Abstract

Workers in Québec underground mines are often transported using a cage suspended from a single cable and moved with a mine hoist. If the hoist control system fails to respond, the cage may crash.

The Regulation respecting occupational health and safety in mines (ROHSM) governs the use of programmable logic control systems (PLCs) and programmable robots with technical fact sheet RF-412 on the safety of mine hoists controlled by programmable systems.

Published by the IRSST in 2005, this technical fact sheet needs to be updated. Moreover, controller technology has evolved over the last 15 years and this technical fact sheet is based on an informal risk analysis that was extended to hoist control and supervision systems.

Loss of control of the hoisting cage is not a purely theoretical risk—a cage, fortunately empty, was totally destroyed in 2013 in Québec when it crashed to the bottom of a shaft.

To improve the safety of workers who use these cages on a daily basis and prevent the recurrence of similar accidents, the CSST’s subcommittee on hoists, supported by committees 3.57 et 3.57.1, tasked the IRSST with updating this technical fact sheet. The current status of mine hoists used in Québec, changes in safety standards and the reliability of control systems, as well as worldwide developments in mining practices (hoist automation), will be considered.