Cargo securing fastens cargo in place to prevent it shifting or breaking loose from ship motion at sea — a genuinely safety-critical process, since improperly secured cargo has caused real vessel losses, particularly on container ships in heavy weather.
The Cargo Securing Manual (CSM)
Every vessel subject to the requirement carries an approved Cargo Securing Manual — a vessel-specific document specifying approved securing arrangements, equipment, and maximum permissible loads for different cargo types and stowage locations aboard that particular ship. Securing “by eye” or by habit, rather than by the CSM’s actual specifications, is a real, documented cause of cargo-securing failures.
Common Securing Methods by Cargo Type
- Containers — twist locks (connecting containers vertically), lashing rods and turnbuckles (securing to the ship’s structure), bridge fittings (connecting adjacent container stacks)
- Vehicles (Ro-Ro cargo) — wheel chocks and lashing straps/chains to deck securing points
- Break-bulk and project cargo — chains, wire lashings, and dunnage tailored to each specific cargo unit’s shape and weight
Forces Cargo Securing Must Resist
Securing calculations account for the combined forces of ship motion — roll, pitch, heave — which can generate forces well beyond a cargo unit’s static weight, particularly in heavy weather. This is why securing arrangements are calculated against the vessel’s specific motion characteristics, not just a generic safety margin.
Why Lashing Failures Are a Real, Documented Risk
Container losses overboard, and cargo shift incidents affecting vessel stability, have repeatedly traced back to inadequate securing — either equipment failure, incorrect application, or exceeding the CSM’s specified load limits for a given stowage position. This isn’t theoretical: it’s a recurring, investigated cause of real maritime incidents.
Verification Before Departure
Confirming cargo is secured according to the CSM — not just “secured enough” by visual impression — is a genuine pre-departure responsibility, particularly relevant to weather routing decisions once underway, since a vessel expecting to encounter heavy weather may need extra securing precautions beyond routine practice.
Exam Relevance
Cargo Securing Manual requirements, securing methods by cargo type, and the real forces cargo must withstand at sea are core Cargo Work topics in deck officer competency exams.