Operational Guide · Registers & Logbooks

# Bunkering Operations and Fuel Quality Control

Bunkering is as much a safety operation (spill risk) as a quality one (off-specification fuel): both start well before the barge even arrives.

bunkering BDN fuel quality spill

## Operational Explanation

Bunkering combines an immediate operational risk (spill during transfer) with a longer-term quality risk (off-specification fuel, which can damage machinery or breach applicable sulphur limits). The pre-operation bunkering checklist and MARPOL sampling are the main tools for managing both.

This entry focuses on the operational safety and quality-control aspects of bunkering from the engine room's point of view; for the specific regulatory aspects of fuel changeover in ECA/SECA, see the dedicated entry in the MARPOL Operations module.

## Regulatory Reference

MARPOL Annex I (spill prevention) and MARPOL Annex VI, Regulation 18 (fuel quality and Bunker Delivery Note): every bunkering operation requires a pre-operation safety checklist, the taking of a representative MARPOL sample, and verification of the Bunker Delivery Note.

## Scope of Application

Every fuel bunkering operation, whether in port or ship-to-ship, for every ship type.

## Procedure / How to Complete It

1. Complete the pre-bunkering safety checklist (barge-ship communications, remaining tank capacity, spill containment systems ready).
2. Verify the Bunker Delivery Note for declared sulphur content and consistency with the operating area (ECA or not).
3. Take the representative MARPOL sample according to the standard procedure, sealed and retained for the required period.
4. Continuously monitor the transfer, with ongoing communication between parties and surveillance of tank levels.
5. In case of suspected off-specification fuel, suspend use of the batch and immediately inform the Company before further operations.

## Practical Example

Example procedure: bunkering checklist completed with confirmed communications established, remaining capacity verified at 90% of destination tanks, MARPOL sample taken with a witness from the barge, BDN verified consistent with the Mediterranean SECA for the planned route.

## Real Cases

Damage to main machinery attributable to off-specification fuel (e.g. excessive catalyst fines content, or chemical instability of the fuel) has in several cases been detected only after use, when timely analysis of the MARPOL sample or more careful quality control could have identified the problem before large-scale use.

## Common Mistakes Mistake Library

Mistake | Consequence | How to avoid it
--- | --- | ---
Pre-bunkering safety checklist completed as a formality without genuine verification of conditions | Spill risk not adequately mitigated | Genuinely verify every checklist item, not just sign it as a formality
MARPOL sample not taken with a witness or not sealed correctly | Sample unusable as evidence in the event of a quality dispute | Rigorously follow the sampling, sealing and retention procedure
Fuel used immediately without awaiting quality analysis in case of suspicion | Machinery damage if the fuel proves off-specification | Suspend use of the suspect batch until clarified, when possible

## PSC Observations

PSCOs may verify the Bunker Delivery Note, the retained MARPOL sample and consistency with the fuel log book, especially in relation to sulphur limits applicable to the operating area.

## Operational Tips

- Treat the bunkering checklist as a genuine verification, not a formality to be signed quickly.
- Never use freshly loaded fuel before at least a first consistency assessment (colour, declared density) against expectations.
- Retain the MARPOL sample exactly as procedure requires: it is your only evidence in the event of a quality dispute.

## Checklist

- Pre-bunkering safety checklist completed and genuinely verified
- Bunker Delivery Note verified for sulphur content and operating area
- MARPOL sample taken, sealed and retained correctly
- Transfer monitored continuously with ongoing communication
- Use of the batch suspended in case of suspected non-conformity

## FAQ

Who should be present when the MARPOL sample is taken?
Good practice calls for a witness from the barge/supplier to be present at the time of sampling, with the sample seal countersigned by both parties, to guarantee its validity in the event of a later dispute.
What to do if the fuel received appears inconsistent with the BDN?
Suspend use of the batch when possible, immediately inform the Company, and request a laboratory analysis of the MARPOL sample before any further operational decisions.
Is the bunkering checklist required by a specific rule?
It is not imposed in a specific form by any single convention, but is established safety practice (often also required contractually by charterers and vetting) to prevent spills during fuel transfer.
🎬 Additional photos, videos and interactive diagrams for this topic will be available in a future version of the platform.

## Related Topics

MARPOL Annex VI Purifiers and Separators

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