Liquefaction of Nickel Ore in Bulk Shipping: IMSBC Code, TML, FMP, and Cargo Safety

Liquefaction of nickel ore is one of the most serious hazards in dry bulk shipping because it can rapidly reduce ship stability and lead to a sudden, unrecoverable list or capsize. Nickel ore is usually shipped in bulk from mining areas in countries such as Indonesia, the Philippines, and New Caledonia, often after being stockpiled in exposed conditions and transported to the loading area by barge or landing craft. When the cargo contains fine particles and excessive moisture, the normal motion and vibration of the ship during the voyage can cause the cargo to lose shear strength and behave like a fluid.

The danger is not always visible during loading. Nickel ore may appear dry or solid on the surface while still containing enough internal moisture to liquefy at sea. For this reason, safe carriage depends on proper cargo declaration, representative sampling, reliable laboratory testing, and strict compliance with the International Maritime Solid Bulk Cargoes Code (IMSBC Code). A master cannot safely judge the liquefaction risk by appearance alone, and a simple visual inspection cannot replace moisture-content testing, Flow Moisture Point testing, or Transportable Moisture Limit certification.

Liquefaction casualties involving nickel ore and other mineral cargoes have repeatedly shown that inaccurate declarations, poor sampling, unsuitable laboratories, commercial pressure, and loading during or after rain can create a fatal combination. The commercial value of the cargo can never justify loading a cargo that is not properly documented or that may exceed its safe moisture limit. In practical ship chartering and ship operation, nickel ore must therefore be treated as a high-risk cargo requiring special attention before fixture, before loading, during loading, and before sailing.

What is Nickel Ore Liquefaction?

Nickel ore liquefaction occurs when a solid bulk cargo containing fine particles and moisture loses its internal strength and begins to move like a liquid. In a stable condition, the particles inside the cargo remain in contact with one another and can resist movement. During a sea voyage, ship motion, machinery vibration, rolling, pitching, and wave impact may compact the cargo. As the spaces between the particles reduce, internal water pressure may rise. If the pressure becomes high enough to separate the particles, the cargo can suddenly lose strength.

Once nickel ore enters a flow state, the cargo may shift to one side of the hold during a roll and may not fully return when the ship rolls back. This creates a persistent list. If the list increases, the ship’s righting ability may be reduced quickly. In extreme cases, the ship may capsize with little warning. The danger is especially severe because liquefaction can occur after departure, in heavy weather, in moderate weather, at anchor, or even after a period of apparently normal sailing.

Nickel ore is particularly difficult because it is not a uniform industrial concentrate. It is usually a raw mined material containing clay, fine ore, stones, lumps, and water. Moisture may vary sharply between stockpiles, between barges, and even within the same parcel. Therefore, one apparently acceptable sample does not prove that the whole shipment is safe.

Why Nickel Ore is a High-Risk Group A Cargo

Under the IMSBC Code, cargoes that may liquefy if shipped with moisture content above the Transportable Moisture Limit (TML) are treated as Group A cargoes. Nickel ore must be approached on that basis because it may liquefy when its moisture content exceeds the safe transportable limit. This means that a ship should not load nickel ore unless the shipper provides proper cargo information, including moisture content and TML certificates prepared in accordance with the Code.

Nickel ore shipments often present practical difficulties that are not always present in processed mineral concentrates. Mining locations can be remote, cargo may be exposed to tropical rain, loading facilities may be basic, and cargo may move from mine to shore through several handling stages before being loaded. These circumstances make representative sampling and moisture control more difficult. They also make it essential for shipowners, charterers, masters, surveyors, and shippers to treat the documentation process as a safety requirement rather than a formality.

Nickel ore cargoes from Indonesia and the Philippines have attracted particular attention because several serious casualties and near-misses have been associated with cargo liquefaction. The risks are heightened where cargo is stored uncovered, transported by barge, loaded at anchor, or exposed to rainfall after sampling but before loading. If the cargo condition changes after the moisture test, the earlier certificate may no longer represent the cargo offered for shipment.

Flow Moisture Point (FMP) and Transportable Moisture Limit (TML)

The Flow Moisture Point (FMP) is the moisture content at which a cargo may begin to flow under the effect of compaction and vibration. The FMP must be established by proper laboratory testing using approved methods. It cannot be guessed from the cargo name, appearance, origin, colour, or particle size distribution alone. Even cargoes with similar descriptions may have different flow characteristics.

The Transportable Moisture Limit (TML) is the maximum moisture content at which a Group A cargo may be safely carried in a conventional ship not specially constructed or fitted for such cargo. In practical terms, the TML is normally calculated as 90% of the FMP. This creates a safety margin between the moisture level at which cargo may begin to flow and the moisture level permitted for loading. If the cargo moisture content is above the TML, the cargo should not be accepted for carriage in an ordinary bulk carrier.

The safety margin must be respected strictly. A cargo slightly above the TML is not “almost safe.” The TML exists because sampling, cargo variability, laboratory procedures, rain exposure, and handling conditions can all introduce uncertainty. Loading wet cargo in the hope that it will remain stable during the voyage is a dangerous practice and may expose the ship, crew, cargo interests, charterers, and shipowners to catastrophic loss.

IMSBC Code Requirements for Nickel Ore

Before loading, the shipper must provide the master with accurate written cargo information. For nickel ore and other cargoes that may liquefy, this information should include a cargo declaration, the moisture content of the cargo, the TML, the FMP test result, the cargo’s Bulk Cargo Shipping Name where applicable, and any other information required for safe loading, stowage, carriage, and discharge.

Moisture content testing must be based on representative samples of the cargo actually intended for shipment. The cargo should be identifiable by stockpile, parcel, barge, or other practical method so that certificates can be matched to the material loaded. If different parcels, stockpiles, grades, or sources are involved, separate assessment may be necessary. Wet cargo should not be offset against drier cargo by averaging moisture results across unrelated parcels.

If significant rain occurs between sampling and loading, or if the cargo is exposed to water during storage, transport, or barge operations, additional testing should be required. The master should not accept outdated or unclear certificates when the cargo condition may have changed. The master’s authority under SOLAS to stop loading or refuse unsafe cargo remains fundamental, particularly where the cargo condition or documentation raises safety concerns.

Sampling, Testing, and Cargo Certificates

Reliable sampling is one of the most difficult parts of safe nickel ore carriage. A certificate is only as good as the sample on which it is based. If samples are taken from the wrong stockpile, from only the surface, from a selected dry area, or from material that is not actually loaded, the certificate may provide false comfort. Because nickel ore is heterogeneous, representative sampling must be planned and supervised carefully.

Laboratory testing must be carried out by competent laboratories using approved procedures. Mine laboratories may be useful, but shipowners and masters should be cautious where laboratories are not independent, are poorly equipped, or do not follow the IMSBC Code method. In high-risk trades, shipowners commonly involve P&I Clubs, local correspondents, independent surveyors, and cargo experts before loading begins.

The “can test” can be a useful warning tool, but it must never be treated as proof that a cargo is safe. If a sample shows free moisture or behaves suspiciously during a can test, this is a red flag requiring further investigation. However, a sample that appears to pass a can test may still have moisture content above the TML. Only proper laboratory testing can establish whether the cargo is suitable for shipment.

Loading Nickel Ore Safely

Safe loading begins before the ship arrives. Chartering and operations teams should review the cargo description, loading port, shipper history, local weather, stockpile arrangements, testing facilities, charterparty protections, and P&I Club guidance. If the cargo is nickel ore from a high-risk area, the shipowner should consider appointing an independent surveyor or cargo expert early enough to avoid last-minute pressure at the loading place.

Loading should not commence until the master has received the required cargo declaration and certificates. The documents should be checked carefully for consistency, dates, test methods, cargo identity, stockpile references, moisture content, TML, and laboratory details. If the moisture content is close to the TML, if certificates are missing, if stockpiles are exposed to rain, or if cargo appears wet, loading should be delayed until the safety position is clarified.

During loading, the master and surveyor should monitor weather conditions, cargo appearance, barge condition, and any signs of free water, splashing, mud, flattening, or unusual behaviour. Loading during rain should be avoided. Cargo in open barges should be treated with caution, especially if it has been exposed to rainfall after testing. Where there is doubt, the master should stop loading and seek instructions from shipowners, managers, P&I Club representatives, and cargo experts.

Shifting Solid Bulk Cargoes and Loss of Stability

Solid bulk cargoes can endanger stability by sliding, shifting, liquefying, or dynamically separating. Although these mechanisms differ, their effect can be similar: the cargo moves from its intended position, the ship develops a list, and the righting characteristics of the ship may deteriorate. Dense mineral cargoes are especially hazardous because even a relatively small movement can involve a very large weight.

Nickel ore that liquefies may create a free-surface effect similar to liquid cargo in a partly filled tank. The cargo may move across the hold with the ship’s motion and may not settle back evenly. As the list develops, the ship may roll about a new inclined position, reducing the margin of safety. Further movement can increase the list until deck edge immersion, progressive downflooding, structural damage, or capsize becomes possible.

The risk is not limited to heavy weather. Heavy seas increase the likelihood of compaction and cargo movement, but a cargo loaded above its TML can become unsafe in ordinary voyage conditions. Weather routing may reduce exposure to severe motion, but it cannot make an unsafe cargo safe. The only reliable protection is to ensure that the cargo is suitable for carriage before it is loaded.

Nickel Ore, Iron Ore Fines, Sinter Feed, and Other Liquefiable Cargoes

The principles that apply to nickel ore also apply to other solid bulk cargoes that may liquefy, including iron ore fines, mineral concentrates, sinter feed, mill scale, fluorspar, pyrites, some coal cargoes, and certain industrial dusts. These cargoes may contain fine particles and moisture even when they appear dry. If their moisture content exceeds the TML, they may lose strength during the voyage.

Iron ore fines and sinter feed have caused serious concern in dry bulk shipping, especially where cargoes are misdeclared, left exposed to monsoon rain, or loaded without proper Group A documentation. Sinter feed may be wrongly presented as a non-liquefiable cargo even though its fine particle structure and moisture behaviour may make it unsafe unless properly tested. The same caution applies to any cargo that contains fine particles and moisture, even if it is not clearly listed in the IMSBC Code schedule.

For unlisted cargoes with potential liquefaction characteristics, the parties should not assume the cargo is safe merely because it is not named in a schedule. The IMSBC Code framework requires proper assessment of cargoes that may present hazards. If a cargo can liquefy or dynamically separate, it must be treated with the level of caution appropriate to Group A cargoes.

What Happens if Unsafe Cargo is Already Loaded?

If doubts arise after nickel ore or another liquefiable cargo has already been loaded, the situation becomes much more complicated. It may be difficult to identify which part of the cargo is unsafe, particularly if cargo from different stockpiles or barges has been mixed in the holds. In many cases, the only safe solution may be to discharge the cargo and reload only cargo that has been properly tested and certified.

Discharging cargo at the loading port can create practical, legal, customs, and commercial difficulties. The port may lack suitable equipment, the cargo may have been declared exported, barges may no longer be available, and charterers or shippers may dispute the shipowner’s position. Nevertheless, sailing with unsafe cargo is far more dangerous than facing delay and dispute at the loading place.

Attempts to dry or correct wet cargo onboard are rarely simple and may not produce a reliable safety result, especially when the holds are full. If the master has concerns after loading, the ship should not sail until competent advice has been obtained and the cargo condition has been resolved to the satisfaction of the master and shipowner.

Charterparty Clauses for Cargoes that May Liquefy

Charterparty protection is important when fixing nickel ore or other cargoes that may liquefy. The charterparty should make clear that charterers must provide accurate cargo declarations, moisture-content certificates, TML/FMP certificates, stockpile identification, and any other documentation required by SOLAS and the IMSBC Code. The clause should also preserve the master’s right to stop loading, reject cargo, require independent sampling, and refuse to sail if the cargo is unsafe.

BIMCO, together with the International Group of P&I Clubs, has developed charterparty wording for solid bulk cargoes that may liquefy. Such clauses are designed to support compliance with the IMSBC Code and to protect the shipowner’s position where cargo documentation, sampling, or cargo condition is disputed. Shipowners should avoid clauses that undermine the master’s authority, restrict independent testing, or require loading in circumstances inconsistent with the Code.

For further guidance and current documents, the BIMCO website should be consulted at www.bimco.org.

Intercargo Guidance for Nickel Ore

Intercargo has issued guidance for the safe loading of nickel ore, emphasizing the importance of proper cargo declaration, sampling, testing, and moisture control. The guidance highlights that nickel ore must not be misdescribed and that shippers must ensure the cargo is protected from additional moisture, including rain exposure during storage, transportation, barge movement, and loading.

The guidance also stresses that shipowners should verify that cargo documents comply with the IMSBC Code and that chartering departments should review internal procedures before accepting nickel ore cargoes. Intercargo has also warned that the can test is limited and should not be used as the sole basis for accepting cargo as safe.

Further information can be obtained from Intercargo at www.intercargo.org.

Insurance, P&I Club Cover, and Nickel Ore Cargo Risk

Nickel ore shipments can raise important insurance and P&I Club issues. If a shipowner knowingly loads cargo that is unsafe, misdeclared, improperly tested, or carried in breach of the IMSBC Code, cover may be affected. Shipowners should consult their P&I Club and hull and machinery insurers before accepting high-risk nickel ore cargoes, particularly from ports or shippers with a history of documentation or testing problems.

P&I Clubs often assist shipowners with local correspondents, surveyor recommendations, expert guidance, and advice on cargo documentation. However, survey costs incurred to establish whether a cargo is safe for loading may not automatically be recoverable as a P&I expense. Prior approval should be obtained where possible, especially if the survey is linked to an existing or anticipated dispute.

Insurance protection does not replace operational judgment. The master’s decision to stop loading, reject cargo, or delay sailing should be supported when genuine safety concerns exist. Commercial pressure should never override cargo safety.

Practical Precautions Before Fixing Nickel Ore

Review the cargo and port risk: Identify whether the cargo is nickel ore, nickel laterite, limonite, saprolite, or another ore with liquefaction potential.
Check charterparty permission: Confirm whether the cargo is permitted under the charterparty and whether special clauses are required.
Consult the P&I Club early: Seek guidance before the ship arrives at the loading area, especially in high-risk countries or remote loading places.
Require IMSBC Code compliance: Make clear that loading will not begin without proper declaration, moisture content certificate, TML/FMP certificate, and stockpile identification.
Preserve the master’s authority: Do not agree to terms that restrict the master’s right to reject unsafe cargo or appoint independent experts.

Practical Precautions Before and During Loading

Check certificates carefully: Confirm dates, cargo identity, stockpile references, test methods, laboratory details, moisture content, FMP, and TML.
Monitor weather and cargo condition: Stop loading during rain and investigate any cargo that appears wet, muddy, flattened, splashing, or unstable.
Use independent surveyors: Where risk is high, appoint competent surveyors or cargo experts to assist the master.
Do not rely only on can tests: Treat failed or suspicious can tests as a warning, but use laboratory testing to determine cargo suitability.
Keep records: Record weather, cargo appearance, barge identification, communications, stoppages, protests, and surveyor observations.
Do not sign shipper safety endorsements: The responsibility for proper cargo information rests with the shipper. The master should avoid signing documents that could weaken the shipowner’s rights.

Master’s Authority and Commercial Pressure

The master has a central role in protecting the ship and crew. If required cargo information is missing, unclear, inconsistent, or unreliable, the master should not allow loading to proceed merely because commercial parties are pressing for speed. If rain affects the cargo, if barges are wet, if certificates are outdated, or if the cargo appears unsafe, loading should be stopped until the position is clarified.

Commercial pressure, threats, or attempts to force acceptance of doubtful cargo should be reported immediately to shipowners, managers, the P&I Club, and local representatives. The consequences of accepting unsafe nickel ore can be far more severe than delay, demurrage dispute, or lost freight. The protection of life, ship, cargo, and the marine environment must take priority.

Conclusion: Safe Carriage of Nickel Ore Depends on Discipline

Liquefaction of nickel ore remains one of the most dangerous cargo risks in dry bulk shipping. The cargo may look safe, but if its moisture content exceeds the Transportable Moisture Limit, it can lose strength at sea and cause a catastrophic loss of stability. The most effective safeguards are strict IMSBC Code compliance, accurate shipper declarations, representative sampling, reliable laboratory testing, careful monitoring during loading, and firm support for the master’s authority.

Shipowners, charterers, shippers, masters, surveyors, and P&I Clubs all have roles to play. However, the practical rule is simple: if nickel ore is not properly declared, properly tested, and clearly shown to be below the TML, it should not be loaded. No freight, fixture, or commercial pressure can justify sailing with a cargo that may liquefy.