JTSB investigation: Collision in traffic route linked to miscommunication

The incident

Container ship APL PUSAN, with a master and 22 other crew members aboard, was proceeding to Section 2 in Keihin Port under the pilotage of a pilot, while cargo ship SHOUTOKUMARU, with a master, an officer, and 2 other crew members aboard, was proceeding for anchorage Y1 at Yokohama Section in Keihin Port.

While both vessels were proceeding northwest bound in Uraga Suido Traffic Route on October 15, 2019, around 04:22, they collided on the Traffic Route, and APL PUSAN subsequently collided also with a light buoy.

APL PUSAN suffered a dent on its port bow, SHOUTOKUMARU’s bulwark bow suffered damages, etc. while the light buoy’s guard frame suffered a dent, but there were no casualties on either vessel.

Probable causes

When the ships were proceeding northwestward in the vicinity of the north exit of the Uraga Suido Traffic Route at night, the pilot of APL PUSAN, thought he could safely overtake SHOUTOKUMARU (even if he did not inform SHOUTOKUMARU of his intention to overtake on the starboard side through VHF), so he continued to navigate in a manner to overtake SHOUTOKUMARU, according to JTSB.

When the officer of SHOUTOKUMARU received information from Japan Coast Guard TOKYO WAN Vessel Traffic Service Center (Tokyo MARTIS) that the ship was obliged to navigate the Nakanose Traffic Route, he turned to starboard toward the Nakanose Traffic Route without knowing the existence of APL PUSAN on the starboard quarter, which led to the collision.

It is probable that the pilot of APL PUSAN thought that he could overtake SHOUTOKUMARU safely without informing by VHF because SHOUTOKUMARU, after proceeding toward the center of the Uraga Suido Traffic Route, did not turn to starboard toward Nakanose Traffic Route even after passing through the southwest of Daini Kaiho, and continued proceeding northwestward toward the north exit of the Uraga Suido Traffic Route.

It is probable that the officer of SHOUTOKUMARU turned to starboard toward Nakanose Traffic Route without knowing the existence of APL PUSAN on the starboard quarter because he thought that the speed difference of vessels navigating the Uraga Suido Traffic Route with speed limitation was small and that SHOUTOKUMARU would not be overtaken.

When he received information from the Tokyo MARTIS to the effect that the ship was obliged to navigate the Nakanose Traffic Route, he thought it necessary to enter the Nakanose Traffic Route immediately because he thought it was an instruction, the report notes.

Recommendations

Following investigation, JTSB noted it is necessary to implement the following measures to prevent the recurrence of similar accidents:

1. When masters or pilots intend to overtake another vessel in the same Traffic Route, they should identify the other vessel’s movements, confirm the other vessel’s maneuvering intentions at an early stage, and if they could not clarify the movements of the other vessel, or could not maintain a safe distance, they should not overtake the other vessel.
2. When pilots, bridge watch-keeping personnel, etc., are faced with a situation where there is a risk of another vessel approaching, they should keep in mind the possibility that the other vessel might not be aware of their own vessel, so they must inform about their presence and their maneuvering intention on the VHF or with a whistle, etc. at an early stage.
3. When navigating, bridge watchkeeping personnel should regularly conduct an adequate lookout of not only the vessel’s bow side but also her stern side.
4. Owners and managers, etc., should actively support the master to establish an environment in which the master can securely go up to the bridge and command the vessel in narrow channel navigation, and the master should go up to the bridge and command the vessel in narrow channel navigation.
5. Master, bridge watch-keeping personnel, etc., should appropriately share information necessary for navigation such as navigation plans, etc., by providing navigation plans, etc., on the bridge, in which scheduled anchorages, ports of destination, etc., are recorded.
6. Bridge watchkeeping personnel, etc., should make the effort to collect the necessary information about the navigational plan before taking over the duty, and if they found out that they do not have the information while they are on duty, they clarify with the master after checking the safety of the vicinity, and when reporting information to Tokyo MARTIS, such as the notification of entry, should provide accurate information.
7. Bridge watchkeeping personnel, etc., should be familiar with the laws and regulations such as the Maritime Traffic Safety Act that stipulate the necessity for vessels 50 m or more to navigate between Line b and the mouth of Tokyo Bay to navigate Uraga Suido Traffic Route and Nakanose Traffic Route.
8. Bridge watchkeeping personnel, etc., when conducting VHF communications and intercepting communications related to their own vessel, should listen carefully until the communication is completed.
9. Masters and bridge watchkeeping personnel, etc., should recognize that the provision of information to vessels by the Tokyo MARTIS, etc. is intended to convey facts and situations observed for the purpose of assisting safe navigation, and not to give instructions on maneuvering, and should endeavor to ensure safe navigation by effectively utilizing this information.

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