IMO Resolution MSC.552(108) Explained

IMO Resolution MSC.552(108): Updates to the Grain Code

Introduction

The maritime industry continues to evolve with stricter safety and operational standards. One of the most significant recent updates is IMO Resolution MSC.552(108), which introduces amendments to the International Code for the Safe Carriage of Grain in Bulk (Grain Code). These changes aim to improve safety, operational flexibility, and clarity in grain loading practices for bulk carriers worldwide.

Adopted in May 2024, the amendments will enter into force on 1 January 2026 and apply to ships carrying grain cargo under SOLAS regulations.

Background: Why the New Standards Were Introduced

Traditionally, the Grain Code recognized three loading conditions:

• Filled compartments (trimmed)
• Filled compartments (untrimmed)
• Partly filled compartments

However, real-world operations often involve intermediate loading scenarios that were not clearly addressed by existing rules, creating uncertainty in stability calculations and compliance.

The new resolution addresses this gap by formally introducing an additional loading condition, improving regulatory clarity.

Key Change: New Grain Loading Condition

The most important update under MSC.552(108) is the introduction of a new optional loading condition:

“Specially Suitable Compartment, Partly Filled with Ends Untrimmed”

This condition applies when:

• The compartment is not filled to maximum capacity
• Grain is loaded up to or above the bottom edge of hatch end beams
• The ends outside the hatch opening remain untrimmed

Previously, this loading scenario was not formally recognized despite being common in practice.

Technical Implications for Stability

• Heeling moment calculations must include the new loading condition
• Assumptions regarding grain shift and surface slope are updated
• Stability software and onboard systems require revision

The amendments also provide updated guidance for calculating volumetric heeling moments in untrimmed grain surfaces.

Operational Benefits

1. Improved Safety

Formal recognition of real loading conditions reduces the risk of incorrect stability assumptions.

2. Greater Operational Flexibility

Operators can optimize cargo loading without unnecessary trimming constraints.

3. Reduced Port Time

Less manual trimming leads to faster cargo operations and reduced costs.

4. Regulatory Clarity

Clear guidance ensures consistent compliance across the industry.

Compliance Requirements

To comply with MSC.552(108), shipowners and operators must:

• Update Grain Loading Manuals to reflect the new condition
• Revise stability calculations and documentation
• Upgrade onboard loading software and systems
• Obtain approval from Flag Administration or Recognized Organizations

Non-compliance may result in operational restrictions and SOLAS-related deficiencies.