IMSBC Code amendments: What will change for bauxite

As the Amendment 05-19 of the International Maritime Solid Bulk Cargoes (IMSBC) Code is expected to come into force on 1 January 2021, BIMCO informs shipping industry what to expect regarding the changes made to “Bauxite” cargoes.

The International Maritime Solid Bulk Cargoes (IMSBC) Code is subject to updates every two years to reflect the changes in the nature and variety of solid bulk cargoes presented for shipment. In June 2019, IMO’s Maritime Safety Committee adopted Resolution MSC.462 (101) specifying forthcoming amendments (05-19) to the IMSBC Code.

In this article, BIMCO’s focus is on bauxite cargoes and the new criteria distinguishing a bauxite cargo that may liquefy (Group A) from one that will not (Group C).

The work of the Global Bauxite Working Group culminated into the revision of the Group C bauxite schedule and a new Group A bauxite fines schedule, together with a new testing procedure developed just for bauxite cargoes.

See also: Bulk Jupiter sinking: A stark reminder of bauxite cargo risks

-PSD criteria and Group A and C bauxite cargoes

A bauxite cargo will be classified as Group A if it has the following PSD formula:

1. more than 30% of fine particles less than 1 mm (D30 < 1 mm); and
2. more than 40% of particles less than 2.5 mm (D40 < 2.5 mm).

The Group C bauxite cargo schedule has been revised to include the above PSD criteria.

A bauxite cargo can only be classified as Group C under any of the 4 scenarios:

-It has 30% or less of fine particles less than 1 mm (D30 ≥ 1 mm);

-It has 40% or less of particles less than 2.5 mm (D40 ≥ 2.5 mm);

-It has both of the above;

-freely draining cargo.

-Freely draining cargo – PSD irrelevant 

As BIMCO clarifies, the PSD is irrelevant if the shipper is able to provide the master with a certificate, in accordance with the result of the test approved by the competent authority of the port of loading, stating that the moisture of the cargo freely drains from the cargo so that the degree of saturation is not liable to reach 70% (the certificate). When such a certificate is produced, the bauxite cargo can be classified as a Group C bauxite cargo.

-When a Group A bauxite can become a Group C bauxite cargo

Even if a Group A cargo meets the PSD criteria as set out in the Group A bauxite schedule, it can still be classified as a Group C if the shipper is able to provide the master with the certificate as mentioned above.

-New testing Procedure for Bauxite

A new testing procedure developed just for bauxite cargoes can be found in Appendix 2 (Laboratory test procedures, associated apparatus and standards) of the new Amendment 05-19. It is called the modified Proctor/Fageberg test procedure for bauxite.

This new procedure works as follows:

• The transportable moisture limit (TML) of a cargo is taken as equal to the critical moisture content at 80% degree of saturation where the optimum moisture content (OMC) of the bauxite tested occurs at saturation levels greater than or equal to 90%.
• The TML of a cargo is taken as equal to the critical moisture content at 70% degree of saturation where the OMC of the bauxite occurs at saturation levels less than 90%.
• Where moisture freely drains from the sample such that the test sample compaction curve cannot extend to or beyond 70% saturation, the test is taken to indicate a cargo where water passes easily through the spaces between particles. Therefore, the cargo is not liable to liquefy.

Even though this is a new procedure, section 8 of the IMSBC Code stipulates that it is ultimately the competent authority in the country of origin of the cargo that determines the procedure for testing of moisture content and TML of a cargo. Only in the absence of such test procedures, the Appendix 2 test procedures as appropriate for the cargo in question are recommended.