Guide to Mooring Lines: Types, Materials, and Equipment
Mooring Lines
Types of Mooring Lines
Lashes: Lines that secure a boat to a pier or dock. They are typically made of synthetic fibers like:
- Polyamide (Nylon): Elastic, heat-resistant, and resistant to oils and solvents. However, they lose strength when wet.
- Polyester (Terylene): Durable, resilient, and resistant to abrasion, acids, oils, and solvents. They are not as elastic as polyamide lines.
- Polypropylene: Similar elasticity to polyester, heat-resistant, lightweight, and buoyant. However, they have limited resistance to cyclical pressures.
Natural fiber ropes include:
- Hemp: Strong and historically used for mooring and anchoring.
- Abaca: More expensive than hemp but stronger.
- Sisal: Less harsh than hemp but weaker.
- Esparto: Weaker than sisal and not recommended for mooring.
Synthetic fibers offer advantages over natural fibers:
- Rot and rust-resistant
- Superior strength
Highly Resistant Lines: These lines are made of steel cable or strong synthetic compositions and are used for large ships that require secure mooring.
Elasticity Solutions: To withstand dynamic stresses, two solutions are available:
- Using more elastic ropes
- Combining ropes with varying elasticity, with the end of the tie having greater elasticity
Mooring Lines Based on Direction:
- Larges: Lines that run from the bow or stern and work in the same direction, preventing longitudinal movement.
- Springs: Lines that run from the bow or stern and work in the opposite direction, preventing longitudinal movement.
- Traverses: Lines that work perpendicular to the ship’s axis, preventing lateral movement.
- Elbow-Cabos: Lines that run from the bow, go in the opposite direction of the tie, and are tied to the concave part of the dock, preventing the ship from hitting the jetty.
Mooring Terminology
- SF (Safe Factor): A measure of the safety margin of a mooring line.
- Beam Wind: Wind blowing across the beam of a ship.
- SWL (Safe Working Load): The maximum load a mooring line can safely hold.
- MBL (Minimum Breaking Load): The minimum load that will break a mooring line.
Mooring Equipment
Cubiertason Fittings: Elements that guide and secure ropes on board.
Bita: Iron columns used for securing mooring ropes.
Bozza – Stopper: A tool used to hold the tension of a rope.
Cornamusa: A T-shaped metal piece used for mooring ropes on pleasure boats.
Cabos: Metal guides that direct the path of mooring lines.
Special Alavante: Guide ropes fitted with rollers to reduce friction.
Closed Fairleads: Guides with horizontal and vertical rollers to minimize friction.
Panama Guide: A circular or elliptical guide located on the centerline of the ship.
Maquinilla: A mooring winch used to haul or cast off mooring lines.
Types of Mooring Winches:
- Automatic or manual
- Number of drums
- Simple or divided drums
- Hydraulic or mechanical brakes
- Type of riding
The brake on a mooring winch is essential for stopping the drum and holding the line. It also prevents the line from slipping if the tension becomes excessive.