A Tip From The Experts
Proper Wire Rope Installation
The strength of a wire rope will naturally decrease over time; however, what we have found over the years is that many wire rope issues can be traced back to the installation. Check out these tips from WireCo and Fulcrum Lifting to avoid installation errors and save a lot of time and money down the road.
- Unload rope properly and relieve any twists
- Don’t attempt to unwind a rope from a stationary reel or coil.
- Pull the rope off the shipping reel or coil and lay the rope on the ground in a direct line with the boom to release any twist in the rope.
- One of the primary concerns when installing wire rope is getting the rope on the equipment without trapping any twists.
- Attach rope’s end to drum
- Pull the rope over the point sheave and attached the end to the drum; be sure the rope strands are free to adjust.
- Wind rope onto drum slowly and carefully
- Spool first layer tightly
- Make sure the first layer wraps tightly and close together because the first layer forms the foundation for succeeding layers.
- If needed, consider using a rubber, lead or brass mallet – never a steel hammer – to tap the rope into place.
- Spool multiple layers with sufficient tension
- It’s important to apply a tensioning load to the ropes during the breaking-in process
- The tensioning load should range from 2 to 3% of the minimum breaking strength of the rope.
- Do not run the rope through a tightening device as this will ruin the rope.
- For ropes in multi-part systems
- Reeve the traveling block and boomtip sheaves so the rope spacing is maximized and the traveling (hook) block hangs straight and level to help assure block stability.
- Avoid dead-ending the rope at the traveling block, if possible.
- Check rope for twist
- With the rope slack, pull enough rope out to allow it to hang in a loop. If the rope hangs without twisting together, there is no twist in the rope. If the rope twists, it’s likely that a twist is trapped in the rope.
- To relieve a rope twist, raise the boom to its highest position while letting out the rope until the rope almost touches the ground. Once the twist is fully relieved, proceed with rigging the crane.
- Secure ends before cutting
- The plain end of a rope must be properly secured to avoid core slippage. Many high-performance ropes are not preformed.
- Wire rope grips
- When installing a new line, connect the old and new lines by using a wire rope grip, like the Lewis LSG-X Snake Grip.
- Never weld or splice the old rope to the new rope. Doing so can transfer torque into the new rope causing premature cause for removal.
- Using a wire rope grip with a swivel allows the rope to properly rotate during installation.
- After installation
- Perform a break-in procedure to achieve maximum service life: run the new rope through a light load (10% of working load limit) at a reduced speed to gradually adjust to working conditions.
- Lubricate ropes often for a longer life. Although lubrication is applied during the manufacturing process, lubricants will dry out over time and corrosion will occur. First remove excess dirt, dust or materials before applying lubricant.
- Never shock load a wire rope; a sudden application of force or load can cause both external and internal damage. Avoid a sudden release of the load as well.
- Additional tips
- Rigging in tight quarters: If you’re rigging in tight quarters and can’t lay the new rope out on the ground before rigging, further steps are necessary. You should mount the reel on a shaft through flange holes and on jack stands. While unspooling, do not allow the reel to “free-wheel.” Brake the reel by applying pressure to the flange (never apply braking pressure to the rope on the reel).
- Use a cable snake: When installing a new line, connect the old and new lines by using a wire rope grip, like the Lewis LSG-X Snake Grip. Never weld or splice the old rope to the new rope. Doing so can transfer torque into the new rope causing premature cause for removal. Using a wire rope grip with a swivel allows the rope to properly rotate during installation.
- Fleet angle: Twist will be induced into the reeving system should you set up the new rope reel to be installed too close to the crane point sheave or the rope drum. If the reel is 4 feet wide you must set it back a minimum of 80 feet. If the reel is 3 feet wide the reel must be set back a minimum of 60 feet. Set up closer than noted above will induce twist into your system, which can be an expensive and time-consuming mistake.
For more information about properly installing wire rope, visit WireCo WorldGroup.