By Dean McDonald, founder, Crane Rope Solutions
Have you ever wondered what separates a "premium" or "high-performance" rope from an economical one?
A more expensive rope doesn't simply mean a longer-lasting rope. Often the real difference is that a better rope is less likely to be damaged by accident. Better ropes tend not to jump sheaves during installation or turn into a rat's nest if the drum loses tension.
Domestic or import is the wrong question
Over the past 15 years I've watched our industry adopt a bad habit: dividing ropes into two camps, domestic or import. Domestic usually means made in North America, South America or Europe. Import usually means Asian or Indian origin. Some food for thought:
- Major OEMs such as Liebherr, Manitowoc and Kobelco have been known to supply ropes made in these "import" regions.
- Some "domestic" manufacturers source their raw material from Asia or use recycled steel from Mexico or abroad.
- Some "domestic" brands make only a small minority of their ropes in domestic regions, with most produced in countries labelled "import".
Meanwhile, manufacturers in every region have adopted the same vague label: "high performance". The point: buying rope on "domestic or import" is a fast track to wasting money.
Every wire rope, regardless of brand, is its own product, so "a better brand" can't be used as a blanket term. A rope made offshore in one diameter and lay type can outperform the domestic or European rope of the same size, and in the next diameter up the opposite can be true.
Wire rope is a machine, and a hard one to make. A single wire rope can have as many moving parts as a Rolex watch, and it has to be made to that same precision over thousands of metres. A Rolex can be adjusted if it falls out of time. A rope's geometry can't be adjusted once it's made, yet it has to carry dynamic loads and "keep time" for thousands of hours and countless bending cycles.
So what does "premium" mean?
If I had to define it: a company that truly stands behind its product and has competent technical support available in your time zone, the same day. Of roughly 20 big-name rope manufacturers worldwide, I'd put five or fewer under that umbrella. By that definition, a brand that's premium in one region may not earn the title in another.
And rope life is not as simple as "this rope is built better than that one." Build quality plays a big role, but service life varies widely with installation, the rope's fit with the drum and sheaves, the operating environment and maintenance.
What a better rope does over its life
On day one, an economical rope and a higher-quality rope perform the same. The difference shows over time. A higher-quality rope keeps its rotation resistance and stability for its whole life, until it reaches its limit through normal wear such as crown wire breaks. A cheaper rope tends to become less stable as it ages: it starts to twist up without obvious, visible signs of wear, and it is more likely to jump sheaves later in life.
That sets up a nasty cycle we see often. Crane companies choose cheaper ropes because their ropes tend to get damaged before they can live their full life, not realizing that a better rope reduces the risk of the very incidents doing the damage, such as loose drums and jumped sheaves.
Match the rope to the job
Wire rope design is always a trade-off. There's no perfect rope for every application, but we can always narrow the options by matching the rope to its operating environment.
Should a rope that is constantly shock-loaded but sees relatively few bending cycles, like the Kelly winch on piling equipment, be the same rope as the hoist rope on a tower crane or offshore pedestal crane, which sees smoother motion and far more bending cycles? Of course not.
Lowest upfront cost or lowest annual spend
If lowest upfront cost matters most to your fleet, we'll supply a rope that meets it. If your goal is to lower your annual rope spend, we'll give you a list of ropes suited to that instead.
Related: How to order a replacement crane rope · Wire rope abbreviations explained · Crane rope names · Diameter tolerance and spooling · Synthetic sheaves and rotation-resistant rope