Coal Cargo Are Liable to Liquefy and Have a Chemical Hazard



  • Coal cargoes liquefaction heavily affects shippers and hence there’s a proper code for this.
  • According to the IMSBC Code shippers should declare the Group A or Group B cargo.
  • Accordingly, a TML and moisture certificate should be shown to the port authorities.
  • In places where lab testing is available TML testing will be done, for others documents are important

Coal cargoes liquefaction is a major issue in shipping and IMSBC has set out to modify their codes to make it more stringent. The Gard reports on the new IMSBC Code and their implications on shipping. Here’s an insight on that.

Criteria of Coal Cargoes

The International Maritime Solid Bulk Cargoes (IMSBC) Code describes coal as a natural, solid, combustible material consisting of amorphous carbon and hydrocarbons. Although coal is best known for its flammable and self-heating properties, certain coal cargoes may also be liable to liquefaction. The upcoming amendments to the IMBC Code concern the criteria under which coal cargoes are considered Group A, i.e. liable to liquefy, in addition to the Group B chemical hazards which apply to all coal cargoes, such as potential self-heating or methane emissions. Coal cargoes may, therefore, require the same TML and moisture certification as other Group A cargoes, such as concentrates, nickel ore, and iron ore fines.

Why the sudden change in classification?

The classification of coal has changed so that all coal is to be treated as both Group A and B unless otherwise tested. This means that all coal cargoes are to be considered as both liable to liquefy and have a chemical hazard – unless they meet the new criteria as detailed in the IMSBC Code.

Alternatives for Shippers

There are two alternative ways in which shippers may demonstrate that a coal cargo is not Group A:

Coal cargoes are not subject to Group A requirements if they have a particle size distribution such that: Not more than 10% is less than 1 mm AND not more than 50% is less than 10 mm.

It is important to note the use of “AND” in the above, which means that cargoes exceeding either of these limits will not be exempt from Group A requirements. This differs from (and covers a wider range of cargoes than) the equivalent size criteria for iron ore fines.

Deciding on the Category

Alternatively, the competent authority of the country of loading can specify laboratory criteria to assess whether or not a coal cargo possesses Group A properties. Such criteria would most likely be based on the outcome of the test methods for Group A cargoes in Appendix 2 of the IMSBC Code.

For cargoes that are Group A (and B), shippers can now test the cargo for its Transportable Moisture Limit (TML) using a newly developed test method for coal. The coal TML method is a modified Proctor/Fagerberg (PF) procedure which is significantly different from the existing PF methods (e.g., those modified for iron ore fines) in that there is a new procedure on how to deal with lumps over 50 mm in the sample, as well as different Proctor hammer and a different cylinder than other PF methods.

Drying ovens should have forced circulation or use an inert gas, unlike ovens used for the other TML test methods. It is anticipated that suitable TML test facilities will not be widely available in commercial coal laboratories, at least in the short term.

When there are no lab facilities

Some coal loading locations, such as in Indonesia, have fairly remote access and the shippers may not have specialist lab facilities at the loading ports. All TML testing and certification should be completed prior to the start of loading. However, it may not be possible to achieve either the sizing or TML testing at the load port should there be any dispute.

As with all solid bulk cargoes, the IMSBC Code requires all proper documentation to be provided to the master prior to any loading commencing, and this will now include the information on the coal classification.

The Necessity of Categorization

The rationale for shippers declaring a cargo as either Group B only, or Group A and B, will need to be clearly stated. The sizing criteria could be included on the cargo declaration, or it could be issued as a separate certificate. If there are no sizing criteria provided, the coal should be assumed to be both Group A and B, and hence require a TML and moisture certification prior to loading. As with all Group A cargoes, if the coal has a TML certificate then it must be protected from rain in shore stockpiles and barges during loading, and the moisture content will need to be re-checked after any rain at the load port.

The above does not have any bearing on the other hazards of coal, such as self-heating or methane emissions, and these hazards will still need to be monitored and controlled for each cargo.

Did you subscribe for our daily newsletter?

It’s Free! Click here to Subscribe!

Source: Gard



This site uses Akismet to reduce spam. Learn how your comment data is processed.