A single-deck cargo vessel designed to carry unpackaged dry bulk cargoes such as grain, coal, iron ore, or fertiliser.
In practice
Fatigue cracking at hatch corners, corrosion of the inner bottom, and flooding through hatch covers in heavy weather have caused catastrophic structural failures and total losses in the bulk carrier fleet. IACS Unified Requirements S11 and S18 prescribe minimum longitudinal strength and corrosion allowances, and common structural rules jointly adopted by IACS classification societies set modern design standards. Officers and engineers inspect holds for corrosion, crack formation, and hatch cover seal condition before every voyage and record findings in the ship's structural maintenance records as required by flag state and class.
Regulatory detail & full definition
Bulk carriers are single-deck vessels with large box-shaped cargo holds, sloping hopper side tanks, and wing ballast tanks, designed for the efficient loading and discharge of unpackaged dry commodities including coal, iron ore, grain, fertiliser, bauxite, and phosphate rock. They range from small handy-size vessels of around 25,000 DWT through supramax and kamsarmax sizes to large capesize bulk carriers exceeding 180,000 DWT, which are too wide for the Panama Canal and must route via Cape Horn or the Cape of Good Hope. The IMO Bulk Carrier Code (BC Code) and SOLAS XII address the specific safety risks inherent in their structural arrangement and the properties of cargoes that can liquefy, generate toxic gases, or become spontaneously combustible.
Fatigue cracking at hatch corners, corrosion of the inner bottom, and flooding through hatch covers in heavy weather have caused catastrophic structural failures and total losses in the bulk carrier fleet. IACS Unified Requirements S11 and S18 prescribe minimum longitudinal strength and corrosion allowances, and common structural rules jointly adopted by IACS classification societies set modern design standards. Officers and engineers inspect holds for corrosion, crack formation, and hatch cover seal condition before every voyage and record findings in the ship's structural maintenance records as required by flag state and class.