Construction of wire rope
The design of a rope is determined by
* STRAND CONSTRUCTION
The number and arrangement of wires in each strand
* ROPE CONSTRUCTION
The number and arrangement of strands in each rope
* THE CORE
A wire rope is much more than a collection of wires, even the finest quality of wires has a centre core, it may consist of Fiber, standed Wire, Synthetic material or a complete "Independent" Wire Rope within a wire rope.
The strand centre is a wire or fiber above which the covering wires are laid.
This centre wire is know as the king wire.
The rope is a number of strands laid helically around the core.
The most common construction consists of 6 stands laid around a fiber core or Independent Wire rope Gore as FMC or IWRC/WSC.
Wire Rope Lay
Right Lay : Clockwise
Left Lay : Counter-clockwise
Regular Lay : Wires in strands are laid in the opposite direction of the strands and are parallel to the rope axis. Ropes with regular lay are easy to handle and have greater resistance to crushing than those with lang lay.
Lang lay : Wires are laid in the same direction as the strands of the rope, and in an angle to the rope axis. Longer lengths of the individual wires are exposed, creating greater resistance to wear and improved flexibility. Lang Lay ropes should only be used where both rope ends are "fixed" and therefore, not be used with a swivel type terminal
How to Handle Steel Wire Rope
Winding Method of Drum or Winch
How to Measure Rope Size
The number and size of wires in a strand, and the number of strands in a rope vary according to the work the rope has to do. Strength, flexibility, abrasion resistance and other characteristic dictate the rope you ultimately select. The equipment has also to be considered when using ropes, the type and size of drum and pulley, the load and the speed at which the rope will work, is sometimes thought that a rope with the highest breaking strength is the best of the job. This is not always the case. For example a rope made from 180 kgf/mm2 wire with its superior ductility and flexibility may out-perform a rope of say 200 kgf/mm2 in the same construction with reduced ductility due to its higher tensile.
PS = Plow Steel,
IPS = Improved Plow Steel
EIPS = Extra Improved Plow Steel
Grade = = Indian Standard Grade (kg/mm2)
IWRC/WSC = Independent Wire Pope Core / Steel Core.
All Ropes are right-hand, regular lay (ordinary lay) (unless otherwise stated)
For Drilling, Shipping Marine, Logging, Aircraft, Lifting Slings, Fishing,
Excavating, Mining, Aerial Tramways, Ropeways and Suspension Structures.
Flexibility and Durability:
When compared with the ropes of same diameter, the ropes having more wires is more flexible than that having fewer wires, but reduces it's durability.
Can be Approved:
Indian Standard Institute, Indian Register of Shipping, American Petroleum Institute, Lloyd's Register of Shipping, American Bureau of Shipping, Det Norske Veritas, Bureau Veritas of Shipping, however all our supplies will a company with Test Certificate of Manufacturers and Dock Workers (Safety, Health & Welfare) Regulations 1990.
Cores for wire ropes
* Steel IWRC (Independent Wire Rope Core) The main core is an independent wire rope, normally having the construction 7x7 WSC (Wire Strand Core) The main core is an independent wire strand, normally having the same construction as the outer strands of the rope.
* Fiber Fiber cores are stranded and comprise either: Natural fibers such as sisal, hemp, jute, and cotton.
Synthetic fibers such as polyamide, polyetheylene, and polypropylene. Asbestos fibers (heat resistant)
In the preforming process the wires and strands are given their final helical pitch before being laid up into rope. Ropes made in this way show no tendency to untwist when cut.
Lubrication reduces internal friction of the wires and strands and protects against corrosion. Grease is applied to all rapes supplied. If special lubricants are required this must be specifically stated at time of ordering.
Diameter of wire ropes
The diameter of a wire rope is the diameter of the circle which incloses all of the wires.
When measuring wire rope it is important to take greatest distance of the outer limits of the 'Crowns' of two opposite strands. A measurement across the valleys will result in incorrect lower readings.
Useful chart for wire rope selection