Direct Reduced Iron (DRI) Cargo by Sea: IMSBC Code, Safety Risks and Chartering Guide

Direct Reduced Iron (DRI) is one of the most important and most sensitive metallic cargoes carried by sea. It is valuable because it provides the steel industry with a high-iron feedstock, but it is also demanding because it can react with air and moisture, generate heat, produce hydrogen gas, and create serious safety risks if the cargo is wrongly declared, wrongly prepared, or wrongly carried. For shipowners, charterers, shipbrokers, masters, cargo interests, surveyors, P&I Clubs, terminals, and receivers, DRI is not a cargo that should be treated as ordinary iron ore or ordinary steel raw material. It requires exact identification, strict compliance with the International Maritime Solid Bulk Cargoes Code, careful documentation, proper ship suitability, controlled loading, voyage monitoring, and disciplined emergency planning.

The carriage of DRI by sea is commercially attractive because steel production is changing. Electric arc furnace steelmaking, direct reduction technology, and lower-carbon steel strategies have increased attention on metallic iron units such as DRI, Hot Briquetted Iron (HBI), and related by-product fines. As production patterns develop, more cargo may move between reduction plants, steel mills, export terminals, and industrial consumers. However, greater trade in DRI does not reduce the danger. On the contrary, increased movement makes proper cargo classification and safe carriage procedures even more important.

At first glance, DRI may look like a relatively simple bulk cargo. It can appear as briquettes, pellets, lumps, fines, chips, or other processed metallic material. Yet the cargo’s appearance can be misleading. The danger is not only what can be seen on the surface but what may happen inside the stow. Porous iron can re-oxidize. Moisture can trigger reaction. Heat can build up. Hydrogen can accumulate in cargo spaces. Oxygen can be consumed. A hold atmosphere can become unsafe for entry. If ignition sources are present, a dangerous atmosphere may become explosive. For this reason, a DRI shipment must be planned as a controlled operation rather than a routine loading of heavy bulk cargo.

This article explains the carriage of Direct Reduced Iron (DRI) by sea from a practical shipping and chartering perspective. It covers the nature of DRI, the main forms of DRI, the difference between DRI (A), DRI (B), DRI (C), and DRI (D), the principal hazards, the importance of the IMSBC Code, cargo declarations, ship suitability, hold preparation, loading controls, weather restrictions, inert gas requirements, ventilation requirements, temperature and gas monitoring, charterparty issues, stowage factors, voyage management, discharge precautions, and loss-prevention points. The purpose is to provide a clear professional guide for anyone involved in the fixing, loading, carriage, and discharge of this cargo.

What is Direct Reduced Iron (DRI)?

Direct Reduced Iron is produced when iron oxide is reduced to metallic iron without melting the material. The process usually takes place below the fusion point of iron. Instead of being converted into molten pig iron in a blast furnace, iron ore in the form of pellets, lumps, or fines is exposed to reducing gases, often containing hydrogen, carbon monoxide, or a mixture of gases. Oxygen is removed from the ore, leaving a metallic iron product with a high iron content and a porous structure.

Because the reduction process does not melt the iron, the finished material retains a solid form. Depending on the production route and subsequent processing, the cargo may be shipped as pellets, lumps, hot-moulded briquettes, cold-moulded briquettes, by-product fines, or other related forms. DRI is sometimes called sponge iron because its internal structure may contain pores and a large reactive surface area. This structure is important because it contributes to the cargo’s commercial value in steelmaking but also to its carriage risks at sea.

DRI is used as a metallic feedstock in steel production, especially where electric arc furnaces require cleaner or more consistent iron units than ordinary scrap metal can provide. It can improve metallic yield, help control impurities, and support the production of particular steel grades. In a steel mill, DRI may be blended with scrap or used to increase the iron content of the furnace charge. In a shipping context, however, the same reactivity that makes DRI a useful industrial material makes it a cargo requiring special precautions.

The essential point is that DRI is not simply “iron ore” and not simply “metal.” Iron ore is an oxide. DRI is a reduced material capable of reacting back toward oxidation. When DRI reacts with air or moisture, heat and gases may be produced. If the reaction is uncontrolled, the cargo can heat, deplete oxygen, generate hydrogen, and create a hazardous hold atmosphere. Safe carriage therefore depends on preventing the wrong cargo from being shipped under the wrong name and ensuring that the ship follows the correct cargo schedule.

Main Types of DRI Carried by Sea

For maritime carriage, the correct identification of DRI type is fundamental. Different forms of DRI have different IMSBC Code schedules and different carriage requirements. A ship should not accept a vague cargo description such as “iron fines,” “metallic fines,” “sponge iron,” “HBI fines,” “iron concentrate,” or “steel raw material” without clear classification. The correct schedule determines whether the cargo requires inert gas, mechanical ventilation, gas monitoring, temperature measurement, moisture control, or other special precautions.

DRI (A): Briquettes, Hot-Moulded

DRI (A) is generally associated with Hot Briquetted Iron, often known as HBI. It is produced when hot DRI is compacted into dense briquettes at high temperature. The briquetting process increases the density of the material and reduces its exposed surface area compared with ordinary pellets or lumps. Because of this, HBI is normally considered the safer and more stable form of DRI for sea transport, provided it is correctly produced, cooled, handled, and declared.

Although DRI (A) is usually less reactive than other DRI forms, it is not risk-free. It can still react with moisture, generate hydrogen, and create oxygen depletion in cargo spaces. Holds must be clean and dry. Water ingress must be prevented. Cargo temperature must be monitored in accordance with applicable requirements. Surface ventilation may be required, but air should not be driven deep into the body of the cargo in a way that could stimulate reaction. Cargo spaces should not contain combustible debris, wooden fittings, loose dunnage, oil residues, salt residues, or previous cargo contamination.

The practical advantage of DRI (A) is that it is generally easier to ship than DRI (B) or DRI (C). Many commercial DRI movements are therefore structured around HBI where the supply chain allows. However, shipowners should not accept HBI merely because the name sounds safer. They must still obtain the shipper’s declaration, cargo certificate, moisture and temperature information, and clear confirmation that the cargo genuinely falls within the appropriate schedule.

DRI (B): Lumps, Pellets and Cold-Moulded Briquettes

DRI (B) covers more reactive forms such as pellets, lumps, and cold-moulded briquettes. These materials generally have a higher reactive surface area and may be more prone to self-heating and hydrogen generation. The cargo may require carriage under an inert atmosphere with oxygen concentration kept below the required limit. The ship must be equipped and arranged to maintain and monitor that atmosphere throughout the voyage.

DRI (B) creates a much higher level of operational complexity than ordinary dry bulk cargo. The ship may need nitrogen or another suitable inert gas arrangement, installed gas lines, cargo temperature monitoring points, remote reading equipment, oxygen and hydrogen measurement procedures, and trained personnel. Many dry bulk ships do not have the equipment or design features needed to carry DRI (B) safely. The owner must therefore assess ship suitability before fixing and not after the cargo is already nominated.

The master and owner should be especially careful where the cargo has been stored outside, exposed to rain, mixed with fines, or described with unusual trade names. DRI (B) must be kept dry before shipment and during loading. If the cargo is wet, heating, steaming, giving off unusual odor, or showing evidence of reaction, loading should be stopped and expert advice obtained. The commercial pressure to keep a berth moving must never override the safety requirements for this cargo.

DRI (C): By-Product Fines

DRI (C) is associated with by-product fines generated during the manufacture or handling of DRI. Fines can be more dangerous than larger pieces because their surface area is high and their behavior may be less predictable. Historically, DRI fines created considerable concern because some cargoes did not fit neatly into earlier categories. If fines were too wet, too reactive, or wrongly declared, the risks could include self-heating, hydrogen generation, oxygen depletion, and, in some circumstances, liquefaction-like behavior.

Because DRI (C) is a fine material, moisture control is critical. The cargo should not be accepted if it does not meet the required moisture conditions. The shipper must provide accurate information, and the owner should not rely on assumptions. If the cargo is described as “fines” but does not meet the DRI (C) schedule, the parties must identify the correct alternative schedule or obtain proper competent-authority guidance before loading. A ship should not carry uncertain DRI fines merely because a commercial fixture has been concluded.

For DRI (C), as with DRI (B), inerting and atmosphere control may be central to safe carriage. The ship must be able to monitor hold gases and cargo temperature without compromising the inert atmosphere. This requirement makes DRI (C) unsuitable for many ordinary bulk carriers unless special arrangements have been made and verified.

DRI (D): By-Product Fines with Higher Moisture Content

DRI (D) is a newer and highly important schedule in the maritime carriage of direct reduced iron. It was introduced to address by-product fines with moisture content at least 2 percent, reflecting practical handling realities where fines may contain more moisture than the strict limits applicable to other DRI fine cargoes. DRI (D) is important because it recognizes a cargo stream that previously created classification and safety difficulties.

DRI (D) is not simply “wet DRI that can now be shipped freely.” It remains a dangerous cargo requiring strict compliance. The principal hazard is hydrogen generation, with additional concerns such as self-heating and possible liquefaction. The schedule requires careful control of cargo information, moisture and temperature measurements, ventilation arrangements, and gas monitoring. Mechanical surface ventilation is central to keeping hydrogen concentration within safe limits, but ventilation must be managed in accordance with the relevant Code requirements and not improvised casually.

For shipowners and charterers, the introduction of DRI (D) means that cargo descriptions must be reviewed more carefully than ever. A shipment of DRI fines should no longer be forced into an unsuitable category simply because older wording is familiar. The correct question is: what exactly is the cargo, what is its moisture content, what schedule applies, what certificates are required, and is the nominated ship capable of complying with every operational requirement?

Why DRI Is a Dangerous Cargo

The danger of DRI comes from its chemical and physical properties. DRI contains metallic iron that has been produced by removing oxygen from iron oxide. In simple terms, the material has a tendency to react with oxygen again. When the reaction occurs, heat is released. If enough heat is produced and not dissipated, the cargo can self-heat. If water is present, the reaction may also produce hydrogen gas. Hydrogen is flammable and can form an explosive mixture with air. At the same time, oxygen in the cargo space may be consumed, creating a danger to personnel entering the hold.

These hazards are serious because they can develop inside the cargo mass and inside enclosed cargo spaces. The outside surface may appear normal while the inside of the stow is changing. A hold atmosphere may look harmless but contain insufficient oxygen or elevated hydrogen. A cargo temperature may rise gradually until intervention becomes difficult. If the crew enters the hold without proper testing, there may be risk of suffocation, poisoning by unsafe atmosphere, or exposure to fire and explosion hazards.

DRI hazards may be summarized as follows:

• Self-heating caused by oxidation of metallic iron. • Hydrogen generation when the cargo reacts with water or moisture. • Oxygen depletion in enclosed cargo spaces. • Explosion risk if hydrogen accumulates and meets an ignition source. • Fire risk if heating progresses and combustible materials are present. • Liquefaction risk for certain fine materials when moisture conditions are unsuitable. • Personnel safety risk during sampling, inspection, entry, ventilation, and discharge. • Structural and operational risk if emergency response is delayed or incorrectly handled.

The safest DRI shipment is one in which all parties understand these hazards before the fixture is concluded. The most dangerous DRI shipment is one in which the cargo is treated as an ordinary bulk cargo, the ship is not suitable, the paperwork is incomplete, the cargo is wet, and the crew is expected to solve the problem after departure.

The Role of the IMSBC Code

The International Maritime Solid Bulk Cargoes Code, commonly known as the IMSBC Code, provides the global framework for the safe carriage of solid bulk cargoes. It identifies the hazards of many bulk cargoes and sets out schedules, precautions, loading requirements, stowage requirements, carriage requirements, and emergency measures. For DRI, the IMSBC Code is not a formality. It is the central reference that determines whether the ship may load, what conditions must be satisfied, and what must be monitored during the voyage.

The IMSBC Code divides solid bulk cargoes into broad hazard groups. Some cargoes may liquefy. Some cargoes have chemical hazards. Some cargoes have both. DRI cargoes fall into categories that may involve chemical hazards, self-heating, hydrogen generation, and, in the case of certain fines, liquefaction-related concerns. The exact classification depends on the specific DRI schedule.

Before loading DRI, the shipper must provide cargo information. This should include the proper bulk cargo shipping name, the applicable IMSBC schedule, moisture content where relevant, temperature limits, physical characteristics, chemical hazards, trimming requirements, certificates, test results, and any special instructions. If the cargo information is incomplete or inconsistent, the master should not proceed as though everything is acceptable. The correct response is to seek clarification and, where necessary, involve the owner, P&I Club, classification society, flag state, or competent authority.

The IMSBC Code also matters contractually. A charterparty may allocate costs and responsibilities, but it cannot make an unsafe cargo safe. If a cargo requires inert gas, the ship must have the means to provide and maintain it. If a cargo requires mechanical ventilation, the ship must have suitable mechanical ventilation. If moisture limits apply, the cargo must meet them. If loading must stop during rain, the terminal and charterer must cooperate. A clause stating that the ship is “suitable” should not be used to hide an unsuitable ship or an incorrectly declared cargo.

Cargo Information and Shipper’s Declaration

A DRI shipment should begin with accurate cargo information. The shipper’s declaration is not merely a document for the file. It is the basis on which the master decides whether the ship can safely accept the cargo. Inaccurate or vague declarations are a major source of risk. The declaration should identify the exact cargo name and schedule, not a commercial nickname. It should specify whether the cargo is DRI (A), DRI (B), DRI (C), or DRI (D). It should also provide relevant details about moisture, temperature, fines content, particle size, storage history, treatment, and required carriage conditions.

Owners should ask for cargo documentation at the pre-fixture stage wherever possible. Waiting until arrival at the load port may leave the ship exposed to delay, pressure, and dispute. If the ship is not fitted for the required schedule, the owner may be forced into conflict with the charterer. If the cargo is unsuitable, the ship may lose time at the berth. If the ship loads anyway, the consequences may be far more serious than a commercial delay.

The cargo declaration should be reviewed against the ship’s actual capability. For example, a declaration showing DRI (B) or DRI (C) may require inert atmosphere. If the ship has no inert gas system or no temporary arrangement acceptable to all relevant parties, the cargo should not be fixed for that ship. A declaration showing DRI (D) may require mechanical surface ventilation and regular hydrogen monitoring. If the ship cannot comply, the ship should not load. A declaration showing HBI should still be checked for moisture, temperature, fines, and contamination.

Good practice is to keep a clear paper trail. Owners should record when the cargo information was received, who reviewed it, what questions were raised, what answers were given, and what decision was made. Masters should keep copies of certificates, terminal instructions, survey reports, temperature records, gas readings, hatch-cover test records, and loading logs. In the event of a dispute, the documents may be as important as the physical evidence.

Pre-Fixture Assessment: Should the Ship Accept DRI?

DRI cargo should be evaluated before the ship is offered or finally fixed. The owner and broker should not assume that any bulk carrier can carry DRI. Many ships are commercially attractive for heavy bulk cargoes but technically unsuitable for certain DRI schedules. The pre-fixture stage should therefore include a detailed suitability review.

The owner should ask the following questions:

• What is the exact DRI type and IMSBC schedule? • Is the cargo HBI, pellets, lumps, cold-moulded briquettes, fines, or by-product fines? • What is the moisture content? • What is the cargo temperature at loading? • Has the cargo been exposed to rain, seawater, fresh water, snow, condensation, or wet storage? • Does the cargo require inert gas? • Does the ship have the means to maintain an inert atmosphere? • Does the cargo require mechanical ventilation? • Are the ship’s ventilation arrangements suitable and certified where required? • Can the ship measure hydrogen, oxygen, and cargo temperature during the voyage? • Are the hatch covers weather-tight? • Are the holds clean, dry, salt-free, and free of combustible material? • Are adjacent tanks suitable for the planned carriage conditions? • Is the crew trained for gas testing and emergency procedures? • What do the P&I Club and technical managers say about the proposed shipment? • Is the charterparty wording adequate to protect the owner?

If any answer is uncertain, the owner should obtain clarification before fixing. This is not excessive caution. It is ordinary prudence for a cargo that can create fire, explosion, and life-safety hazards. A freight premium does not compensate for accepting an unsafe cargo on an unsuitable ship.

Ship Suitability and Equipment

Ship suitability depends on the DRI schedule. For some DRI cargoes, ordinary dry bulk arrangements may be insufficient. For other forms, such as properly produced HBI, carriage may be possible with strict hold cleanliness, water-tightness, surface ventilation, gas monitoring, and cargo temperature records. The ship must be judged against the cargo’s actual requirements, not against broad assumptions about “metal cargo.”

Important ship suitability factors include:

• Clean and dry cargo holds. • Weather-tight hatch covers and closing arrangements. • No loose rust scale, salt residue, previous cargo residue, oil contamination, or combustible debris. • Removal of wooden fittings, loose dunnage, and other combustible materials where required. • Suitable ventilation arrangements for the applicable schedule. • Explosion-proof equipment where required. • Reliable gas detection instruments for hydrogen and oxygen. • Temperature measurement equipment, including cargo thermocouples where required. • Procedures for sampling and monitoring without unsafe hold entry. • Crew training in enclosed-space entry and gas hazards. • Emergency response plans for heating, hydrogen increase, oxygen depletion, smoke, or fire.

For inerted cargoes, the ship must be able to establish and maintain the required atmosphere. This is not the same as briefly introducing gas at loading and hoping the atmosphere remains safe. The system must be reliable, monitored, and capable of being maintained throughout the voyage. Sampling points and measurement methods should minimize loss of inert gas. Crew must understand what readings mean and what action to take if limits are approached.

For mechanically ventilated cargoes such as DRI (D), the ship must be able to maintain ventilation as required to control hydrogen concentration. Ventilation must be appropriate to the schedule. It is not enough to say that the ship has fans. The fans must be available, operational, suitable for the intended cargo, and capable of performing the required function. If ventilation equipment fails, the ship must know the emergency response procedure.

Hold Preparation Before Loading

Hold preparation for DRI must be stricter than for many ordinary bulk cargoes. Holds should be clean, dry, and free from salt and residues. Any remaining cargo residue may react, retain moisture, contaminate DRI, or create claims. Salt contamination is particularly undesirable because salt may attract moisture and support corrosion or reaction. Combustible material should be removed because it can worsen a heating or fire situation.

Hatch covers should be inspected and tested before loading. Water ingress is one of the greatest dangers in DRI carriage. Even a small leak can be serious if water reaches reactive cargo. Ultrasonic hatch testing or another suitable method should be considered where required or where the risk justifies it. Drainage arrangements, vents, sounding pipes, bilges, manhole covers, access covers, and any route by which water might enter the hold should be checked.

Bilges should be clean and dry. Bilge wells should be protected as required, but the arrangement should not allow hidden water to accumulate near the cargo. The ship should verify that no adjacent tank leakage can affect the hold. If ballast tanks adjacent to the cargo space are subject to restrictions under the applicable schedule, those restrictions must be followed. Warm bulkheads or heated spaces near cargo should be considered carefully because heat can contribute to reaction.

The master should document hold condition before loading. Photographs, hold inspection records, hatch-cover test reports, and surveyor certificates may be valuable. If the charterer later alleges that cargo deterioration resulted from poor hold condition, the owner’s evidence will matter. If the owner later alleges that cargo was loaded wet or hot, loading records will matter. DRI carriage is an evidence-intensive operation.

Loading Conditions and Weather Restrictions

DRI cargo should be loaded only under the conditions permitted by the applicable schedule. Loading in rain, snow, or wet conditions may be prohibited or unsafe. Cargo should not be loaded if it is wet, if it exceeds permitted temperature, if moisture limits are exceeded, if it contains excessive fines where relevant, or if there are signs of ongoing reaction. The terminal, charterer, shipper, master, and surveyor must cooperate to stop loading when conditions are unsafe.

During loading, cargo temperature should be monitored and recorded. The common practical reference in many DRI contexts is that cargo should not be accepted if temperature exceeds the permitted limit, such as the 65°C figure referred to in traditional guidance and many cargo requirements. Temperature monitoring should not be a single casual measurement at the beginning. The cargo can vary across stockpiles, conveyors, trucks, barges, or loading streams. A systematic approach is needed.

Moisture checks are equally important. For DRI schedules with strict moisture limits, the cargo must be tested in accordance with proper procedures. For DRI (D), the moisture regime is different, but this does not remove the need for control. The cargo may still require transportable moisture limit considerations and proper certification. If the cargo becomes wet after loading, emergency procedures may be required. Wet cargo should not be covered up and forgotten.

Loading equipment should be dry where required. Conveyor belts, grabs, hoppers, trimming equipment, and loading chutes should not introduce water. Drop heights should be controlled where cargo degradation and fines generation are concerns. Dust may require precautions for personnel and equipment. The cargo should be trimmed in accordance with Code requirements and safe stowage practice. Proper trimming can help reduce shifting risk and support monitoring, but it must not conceal unsafe cargo conditions.

Inert Atmosphere Requirements

For certain DRI cargoes, inert atmosphere is essential. Inerting means replacing or reducing the oxygen content in the cargo hold atmosphere, usually with nitrogen or another suitable inert gas, to control oxidation and reduce fire and explosion risk. The requirement is especially associated with more reactive DRI cargoes such as pellets, lumps, cold-moulded briquettes, and certain fines, depending on the applicable schedule.

An effective inert atmosphere requires planning. The ship must have appropriate gas supply, distribution arrangements, sealing arrangements, monitoring points, and measurement equipment. Inert gas must reach the relevant parts of the stow. If gas is introduced in a way that leaves pockets of oxygen-rich atmosphere, the protection may be incomplete. If gas sampling causes repeated loss of atmosphere, the system may become unstable. If hatch covers or access points leak, the atmosphere may not be maintained.

The master must understand the target gas levels. Oxygen concentration may need to be kept below a specified percentage, and hydrogen concentration must be monitored. The crew must know the difference between ordinary air, inert atmosphere, oxygen-deficient atmosphere, and explosive atmosphere. They must also understand that inerted holds are dangerous for entry. No one should enter a hold or enclosed space without proper enclosed-space procedures, testing, permits, supervision, and rescue arrangements.

Where temporary inerting systems are fitted, the owner should ensure that the installation is professionally designed and inspected. Temporary piping, manifolds, sampling tubes, and monitoring equipment must be suitable for the voyage. The system should not interfere with hatch sealing, cargo stowage, crew safety, or emergency access. Any temporary arrangement should be agreed before loading and documented clearly.

Ventilation Requirements

Ventilation rules for DRI depend on the cargo type. Some DRI cargoes should not be ventilated in a way that introduces oxygen into the cargo body. Other forms, such as HBI, may require surface ventilation. DRI (D) requires special attention because mechanical ventilation may be required to control hydrogen concentration. The key point is that ventilation is not a matter of general seamanship alone. It must follow the applicable IMSBC schedule and the cargo-specific instructions.

Wrong ventilation can be dangerous. If air is driven into a reactive cargo, it may feed oxidation and heat generation. If ventilation is insufficient, hydrogen may accumulate. If ventilation equipment is not explosion-proof where required, it may introduce an ignition risk. If the crew ventilates based on habit rather than cargo instructions, the ship may create the very danger it is trying to prevent.

For surface ventilation, air should generally pass over the cargo surface rather than through the cargo mass. This helps remove gas from the hold atmosphere without unnecessarily stimulating reaction inside the stow. For mechanical ventilation required to keep hydrogen below a specified level, fans must be operational and monitored. The crew should record fan use, gas readings, weather conditions, and any abnormalities.

Ventilation also interacts with weather. If rain, sea spray, heavy weather, or hatch leakage can introduce water, ventilation openings may need to be managed carefully. The ship must maintain safety without compromising water-tightness. On some voyages, the practical challenge is to control hydrogen while also keeping the cargo absolutely dry. This is why voyage planning, route assessment, weather routing, and hold integrity are all relevant to DRI carriage.

Gas Monitoring: Hydrogen and Oxygen

Gas monitoring is central to DRI safety. Hydrogen is flammable. Oxygen deficiency can kill. Oxygen concentration also indicates whether inert atmosphere is being maintained where inerting is required. Gas readings should be taken with suitable calibrated instruments by trained personnel. Readings should be recorded in a dedicated log and compared with the relevant limits and action levels.

The monitoring plan should identify:

• Which gases are to be measured. • Where sampling points are located. • How often readings are taken. • What instruments are used. • How instruments are calibrated and checked. • Who is responsible for measurement. • What action is required if readings change. • How readings are reported to the owner, charterer, and managers. • How crew safety is protected during measurement.

Hydrogen readings should be treated seriously even when they appear low. A rising trend may be more important than a single number. If readings are increasing, the crew should consider the cause: water ingress, cargo reaction, ventilation failure, inert gas loss, or measurement error. Rechecking instruments is sensible, but assuming the instrument is wrong without evidence can be dangerous.

Oxygen readings are also critical. Low oxygen may indicate an inert atmosphere or oxygen consumption. In either case, the hold is dangerous for entry. Crew should never rely on smell or appearance. Many fatal enclosed-space accidents occur because people underestimate invisible atmosphere hazards. DRI carriage must reinforce strict enclosed-space discipline.

Cargo Temperature Monitoring

Temperature monitoring helps detect self-heating. The cargo may begin warming slowly before reaching a dangerous condition. Regular readings provide a trend. A stable low temperature may indicate normal carriage. A rising temperature may indicate oxidation, moisture reaction, or another developing problem. The master should know what temperature limits apply and what action is required if readings exceed normal expectations.

Temperature readings may be taken through fixed thermocouples, portable probes, or other approved arrangements depending on cargo type and ship equipment. For some DRI cargoes, thermocouples may need to be placed within the stow at various locations and heights. The purpose is to detect changes inside the cargo, not merely at the surface. Surface readings alone may not reveal deeper heating.

Records should include date, time, hold number, location, temperature, gas readings, ventilation status, weather, and any action taken. If a temperature increase is observed, the ship should inform technical managers and the P&I Club promptly. Delay can reduce available options. The crew should not open hatches, ventilate, flood, or discharge cargo without considering the cargo schedule and expert advice, because the wrong response can make the situation worse.

Water Ingress and Moisture Control

Water is one of the principal enemies of safe DRI carriage. Fresh water, seawater, rainwater, condensation, wash water, ballast leakage, hatch leakage, and wet loading equipment can all create problems. Moisture may trigger hydrogen generation and heat. It may also affect fine cargoes that have moisture-related stability concerns. For this reason, moisture control begins before loading and continues until discharge is complete.

Before loading, the ship should confirm that holds are dry and hatch covers are sound. During loading, the master should stop operations if rain begins where the schedule requires dry loading. After loading, hatch covers should be closed and secured. During the voyage, hatch covers, vents, ventilators, access covers, and sounding pipes should be checked as far as safely possible. After heavy weather, the ship should be alert for signs of leakage.

Condensation should also be considered. DRI must be kept dry, but ventilation decisions may be complex. Introducing humid air into a cargo space may create condensation risk. Closing ventilation may create hydrogen accumulation risk for some cargoes. The applicable schedule should govern, and expert advice should be sought where conditions are uncertain.

Water should not be used casually as an emergency response to DRI heating or fire. In many DRI situations, water can worsen the reaction and increase hydrogen generation. Emergency response must follow the cargo schedule and expert instructions. The crew must know this before an emergency occurs, not discover it during crisis.

Fire and Explosion Risk

DRI fire and explosion risk arises from the combination of self-heating, hydrogen generation, oxygen, and ignition sources. Hydrogen is particularly dangerous because it can form explosive mixtures with air and may be difficult to detect without instruments. If hydrogen accumulates under hatch covers or in poorly ventilated areas, opening, ventilation, hot work, electrical equipment, or mechanical sparks may create danger.

Fire prevention begins with cargo acceptance. Do not load wet, hot, wrongly declared, contaminated, or non-compliant DRI. Remove combustible materials from cargo spaces. Ensure hatch covers are weather-tight. Monitor gas and temperature. Follow ventilation or inerting requirements. Prevent unauthorized hold entry. Control smoking, hot work, and ignition sources. Maintain records. Report abnormal trends early.

If smoke, abnormal heat, gas increase, or suspected reaction occurs, the master should avoid improvisation. The ship should notify owners, managers, charterers, P&I Club, flag state or coastal authorities as appropriate, and obtain expert advice. Depending on the cargo type, adding water may be prohibited or dangerous. Opening hatches may feed oxygen. Stopping ventilation may increase hydrogen. Continuing ventilation may increase oxidation. The correct response depends on the specific cargo and situation.

Discharge Precautions

Discharge is not the end of the risk. DRI can remain reactive during discharge, especially if it has heated, generated gas, or been exposed to moisture during the voyage. Before opening hatches, the ship should check gas readings and temperature. If hydrogen is present, opening procedures must consider ignition risk and crew safety. If oxygen is depleted, no person should enter until the atmosphere is tested and declared safe under enclosed-space procedures.

Discharging equipment should avoid unnecessary sparks and excessive breakage. If cargo is hot or reacting, discharge may require special arrangements. Receivers and terminal operators should be informed of any abnormal voyage readings. Cargo should not be discharged into rain or wet areas if that creates further hazard. Fines and dust should be controlled to protect personnel and prevent contamination.

After discharge, holds should be cleaned carefully. Residues may remain reactive or may stain, corrode, or contaminate future cargoes. Crew should treat residues with caution until confirmed safe. Bilges should be inspected for water and cargo residue. If any incident occurred, evidence should be preserved, including samples, photographs, gas logs, temperature logs, hatch records, and communications.

Stowage Factor and Cargo Intake

DRI is a dense cargo. Traditional guidance often gives stowage factors around 15/17 cubic feet per ton for cold direct reduced iron and around 12/13 cubic feet per ton for hot forms, although actual figures depend on cargo form, density, briquette shape, fines content, and packing. Because DRI is heavy, cargo intake is usually controlled by deadweight, draft, load line, tank top strength, and local weight distribution rather than by the ship becoming space-full.

Tank top strength and cargo distribution must be considered. Dense cargo concentrated in one area can overstress structure. Loading plans should distribute weight safely across holds and tank tops. The master should consider bending moments, shear forces, stability, trim, draft, and port limitations. Even if the ship can physically carry the cargo weight, she must be loaded within structural limits.

For chartering purposes, stowage factor also affects freight economics. A dense cargo may allow the charterer to lift a high weight in relatively little space, but port draft and ship deadweight will determine the final quantity. Owners should calculate bunkers, freshwater, constants, draft restrictions, and voyage requirements before confirming intake. Because DRI may require special precautions, the owner should not assess the business only by freight rate and quantity. Risk, equipment, time, survey cost, and insurance implications must also be considered.

Charterparty and Contractual Issues

DRI carriage should be supported by clear charterparty wording. A standard voyage charterparty may not be enough unless the rider clauses address the cargo’s special nature. Owners should ensure that the charterparty identifies the exact cargo, applicable IMSBC schedule, shipper documentation, loading weather restrictions, moisture and temperature limits, survey requirements, responsibility for delays, cost of inert gas or ventilation arrangements, gas monitoring, cargo rejection rights, and indemnities for inaccurate cargo declaration.

Key charterparty points include:

• Exact cargo name and DRI type. • Confirmation that the cargo will comply with the IMSBC Code. • Shipper’s obligation to provide certificates and declarations before loading. • Owner’s right to reject cargo that is wet, hot, misdeclared, non-compliant, or unsafe. • Charterer’s responsibility for delays caused by non-compliant cargo or missing documents. • Allocation of costs for surveys, sampling, testing, inert gas, nitrogen, ventilation equipment, and monitoring. • Loading only in dry weather where required. • No loading during rain, snow, or wet conditions where prohibited. • Terminal cooperation with temperature and moisture checks. • Charterer’s obligation to provide safe berth and safe loading/discharging procedures. • Indemnity for consequences of wrong cargo declaration or unsafe cargo presentation. • Clear law and arbitration clause.

A shipowner should be cautious about broad cargo descriptions such as “DRI/HBI in bulk” without precise classification. If the charterer has an option to ship different forms, the ship may be exposed to a cargo she cannot safely carry. If the owner is prepared to carry only DRI (A), the charterparty should say so clearly. If DRI (B), DRI (C), or DRI (D) is contemplated, the equipment and cost consequences must be addressed before fixture.

Bill of Lading Description

The bill of lading should accurately describe the cargo. A misleading bill of lading description can create legal, insurance, and safety problems. If the cargo is DRI, the bill should not hide the dangerous nature of the cargo behind a vague trade name. The master should not sign a bill of lading that incorrectly describes the cargo or omits material information known to be relevant. If pressure is applied to issue a clean or vague description, the master should contact owners and P&I Club immediately.

The bill of lading also interacts with cargo condition. If cargo appears wet, hot, contaminated, or otherwise abnormal at loading, the master should consider appropriate remarks and obtain advice. A clean bill of lading may later be used as evidence that cargo was shipped in apparent good order and condition. For DRI, “apparent” condition may not reveal internal moisture, reactivity, or gas risk, but visible wetness, steaming, or contamination should not be ignored.

Surveyors and Expert Attendance

Independent surveyor attendance is strongly recommended for DRI shipments. The surveyor can help verify cargo declaration, sampling, temperature checks, moisture certificates, hold cleanliness, hatch-cover condition, loading weather, and compliance with the relevant schedule. However, the surveyor does not replace the master’s authority or the owner’s responsibility. The surveyor’s role is to advise and record, not to force the ship to load unsafe cargo.

For complex DRI shipments, the owner may need a specialist cargo expert rather than an ordinary draft surveyor. The expert should understand IMSBC Code requirements, DRI chemistry, gas monitoring, inerting, ventilation, and emergency response. The cost of expert attendance should be considered part of the cargo risk. It is usually far cheaper to prevent an unsafe shipment than to manage a fire, explosion, detention, cargo rejection, or casualty.

Insurance and P&I Considerations

DRI cargo can raise significant P&I and hull insurance issues. P&I Clubs often publish detailed guidance because cargo misdeclaration, non-compliance, and unsafe loading can lead to expensive claims. Owners should notify their Club before accepting unusual DRI shipments, especially DRI (B), DRI (C), DRI (D), fines, wet cargo, or cargo requiring special equipment. If the ship accepts cargo contrary to Code requirements, insurance cover may be affected depending on the circumstances and policy terms.

Charterers should also consider insurance. If cargo is delayed, rejected, damaged, or involved in a casualty due to incorrect declaration or poor preparation, the financial exposure may be considerable. Cargo interests should ensure that the cargo is properly produced, stored, sampled, tested, certified, and presented for shipment. Terminals should understand that rain exposure, wet conveyors, or poor stockpile management may create serious downstream risk.

Common Mistakes in DRI Carriage

Many DRI problems begin with avoidable mistakes. The most common include:

• Treating DRI as ordinary iron ore. • Accepting vague cargo descriptions. • Failing to identify the correct IMSBC schedule. • Fixing an unsuitable ship. • Assuming HBI and DRI are always the same risk. • Loading during rain or wet conditions. • Accepting cargo above permitted temperature. • Ignoring moisture limits or transportable moisture requirements. • Failing to test hatch covers. • Leaving wooden fittings or combustible debris in holds. • Not installing or verifying inert gas arrangements where required. • Using ventilation incorrectly. • Failing to monitor hydrogen and oxygen. • Entering holds without enclosed-space precautions. • Signing inaccurate bills of lading. • Failing to keep proper records. • Delaying expert advice when readings become abnormal.

Each mistake may appear small at the time. Together, they can create a serious casualty. Safe DRI carriage depends on discipline at every stage.

Practical Loading Checklist for DRI

Before arrival, the owner and master should obtain the full cargo declaration, IMSBC schedule, certificates, moisture data, temperature data, cargo history, and terminal loading plan. The ship should confirm hold readiness, hatch-cover integrity, ventilation or inerting arrangements, gas detection instruments, temperature monitoring equipment, and crew procedures.

At the loading port, the master should hold a pre-loading meeting with the terminal, shipper, surveyor, and agent. The meeting should confirm cargo identity, weather restrictions, stop-loading criteria, sampling procedures, temperature checks, moisture checks, communication channels, emergency actions, and documentation. If the terminal cannot comply with the requirements, the ship should not proceed blindly.

During loading, the ship should monitor weather, cargo appearance, cargo temperature, loading rate, dust, wetness, and any sign of reaction. Loading should stop if rain begins where dry loading is required. Cargo that appears wet, steaming, contaminated, or abnormal should be investigated. The master should record all stoppages and reasons.

After loading, the ship should close and secure hatch covers, establish the required atmosphere or ventilation regime, take initial gas and temperature readings, confirm voyage monitoring procedures, and report completion to owners and charterers. All documents should be retained on board.

Voyage Monitoring Checklist

During the voyage, the crew should follow the monitoring schedule required by the cargo type. Gas readings and temperature readings should be taken at the required frequency and recorded. Ventilation or inert gas systems should be checked. Hatch covers and openings should be inspected when safe. Weather conditions should be logged. Any abnormal reading should be reported promptly.

The voyage log should show a continuous chain of care. It should include readings, equipment status, weather, ventilation, inert gas pressure or supply where relevant, alarm events, maintenance actions, and communications. If readings remain stable, the log supports the owner’s position that the cargo was carried properly. If readings change, the log helps experts diagnose the problem.

The crew should avoid hold entry. If entry is absolutely necessary, it must follow enclosed-space entry procedures. The presence of DRI makes atmosphere testing even more important. Hydrogen, oxygen deficiency, and unstable cargo conditions can create invisible dangers.

Emergency Response During the Voyage

If DRI begins to heat, generate hydrogen, smoke, or show signs of reaction, the master should act methodically. Immediate steps may include increasing monitoring frequency, informing owners and managers, notifying the P&I Club, seeking cargo expert advice, reviewing the IMSBC emergency schedule, and considering nearest suitable port options. The ship should not take dramatic action without understanding the cargo type and likely consequences.

Potential emergency actions depend on the cargo and situation. For some cargoes, maintaining inert atmosphere may be critical. For others, controlled ventilation may be necessary to prevent hydrogen accumulation. Water may be dangerous. Opening hatches may be dangerous. Stopping ventilation may be dangerous. Hot work is prohibited. Entry is dangerous. Because many options carry risk, early expert advice is essential.

The master should preserve evidence and keep detailed records. Times, readings, weather, actions, communications, photographs, and expert instructions should be logged. If the ship diverts, discharges, or seeks port refuge, authorities and insurers will require information. Clear records may protect the shipowner and crew.

Commercial Importance of DRI in Modern Shipping

DRI trade is likely to remain important because steel production is evolving. Electric arc furnaces, metallic feedstock demand, and lower-carbon steel initiatives support continued interest in DRI and HBI. Hydrogen-based direct reduction may become more significant as steelmakers attempt to reduce emissions. As a result, DRI cargo flows may increase, diversify, and involve new loading regions and new receiving markets.

This commercial development creates opportunities for shipowners and charterers, but it also requires competence. Ships that can safely carry DRI under the appropriate schedule may find specialized employment. Charterers with reliable cargo preparation and documentation may gain market confidence. Terminals with proper storage, sampling, and loading procedures may become preferred export points. Conversely, parties associated with unsafe or poorly declared DRI may face delay, claims, and reputational damage.

In modern maritime trade, technical cargo knowledge is a commercial advantage. The safest and most professional parties will not ask whether DRI can be fixed at any price. They will ask whether the exact DRI cargo can be carried by the exact ship under the exact Code requirements for the exact voyage.

Conclusion

Carriage of Direct Reduced Iron (DRI) by Sea requires more than ordinary bulk cargo experience. It demands accurate cargo classification, strict IMSBC Code compliance, proper ship selection, careful hold preparation, dry loading, moisture control, temperature monitoring, gas monitoring, correct use of inert atmosphere or ventilation, and clear charterparty allocation of risk. The differences between DRI (A), DRI (B), DRI (C), and DRI (D) are not academic details. They determine how the cargo must be carried and whether the nominated ship is suitable.

DRI can self-heat. It can generate hydrogen. It can deplete oxygen. It can create fire, explosion, and enclosed-space risks. Certain fine forms can raise moisture-related stability concerns. These hazards do not mean that DRI cannot be shipped safely. They mean that it must be shipped with discipline, documentation, equipment, and expertise.

For shipowners, the safest position is to review the cargo before fixture, confirm the correct schedule, involve technical managers and P&I advisers where appropriate, and refuse any cargo that is wet, hot, misdeclared, or outside the ship’s capabilities. For charterers and shippers, the safest position is to provide accurate declarations, compliant cargo, dry loading, reliable certificates, and full cooperation with the master. For masters, the safest position is to enforce the Code, keep records, monitor continuously, and seek advice early if conditions change.

DRI is a valuable cargo in global steelmaking, but it is also a cargo that punishes shortcuts. A professional DRI shipment begins long before the first grab, conveyor, or loader starts work. It begins with correct information, correct classification, correct ship selection, and a shared understanding that safety requirements are not negotiable conveniences but essential conditions for the voyage.