Damage detection for rotating equipment

Two critical exhaust fans in an oil tanker were damaged, putting the ship out of action for two weeks and costing its owners around €60,000. A hand-held device used for the early detection of damage in rotating elements, such as roller bearings, soon identified the problem.

Determining the root cause of the problem using Fag Detector III.
Determining the root cause of the problem using Fag Detector III.

A 228 m long tanker recently had to spend 14 days in a German port due to defective exhaust fans. With twelve tanks and a capacity of almost 80,000 m3, the tanker cannot afford to be out of operation for long, because each week the tanker is out of operation costs the shipping company around €30,000.

The tanker is part of a fleet of more than 30 ships, moving around 1.3 million tonnes of cargo each week. It is managed by a company that provides a comprehensive range of services, from shipbuilding and crew provision, to the handling of all administrative tasks.

The two damaged exhaust fans are critical to the tanker's power supply system. If the fans are out of operation for any reason, critical operational systems on the tanker are affected.

Technicians from the German shipping company responsible for maintaining the tanker, spent two weeks attempting to repair the damage to the exhaust fans and contacted FAG Industrial Services (FIS), a maintenance management and condition monitoring and member of the FAG Group which supports UK-based Schaeffler Group, one of the world's leading rolling bearing manufacturers and automotive component suppliers.  

Finding the root cause

A technician used FAG Detector III, a handheld device used for the early detection of damage in rotating machine elements such as rolling bearings.

The device is available with an optional, extended operational balancing function which can be activated at a later stage after purchasing the basic unit. It can be used to balance rotors and shafts in both static and dynamic balancing applications, on a range of rotating equipment, including machine tools, pumps, electric motors, fans, compressors, ventilators, gearboxes and spindles.

FAG Detector III is available with a full range of accessories required to carry out a balancing process, including sensors, trigger, magnetic holder and reflection marks.

Using the device, the technician was able to determine the root cause of the problem – an imbalance of the fan impellers – and then repair this fault immediately.

Since any damage to an exhaust fan can prevent the tanker from continuing its journey, FIS provided the shipping company with clear recommendations on how failures such as these could be avoided in the future. This included regular cleaning, maintenance and vibration monitoring of the fans.

The tanker has now been restored to full operation due to rapid diagnosis and repair work by engineers from FIS.