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Exposing problems beneath the surface

July 15, 2016

A RopeQ inspection lets you know when a wire is at the end of its tether, even when there are no visible signs of fatigue.

In hoisting applications, one of the most critical elements for safety is the durability of wire ropes. As corrosion, tension and abrasion wear away at the wires and core of the rope, its working life is inevitably finite. Regular inspection to detect breaks and fatigue can detect a timely replacement before dangerous situations occur.

Optimizing the right change intervals for ropes can be difficult, as some types of damage are difficult to observe with the naked eye.

“Rotation-resistant ropes, for example, are keen to suffer from internal wire breaks that are left unseen with visual-only inspections,” says Saku Aspelin, Product Manager, Consultation Services at Konecranes.

SHOWING YOU THE ROPES

In other cases, internal corrosion is a major problem. For instance, the boom ropes of a ship-to-shore crane are exposed to the elements and are stationary for long periods of time. With time, rain water slowly penetrates the rope and corrodes it from the inside. Lubrication added to protect the rope’s surface can lock the water in, contributing to the damage.

To detect non-visible defects such as these, Konecranes uses a special inspection method called RopeQ. A RopeQ inspection combines a regular visual check with magnetic-inductive leakage technology, providing accurate data on the integrity of the rope’s interior. This way, the outside and inside of the wire rope can be inspected in a non-destructive manner.

“It’s not only the rope we’re inspecting, but also the other parts of the rope reeving system, including rope fixings, rope drums, rope guides, sheaves and anything that has an effect on rope life and reliability. We also measure the wear on running surfaces and the diameter of the rope itself,” adds Aspelin.

BENEFITS OF REGULAR EXAMINATIONS

A single, isolated RopeQ inspection yields an assessment of the rope’s current condition and provides information on the remaining useable life of the rope. The best benefits, however, come with regular inspections, which form a trend line over the rate of wire breaks forming.

“With continuous information, we can optimize the rope change interval, maximizing safety and minimizing costs,” Aspelin explains.

An optimized change interval reduces equipment downtime and brings down maintenance costs. RopeQ inspections are recommended for all types of wire rope applications, but are especially effective for process cranes in constant use, cranes that are used only occasionally, ropes that are particularly hard to inspect visually and post-accident inspections.

 

KEY ADVANTAGES OF ROPEQ

1. Improved safety from detecting nonvisible defects

2. Optimized wire rope change interval

3. Repeatable and reliable results

4. A report that is easy to read and interpret, with recommendations for action

Text: Mari Suonto
Photos: Konecranes, Niklas Sandström

 

Fast File

  • Saku Aspelin is responsible for managing the Consultation Services offering of Konecranes globally.
  • He has also held positions in R&D and Global Product Management.
  • Aspelin started his career with Konecranes as a technician in 2002.