IT may seem strange at first glance that when the entire shipping industry is talking about unmanned ships in the 21st century, we are still worried over liquefaction of dry bulk cargoes.

Bulk cargoes that liquefy and the issues arising from the carriage of those cargoes have been well known for decades. However, incidents still occur.

Quite how Stellar Daisy foundered is not yet clear, but if liquefaction was a factor, as many in the shipping industry suspect, it would have been another entirely avoidable tragedy.

Evidence compiled by DNV GL suggests that there are some distinct and disturbing features of accidents caused by cargo liquefaction.

First, these accidents happen very fast — the period of time from when liquefaction is detected, if it is detected at all, until the vessel has capsized could in some cases be only a few minutes.

This gives very little time for remedial measures or safe evacuation of the ship, leading to losses of crew members.

What is more bizarre is that an accident on one vessel is often followed by a new accident, or near-accident, on other vessels that have loaded similar cargo at terminals in the same area.

The best-known example is the loss of the bulk carriers Jian Fu Star, Nasco Diamond and Hong Wei, which occurred during a six-week period in the autumn of 2010. All the ships were carrying nickel ore from Indonesia.

The IMSBC Code obligations

Provisions for safe stowing and shipping of cargoes prone to liquefaction are described in the International Maritime Solid Bulk Cargoes Code.

The code as it stands would possibly prevent many incidents due to liquefaction if followed strictly, as it sets out a maximum moisture content of the cargo which is considered safe for carriage in ships, known as total moisture limit.

The latest amendment to the IMSBC Code entered into force in January this year. It primarily targeted providing clarity on the carriage requirements for cargoes that in the past may have created uncertainty.

The amendment also introduced new schedules for iron ore fines and scale generated from the iron and steel making process.

Under the code, the shipper bears the legal responsibility to provide all information on the cargo, including certificates on the moisture content level, sufficiently in advance of loading operations, which must then be approved by the competent authority.

The pressure on those who verify the safety of the cargo is significant.

Often the shipowners point the finger of blame at the master of when some untoward incident occurs. However, many insurance experts studying such incidents have uncovered that misdeclaration of moisture levels is very common. That compromises vessels' safety and increases the risk of capsizing.

There are many other issues involved in the carriage of solid bulk cargoes that hinder compliance with the code. These include unreliable laboratories and inadequate facilities in the countries of shipment where the tests to determine the moisture content are carried out.

In many occasions, high demand for ores induces loading operations to be carried out during monsoon seasons, exposing piles of cargoes at terminals to heavy rain that in turn increases the moisture content and enhances the chances of liquefaction.

Further, there have been instances in which cargoes classified under the IMSBC as not liable to liquefy have in fact undergone liquefaction.

For example, in 2015, Bulk Jupiter, a bulker carrying bauxite from Indonesia, sank with the loss of 18 crew members. Until then, bauxite was not specifically included in Group A cargoes — those prone to liquefy — under the IMSBC code.

The Can Test

The accidents due to liquefaction often involve serious casualties, and thus masters should not start loading cargoes into their vessels if the cargo declarations have not been provided, as per the guidance provided by various P&I clubs.

A master has the power to halt any loading operations if he or she fears that the moisture levels in the cargoes being loaded exceed the predetermined transportable moisture limit, said a Singapore-based operator.

“If the master has any doubts regarding the safety of the cargo, even after the cargo is loaded, he should not sail,” said Clyde & Co’s Singapore-based partner Chris Metcalf.

“Obviously, having to make such a decision can place a lot of pressure on the master.  If he decides to involve the P&I Club and call for the attendance of an independent surveyor then there is going to be delay,” Mr Metcalf added.

“But the master has to weigh that against the potential loss of life, loss of the vessel and loss of the cargo.”

In practice, the implications of not loading cargo can be severe.

The shipowners have to pay huge demurrage costs as the vessels can be delayed for months before a surveyor objectively samples and tests the cargo.

“Most of the bad decisions from the master to continue shipments comes from commercial pressures,” said a Hong Kong based shipping lawyer.

However, in cases where a master believes that the cargo certificates have been manipulated, he or she can make sure that the cargo is safe by performing a complementary test on board, known as the Can Test, to determine approximately whether the cargo about to be loaded, or loading, has the possibility of flowing.

London P&I Club says in its new guide that the Can Test can be carried out in a cylindrical can, preferably a tin or similar container of about a litre capacity, half-filled with a sample of the cargo.

The crew should then strike the can over a hard surface, such as the deck or a bollard, from a height of about 0.2 m and repeat this procedure around 25 times at one- to two-second intervals. This would give an idea of free moisture or fluid conditions of the cargo.