Lifting the biggest loads, such as space shuttles and precast concrete components, is a sophisticated machine with wire rope.
FREMONT, CA: Wire rope is a piece of machinery. On wire rope hoists, it is the workhorse that lifts the large weights. Lay has a variety of meanings and definitions in the field of wire rope. The direction in which the strands are twisted around the wire rope’s core is referred to as lay. When the terms left-hand and right-hand lay are used interchangeably, it means the strands are twisted clockwise (left hand) or counter-clockwise (right hand) around the core.
For wire rope, different countries and sectors may have different standards or best practices. The wire rope industry in the United States recommends that a Right Hand (RH) lay rope be used on a Left Hand (LH) drum corkscrew and a Left Hand (LH) lay rope to be used on a Right Hand (RH) drum corkscrew. This is recommended for good rope spooling, especially when using a groove-less drum. Wire rope hoists are designed in most cases in contravention of this best practice, but for a major engineering reason, that benefits the user and for added safety.
The cut of the groove corkscrew in the drum is sometimes referred to as lay, and the corkscrew can go to the left or right. In the case of a left lay, the wire rope will begin to accumulate on the drum’s left side, whereas in the case of a right lay, the wire rope will begin to gather on the drum’s right side. The term lay refers to the length of a complete wrap of a strand once it has been wrapped around the core. Knowing how to measure the lay is crucial when doing a wire rope inspection. It is calculated by measuring the distance from the outside to the same outside point after wrapping the strand one complete time.
Lifting the biggest loads, such as space shuttles and precast concrete components, is a sophisticated machine with wire rope. When a weight is raised by a crane and wire rope hoist, it accomplishes the heavy lifting. All crane technicians must have a thorough understanding of wire rope. Understanding what lay means and identifying the type of rope on an existing hoist is only the beginning. This information will not only help one be a more successful technician for the customers, but it will also help improve industrial safety.
