Steel wire ropes in RTG and RMG container gantry cranes – reliability in port operations
RTG (Rubber Tyred Gantry) and RMG (Rail Mounted Gantry) container cranes are strategic assets in handling operations at container terminals. Their job is to move containers quickly and precisely between ships, storage yards, trucks, and trains. Throughout this process, the steel wire rope plays a critical role, ensuring lifting, lowering, and the stability of the handled loads.
What tasks do ropes perform in RTG and RMG cranes?
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Lifting and lowering containers – the main rope is attached to the hoist block (spreader), enabling vertical transport of containers weighing even several dozen tonnes.
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Stabilizing the lifting system – ropes running in guides or tensioning systems ensure precise movement and protect the container from swaying.
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Transmitting drive forces – in some designs, ropes transfer mechanical forces from the drives to lifting or travelling components.
Challenges of working in a port – why is selecting the right rope so important?
Port cranes operate in extreme environmental conditions: high humidity, salty air, and intensive 24/7 duty cycles. For this reason, the ropes used must feature:
✔ corrosion resistance (e.g., a galvanized coating or anti-corrosion lubricant),
✔ high resistance to fatigue and bending,
✔ an appropriate strand construction that prevents rope rotation and ensures even spooling on the drum,
✔ compliance with the crane’s DTR and relevant industry standards (e.g., ISO, EN, FEM).
Main hoist rope – the heart of the lifting system
The main hoist rope does the heaviest work. It must ensure smooth and safe container lifting, withstand intensive duty cycles, and meet strict requirements for strength, flexibility, and compatibility with guides and rope sheaves.
Ropes recommended by the manufacturer – a documentation-compliant choice
For many users, it is crucial to use ropes from a manufacturer that:
- is listed in the technical and operational documentation (DTR),
- has approval from the crane designer/manufacturer,
- has already proven reliable in practice—operators often don’t want to change suppliers if the current rope performs fault-free.
Replacement ropes with equivalent parameters can be an attractive, cost-effective alternative—provided they comply with the relevant standards and the operating requirements of the specific crane model.
