IMO cargo-securing guidance moves toward harmonised lashing-software standards

The IMO Sub-Committee on Carriage of Cargoes and Containers (CCC 12), which met in London from 14 to 18 September 2026, completed a revision of the Guidelines for the Preparation of the Cargo Securing Manual (MSC.1/Circ.1353/Rev.2). The revision includes a harmonised performance standard for lashing software, intended to permit such software to supplement—not replace—the ship’s Cargo Securing Manual (CSM).

The outcome still requires approval by the IMO Maritime Safety Committee (MSC 113), according to post-session summaries from Bureau Veritas and ABS. Accordingly, this is not yet a new mandatory onboard requirement. It is, however, a significant step toward a more consistent technical basis for software used in planning and checking container lashing arrangements.

The distinction between a supplement and a replacement matters. The CSM remains the approved ship-specific foundation for cargo stowage and securing. Software outputs will need to be understood within the approved operating limits, the actual securing arrangement, container weights and positions, equipment condition, weather-routing assumptions, and the vessel’s loading condition. A favourable calculation cannot cure inaccurate input data, unserviceable twistlocks or lashings, departures from the approved plan, or inadequate onboard supervision.

For cargo claims and loss prevention, the development strengthens the case for preserving a traceable planning record. Following a container loss, cargo shift, damage allegation or port-state-control deficiency, parties may need to establish not only what was loaded, but also which lashing calculation was run; the software version and approved parameters used; inputted verified gross masses and stack weights; any manual overrides; the final stowage plan; inspection and re-tightening records; weather information; and decisions taken by the master during heavy weather.

**Why this matters:** Operators should treat this as a governance and evidence-readiness issue now, rather than waiting for formal MSC approval. A practical gap assessment should compare vessel-specific CSM limits with current lashing-software workflows, identify who may create, alter and approve calculations, and ensure records can be retained and retrieved after discharge. Masters and shoreside teams should also rehearse how a calculation is independently checked against the physical cargo and securing gear actually on board.

The wider safety rationale is clear: IMO identifies improper stowage, securing and packing as causes of serious casualties, cargo damage and injuries. Harmonised software standards can improve consistency, but their loss-prevention value will depend on disciplined data control, competent use, physical verification and prompt preservation of evidence when an incident occurs.