In April 2022 a plant was in the process of carrying out its yearly engineering shutdown. One of the planned tasks was for operators to dig out the vac crust pit located under the vac and cutting line. The operators had taken out the castell key to enter the vac area and put into the lock box. All the operators individually locked off to the box securing the area to work in, then entered the area and began to dig out the crust pit. While carrying out a walk of the area, a safety rep and maintenance manager identified the agitators within the area were switched off (To “Manual”) on the MCC panel on the mezzanine floor but the panel was not fully isolated, and no isolation document had been completed.
Although a LOTOTO SOP for this task was present and clear, including all the isolation points, the responsible person failed to own the isolation process and to make sure all the measures were in place before work commenced.