be used. At least eight yarns are braided together to create an almost square cross-section. Square braided ropes are highly flexible, easy to secure, and do not kink. Among braided constructions, square braided ropes have the highest stretch, making them also effective in damping.

Core-sheath construction: Another braided construction is the core-sheath construction, where a rope core bears most of the load. The core is surrounded by a protective sheath to shield it from damage due to abrasion and weathering. Mooring lines with a core-sheath construction are very robust and easy to handle. The main drawback is usually the lower elasticity compared to other construction types.

The materials commonly used for mooring lines are polyamide, polyester, and polypropylene. Unfortunately, these materials cannot simultaneously or equally fulfill all the previously mentioned characteristics of an ideal mooring line. Here are the advantages and disadvantages of each material regarding their use as mooring lines:

  • Polyamide: Mooring lines made of polyamide (nylon, perlon) are cost-effective. The material is particularly elastic and has excellent resistance to abrasion. The strength and UV resistance of polyamide ropes are good. However, polyamide readily absorbs water and swells slightly, reducing its strength by up to 10% over time and becoming less flexible. Older polyamide ropes have low flexibility. Polyamide is not buoyant.
  • Polyester: Mooring lines made of polyester are highly resistant to chafing, UV radiation, and weather conditions. The breaking strength and price-performance ratio of polyester mooring lines are also very good. Polyester absorbs very little water, maintaining its strength and flexibility. The main disadvantage of polyester as a mooring line material is its relatively low elasticity compared to polyamide and polypropylene. Polyester is the least stretchable among these materials. However, this drawback can be compensated by using longer lines, choosing twisted construction, and using shock absorbers if necessary. Polyester is not buoyant.
  • Polypropylene: The biggest advantage of polypropylene mooring lines is their buoyancy. Whenever buoyancy is essential, polypropylene is the material of choice. Polypropylene also has good elasticity and pleasant handling. However, it is generally inferior to the other materials in terms of strength, UV resistance, and abrasion resistance.

The diameter of ropes significantly determines their breaking strength (alongside the material). Therefore, the diameter of mooring lines should always be chosen to match the specific boat. It is also advisable to include a safety margin to compensate for strength reductions due to knots or chafing, for example. When in doubt, it is better to choose a larger diameter.

As a rough guideline for determining the appropriate diameter of mooring lines, the boat's length is often used. For boats and yachts up to approximately 16 meters in length and mooring lines made of polyamide or polyester, the following formula can be used for simplicity: Mooring line diameter (mm) = Boat length in meters + 2

If you have any doubts or need mooring lines for larger vessels, please contact us for advice. Our team will assist you in determining the appropriate mooring line size.

Alternatively, you can refer to the following table to select the correct mooring line diameter for your boat:

The general recommendation for mooring lines is to have four lines on board: one stern line and one bow line, each with a length of 1 to 1.5 times the boat's length, and one stern spring line and one bow spring line, each with a length of 1.5 to 2 times the boat's length. Depending on the boat's length, the following recommendations apply:

Boat Length (feet)Boat Length (meters)Length Recommendation for Stern Line or Bow Line-
-Length Recommendation for Stern Spring Line or Bow Spring Line
1 times boat length1.5 times boat length2 times boat length
20 ft6.1 m6 m9 m12 m
22 ft6.7 m7 m10 m13 m
24 ft7.3 m7 m11 m15 m
26 ft7.9 m8 m12 m16 m
28 ft8.5 m9 m13 m17 m
30 ft9.1 m9 m14 m18 m
32 ft9.8 m10 m15 m20 m
34 ft10.4 m10 m16 m21 m
36 ft11.0 m11 m16 m22 m
38 ft11.6 m12 m17 m23 m
40 ft12.2 m12 m18 m24 m
45 ft13.7 m14 m21 m27 m
50 ft15.2 m15 m23 m30 m
55 ft16.8 m17 m25 m34 m
60 ft18.3 m18 m27 m37 m

We are pleased to offer custom-made mooring lines from our metered ropes precisely tailored to fit your boat's requirements. For urgent orders, we also have a selection of pre-assembled mooring lines available in our warehouse.

In general, the ability to absorb energy increases with elasticity and length of the mooring line. In other words, with the same length, a more elastic mooring line can absorb more energy than a less elastic one. Conversely, a longer mooring line can compensate for reduced stretch due to the material used.

The damping effect should primarily be achieved through the mooring line itself, by selecting the appropriate material and construction. For small boats, additional shock absorbers made of hard rubber or in the form of a steel spring can be used at the mooring point. For larger vessels, so-called "snubbers" or mooring tails are sometimes used for damping.

At Kanirope, you can find pre-assembled mooring lines with total lengths of 6 meters, 10 meters, or 15 meters, featuring a professionally spliced eye of 40 cm at one end.

If you prefer a custom configuration for your mooring lines, please feel free to contact us. We can adjust the length of the mooring lines or the size of the spliced eye according to your preferences.

Furthermore, we offer the ropes from which we make our mooring lines as metered or spooled ropes. This option is particularly suitable if you need very long lengths and are able to perform splicing yourself.

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