Operational Guide · Registers & Logbooks

# Heavy Lift Cargo and Project Cargo

Project cargo and heavy lift cargo do not fall within the CSS Code's standard tables: Annex 13 provides the calculation methodology for bespoke securing arrangements, and recent amendment proposals aim to clarify the most ambiguous criteria.

heavy lift project cargo CSS Code Annex 13 special cargoes

## Operational Explanation

Project cargo and exceptionally heavy or out-of-gauge cargo (heavy lift) do not fall within the CSS Code's standardised securing tables, which are designed for containers, vehicles and other conventional cargo units. For these non-standardised cargoes, Annex 13 of the CSS Code provides the calculation methodology for assessing the effectiveness of the securing arrangement on a case-by-case basis.

The calculation is based on multiplying the mass of each individual cargo item by the design accelerations tabulated in Annex 13, verifying the balance between sliding and tipping while taking account of friction and rotational inertia moments.

## Regulatory Reference

The CSS Code (Cargo Stowage and Securing), Annex 13, governs the calculation methodology for securing non-standardised cargoes. Recent amendment proposals (discussed in the sector in 2024-2025) aim to clarify eight ambiguous areas: weather-dependent load assumptions, speed reduction in head seas, the ship's survival criteria in the event of major cargo shift, the additional tipping moment due to rotational inertia, the balance between longitudinal sliding and tipping, the interpretation of "on deck high", the wind moment in the tipping balance, and the consistency of securing arrangements.

## Scope of Application

Ships carrying project cargo or heavy lift cargo (industrial machinery, wind turbine components, plant modules, prefabricated structures) that exceed the dimensions or weight covered by the CSS Code's standard tables.

## Procedure / How to Complete It

1. Identify every non-standardised cargo item that requires a specific calculation under Annex 13, instead of the standard CSS tables.
2. Calculate the forces acting on each item by multiplying the mass by the tabulated design accelerations, taking account of the weather conditions expected on the route.
3. Verify the balance between sliding and tipping for every proposed securing configuration, including the effect of wind on the tipping balance for cargo exposed on deck.
4. Arrange a sea fastening survey (verification of the securing arrangement) by a competent surveyor before departure for the most critical cargoes.
5. Document the calculation methodology used and retain it on board together with the loading plan for the entire duration of the voyage.

## Practical Example

Example: a wind turbine component (a turbine blade) carried on deck is calculated under Annex 13, taking into account the design accelerations for the planned route, the wind moment on the exposed item, and the balance between longitudinal sliding and tipping, with a sea fastening survey conducted by an independent surveyor before departure.

## Real Cases

Industry analyses of the practical limits of the CSS Code in the transport of project cargo (for example, the case study on the grillage design for the sea transport of gas slug catchers) have highlighted how a literal application of the standard tables is not sufficient for atypical cargo configurations, requiring dedicated engineering analysis under the Annex 13 methodology rather than a rough extrapolation from the conventional tables.

## Common Mistakes Mistake Library

Mistake | Consequence | How to avoid it
--- | --- | ---
Applying the standard CSS securing tables to a non-standardised cargo by rough analogy | Underestimation of the real forces acting on the cargo and insufficient securing | Always apply the Annex 13 calculation methodology for non-standardised cargoes, without shortcuts by analogy
Failure to consider the wind moment in the tipping balance for cargo exposed on deck | Underestimation of the tipping risk in strong wind conditions | Always include the wind moment in the calculation for exposed cargo, not only the accelerations due to the ship's motion
Sea fastening survey omitted for heavy lift cargoes considered 'routine' by the Company | Securing arrangement not verified by an independent third party before departure | Request a sea fastening survey for every significant heavy lift cargo, regardless of how frequently the Company carries it

## PSC Observations

Although the securing of non-standardised cargoes is not typically subject to routine PSC verification, PSCOs may request the calculation documentation under Annex 13 and verify the consistency between the declared securing arrangement and what is actually observed on board.

## Operational Tips

- Never rely on a rough extrapolation from the standard CSS tables for a cargo that exceeds the covered dimensions or weight: always use the Annex 13 methodology.
- Always include the wind moment in the tipping balance for cargo exposed on deck, a factor often underestimated.
- Request an independent sea fastening survey for every significant heavy lift cargo, even when the Company considers it a routine shipment.

## Checklist

- Non-standardised cargo items identified and calculated under Annex 13
- Design accelerations applied consistently with the weather conditions expected on the route
- Sliding/tipping balance verified, including the wind moment for exposed cargo
- Sea fastening survey conducted by a competent surveyor before departure
- Calculation methodology documentation retained on board with the loading plan

## FAQ

What is Annex 13 of the CSS Code?
The section of the CSS Code that provides the calculation methodology for assessing the effectiveness of securing arrangements for non-standardised cargoes, which do not fall within the conventional tables for containers, vehicles and other standard units.
Why is the wind moment important in the calculation for heavy lift cargo?
Because project cargo is often bulky and exposed on deck, making the moment generated by wind a significant contribution to the tipping balance, which must be added to the effects of the ship's motion.
What do the recent amendments to Annex 13 propose?
Eight clarifications on ambiguous areas of the current methodology, including weather-dependent load assumptions, speed reduction in head seas, survival criteria in the event of cargo shift, and the consistency of securing arrangements.
🎬 Additional photos, videos and interactive diagrams for this topic will be available in a future version of the platform.

## Related Topics

Cargo Securing Manual and Cargo Lashing Ro-Ro Cargo Securing

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