Carriage of Bauxite

Following work undertaken by the industry Global Bauxite Working Group (GBWG), in conjunction with competent Authorities, and consideration of the circumstances surrounding the loss of the “Bulk Jupiter” carried out by the IMO sub-committee on Carriage of Cargoes and Containers (CCC), bauxite was identified as posing a risk of liquefaction if carried with excessive moisture. As such it was determined that some bauxite cargoes should be treated as Group A.

As a result of these findings the CCC produced a circular on Carriage of Bauxite Which May Liquefy to raise awareness of the potential hazards posed by moisture in bauxite cargoes. The latest revision of the circular CCC.1/Circ.2/Rev.1 can be read here.

As some bauxite cargoes should be categorised as Group A the CCC sub-committee has produced:

• a draft test procedure for determining the Transportable Moisture Limit (TML) of bauxite
• a draft schedule for bauxite Group A cargoes having the Bulk Cargo Shipping Name “BAUXITE FINES”
• draft amendments to the current schedule for Bauxite Group C

Bauxite categorised as a Group A cargo is not currently listed in the International Maritime Solid Bulk Cargoes Code (IMSBC Code). Therefore any cargo which does not fall within the current IMSBC Code schedule for Group C bauxite must be carried in accordance with section 1.3 of the IMSBC Code – Cargoes Not Listed in This Code until such time as the draft amendments enter into force. The draft amendments are expected to enter into force on 1 January 2021.

The CCC sub-committee has invited Member states to apply the draft testing procedure and individual schedules for bauxite Group A and C when determining the carriage requirements for cargoes to be carried under section 1.3 of the Code.

As a result of the research carried out into the effect of moisture content on bauxite cargoes, the GBWG noted that atypical motions (wobbling) observed on vessels may be an indicator of cargo instability. This cargo instability can be as a result of a free surface slurry forming over the top of the cargo which can result in a loss of a vessel’s stability.

Testing Procedure

The draft testing procedure for determining the TML of bauxite cargoes is based on a modified Proctor/Fagerberg test, similar to that used for Iron Ore Fines. This testing method is only suitable for bauxite cargoes containing more than 30% of particles of less than 1mm diameter and more than 40% of particles of less than 2.5mm diameter.

The procedure provides detailed instructions covering:

• the equipment required for testing
• the number and quantity of samples required
• the method of preparing samples
• and details how samples should be compacted and the moisture content determined

IMSBC Code Schedules

The draft schedules for inclusion into the IMSBC Code include a new schedule for Bauxite Fines (for Group A cargoes) and an amended Bauxite schedule (for Group C cargoes) based on the material particle size.

Irrespective of the particle size restrictions, a fines cargo can be carried under the bauxite Group C schedule provided that: “…the shipper provides the master with a certificate, in accordance with the result of the test approved by the competent authority of 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%”

While these draft schedules will not enter force until 1 January 2021, Members should be aware that the requirements contained within the CCC circular regarding the testing and carriage of bauxite may be used by some shippers prior to this date.

North members loading bauxite fines should not hesitate to contact loss.prevention@nepia.com should they require further advice.