The maximum load a cargo-securing device may sustain — used in cargo-securing calculations per the CSS Code.
Regulatory detail & full definition
Maximum Securing Load is the maximum load a cargo-securing device is allowed to sustain in service, typically 50% of the breaking load for chains + wire ropes, 33% for synthetic ropes + web lashings. Used in the cargo-securing calculation per the IMO Code of Safe Practice for Cargo Stowage + Securing (CSS Code). Chief Officer calculates required MSL for each cargo unit against expected sea-motion forces.