The National Transportation Safety Board (NTSB) has released an investigation report on an incident where, on April 21, 2023, a bulk carrier grounded twice in Port Dolomite, Michigan.
The bulk carrier grounded while loading cargo. About 1445, after getting underway, the crew discovered flooding and damage to the hull of the vessel. No pollution or injuries were reported. Damage to the vessel was $776,125.
Analysis
While the vessel was tied up at the Cedarville dock, primary loading was completed, and trimming (final loading to the target drafts) began under the supervision of the oncoming first mate. During the trimming operation, the vessel grounded twice. During attempts to free the vessel, the hull was damaged, causing two port ballast tanks to flood. According to the vessel’s operating company, damage o the hull was incurred from a shoal along the southern half of the dock.
The off-going first mate created the load plan based on past load plans, using he ship’s loading and stability software and the operating company’s draft guidance spreadsheet, which established the depth at the Cedarville dock as 25 feet at low water datum (the master approved the load plan). Based on the established depth in the draft guidance and the application of the preferred reference gage (Mackinaw City), which was 20 inches above low water datum during the time the vessel was to be loaded, the offgoing first mate calculated the vessel could be loaded to no greater than 26 feet 8 inches draft at the Cedarville dock. The off-going first mate believed that the operating company’s draft guidance included an 18-inch ”safety factor” that would provide additional underkeel clearance between the vessel and the shoal, and he therefore determined the calculated draft should have been sufficient to load without grounding. However, the operating company’s draft guidance did not reference a safety factor.
Additionally, the vessel grounded twice as the vessel’s draft approached the limiting draft, which indicates that there was no safety factor built into the guidance. Further, the operating company’s SMS did not provide guidance related to minimum underkeel clearances to be maintained during loading operations, and there was no explanation as to how the draft guidance (last updated for Cedarville in 2015) was calculated. Therefore, the operating company did not provide adequate guidance to create a load plan with sufficient underkeel clearance.
The draft guidance spreadsheet contained a note that a shoal (at 24 feet 9 inches) existed along the south half of the dock and that the bow should be held off at least 12 feet during trim loading; however, the load plan did not include this instruction. The mates on watch referenced the load plan to load cargo, and the oncoming first mate (who relieved the off-going first mate during loading) used the load plan to conduct trimming operations. At the time of the grounding, the depth of the shoal referenced in the operating company’s draft guidance would have been bout 26 feet 5 inches (based on the Mackinaw City gage and dock bathymetry survey completed 16 days after the grounding)—3 inches less than the planned limiting draft. While trimming the vessel, the oncoming first mate intended to load to a forward draft of 26 feet 10 inches (noting that when load trimming aft, this would bring the forward draft to the target draft of 26 feet 8 inches).
However, when the forward draft reached 26 feet 7 or 8 inches, the draft stopped increasing while product was still being added to the hatch, indicating the vessel had touched bottom. Although the forward draft that it stopped at was still within the limits of the load plan, it exceeded the depth of the shoal by 2 to 3 inches. Therefore, the load plan for the John J Boland was inadequate because it did not take into account the shoaling at the Cedarville Dock.
Conclusions
Probable Cause
The National Transportation Safety Board determines that the probable cause of the grounding of, and resulting hull damage to, the self-unloading bulk carrier John J Boland was inadequate operating company guidance to create a load plan with sufficient underkeel clearance and the master’s decision to use the main engine to free the vessel after it was aground. Contributing was the master and first mate becoming desensitized to the risk of vessel damage associated with grounding during loading operations.
Lessons Learned
Developing Load Plans
To safely carry out cargo loading operations, it is important for vessel crews to understand the characteristics of the facilities where they will be operating, including the depth of water at the dock and potential hazards, such as nearby shoaling, that could impact the loading process. Effective company policies and guidance for cargo loading include pertinent information, such as clear expectations for required underkeel clearance, to assist personnel developing load plans with identifying and mitigating hazards. Additionally, crewmembers can consult nautical charts and surveys, tidal and/or water gage information, ship-specific stability and loading information, and information from the dock/facility when developing a load plan.
Did you subscribe to our daily Newsletter?
It’s Free! Click here to Subscribe!
Source: National Transportation Safety Board
