Scenario $6$: Confined Space Work Inside a Silo

a$.$ Context $-$ Two workers are assigned to inspect and clean the interior of a $20-$

meter$-$tall grain silo. To access the silo, they use a vertical ladder inside the

structure, and one worker wears a full$-$body harness connected to a tripod and

winch system outside the silo.

b$.$ Challenge $-$ While performing the inspection, one worker loses consciousness

due to lack of oxygen. The second worker, unsure whether to climb out or

attempt to help, is at risk of being exposed to the same hazardous atmosphere.