⎪ Maintenance and asset management ⎪
Lubrication is critical for the life of galvanised wire rope Simon Norton, director of the International Zinc Association (Africa), discusses the important role of lubricants in providing corrosion protection and to prevent internal wear and degradation in zinc-coated wire ropes. I n harsh industrial environments, from South Africa’s busy ports to offshore drilling operations, zinc-coated wire ropes are widely recognised as a first line of defence against corrosion. However, while galvanising and Galfan (zinc-aluminium) coatings provide essential protection, they represent only part of the equation.
Key performance requirements include strong adhesion to resist water washout and ‘fling-off’ during high-speed operations, as well as the ability to penetrate deep into the rope’s core rather than simply coating the surface. Effective lubricants also incor- porate corrosion inhibitors that stabilise the protective oxide layers formed on zinc and aluminium surfaces. For offshore and shipboard applications, environmental compliance is increasingly important. Environmentally acceptable lu- bricants (EALs), which are biodegradable and low in toxicity, are often required to meet international regulatory standards without compromising load-carrying capability or corrosion protection. The effectiveness of lubrication depends not only on the product used, but also on how it is applied. Pressure lubrication systems are widely regarded as best practice for high- duty applications such as port cranes. These systems force lubricant into the rope under pressure while removing old grease and contaminants, ensuring that internal friction zones are properly protected. By contrast, manual application methods, such as brushing or pouring lubricant onto the rope, often fail to penetrate to the core. If not preceded by thorough cleaning, they can also trap moisture and debris, accelerating internal corrosion rather than preventing it.
cranes, periods of inactivity can pose distinct risks. If lubricants dry out or crack, moisture can become trapped against the zinc coating, leading to localised corrosion. In these cases, flexible, film-forming lubricants that remain stable over time are preferred. Even with effective lubrication, regular inspection remains essential. Standards such as ISO 4309 provide guidance, but coated ropes require particular attention, as surface appearance can mask internal damage. A consistent reduction in rope diameter may indicate internal corrosion or core deg- radation, while the presence of “white rust” suggests that the zinc coating is reacting to moisture and that lubrication has failed. Wire breaks occurring between strands, rather than on exposed surfaces, are a key indicator of internal fretting caused by insufficient lubrication. Zinc coatings, whether galvanised or Galfan, provide a crucial foundation for cor- rosion resistance. However, their full ben- efits can only be realised when combined with appropriate lubrication technologies and disciplined maintenance practices. High-performance greases High-performance greases, including those fortified with solid lubricants such as graphite or molybdenum disulphide, help maintain protection under extreme pressure. Modern formulations also offer enhanced adhesion, water resistance and compatibility with high-pressure lubrication systems, ensuring that protection reaches the rope’s core. By integrating these approaches, opera- tors can significantly extend service inter- vals, reduce downtime, and minimise the risk of failure in critical lifting applications. “Zinc gives wire ropes a vital head start in resisting corrosion, but long-term perfor- mance depends on what happens in opera- tion,” highlights Norton. “When advanced coatings are combined with the right lubri- cation strategy and consistent maintenance, operators can achieve far greater reliability, safety, and service life in even the harshest environments,” he concludes. https://www.zinc.org/
To achieve full design life and ensure operational safety, these coatings must be supported by a rigorous maintenance and lubrication strategy. According to Simon Norton, director of the International Zinc Association (Africa), wire rope performance depends on understanding that these sys- tems are not static components but dynamic mechanical assemblies. “Zinc coatings provide critical corrosion protection, but wire ropes are constantly in motion,” explains Norton. “Without proper lubrication and maintenance, internal wear and degradation can occur even when the external coating appears intact.”
A dynamic system, not a static product
Wire ropes consist of hundreds of individual wires working together under continuous stress. As ropes pass over sheaves and wind onto drums, these wires slide against one another, generating internal friction. While zinc coatings protect against en- vironmental corrosion through sacrificial action, they do not eliminate mechanical wear. Without adequate lubrication, this internal movement leads to fretting corrosion, ac- celerated fatigue, and ultimately premature failure. In this context, lubrication is not an option- al extra, but a critical functional component. It reduces internal friction, protects against moisture ingress, and preserves both the steel core and the zinc coating itself. Selecting the right lubricant for harsh environments In marine and high-humidity environments, lubricant selection is particularly demanding. Products must be engineered to withstand salt spray, heavy rain, and continuous me- chanical stress while maintaining perfor- mance over time.
Maintenance strategies across industries
Different operating environments present distinct challenges, requiring tailored main- tenance approaches. In port and harbour cranes, ropes are exposed to salt-laden air and high-frequency operating cycles. Maintenance efforts should focus on the working sections of the rope, where repeated bending occurs. Regular cleaning is essential to prevent the build-up of abrasive mixtures formed by dust, pollutants, and grease. Offshore drilling operations introduce ad- ditional complexity, particularly in the ‘splash zone’ where ropes are intermittently exposed to seawater. Here, lubrication must remain stable across varying temperatures and resist rapid depletion of protective coatings. For ship derricks and civil engineering
July-August 2026 • MechChem Africa ¦ 37
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