What must be done to the main propulsion shaft before inflating the shaft?

Before inflating the shaft, it is crucial to ensure it is safely secured in a stationary position. Stopping and locking the main propulsion shaft eliminates any risk of movement during the inflation process, which could lead to serious safety hazards or mechanical failures. This step is essential for maintaining control over the propulsion system and ensuring comprehensive safety protocols are followed.

While other activities like inspection, polishing, or repairs could be relevant in different contexts, stopping and locking is specifically tied to the preparation for inflation to ensure that the system is stable and secure. By prioritizing this step, engineers and technicians can safely proceed with the inflation process without the risk of unintended rotation or movement.