Steel Scrap: IMSBC Schedule and Carriage Guide

Steel and iron scrap shipped in bulk is classified Group C under the IMSBC Code, meaning it is neither liable to liquefy nor poses a chemical hazard in normal sea transport. The primary operational risks are structural: the cargo is dense and irregularly shaped, loading by magnet grab can concentrate point loads on the tanktop, and contaminated scrap brings secondary fire hazards. A critically different cargo, ferrous metal borings, shavings, turnings, or cuttings (UN 2793), is a Class 4.2 self-heating solid that must meet specific controls to prevent spontaneous ignition.

Global seaborne steel scrap trade runs at roughly 90 to 100 million tonnes per year, making it the third or fourth largest dry bulk commodity by volume after iron ore, coal, and grain. The cargo flows from mature industrialised economies that generate surplus scrap (the United States, the European Union, Japan, South Korea, and Australia) to electric arc furnace (EAF) steelmakers that depend on scrap as their primary iron unit. Türkiye is consistently the single largest importer, taking 25 to 30 per cent of world seaborne scrap and supplying the EAF-dominated Turkish steel sector. India, Bangladesh, Pakistan, Vietnam, and Egypt are the other major destinations.

The IMSBC Code schedule for bulk metal scrap sits alongside the far more dangerous FERROUS METAL BORINGS, SHAVINGS, TURNINGS or CUTTINGS (UN 2793) schedule. Understanding where ordinary scrap ends and the Class 4.2 self-heating material begins is the first thing every master and cargo officer must establish before accepting any ferrous scrap shipment.

The IMSBC Code classification: Group C and the Group B exception

Bulk steel scrap is Group C

The IMSBC Code places ordinary bulk steel and iron scrap in the Group C category. A Group C cargo is defined as one that is neither liable to liquefy (and therefore does not require transportable moisture limit testing) nor possesses a chemical hazard that would require it to be classified as a dangerous good for bulk transport purposes. Group C is the lowest regulatory burden category: the cargo does not need a TML certificate, does not need segregation from other cargoes because of chemical reaction risk, and does not trigger the Group B emergency procedures for chemical releases or toxic atmosphere.

That classification covers the commercially traded grades of bulk ferrous scrap: heavy melt scrap (HMS 1 and HMS 2), shredded scrap, bushelling, plate scrap, and similar processed grades. These cargoes consist of large, low-surface-area steel and iron pieces. Their iron surface area per unit mass is small enough that normal atmospheric oxidation generates trivial heat, and the absence of cutting fluid contamination means there is no fuel for the self-heating mechanism that characterises machining swarf.

The IMSBC Code cargo schedule for METAL SCRAP specifies: bulk density range, stowage factor, angle of repose, characteristics (including any special conditions on contamination), and the requirement for cargo information from the shipper confirming the nature of the material. The shipper’s declaration under IMSBC Code Section 4 must state that the cargo is metal scrap and not a dangerous solid in bulk as defined by the Code.

Ferrous borings, turnings, and cuttings: Group B with a Class 4.2 designation

The distinction between ordinary scrap and machining swarf is not academic. The IMSBC Code carries a separate schedule for FERROUS METAL BORINGS, SHAVINGS, TURNINGS or CUTTINGS, which references UN 2793 and Class 4.2 (self-heating solid). This cargo is Group B, not Group C, when it is in a form and condition that makes it liable to self-heating.

UN 2793 is classified under the IMDG Code as a self-heating solid because iron machining swarf meets two conditions simultaneously: a high specific surface area (from the thin curled or powdered geometry of turned or bored metal) and the potential presence of residual cutting oil, coolant, or metalworking fluid. The heat of oxidation per unit of iron surface area is fixed by chemistry, but the total heat release rate scales with total surface area. Thin turnings present orders of magnitude more surface per kilogram than a plate scrap fragment.

When oily swarf is placed in bulk in a ship’s hold, oxygen diffuses from the surface down through the cargo. The iron-oil interface oxidizes, releasing heat. That heat drives off volatile hydrocarbons from the cutting fluid, which are flammable vapors. If ventilation is inadequate and the heat cannot dissipate, temperatures can reach the autoignition point of the oil vapor. Cargo fires in ferrous swarf have occurred at sea, which is why the IMSBC Code requires specific pre-shipment testing and controls for this material.

The IMSBC Code schedule for FERROUS METAL BORINGS, SHAVINGS, TURNINGS or CUTTINGS (UN 2793) requires: a hazardous goods declaration from the shipper; evidence that the cargo has been drained and dried to reduce oil and moisture content below specified limits; hold preparation appropriate for a dangerous good; and monitoring of hold temperatures during the voyage. Masters carrying UN 2793 must treat it as a Group B cargo with all attendant procedures, not as routine ferrous scrap.

Distinguishing the two in practice

The boundary matters commercially as well as operationally. Scrap dealers sometimes offer mixed consignments that include turnings and borings as bulk fill or diluted into larger scrap streams. The key questions for a master or cargo superintendent are:

1. Is any portion of the consignment machining swarf from iron or steel operations?
2. Is it free-cutting swarf in the original turned or bored form, or has it been processed (briquetted, compressed, or melted) to the point where it no longer presents a high surface area?
3. Has the shipper provided a dangerous goods declaration covering UN 2793 if swarf is present?

Briquetted or compressed turnings, where the material has been compressed under high pressure into dense blocks, may not meet the self-heating criterion and can in that form be carried under different conditions. The shipper bears the burden of providing test evidence and the appropriate declaration. A master who accepts a consignment of loose oily turnings under a plain metal scrap declaration, without a UN 2793 dangerous goods declaration, is accepting regulatory and legal exposure if the cargo self-heats.

Comparison of bulk steel scrap and ferrous borings (UN 2793)

The global steel scrap trade and why carriers need to understand it

Electric arc furnace steelmaking and scrap demand

Steel scrap is the feedstock for electric arc furnace steelmaking. EAF production accounts for roughly 28 to 30 per cent of global crude steel output (approximately 540 to 560 million tonnes per year as of the early 2020s), but EAF’s share of steelmaking capacity in importing regions is far higher. Türkiye’s steel industry is about 70 per cent EAF. The Indian mini-mill sector and the US long-products sector are also predominantly EAF. These producers depend on seaborne scrap because they lack access to domestic ore-based iron units.

Scrap quality determines the end product. HMS 1 (heavy gauge ferrous scrap, at least 6 mm thick and free from auto bodies, food cans, and similar light material) is the premium grade. HMS 2 permits lighter material and is traded at a discount. Shredded scrap, produced by passing auto hulks and mixed scrap through a shredder, is denser than HMS and lower in tramp metal, which EAF operators value because tramp elements like copper, tin, and nickel contaminate steel that must meet strict chemical specifications. Shredded scrap commands a premium over HMS 2 on most markets.

Main trade lanes

The United States East and Gulf Coast is the dominant scrap-exporting region, shipping primarily to Türkiye (via transatlantic routes through the Strait of Gibraltar), India, and Bangladesh. US scrap terminals at ports including Baltimore, Philadelphia, New Orleans, Houston, and Tampa load handy, supramax, and panamax bulk carriers directly. The EU exports significant volumes through Rotterdam, Hamburg, Antwerp, and Mediterranean ports to Türkiye, Egypt, and North Africa. Japan and South Korea ship to Vietnam, Bangladesh, and regional EAF markets in Southeast Asia.

Türkiye’s main receiving ports are Iskenderun in the Gulf of Iskenderun, Aliağa near Izmir, and Dilovası near the Bosphorus. These terminals have heavy industrial infrastructure with multiple electromagnet cranes capable of direct-discharge into mill stockyards. The same vessel that loads 50,000 tonnes of HMS in Baltimore can discharge at Iskenderun in four to five days.

Physical and chemical properties relevant to carriage

Bulk density and stowage factor

Steel scrap does not behave like grain or coal in how it fills a hold. Large HMS 1 pieces can have void fractions of 40 to 50 per cent, meaning a 5,000 m3 hold might carry only 10,000 to 12,500 tonnes before reaching structural limits, despite the steel density of 7.8 t/m3 for the solid metal. Shredded scrap, with its smaller and more uniform pieces, packs more tightly: 1.8 to 2.0 t/m3 is common. Stowage factor for shredded scrap typically runs 0.50 to 0.55 m3/t. HMS 1, depending on piece size and loading compaction, ranges from about 0.40 to 0.56 m3/t.

These figures matter for cargo planning. A supramax bulk carrier with five holds totalling 52,000 m3 of grain capacity will reach its 57,000-tonne deadweight at roughly 1.1 t/m3 average stowage. Shredded scrap at 0.52 m3/t would fill only about 29,000 m3 to reach 57,000 tonnes, leaving nearly half the hold volume empty. The cargo sits low and concentrated in the bottom of each hold, which has stability and structural consequences.

Angle of repose

Bulk steel scrap does not behave like a granular solid. Large interlocking pieces can maintain very steep or vertical faces without slumping. Shredded scrap behaves more like coarse gravel and has a practical angle of repose of around 35 to 45 degrees. HMS pieces can lock together at essentially any angle during loading but may shift unpredictably if the vessel rolls heavily. The IMSBC Code schedule acknowledges this: trimming is required for hatch closure but the non-flowing characteristic means liquefaction and cargo shift in the classic sense are not the risk. The risk from HMS is that heavy pieces drop from interlocked positions during severe rolling and impact the hold structure.

Radioactive contamination

Orphan radioactive sources from industrial applications (gauges, medical equipment, measuring devices) occasionally enter scrap streams. The primary concern is cobalt-60, caesium-137, and radium-226 sources, which cannot be detected by sight or smell. Detection gates are standard at major US, European, and Japanese scrap export facilities. Some cargoes originating from less controlled sources in Eastern Europe, the former Soviet states, and parts of South Asia carry residual detection risk. Most receiving terminals in Türkiye, India, and South Korea also operate detection gates, but contaminated cargoes that pass undetected at loading represent a serious hazard both during the voyage and at the receiving terminal. There is no routine onboard detection procedure specified in the IMSBC Code schedule, but shipper certification and loading port screening are the expected controls.

Structural risks: tanktop damage and point loading

Why scrap is hard on bulk carriers

Steel scrap is the cargo most closely associated with tanktop damage in dry bulk shipping. The combination of dense irregular pieces, grab or electromagnet loading from height, and the mechanical impact of each drop creates dynamic point loads that can exceed the tanktop’s structural design allowance. The tanktop is not designed for the free-fall impact of a 200-kilogram piece of plate scrap dropped from 10 metres. Even at lower drop heights, the concentrated load from a grab releasing three tonnes of HMS at once can create local stresses above the design yield stress.

IACS Unified Requirement S25 and S25A specify the minimum strength requirements for bulk carrier hatch covers and double-bottom structures. These requirements define the maximum distributed load per unit area of tanktop under static conditions. They do not account for drop impact. Classification society rules for bulk carriers require the operator to follow cargo-loading procedures that limit free-fall height and avoid point-concentrated discharge onto the tanktop. In practice, loading to specification means loading with reduced grab volumes, reduced drop heights, and progressive building-up of a scrap cushion layer before loading at full rate.

Tanktop protection methods

A scrap cushion is the standard mitigation. The first passes of the grab load at reduced rate and height, building a 500 mm to 1,000 mm layer of material across the tanktop surface. Once this cushion is in place, subsequent loading at higher grab volumes and greater drop heights distributes the impact energy across the compacted scrap below rather than concentrating it on the bare steel tanktop plate.

Some operators carry rubber mats or heavy conveyor belting as additional tanktop protection, placed on the tanktop before loading begins. These are not specified in the IMSBC Code but appear in P&I Club guidance and charter party annexes for scrap voyages. The mats reduce the coefficient of impact transmission and help protect the paint coating, but they don’t substitute for a scrap cushion; they’re a supplement.

Hold paint damage is essentially guaranteed on scrap cargoes. The question is whether the paint system is one that was designed to be abraded and replaced, or one where structural corrosion protection is at risk. Bulk carriers that carry frequent scrap cargoes use hard epoxy coatings, bare metal with regular touch-up, or accepted sacrificial paint schemes. Holding a scrap vessel to the paint standards of a clean grain vessel is not realistic; what matters is that structural integrity is maintained.

Hold and hatch cover structural strength

The IMSBC Code Section 9 requires the master to verify, before loading, that the vessel’s hold structure is adequate for the cargo density and planned loading pattern. For dense cargoes like scrap, this involves checking the class-approved maximum deadweight per hold and the allowable tanktop loading in tonnes per square metre. These figures appear in the vessel’s loading manual. A shipper who presents 60,000 tonnes of HMS for a vessel with a 45,000-tonne tanktop capacity requires the master to decline or redistribute the cargo.

The concern extends to the hatch covers. Scrap that is loaded above the hatch coaming line, common on heavily laden scrap voyages, creates a secured deck cargo, and the hatch cover must bear the weight of any scrap stacked on it during loading or in the event that scrap slides over the coaming. The IMSBC Code requires hatch covers to be capable of bearing cargo without structural failure. At major scrap terminals, vessels are sometimes loaded with the hatches deliberately overfilled, with trimming equipment used to push scrap below the coaming level before covering.

Contamination and fire risk

Combustible contaminants in steel scrap

Steel scrap feedstocks are heterogeneous. Industrial and demolition scrap includes structural steel, machinery frames, pipework, and fittings. Domestic appliance scrap includes refrigerator and washing machine casings, which may include insulating foam, plastic liners, and residual refrigerant. Auto scrap includes vehicle bodies with rubber seals, upholstery, glass, and residual fuel and oil. The shredding process removes much of the non-metallic content, but shredded scrap still contains a fraction of fluff (plastics, foam, rubber, and fiber) that did not separate cleanly.

HMS and plate scrap may include sealed paint or chemical containers, gas cylinders from welding or industrial use, sealed pressure vessels, and aerosols. These items are prohibited from bulk scrap consignments by the IMSBC Code schedule conditions, but they appear in practice. A sealed gas cylinder that passes undetected through the loading process and is compressed by the weight of overlying scrap can rupture during the voyage. A full propane cylinder rupturing in an enclosed hold is an explosion hazard.

Pre-loading inspection is therefore a critical step. Most charterers and P&I Clubs require an independent cargo superintendent’s inspection before any scrap cargo is accepted. The inspection must confirm that visible contamination (cylinders, aerosols, combustible material) is absent or has been removed, and that the scrap is reasonably free of excessive oil. This is not a perfect process; inspection from the surface of a large pile is limited. But the inspection report is a document of record if a fire or incident follows.

Self-heating from oily scrap

Ordinary bulk steel scrap does not self-heat at dangerous rates under normal conditions. But scrap heavily contaminated with oil, particularly waste oil or cutting fluid, can support a slow oxidation process in the hold. The mechanism is different from the swarf mechanism (the surface area is lower), but if sufficient oil is present as a fuel, and if the cargo contains combustible contaminants (plastic, rubber, organic material), smoldering fires in the interior of a dense scrap pile are possible. These fires are hard to detect from the surface and difficult to extinguish because water penetration through a dense scrap pile is poor.

The fire detection and fighting systems on a bulk carrier are designed for cargo hold fires. CO2 fixed fire-fighting systems are standard on bulk carrier cargo holds. However, a smoldering scrap fire may not produce enough smoke or CO2 to trigger detection at the hold level until it is well established. Temperature monitoring at multiple points in the hold is not standard for Group C scrap but is good practice for any voyage where contamination was detected or suspected at loading.

If a hold fire is detected on a scrap voyage, the master’s options are limited. CO2 flooding will suppress a fire only if the hold can be sealed. Scrap holds are difficult to seal completely because the cargo is irregular and may prevent hatch covers from landing gas-tight. Water is generally available but penetrates poorly into dense scrap and may increase stability risk. The preferred response is CO2 flooding and monitoring, with port diversion if the fire cannot be controlled. P&I Clubs and flag state guidance uniformly recommend against opening hatch covers on a suspected hold fire (which introduces fresh air and can trigger flashback).

Gas cylinders, aerosols, and sealed containers

The IMSBC Code is explicit: bulk cargoes must not contain items that would make them dangerous. For steel scrap, this means no sealed pressure vessels. The prohibition is stated in the cargo schedule conditions. In practice, shippers certify compliance but inspection is imperfect at large export terminals where scrap arrives from multiple aggregators. The risk is not theoretical: there are documented cases of cylinders present in scrap cargoes causing fires or incidents at receiving terminals, though hull-loss events from this cause at sea are rare.

The practical control is contractual as well as operational. Charterers typically include a clause in the charter party requiring the shipper to warrant that no dangerous items are included in the scrap, and making the shipper liable for any damage from undisclosed hazardous material. This shifts but does not eliminate the risk. The master’s right and duty to inspect before loading is the operational backstop.

Hold preparation for steel scrap

Cleaning and dryness requirements

The IMSBC Code Section 4 requires the shipper to provide cargo information. The Code does not mandate a specific hold preparation standard for Group C dry cargoes beyond what good seamanship requires, but cargo hold preparation standards for scrap differ from those for food-grade cargoes. Scrap is generally tolerant of pre-existing rust or residue in the hold, since the cargo itself is iron and steel. The preparation concern for scrap is structural and safety-oriented, not contamination-of-cargo:

• Bilge strum boxes and bilge covers should be cleared and covered to prevent scrap fragments from blocking bilge suctions.
• Hold limbers must be clear so that any water ingress (from rain during loading or hatch seal leakage at sea) can drain to the bilge.
• Firefighting system piping and CO2 distribution heads must be free of obstructions.
• Any residues from the previous cargo that are incompatible with ferrous metal (particularly chemical fertilizer residues or corrosive cargoes that could attack the steel structure) must be removed.
• Hold ventilation openings should be accessible and operable.

Bilge cover protection

A practical issue on scrap voyages is small scrap pieces falling through bilge covers and blocking the bilge system. A blocked bilge on a bulk carrier represents a serious hazard if water ingress occurs (from hatch seal failure, weatherdeck drainage, or washing in heavy weather). The standard solution is to lay grating or perforated plate over bilge limbers before loading, sized to allow water passage while blocking small scrap fragments. Some operators use a layer of burlap or geotextile. The arrangement must be strong enough to survive being covered by tonnes of scrap and still allow drainage.

Tanktop dunnage and cushion loading

As discussed above, tanktop protection starts before the first grab. The first step in hold preparation for a dense or heavy bulk like scrap is to establish what tanktop protection the vessel’s loading manual requires. Class-approved loading procedures for scrap voyages specify maximum drop height and minimum cushion thickness before full-rate loading commences. These procedures are not universal; they are vessel-specific and must be available onboard. Masters who do not have a class-approved scrap loading procedure should request one from the owner or operator before accepting a scrap voyage.

Loading operations: grabs, magnets, and clamshells

Loading equipment at scrap terminals

Scrap terminals use several types of loading equipment. Shore-based grab cranes are the most common: hydraulic or mechanical grabs, typically 8 to 25 cubic metres in capacity, drop loads of 8 to 40 tonnes per grab. Electromagnet cranes are used at many terminals, particularly for sorted or shredded scrap, and release the cargo in a less controlled manner than a mechanical grab (the field switches off and the load drops essentially in free fall). Clamshell buckets are used at some terminals.

The distinction matters for tanktop protection. A mechanical grab closes around the scrap and releases it in a relatively controlled drop. An electromagnet lifts material magnetically and drops it instantaneously when the field cuts; there is no gradual release. For tanktop purposes, electromagnet loading places higher instantaneous impact loads than grab loading. The cushion thickness required before electromagnet loading is typically greater than for grab loading.

At terminals that mix grab and electromagnet loading within a single voyage, the loading procedure must accommodate the worst case.

Loading sequence and weight distribution

The IMSBC Code requires that bulk cargoes are loaded in accordance with the approved loading manual and within the structural limits of the vessel. For scrap, the loading sequence must:

1. Build a scrap cushion across the tanktop of each hold to the specified minimum depth before proceeding to normal loading rate.
2. Distribute cargo evenly between holds to avoid exceeding the maximum deadweight per hold.
3. Monitor the calculated shear force and bending moment throughout loading and confirm they remain within the approved maximum still-water values.
4. Trim the cargo surface below the hatch coaming before fitting the hatch covers.

Self-trimming is not applicable to steel scrap. The cargo will not flow to fill voids. Bulldozers or compact track loaders are commonly deployed on the cargo surface to push scrap away from the coaming and level uneven peaks. This equipment is lowered into the hold by crane during loading and must be removed before sealing.

Loading rate for scrap at a well-equipped terminal is 1,500 to 3,500 tonnes per hold per hour, depending on crane capacity, grab size, and vessel hold geometry. A 50,000-tonne cargo into five holds might complete loading in 30 to 50 hours of crane time, but total port time including inspection, survey, trimming, and hatching adds to this.

Wet scrap and weather

Steel scrap is not adversely affected by rain during loading; it is metal and it will rust, but moisture does not change its cargo group classification. However, wet scrap at loading creates two operational issues. First, free moisture in the hold drains to the bilge, and a scrap voyage with a rain-soaked cargo will pump more bilge water than a dry one. The bilge system must be operational. Second, wet scrap that contains combustible material (oil, organics) can heat more readily in the early stages of the voyage if the subsequent hold atmosphere becomes oxygen-depleted and humid. This is not a major concern for clean, inspected scrap but it is a factor for contaminated consignments.

Marine cargo hold ventilation for scrap is not typically required or mandated in the IMSBC schedule for Group C metal scrap; scrap does not require controlled ventilation to prevent moisture damage or gas emission in the way that grain or coal does. However, if the scrap contained any suspicious contamination, keeping holds closed and monitoring temperature is better practice than ventilating a hold that might contain smoldering material.

Discharge operations

Receiving terminal equipment

Türkiye’s receiving terminals at Iskenderun and Aliağa represent the operational standard for scrap discharge. Facilities typically operate multiple bridge cranes with electromagnet heads on reinforced quaysides designed for bulk scrap operations. Discharge rates per crane are 400 to 800 tonnes per hour. A 50,000-tonne parcel with three to four cranes working simultaneously might take 25 to 35 hours of crane time plus mooring, survey, and drafts.

The electromagnet picks a layer at a time rather than grabbing a fixed volume, which means it clears the hold surface but leaves residue in corners and bilges that requires grab or shovel cleanup. At some terminals, shoreside workers enter the hold to shovel residue for final cleanup before draft survey. This confined space entry requires gas testing and formal entry procedures. The scrap hold environment after a voyage is typically clean (Group C, no toxic gas), but residual water in the bilge, dust from corroded scrap, and the confined space hazard require standard precautions.

Draft survey and weight determination

Weight at discharge is typically determined by draft survey in international steel scrap trade, particularly for US-origin cargoes. Shore weigh scales at the receiving facility may also be used, and some contracts specify bill of lading weight as binding. The choice of weight determination method is a commercial matter but has operational consequences: a scrap cargo that absorbed rain water during loading will weigh more at discharge than at loading, and draft surveys at both ends can reveal this discrepancy.

Residues and hold cleaning

After discharge, steel scrap leaves no toxic residue. The main post-voyage concern is the physical damage: broken weld beads from hold framing, scratched or missing paint, abraded tanktop plate, and bent or damaged bilge covers. The post-voyage hold inspection establishes the scope of damage and informs repair decisions before the next cargo.

If the next cargo requires clean holds (grain, fertilizer, or food-grade bulk), the scrap residues must be removed completely. If the next cargo is another ferrous product or coal, the standard may be lower. Charter party terms on hold cleanliness govern the division of responsibility between owner and charterer for post-discharge cleaning.

IMSBC Code amendment history relevant to metal scrap

The IMSBC Code has undergone multiple amendment cycles since it entered mandatory force on 1 January 2011 under SOLAS Chapter VI. The cargo schedules are updated periodically to reflect new knowledge about self-heating, moisture content behaviour, and contamination risk.

Amendment 06-19 (adopted via IMO MSC.462(101) in 2021) consolidated several earlier amendments and updated cargo schedule conditions for numerous cargoes including some metal scrap grades. Amendment 07-21 was adopted by the IMO Maritime Safety Committee in resolution MSC.500(105) in November 2022. Amendment 08-23 was adopted by MSC.539(107) in 2024. Both are in force for contracting governments that have accepted them under SOLAS VI/1-1.

Masters and operators should confirm which amendment is in force under their flag state and for their trading routes. The IMSBC Code text is available from the IMO Publishing Service. The IMSBC Code is not a free download; IMO sells the official text. Commercial reproductions and third-party schedule databases may be incomplete or out of date and should not be relied on for compliance purposes.

The key point for metal scrap operators is that the FERROUS METAL BORINGS, SHAVINGS, TURNINGS or CUTTINGS (UN 2793) schedule and the general METAL SCRAP schedule conditions should be read in their current form from the official text, not from older reproductions. The conditions on oil content and moisture have been subject to refinement across amendments.

SOLAS Chapter XII and structural protection for scrap carriers

SOLAS Chapter XII (Additional Safety Measures for Bulk Carriers), implemented via IMO resolution MSC.134(76) and subsequent amendments, applies to bulk carriers of 150 metres in length and above. Its requirements include structural strength standards for the double bottom and inner hull, hold flooding detection, and stability requirements that address the risk of hold flooding after grounding or collision.

For scrap voyages, the Chapter XII requirements translate into confirmed hold structural adequacy before loading. If a vessel loading heavy scrap does not meet the Chapter XII double-bottom strength requirements for the intended loading pattern, it must refuse or redistribute cargo to comply. This is not an abstract concern for scrap voyages: the combination of high cargo density, bottom-loading concentration, and potential impact damage from grab loading creates exactly the scenario Chapter XII addresses.

The SOLAS Chapter XII article covers the specific criteria. For practical purposes, a master loading scrap on a Chapter XII vessel should ensure that the cargo distribution plan has been approved by the relevant officer or surveyor, that the stability booklet’s maximum still-water limits are not exceeded at any stage of loading, and that the tanktop loading does not exceed the class-approved figures.

Contamination controls at the loading terminal

The shipper’s obligations

IMSBC Code Section 4 places the primary responsibility for accurate cargo declaration on the shipper. For bulk metal scrap, the shipper must declare:

• That the cargo is metal scrap as defined in the schedule.
• That no items prohibited under the schedule conditions (sealed containers, gas cylinders, explosives, radioactive material) are present.
• The estimated bulk density and stowage factor.
• Any special conditions relevant to the specific consignment (for example, if any component of the scrap is from industrial or automotive sources that may carry residual contaminants).

The shipper’s declaration is a legal document under SOLAS VI/2. A false declaration that results in cargo-related damage or loss is grounds for criminal liability in most jurisdictions in addition to civil exposure.

The master’s pre-loading rights and duties

The master has both the right and the duty to refuse cargo that does not meet the IMSBC Code schedule conditions. If the pre-loading inspection reveals sealed cylinders, heavy oil contamination, or other prohibited material, the master can and should refuse to load until the shipper clears the problem. This is not a commercial decision at the discretion of the charterer. The master’s authority under SOLAS and the IMSBC Code to refuse an unsafe cargo is unambiguous.

P&I Clubs generally support masters who refuse non-compliant scrap cargoes and document their reasons. A master who loads a visibly contaminated consignment without protest, and then suffers a hold fire, will face difficult questions from hull underwriters and the P&I Club about the failure to exercise the right of refusal.

Unexploded ordnance and legacy contamination

A less common but serious contamination risk specific to scrap from conflict zones or former military areas is unexploded ordnance (UXO). Artillery rounds, grenades, land mines, and other military munitions have been found in scrap consignments from Eastern Europe, North Africa, and parts of Asia. A UXO item that survives initial screening at the export terminal and is subjected to the impact forces of grab loading or cargo compaction can detonate.

There is no mandatory onboard inspection procedure for UXO. The control is upstream: export terminal screening and certification. Some charterers specifically restrict scrap origins to terminals with audited UXO screening protocols. For cargoes from regions with known military activity histories (the Balkans, North Africa, the former Soviet republics), the charter party should address this risk explicitly and require certification from the terminal.

Stability considerations for dense scrap cargoes

Low stowage factor and its stability effects

Bulk steel scrap loaded to deadweight in a normal supramax or panamax bulk carrier occupies only 40 to 60 per cent of the total hold volume. The cargo mass is concentrated in the lower portion of each hold, below the level where it would be if the same deadweight were a lighter cargo filling the holds completely. The low vertical center of gravity that results gives a high initial metacentric height (GM), typically 2 to 4 metres or more, well above the minimum standard.

A high GM produces stiff rolling behaviour: the vessel responds sharply to wave action with a short, rapid roll period. This is uncomfortable but not inherently dangerous. However, if the roll period is close to the natural wave period in a given sea state, parametric rolling or synchronous rolling can develop and the amplitude can grow significantly even from a high-GM starting point. The ship’s Master should calculate the natural roll period and compare it with the dominant wave periods in the forecast sea state. If synchronous rolling risk is identified, a course or speed change to alter the relationship between the natural roll period and the wave encounter period is the standard mitigation.

Free surface effects and ballast

On loaded scrap voyages, ballast tanks should be either full or empty, not partially filled. A partially filled ballast tank generates a free surface moment that reduces the effective GM. For a high-GM scrap vessel this may not be critical to stability compliance, but it is good practice. The stability calculation in the loading computer should use the actual free surface correction, not an assumed full-tank condition.

Limitations

This article covers the IMSBC Code schedule structure and principal handling risks for bulk steel and ferrous scrap as of the 2021 IMSBC Code edition and Amendment 07-21 (MSC.500(105)). Amendment 08-23 (MSC.539(107)) may modify specific schedule conditions; the IMO official text should be consulted for any voyage subject to that amendment cycle.

The article does not address the full regulatory regime for UN 2793 (FERROUS METAL BORINGS, SHAVINGS, TURNINGS or CUTTINGS) under the IMDG Code. Masters and operators carrying UN 2793 must consult the full IMDG Code text, the applicable IMSBC Code schedule, and their flag state’s implementation of both instruments. The conditions on oil content, moisture, and hold monitoring for UN 2793 are specific and technical; a summary in an encyclopedia article is not a substitute for the primary regulatory text.

Scrap cargo characteristics vary significantly by origin, grade, and processing method. The bulk density, contamination level, and self-heating propensity of any given consignment depend on specific pre-loading conditions that cannot be determined from grade descriptions alone. Pre-loading inspection by a qualified cargo superintendent is standard industry practice and should not be omitted on the basis that the cargo’s general Group C classification makes it low-risk.

Structural limits (tanktop allowable load, maximum deadweight per hold) are vessel-specific and must be taken from the vessel’s approved loading manual and stability booklet, not from this or any other general reference. Class-approved scrap loading procedures are vessel-specific documents.

See also

• IMSBC Code: Overview and Cargo Groups
• IMSBC Group C Cargoes
• IMSBC Group B Cargoes
• IMDG Class 4: Flammable Solids, Self-heating Substances
• Pig Iron: IMSBC Code Schedule and Carriage
• Direct Reduced Iron: IMSBC Code Schedule and Carriage
• Iron Ore: IMSBC Code Schedule and Carriage
• Bulk Carrier: Design, Structure, and Operation
• Cargo Hold Preparation Standards
• Marine Cargo Hold Ventilation
• Marine Fire Detection and Fixed Fire-Fighting Systems
• SOLAS Chapter XII: Additional Safety Measures for Bulk Carriers

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