ATSB: Grounding of bulk carrier World Diana at Port of Bunbury

The ship had to be manoeuvred into the inner harbour turning basin and turned to port to exit the harbour entrance. The turn did not go as planned and the ship’s bow grounded on a shallow bank to the east of the entrance. The ship was then manoeuvred clear of the bank and departed the port. Subsequent inspections and surveys indicated minor hull damage and the ship was cleared to continue trading.

Safety analysis

As World Diana was starboard side alongside berth no 3, its departure required the ship to be manoeuvred into the inner harbour turning basin and turned to port to exit the harbour entrance. During the master pilot information exchange on the morning of 22 April, the pilot provided a diagram of the departure plan, indicating the turn and the locations of the 2 assisting tugs. No specific information such as ship’s speed, rate of turn, clearing distances or associated limits was
shown on the plan and no evidence was provided that these items were discussed. At approximately 0632, shortly after the ship had left the berth, the pilot began turning the ship to port earlier than planned using both tugs, the ship’s main engine and steering. According to the pilot, the turn was started early to keep clear of the submerged rock near berth no 5. However, the rock was located off the farthest end of berth no 5, over a ship length ahead of the ship’s bow.

Significantly, starting the turn early also reduced the sea room available to turn. By 0636, use of the ship’s main engine had resulted in developing slight headway (0.3 kt). Four minutes later, the speed had increased to 1.5 kt and the ship was turning rapidly towards the shallow waters to the east of harbour entrance. In response to the developing situation, the pilot reversed the main engine (half astern) and instructed the aft tug to push at full power on the port
side to turn the ship in the limited sea room. After a couple of minutes, the pilot realised that the turn could not be made in time to avoid the shoals and attempted to arrest the turn followed by an attempt to arrest the headway by using the tugs. These measures were unsuccessful, and shortly after 0643, the ship’s bow grounded.

The pilot’s portable pilot unit (PPU) was accurately displaying the ship’s position and progress in real time and indicating useful data, such as speed and rate of turn, to safely complete the turn. At 0641, the PPU predicted that the ship would ground. However, neither the pilot nor others on the bridge were using the PPU or paying attention to its display. Additionally, the forward tug’s master identified that the ship was turned early but raised no concern with the pilot until the shallow water was extremely close, a minute before the grounding.

Overall, bridge resource management (BRM) was ineffective, most likely as specific information and limits for the departure plan were only known to the pilot, which made it difficult for the bridge team to raise concerns with the pilot. Nevertheless, had the ship’s master, being a ship-handler familiar with the ship’s manoeuvring characteristics, been actively monitoring the pilotage, the early turn and ship’s increasing headway, should have become evident on the ship’s monitors as well as the PPU. The PPU was displaying information to help avoid the grounding but this was not detected. Neither the bridge team nor the forward tug master raised any concerns with the pilot about the ship-handling errors until the grounding was imminent. In addition, when the pilot became aware of the imminent grounding, they did not make full use of the ship’s main engine, which remained at half astern (not full or emergency full astern) nor were the anchors dropped.

The investigation identified that no procedures had been developed that included arrival and departure plans for larger ships that were required to berth starboard side alongside berth no 3. This reduced the information available to pilots for these ship movements and to share with bridge teams and tug masters to ensure a common understanding of how manoeuvring would be conducted.

Findings

ATSB investigation report findings focus on safety factors (that is, events and conditions that increase risk). Safety factors include ‘contributing factors’ and ‘other factors that increased risk’ (that is, factors that did not meet the definition of a contributing factor for this occurrence but were still considered important to include in the report for the purpose of increasing awareness and enhancing safety). In addition ‘other findings’ may be included to provide important
information about topics other than safety factors. These findings should not be read as apportioning blame or liability to any particular organisation or individual.

From the evidence available, the following findings are made with respect to the grounding of World Diana when departing berth no 3 in Bunbury, Western Australia on 22 April 2023.

Other factor that increased risk

• The Port of Bunbury had not developed adequate procedures that included arrival and departure plans for larger ships that were berthed starboard side alongside berth no 3.

Safety actions

Whether or not the ATSB identifies safety issues in the course of an investigation, relevant organisations may proactively initiate safety action in order to reduce their safety risk. The ATSB has been advised of the following proactive safety action in response to this occurrence.

Safety action by Southern Port Authority

The Southern Port Authority has updated its Marine Pilotage Standards and Procedures Manual to include:

• standard procedures for departing all berths, including berth no 3 after berthing starboard side alongside.
• a maximum rate of turn for turning ships in the harbour of 20° per minute.

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