Trench boxes are used to prevent collapse when working in the trenches.
Samatar Sahal, 40, was killed when he was trapped under the cross member of the structure as it was dismantled by the side boom operator and three other workers.
The Canadian Energy Regulator has ordered Trans Mountani to ensure that SA Energy Group stops using trench boxes until it is proven that they can be safely assembled, deployed and dismantled .
Trans Mountain must also ensure that it has a process to give inspectors and workers competent training and knowledge to operate the equipment.
A report identifying the gaps and any human, organizational or other factors in the October 27 death is expected on November 13.
Work on the site was halted Tuesday afternoon.