At the end of this module, you will be able to:
- Identify the parts of a wire rope
- Describe wire rope materials
- Define lay length
- Define lay direction
- Describe the classifications of wire rope
- Identify and describe different strand constructions
- Define wire rope diameter, strength, design factor, and working loads
The following key questions are answered in this module:
How are wire ropes commonly used in an industrial application?
Examples of wire rope applications include: wire rope slings, derricks, cranes, and hoists.
What are the three basic components that make a wire rope?
The basic components are the core, strands, and wires. The core is at the center of the rope and is made of a fiber material or steel. Strands are groups of individual wires that wrap around the core. Wires are single individual pieces of metal that are drawn to a small diameter.
What does the term "lay" mean, in regards to wire ropes?
The term, "lay" is used in wire rope design to describe three characteristics of the rope: the direction the strands wrapped or are laid around the core, right lay or left lay, the relationship between the wrap direction of the strands and the wrap direction of the wires within each strand, regular lay or lang lay, and the linear distance a strand travels while making a single revolution around the wire's core, or the lay length.
What are rotation-resistant ropes?
Rotation-resistant ropes are specially designed to resist the tendency to rotate when the rope is supporting a load. One common design includes a central core, a middle second layer, laid to the left, and a third outside layer, laid to the right. The overall result of these two rotational tendencies is to reduce or prevent rotation of the rope as a whole.
How is the maximum working load determined?
To find the maximum working load for a rope, divide the rope's nominal strength by the rope's design factor. The design factor was once referred to as the rope's safety factor.
Below is a transcript of the video sample provided for this module:
Wire rope is typically composed of three basic parts. A core at the center of the rope, this can be made of a fiber material or steel. Strands, which are groups of individual wires that wrap around the core. And wires, which are single individual pieces of metal that are drawn to a small diameter. Each of these components will be described in more detail.
Use the additional resources and links below to learn more about this topic:
- U.S. Department of Labor’s Occupational Safety & Health Administration (OSHA) – www.osha.gov
- OSHA Training Documents - https://www.osha.gov/doc/outreachtraining/htmlfiles/slings.html
- National Institute for Occupational Safety and Health (NIOSH) – www.cdc.gov/niosh/
- NIOSH Publications - http://www.cdc.gov/niosh/docs/2004-101/chklists/r1n60s~1.htm
- US Bureau of Reclamation (USBR) – www.usbr.gov
- USBR Safety and Health Standards - http://www.usbr.gov/ssle/safety/RSHS/appD.pdf