Mooring Rope and Lines

23 Mar.,2024

 

We keep up to date with the latest developments in this field and will always try to make sure we’re providing the best equipment possible. Our mooring ropes and lines are all safety assured and ship with certification. If you would like a custom length or a factory fresh reel then get in touch today.

All our ropes come with free delivery in the UK, so please contact us to discuss your requirements.

What is a Mooring Rope?

A mooring rope is classified as a type of marine rope, and as such, it has the properties necessary to maintain its effectiveness when in water. Marine-grade rope is constructed from nylon, polyester or Dyneema (or equivalent UHMWPE) fibres or a combination of these. Many of these ropes are constructed to have high levels of UV resistance, are water resistant and some are built with solid cores so they can be made in a smaller diameter while retaining high tensile strength.

Mooring rope is used to attach fittings on a vessel to fittings on a pier or harbour. There are three main types of mooring lines; chain mooring lines, wire mooring lines and synthetic fibre ropes. They are designed to be incredibly durable and strong to keep even the heaviest of vessels securely in place.

The chain mooring line is the most common type in shallow water. It has low elasticity and highbreaking strength which makes it appropriate for long-term mooring. Due to its heaviness and high vertical load, it is not used in deep water operations.

Wire mooring line has a higher elasticity and is considerably lighter than a chain version, which is why a steel wire mooring system is preferred in deep water. The most common constructions for wire rope are six strand and the multiple strand rope.

Synthetic fibre ropes are very lightweight, highly extensible and can be used in both deep or shallow waters. It is now the more preferred choice for mooring ropes thanks to its versatilty, elongation characteristics and high-strength.

Mooring is potentially one of the most dangerous aspects of marine and port operations, as even the smallest error can cause irreparable damage. If a rope was to snap while under pressure it could whip across a ship with a speed of approximately 500mph, destroying anything that it comes into contact with.

Over previous years, the construction of synthetic mooring rope has advanced to minimize breakage, and also reduce the damage caused if a rope was to snap. The use of thick Ultra-high molecular weight polyethylene ropes (UHMWPE) has been one of the most significant developments in this area.

Most mooring ropes found on vessels are now made of polyamide (nylon), polyurethane, polyester or UHMWPE. Some ropes are made of a combinations of these fibres.

Mooring ropes have a typical life span of 5 years, but should be replaced sooner than this is there is any sign of damage. To preserve their life, they should be kept out of direct sunlight or adverse weather conditions and not left in salt-water for long periods of time.

What is the best mooring rope?

All ropes for boats or marine operations need to conform to the relevant safety certifications and there are different materials available that can all be used as marine rope.

Nylon (polyamide) rope is ideal for pulling heavy loads and for weight-bearing. It is strong and has considerable elongation characteristics and has good temperature and abrasion resistance, which is why it is used in mooring and marine operations. Polyamide rope loses just ten percent of its tensile strength when wet.

Polyester rope is one of the most heavy-duty options and is popular in rigging and marine operations. It retains strength when wet thanks to its cyclic loading and is resistant to chemicals. Polyester has a low co-efficient of friction and a high melting point. It has good abrasion resistance. Many marine rope products now have a polyester core, even if other materials are used in the exterior.

UHMWPE is an abbreviation for ultra high molecular weight polyethylene. These ropes are used as high-performance lines across a variety of industries, and has many qualities that make it an excellent choice for wet environments; it is light enough to float, is hydrophobic (repels water) and stays tough at low temperatures. This fibre has a high strength per weight ratio and low stretch characteristics. HMPE fibres have a low coefficient of friction and very good fatigue and abrasion properties but limited temperature resistance. Its maximum continuous working temperature of 65°C.

The best mooring lines must be lightweight yet robust and flexible yet resistant to chemicals, abrasions and harsh weather conditions.

What are the types of mooring lines?

Dockline mooring rope has been developed with impressive strength, high abrasion resistance and easy handling properties. Such lines have good elongation properties and are ideal for anchoring, as well as mooring and docking.

Southern Ropes Dockline is a double braid with a nylon core with a polyester cover, making it highly durable with the appropriate stretch and energy absorption for mooring purposes. A 24mm diameter Dockline rope gives a break load of 14,300kg and a 36mm diameter cut has a 32,300kg break load.

The three-strand multipurpose polyester rope from Southern Ropes is an example of a general purpose line that remains soft and easy to handle when wet. It is easy to splice, has high abrasion-resistance properties and its strength is not affected by water. Made from polyester and available in three colours, this conforms to British and European Standardization (BS EB 697;1997). A 36mm diameter with this rope has a break load of 25,700kg.

Another option for a mooring line is a general-purpose rope made with nylon. The Nylon Rope is one that shrinks and hardens when in water, is highly resistant and conforms to BS EN 943:2002 requirements. It can be used as a mooring line but is a good multi-purpose option that can function as a towing, fishing and anchor line. This type of rope comes in customizable colours and all three types of mooring lines can be custom cut to your preferred diameter and length.

If you have particularly large vessels to moor, then the UHMWPE STEALTH High Strength rope is another type of line that can be used for mooring. UHMWPE is a safer alternative to wire boat rope and is better value for money, especially when used in high-quantities as is needed in mooring. It is an extremely high-strength, lightweight, heat-treated rope. With a high abrasion resistance and low stretching ability, our 12 strand Stealth Fibre® UHMWPE is appropriate for many industrial operations.

With its high strength to weight ratio, low stretch and easy handling properties, UHMWPE ropes are increasingly replacing steel and conventional fibers. They are significantly stronger than steel yet only 1/8th of the weight of comparable steel wires. In other words, they are at least 8 times stronger than steel wire ropes.

UHMWPE lines are thinner, lighter and self-lubricating, so significantly easier to handle than conventional steel ropes. In addition to their strength, they are also much safer, with less recoil force than steel rope. When a steel mooring line breaks, it unravels quickly, whipping around with dangerous force and sharp edges.

When a UHMWPE rope breaks, the recoil is much less. Because it is constructed of long chains of polyethene that are all aligned in the same direction, if they break  it will display a linear, predictable recoil and will be more likely to drop to the ground, rather than whip around.

The self-lubricating fibers tend to have a waxy handle and smooth surface, making them easy to handle, although this means it does not hold knots particularly well. Yet despite their smoothness, they are still more than 15 times more resistant to abrasion than carbon steel.

Our UHMWPE rope exceeds ISO 10325 standards, is competitively priced and comes with free delivery in the UK, so contact us today with your needs.

How long should a mooring rope be?

The length of a mooring rope, or any rope for boats will depend on how you intend to use it, and the size of your vessel.

Generally speaking, you need three mooring lines for a boat:

  • Bow line – to secure the bow to the deck or pier
  • Stern line – to secure the stern to the dock
  • Spring line – to help minimize any surges back and forth

Your bow and stern lines will need to be at least half of the length of the boat, whereas a spring line will need to be at least as long as the full length of your boat.

We also recommend that you keep a spare mooring line to hand, ideally 4 or 5 times longer than the boat. All mooring lines and boat ropes should have an eye splice in one end. Guides are available to help you create this yourself, or we can provide splicing for you as required.

The diameter of the rope will also be important, and the adequate diameter will be determined by the length of the hull. A breakdown of the sizes can be found in the full product descriptions, but the range goes from 10mm for a 26ft hull to 20mm for a 62ft length.

Our range of high-quality mooring products are designed to secure the vessel to any semi-permanent or permanent structure, and they come in a range of diameters, lengths and colours. Our highly knowledgeable team will help you find the best ropes for your needs.