Recommended line diameters of docking and anchoring lines
The length of the ship proves the best guide when recommending the line diameter to be used for docking and anchoring applications. Based on the ship’s displacement, docking and anchoring lines must be primarily able to withstand the pressure of the flood tide, stream and wind pressure, as a function of the type of the ship. Note: The given values are for reference only. When furnishing ships with lines, the legislation and registers of the respective countries must be respected above all else.
|Boat length (feet)||BAHAMA||FLEXI DOCK||KEY WEST||LAGUNA||MALAGA||VISION|
|20 ft||8 mm||10 mm||8 mm||12 mm||8 mm|
|26 ft||10 mm||12 mm||10 mm||14 mm||10 mm|
|33 ft||12 mm||14 mm||12 mm||16 mm||12 mm|
|38 ft||14 mm||14 mm||16 mm||14 mm||18 mm||14 mm|
|45 ft||16 mm||16 mm||18 mm||16 mm||20 mm||16 mm|
|52 ft||18 mm||18 mm||18 mm||24 mm||18 mm|
Recommended line diameters for sheets and halyards of polyester
When using high-strength materials as Vectran or Dyneema®, the line diameter may be reduced by up to 2 mm. Note: The above stated numbers are approximate values only. The legislation and register of the respective country must be followed when outfitting aboat.
|Boat length (feet)||Sheets*||Halyards*|
|20 - 26 ft||8 mm||8 mm||10 mm||8 mm||8 mm||8 mm|
|27 - 29 ft||10 mm||8 mm||10 mm||8 mm||8 mm||8 mm|
|30 - 33 ft||10 mm||10 mm||10 mm||10 mm||10 mm||10 mm|
|34 - 38 ft||12 mm||10 mm||12 mm||10 mm||10 mm||10 mm|
|39 - 42 ft||12 mm||12 mm||14 mm||12 mm||12 mm||10 mm|
|43 - 46 ft||12 mm||12 mm||14 mm||14 mm||12 mm||14 mm|
|47 - 52 ft||14 mm||14 mm||16 mm||16 mm||14 mm||14 mm|
|53 - 58 ft||16 mm||16 mm||18 mm||18 mm||16 mm||18 mm|
Storage of lines
The maximum storage life of yachting lines in unused condition is up to 5 years.
Optimum storage conditions:
- clean place protected against light,
- without chemical, physical and mechanical effects,
- normal climate (15 – 25°C),
- relative humidity of about 65 %.
During the process of line production, the fibres are mechanically doubled, twisted and braided in several stages. In this way the fibres finally attain a condition of mechanically induced stress. A long-term storage leads to relaxation of the material, which means that macromolecules are “relieving”. This effect is not harmful, on the contrary it is connected with an improvement of some properties of the line.
Research works showed that the results of tests of dynamic performance of lines that had been optimally stored for several years were often better than results of tests of lines measured immediately after production.
In case of present-time advanced materials, a considerable negative change of properties of the product in a time interval of 5 years can be eliminated provided that optimum storage conditions are maintained.
Our lines and cords are designed to meet the highest standards, the most severe weather conditions, UV radiation and constant abrasion. Instead of natural materials, we use synthetic fibers which, if compared with natural fibres, have better properties such as greater strength, lower elongation and longer service life.
The following table shows the properties, displayed by the individual materials.
|Material||HMPE||LCP||Aramid fibre||Polyester||Polyamide||Polypropylene multifilament|
|Trade name||Dyneema®||Vectran||Technora||Dacron, Diolen, Travire||Nylon, Perlon||Multitex|
|Tenacity (cN/dtext)*||28 - 38||22 - 25||20 - 25||7 - 8||6.5 - 8.3||6 - 7|
|Elongation at break (%)||3.5||3.3||4.6||10 - 16||16 - 27||20 - 23|
|Specific gravity (g/cm3)||0.98||1.41||1.44||1.38||1.13||0.91|
|Melting point (°C)||144 - 152||330||carbonization at 500°C||260||220||160|
|Abrasion resistance||very good||good||good||excellent||excellent||good|
|UV resistance||very good||sensitive||sensitive||excellent||good||good with stabilizators|
|Salt resistance||excellent||excellent||sensitive||good||good||good at weak concentration|
|Resistance to acids||excellent||excellent||excellent||predemonantly good||-||excellent|
|Resistance to oil products||excellent||excellent||excellent||excellent||good||good|
|Creep||creep under longterm load||immeasurable||immeasurable||immeasurable||immeasurable||immeasurable|
|Knot strength (%)||35 - 50||30 - 35||30 - 40||55 - 60||60 - 65||55 - 65|
* strength related to fibre fineness The data given in the table is for reference only.
For sheet and halyard lines
- we recommend to use materials having low elongation, high strength and long service life
- polyester is used in most cases for this category
- new high-tenacity materials like Dyneema® and Vectran are gaining importance for demanding racing applications
Mooring, anchoring and tow lines
- have to be able to absorb heavy shocks and repeatedly occurring tension, thus they have to be elastic and strong
- materials such as polypropylene are suitable for use as tow lines (floating materials)
- heavier materials such as polyamide and polyester are recommended by us to be used for mooring and anchoring lines
The term “used“ denotes used regularly under normal weather conditions. These are labsimulated at tenfold line loading lasting 10 seconds with the loading force amounting to 20% of the maximum strength of the given line.
- DM 20
- Dyneema®SK 78, Vectran
- Dyneema®SK 78, Vectran with PES Cover Racing Edition
- Double Braided PES with heat set
- Double Braided PES
- Double Braided Nylon