When wire ropes were first invented, they represented a significant leap forward in technology. Industries needed cords that were long and strong and wouldn’t fatigue under constant strain.
Wire ropes material properties provided an alternative to existing cords and worked better in many applications by allowing the tension to be distributed more evenly over the interior surfaces of the rope. So what are the steps to wire rope construction, and how do they help make rope strong?
The 6 Steps of Wire Rope Construction
Step 1: Collect steel wires and wind together
Wire rope construction begins with steel wires. Typically, the steel wires range from 0.6 to 8 mm in diameter. The wires are wound together into a strand. Different applications require different types of wire rope strands, depending on strength and flexibility requirements.
Once the number of wires and their thickness has been determined, the wires are loaded onto a stranding machine—a device which rotates the strands, winding them together.
Stranding machines can support up to 62 wires in a strand. Most strands, however, are made from between 19 and 36 wires, suitable for the majority of wire rope classifications.
The winding process depends on a lubricated die, a kind of opening at the end of the strand winding machine which collects all the wires and determines the thickness of the strand.
The lubrication plays an essential role. Not only does it prevent friction damage to the strand as it spins in the die, but it also gets in between the individual fibers, providing lubrication while the wire rope is in operation.
Step 2: Skim excess lubricant
Once the wound wire strand comes out of the stranding machine, it is fed through a skimmer. The skimmer removes excess oil, preparing the wire for the next step in the manufacturing process.
Step 3: Straightening
Individual wires have a “material memory”—they know that they began life in an unwound state. To convince the material that it should stay in the wound state, manufacturers feed it through straighteners, large concrete or steel wheels, which press the wire into place. Straighteners prevent the wires from unraveling once it exits the stranding machine.
Step 4: Collect wire strands
Manufacturers collect the newly minted wire strands in a large spool. The purpose of this is to protect the wire rope during transit and to ensure that it does not bend more than tolerances allow.
Step 5: Turn wire strands into rope
Some applications require cords with substantial tensile strength, such as in agriculture and shipping. Strands can be wound together to make a thicker, stronger wire rope, capable of supporting more weight in a machine called a closer.
Step 6: Feed through calibration rollers
Wire rope, like wire strands, may not have uniform thickness and consistency. Calibration rollers pressure the rope into the desired shape as it comes out of the closer. Rope is then fed into a reel, ready for shipping.
Safety & Wire Rope Material Properties
Companies ensure that their cables meet the requirements of their customers by subjecting them to pulling tests. They use a machine that pulls on the wire until it snaps, measuring the tensile strength. Ropes must be able to support loads more than their claimed tolerances. In some applications such as mining, ropes are covered in protective plastic to reduce wear and tear.
Supplying the Best Wire Rope Construction
Silver State Wire Rope and Rigging has provided the highest quality or well-constructed wire rope for over 20 years! We know the all the steps of the process and how to check for quality assurance to make sure your rope is the safest it can be. We provide wire rope services focused on entertainment, mining, and utility. If you’re interested in our expertise, contact us today to get an estimate!