Power of Joystick Mode Misjudged During Maneuver Results in Allision

124

The incident

On the morning of May 8, 2016, at 0800 local time, the cruise ship Carnival Pride was attempting to dock in Baltimore, Maryland, when its bow struck the pier, fendering, and an elevated passenger embarkation walkway on shore. The allision caused nearly $2.1 million in damage. The walkway was destroyed, three vehicles that were under it during the collapse were damaged, and the vessel sustained minor damage. No one was injured and no pollution was reported.

How did it happen?

The Carnival Pride was returning to Baltimore from a 7-day round trip cruise to Florida and the Bahamas. As the ship approached the terminal to dock, the onboard Maryland pilot transferred navigational control to the Carnival Pride’s second-in-command, the staff captain. Following the changeover, the pilot assumed an advisory role instead of giving direct orders for the helm and engines. The staff captain had previous experience, under the master’s supervision, operating the controls during berthing maneuvers.

The vessel’s main propulsion and steering (helm) was provided by two stern azimuthing (rotating) propeller pods; supplemented during maneuvering with three bow thrusters. All could be operated independently or together via an integrated joystick. Control of the propulsion and the helm was shifted from the bridge’s center console to the starboard bridge wing console. With a push of a button, the staff captain accepted control at the starboard console, which was in joystick mode. The joystick tested and operated normally.

Unsuccessful Attempts to Transfer to Manual Control

The pier heading at the terminal was 284 degrees, yet, when the bow of the Carnival Pride was about half a ship’s length away from the dock, the vessel was on a heading of 307 degrees and making a speed of 5.3 knots. About that time, the pilot cautioned the staff captain to slow down. To control the vessel’s rate of closure with the dock, the staff captain tried to transfer from joystick to manual control at the starboard console in order to gain more direct control of propulsion. Despite repeated attempts, the staff captain’s efforts to transfer control to the manual levers were unsuccessful.

Collapse of the Walkway

As the distance to the dock continued to decrease, the master took the conn from the staff captain and shifted control back to the center console, regaining full control of the ship’s azipods and bow thrusters. He then applied full thrust away from the berth and slowed the ship’s forward progress, but not before the bulbous bow struck the fendering and under-pier support columns. As the ship continued moving forward, its flared bow and starboard-side retractable observation and mooring platform struck an elevated passenger embarkation walkway. The walkway collapsed onto three vehicles parked on the pier.

The staff captain allowed the Carnival Pride to approach the pier too fast and at an angle too steep because he misjudged the power available in the joystick mode for correcting maneuvers. In the seconds it took him to realize that the joystick control would not be enough to slow the ship, he lost valuable time in shifting to manual control. In his haste to shift control, he was unable to assume manual control at the starboard console, an event the staff captain could not explain. The vessel’s operating company was not able to replicate the failed transfer of control from the joystick mode to the manual mode during testing on subsequent voyages. Thus, the company was unable to determine a cause other than possible human error.

Probable Cause

The NTSB determined that the probable cause of the Carnival Pride’s allision with the pier and elevated passenger embarkation walkway was the staff captain’s errors during the docking maneuver―approaching the pier with excessive speed and at too steep of an angle―and the master’s insufficient oversight during the maneuver.

Did you subscribe for our daily newsletter?

It’s Free! Click here to Subscribe!

Source: NTSB

LEAVE A REPLY

This site uses Akismet to reduce spam. Learn how your comment data is processed.