Inadequate Clearance Caused Grounding of Bulk Carrier: NTSB

The National Transportation Safety Board (NTSB) revealed that inadequate guidance from the operating company on underkeel clearance was the cause of a bulk carrier grounding incident in Lake Huron in April 2023. The 667-foot-long self-unloading bulk carrier John J Boland, owned by American Steamship Company and operated by Grand River Navigation, grounded twice while completing final loading in Port Dolomite, Michigan. The crew discovered flooding and hull damage after departing, resulting in over $775,000 in damages.

The crew had planned to load 30,000 tons of aggregate stone, with the first mate creating a load plan based on past plans, loading software, and the operating company’s draft guidance. However, the operating company’s guidance lacked a safety factor for underkeel clearance, leading to insufficient clearance between the vessel and the shoal. The NTSB determined that the company’s guidance was inadequate for creating a load plan with adequate underkeel clearance.

In addition to the inadequate guidance, the NTSB found that the master’s decision to use the main engine to free the vessel after the second grounding caused further hull damage. The crew initially used mooring lines to move the vessel ahead after the first grounding but continued loading, causing the vessel to ground harder. The master then used the main engine to free the vessel, resulting in scraping along the bottom as it backed off the dock.

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