Monitoring the wheels and bearings of overhead cranes is not easy. If we could detect poor lubrication and bearing defects, we could perform predictive maintenance and get ahead of the P–F curve.

We can use a standard approach to monitor the motor of the hoist system on the crane. The gearboxes for the hoisting installation and the movement of the crane can also be monitored in a standard way. At least, the technology is fairly standard, but the planning is not easy. The cranes are not often available under the conditions we need for measuring.

If the cranes, for example, only travel 20–30 meters, that will not allow us to take decent readings. These cranes are low speed, at 20–50 RPM, and you need it to travel at least 100 meters. As for the bearings in the crane’s wheels, it’s difficult because of the low speed and the difficulty of access. More importantly, because of the contact of the wheels with the rails, we get a lot of background noise. If you perform a standard measurement, you get a lot of influence from the wheel contacting the rails. This noise is not useful—it doesn’t tell us anything about the bearing’s condition. It’s a challenge to remove this vibration.