Professional problem solvers: Boliden’s swinging catenary

ABB | June 20, 2016 | 10:13 am

2016-06-20 – Meet the ABB engineers who solved the mystery of the swinging mine hoist in Garpenberg, Sweden. Their sharp minds and advanced mathematical calculations were put to the test and have resulted in a patent pending solution.

When a new hoist for carrying personnel was completed about a year ago for Swedish mining company Boliden, an unexpected problem was fast to follow. The steel rope used to send the cage one kilometer underground was swinging inexplicably, like a frenzied skipping rope. ABB engineers found out at an early stage that there was no known method on the market to measure and monitor the swings. They have to create one themselves.

To tackle the problem, a team was formed within ABB and a period of intense investigative work followed. Thousands of measurements were taken from the mine hoist and measurement specialists from ABB’s research unit were commissioned to examine these extensive vibration measurements.

Eventually, all of the pieces fell into place. Using ingenious mathematical calculations, ABB engineers managed to identify a method to measure the lateral forces of the catenary on the sheave, which revealed how much it was swinging. This resulted in a patent pending solution that was implemented in the control system, which, in turn, now reduces any uncontrolled movements of the catenary to acceptable levels.