A crash stop rapidly reverses propulsion to arrest a ship, imposing loads far beyond an ordinary reduction in speed. Zigzag trials test steering response and stability, while combinations of turns and emergency stops can make the trial physically punishing for both ship and crew. These tests can break a defective vessel, but that is preferable to discovering the same weakness during an operational emergency.
Chapter · 36:00-44:45
Crash stops and zigzags test the whole ship at once
Extreme maneuvering trials load steering gear, propulsion, and hull structure hard enough to expose failures before operational service.