"Lay" and Rope Design

"Lay" has three meanings in rope design.  The first two meanings are descriptive of the wire and strand positions in the rope. The third meaning is a length measurement used in manufacturing and inspection.

• The direction strands lay in the rope -- right or left. When you look down a rope, strands of a right lay rope go away from you to the right. Left lay is the opposite. (It doesn't matter which direction you look.)
• The relationship between the direction strands lay in the rope and the direction wires lay in the strands. In appearance, wires in regular lay appear to run straight down the length of the rope, and in lang lay, they appear to angle across the rope. In regular lay, wires are laid in the strand opposite the direction the strands lay in the rope. In lang lay, the wires are laid the same direction in the strand as the strands lay in the rope.
• The length along the rope that a strand makes one complete spiral around the rope core. This is a measurement frequently used in wire rope inspection. Standards and regulations require removal when a certain number of broken wires per rope lay are found.

The lay of a rope affects its operational characteristics. Regular lay is more stable and more resistant to crushing than lang lay. While lang lay is more fatigue resistant and abrasion resistant, use is normally limited to single layer spooling and when the rope and load are restrained from rotation.