## 3 MV Milano Bridge Accident and FRAM Application Data  
### Cause Analysis Summary of the MV Milano Bridge Accident  
#### 3.1.1.1 Accident Analysis from a Material Perspective  
When analyzing the arrival track of the MV Milano Bridge at the time of the accident, the port entry speed was 3 knots faster than that in other cases near the \"To\" islet, where a large-angle course alteration was inevitable. Usually, the course alteration to starboard begins after passing by the \"To\" islet and most large ships decelerate to approximately 3 knots until they enter the sea in front of Pier No. 3, where auxiliary means such as tugboats are ready for use. The pilot chose to increase the ship speed to accelerate the turn, expecting the rudder effect to occur early, and the rotational angular velocity to increase with speed during the diagonal turn. When the MV Milano Bridge started to alter its course to starboard at a high speed of 9.5 knots, its ability to maneuver, such as propulsion and turning performance, was significantly reduced owing to the exposure of its propeller. The increase in the turning angular velocity at the beginning of the course alteration was delayed and the advancement of the ship by the rudder force was extended, resulting in an increased turning diameter. Particularly, the remaining distance from Pier No. 3 to the expected berth is approximately 0.45 miles when the large angular course alteration of approximately 90\({}^{\circ}\) terminates. In a normal berthing situation, ships should be sufficiently decelerated before deploying tugboats and bow thrusters. However, deceleration of the MV Milano Bridge was not sufficiently achieved for safe berthing. To avoid the risk of collision with vessel berthing at the port, acceleration was reattempted to increase the ship speed for the starboard turn. Consequently, the use of standby means for maneuvering, such as tugboats or bow thrusters, is difficult when the ship accelerates to avoid collision. Furthermore, emergency measures, such as emergency anchoring, cannot be used. Numerous attempts have been made to increase the ship speed and turn to starboard when the MV Milano Bridge approaches Pier 3, thereby increasing the risk of collisions with berthing vessels. A master should appraise all the information related to a planned voyage or route, establish a detailed passage plan, and execute the established passage plan while monitoring all such processes. The passage plan should include the entire navigation process from one berth to another, including the pilotage area where the pilots board [31]. In addition, when a vessel enters and departs from a port with the assistance of a pilot in the pilotage area, the master and pilot should communicate effectively and exchange information to ensure the safe movement of the vessel in accordance with the passage plan formulated using mutual information on the condition of the vessel, its maneuverability, and pilotage plan [32]. Despite being aware of the exposed propeller caused by the low draft of the MV Milano Bridge since its departure from the repair shipyard in Zhejiang, China, the ship master did not establish an appropriate passage plan to safely enter the Port of Busan. Pilot \"A\" boarded the ship and provided a checklist for exchanging pilot information, but the passage plan information for berthing at the Busan New Port or the condition and maneuverability of the ship was not exchanged. Furthermore, pilot \"A\" was aware of the exposed propeller caused by the low draft before piloting the vessel and was concerned about the decrease in maneuverability brought on by the exposed propeller. Thereafter, the master did not actively intervene or provide adequate guidance. Moreover, pilot \"A\" neither established any communication nor sought any advice from the master.