Do we know enough about cargoes such as bauxite which are prone to liquefaction to be able to carry them safely from loadport to their destination?
The tragic loss of the “BULK JUPITER” and members of her crew questions the industry’s knowledge of cargoes prone to liquefaction. A Group C cargo may look relatively dry and granular when loaded - but the question is: Do we know enough to carry this cargo safely?
Over the years Gard has published a number of updates on the topic of cargo liquefaction. One of the more recent updates covered issues arising from the BULK JUPITER casualty. The vessel sank off the coast of Vung Tau, Vietnam, with the loss of all but one of its 19 crew members, after having loaded Bauxite at Kuantan, Malaysia. Following the sinking the Bahamian Maritime Authority (BMA) published their final investigation report in August this year. The BMA report suggests that, due to the lack of physical evidence as the vessel sank in deep waters, it was not possible to confidently determine a definitive causal event that led to its sinking. However, the report covers some key issues which can provide some indications of what may have led to the incident.
This circular aims to provide Members and clients with some of the key findings of the BMA’s investigation report and touches upon some of the contents of the IMSBC Code itself. A recent IMO circular on the Carriage of bauxite that may liquefy also referred to submissions made to the IMO by the Bahamas in relation to the loss of the BULK JUPITER.
1. The key findings of the BMA report
a) Prior to loading, the cargo was stowed in an open stockpile for days when the port of Kuantan experienced record rainfall.
b) The information provided in the shippers’ declaration was identical for all vessels that loaded the cargo at Kuantan during this time. The moisture content of the cargo was declared to be 10% and the cargo was described as Group C (not liable to liquefy) with particle sizes of 2.5 mm to 500 mm, 70% to 90%.
c) The cargo declaration was six days old at the time of loading, and during these six days the port of Kuantan received 377.6 mm of rain.
d) In the ship’s daily report it is noted that the master had communicated to the owners and charterers that the cargo was very wet. However, the exact moisture content of the cargo was not known as the lab analysis results were released on the 14 January 2015.
e) The independent lab analysis report which was issued on 14 January 2015 declared the moisture content of the samples to be in excess of 20%- twice of what was declared in the shipper’s declaration.
f) Another vessel, the ORCHID ISLAND, loaded an identical cargo at Kuantan and experienced liquefaction in one of its cargo holds. The below photograph, taken from the BMA’s report, shows the condition of the cargo inside the no. 4 cargo hold on the ORCHID ISLAND.
Although it seems that the moisture content of the cargo loaded on board the BULK JUPITER was much higher than declared by the shippers. However, this does not necessarily mean that the cargo is liable to liquefy as an important factor in liquefaction is the particle size distribution and cargoes with larger particle sizes allow moisture to drain freely through the cargo to the bilges. The combination of moisture content and particle size distribution is therefore important in the context of the current categorisation of Bauxite as a Group C cargo in the IMSBC Code. The IMSBC Code is an important part of the decision making process of masters and shipowners to obtain critical knowledge of the bulk cargos to be carried on board. However, detailed knowledge of the IMSBC Code is vital in light of the consequences of the decisions made based on the information.
2. Understanding the contents of the IMSBC Code
The IMSBC Code describes Bauxite as a brownish, yellow claylike earthy mineral with a moisture content between 0 and 10% and with a particle size ranging from 2.5 to 500 mm for 70% to 90% of the cargo. The Group C classification is based on the cargo’s description as stated in the Code’s schedule. If the actual cargo composition does not match the description in the schedule, the cargo’s properties and behavior may not be consistent with those of the Code. It has been reported that Bauxite cargoes shipped from Kuantan is sieved before shipping to remove any large lumps from the shipment. The sieving process involves the use of high pressure water jets to force the cargo into the rotary sieves. This process not only removes the larger particles of the cargo, but also increases the moisture content.
For bulk cargos with a high moisture content, Appendix 3, Art 2 of the Code states:
“Many fine particle cargoes, if possessing a sufficiently high moisture content are liable to flow. Thus any damp or wet cargo containing a proportion of fine particles should be tested for flow characteristics prior to loading.”
The exact definition of “fine particle” is not clear from the Code. However, if cargo parcels are assessed solely based on the particle size, a number of cargoes may fall into the “fine particle” category. Research which lead to the draft new schedule for iron ore fines resulted in that cargo being categorised as Group A, where the particle size distribution is a combination of 10% or more of fine particles less than 1 mm in size, and 50% or more of particles less than 10 mm in size. See P&I Member Circular No. 22/2013: Iron Ore Fines/Iron Ore Cargoes – Early Implementation of recent changes to the IMSBC Code – Australia and Brazil. Furthermore, testing limitations for Group A cargoes suggest that none of the laboratory tests will be effective if the particle size is more than 25 mm. The flow table test, which is the most common form of testing, can only be used for a particle size between 1 and 7 mm. This gives us an indication of what a fine particle cargo could be, but it is not clearly defined.
Gard understands that it is extremely difficult for the ship’s crew to estimate the particle size in a stockpile of 50,000 MT of cargo; therefore, an independent laboratory analysis of the cargo is necessary whenever the ship’s crew is in any doubt about the composition of the cargo or the presence of excess moisture.
Finally, it should be noted that IMO circular CCC. 1/Circ.2 states that the master should stop loading if he is in any doubt that the cargo being loaded is consistent with the shipper’s declaration. He should ask the shipper to verify the cargo properties and, if necessary, seek advice from the competent authorities.
3. Club recommendations
a) Shipowners should bear in mind the limitations of the IMSBC Code when making decisions on the loading of any cargo. The fine particle provision in Appendix 3, Art 2 of the Code is especially important whenever there is doubt as to the moisture content of the cargo.
b) The above photograph taken of the no. 4 cargo hold on the ORCHID ISLAND shows clear signs of splatter on the adjacent bulkheads. If splatter is noted at the time of loading, the master should immediately take all necessary actions to verify the condition of the cargo as the splatter is an indication that the cargo may be prone to liquefaction. We recommend that the master to inform the shipowners and the Club without delay and at the same time cease loading.
c) The Club strongly recommends the appointment of a surveyor if the master suspects that any Bauxite or other cargo declared by the shippers as Group C may be prone to liquefaction, or if the master has any doubt as to the accuracy of moisture content and TML certificates accompanying a Group A declaration. Depending on the findings of the local surveyor, it may be necessary to seek expert advice and to have cargo samples tested at an independent laboratory before the vessel loads any further cargo and/or sails. In the case of the BULK JUPITER the laboratory analysis results were received well after the vessel had been lost. It is worth emphasising that can test results are only an indicator and as the Code itself states in Section 8.4 “even if samples remain dry following a can test, the moisture content of the material may still exceed the Transportable Moisture Limit (TML)”. That said, cargo that fails a can-test should not be loaded in any event.
It remains to be seen how the research initiated by the IMO on the properties of Bauxite will affect the contents of the IMSBC Code. Until that time, we recommend that all Members share our circular with their crew members to raise awareness of Bauxite as a dangerous cargo and at the same time follow the recommendations contained in IMO circular CCC.1/Circ. 2.