The collective term used for all types of rope, twine and lines is cordage. Unlike the past when rope was measured by its circumference, it is now measured across its diameter. It is made either from vegetable or man-made fibres. The fibres are twisted together to form yarns, which are then twisted together in the opposite direction to form strands. Three or more strands are then laid up again, but in the opposite direction to form rope.
Lay of ropes.
When three strands are used, the rope is referred to as “hawser laid”. If four strands are used it is referred to as “shroud laid”. If three hawser laid ropes are twisted together (in the opposite direction to their strands) it is referred to as a “cable laid“ rope.
When the twist of the strands is to the right, it is called a “right hand lay”. If it is to the left then it is called a “left hand lay”.
Besides the above three types of lay, there are also “braided” ropes. They comprise three types, namely diamond braid with a core, diamond without a core (called a hollow braid and a solid braid.
The first and last of the three (diamond with a core and solid braid) cannot be spliced whilst the hollow braid can.
The plaited or eight stranded rope is made up of pairs of braided strands and is mostly used for mooring lines and other general purposes. It is as strong as three stranded rope and wears very well.
Small diameter cordage.
- A bolt rope is made of Italian hemp soft laid and is used for roping the edges of sails and awnings.
- Signal halyards are usually made of soft, white hemp. It is very flexible.
- Log line is plaited or round sennit.
- Twine is made of hemp or flax and is used for seaming.
- Spun yarn is used for all general purposes and can be tarred if required.
- Oakum consists of old condemned cordage which has been picked apart and is used for caulking wooden decks. In times gone by, picking oakum was used as a punishment.
Ropes constructed of man-made fibresare made up in the same way, and they are often plaited as well. Plaiting a rope distributes the wear more evenly over the surface of the rope. Ropes made of man-made fibres are more expensive than the natural ropes but they last much longer. The more strands there are in a rope, the more flexible it will be.