Dry bulk ship-to-ship transfers: controlling the risk

A practical framework for planning and conducting safer STS operations involving bulk carriers and other non-tankers.

Ship-to-ship (STS) transfer is increasingly used where draft restrictions, limited port infrastructure or commercial reasons and logistics prevent direct loading or discharging alongside. For dry bulk vessels however, the operation is not simply a tanker STS model applied to solid cargo. The two vessels must manoeuvre and remain safely alongside while cranes, grabs, conveyors or floating equipment transfer cargo in an exposed and changing environment.

INTERCARGO’s 2026 first edition of ‘Ship to Ship Transfer Guidelines for Bulk Carriers’ is therefore a welcome development; it provides the first dedicated industry framework for planning, risk assessment, manoeuvring, fendering, cargo handling and emergency response in dry bulk STS operations; nevertheless, it is a dedicated industry guidance, rather than a binding ‘standard’. This guidance therefore should be incorporated into Members’/ Operators’ procedures and used alongside the vessel’s safety management system (SMS). It must not be treated though as a substitute for it.

Why dry bulk STS needs particular care

The risk profile extends beyond contact damage: relative movement between vessels can overload moorings, fenders, cranes and cargo gear. Changing displacement, freeboard, trim and list during transfer can alter lead angles and vessel interaction. Cargo operations may create dust, spillage, water pollution, liquefaction or chemical hazards, while simultaneous crane and grab movements expose personnel to suspended loads and snap-back zones. Weather deterioration, poor visibility, traffic and communications failures can quickly reduce and finally eliminate any margin of safety.

There is no single global convention governing every dry bulk STS transfer. Members and Operators must identify the full legal and operational framework for the location and cargo, including Flag, coastal State and port requirements; SOLAS and the ISM Code; COLREGs; MARPOL, particularly Annex V controls on cargo residues and wash water; and, as applicable, the IMSBC Code or International Grain Code. Relevant Class limitations, approved stability information, equipment certification and charterparty terms must also be checked and must be taken into account accordingly.

Before agreeing to the operation

A ship-specific assessment should be completed early enough to influence the arrangements. At a minimum, Members and Masters should confirm:

• Authority and location: all required permissions, notifications and reporting arrangements; a suitable transfer area with adequate depth, sea room, shelter and navigational control.
• Vessel compatibility: hull geometry, parallel body length, freeboards throughout transfer, mooring layouts, safe access, lifting appliances and any structural or operational limitations.
• STS service provider: competence, experience, insurance, equipment, local knowledge and a clear scope of responsibility. Where the operation is unusual or high risk, consider an independent marine warranty surveyor or STS superintendent.
• Environmental limits: agreed maximum wind, wave, swell, current, visibility and relative motion criteria for approach, mooring and cargo transfer – with reliable forecasts and continuous monitoring.
• Cargo hazards: the correct cargo declaration and schedule; moisture/TML controls where relevant; dust, toxicity, flammability, oxygen depletion, self-heating, corrosivity and pollution precautions; and compatibility with the intended transfer method.
• Insurance and CP: prompt review of charterparty or STS clauses, indemnities and knock-for-knock wording, responsibility for fenders/tugs/equipment, off-hire and delay allocation – notifying the Club where assistance is required.

Plan the operation together

The participating vessels, Member, STS provider, cargo interests and relevant authorities should work on only one STS plan. A joint risk assessment and pre-transfer conference should resolve, rather than merely record, differences among procedures. The plan should identify the overall person in advisory control, while preserving each Master’s overriding authority and responsibility for the safety of their own vessel.

 

Control	What good planning should establish
Approach and unmooring	Roles of both bridges, traffic and anchor considerations, tug use, abort points, speed/angle of approach, communications and daylight restrictions where appropriate.
Fendering and mooring	Fender type, size, pressure and certification; deployment and monitoring; line plan, line condition and compatibility; tending arrangements; winch/brake limitations; and snap-back controls.
Cargo transfer	Loading/discharging sequence, maximum rates, crane/grab envelopes, hold access, trimming, ballast operations, stress/stability limits, draught/freeboard changes and emergency stops.
People and communications	Common working language, dedicated channels, call signs, repeat-back protocol, fatigue management, PPE, safe access and exclusion zones.
Emergency response	Stop-work signals; breakaway, contact, pollution, fire, injury, equipment failure and deteriorating weather actions; tug readiness; refuge/escape routes; and authority contacts.

 

During transfer: monitor, communicate and be ready to stop

A signed checklist is not the end of the risk assessment. Conditions and geometry change throughout the operation. The responsible Officers should continuously monitor weather and relative movement, fenders and moorings, safe access, cargo equipment, dust and spillage, vessel stability, draught, trim, list, ballast operations, longitudinal strength and hold loading limits. Mooring lines must be tended by trained personnel from safe positions; mixed or incompatible line arrangements should be avoided.

Cargo work should remain within the agreed sequence and rates. Ballasting and cargo transfer must be coordinated so that neither vessel exceeds permissible shear forces, bending moments, local tank-top/hold limits or stability criteria. No person should work under suspended loads or within an uncontrolled grab, crane or line-of-fire area. Enclosed-space precautions should remain fully applicable.

The stop-work threshold must be understood by everyone. Transfer should be suspended if:

• environmental limits are reached or deteriorated weather forecast is exceeded;
• fenders or moorings are overloaded or ineffective;
• communications are lost; unsafe relative movement develops; cargo, ballast, structural or stability limits cannot be maintained; or any other condition departs materially from the agreed plan. 

Commercial pressure should never displace the Master’s judgement.

Records protect both safety and the Member’s position

Contemporaneous records are essential. Retain the approvals, compatibility assessment, STS plan, risk assessments, checklists, certificates, weather information, communications log, loading/discharging/ballasting sequence, stability and strength calculations, photographs and times of material events. Record any protest, unsafe instruction, suspension and corrective action. Before and after transfer, jointly inspect and photograph the hull, fenders, moorings, decks, hatch coamings and cargo spaces where practicable.

Any contact, pollution, cargo loss or damage, personal injury, equipment failure or near miss should be reported promptly under the SMS and to the relevant authorities. Members should also notify the Club without delay so that evidence can be preserved and appropriate survey, legal or correspondent assistance arranged.

Key takeaway

Dry bulk STS operations can be conducted safely, but only when treated as a distinct high-risk operation. Early due diligence, vessel and cargo compatibility, a single coordinated plan, competent support, disciplined monitoring and a genuine stop-work culture are the principal controls. INTERCARGO’s new guidelines provide a valuable industry benchmark and should be used to strengthen company SMS procedures, training and shipboard checklists.

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Further reading

INTERCARGO – Ship to Ship Transfer Guidelines for Bulk Carriers (First Edition, 2026). www.intercargo.org/publications/ship-to-ship-transfer-guidelines-for-bulk-carriers/

INTERCARGO – Media release: first dedicated STS standard for dry bulk. www.intercargo.org/media-release-first-dedicated-sts-standard-for-dry-bulk-released-by-intercargo-as-operations-increase/

IMO – International Maritime Solid Bulk Cargoes (IMSBC) Code. www.imo.org/en/ourwork/safety/pages/cargoesinbulk-default.aspx