Jet A-1 after dirty cargo: how charterers judge previous cargoes

Why jet fuel is different

Jet A-1 is tested against a strict specification covering things like colour, particulates, water, and contamination from other fuels and additives. Small traces of heavy oil, dyes, or residues from other products can put a cargo off-specification. The fuel supply chain has its own quality assurance rules, and charterers apply them when they nominate a ship.

How charterers judge previous cargoes

Charterers carrying jet fuel commonly look at the ship's last three cargoes, not just the last one. Typical restrictions focus on:

• Dirty petroleum products such as fuel oil and crude
• Products containing additives or components that could be harmful in jet fuel
• Biofuel components such as FAME, which jet fuel specifications strictly limit

Exactly which previous cargoes are acceptable, and how many clean cargoes must come in between, depends on the charterer's and supplier's quality rules. Check the voyage instructions and ask early. It is common for a ship coming out of fuel oil to need one or more intermediate clean cargoes before jet is acceptable.

Preparing tanks for jet

If the cargo history allows it, preparation has to be thorough:

1. Full hot wash of tanks after the dirty cargo, followed by cold and fresh water rinses.
2. Lines, pumps, coils and vapour lines flushed and drained. See lines, pumps and heating coils.
3. Manual finishing of shadow areas, suction wells and coils.
4. Mop and dry every tank. Water is itself a jet fuel quality problem.
5. Check coating condition. Coating that holds black oil is a real risk for a jet cargo.
6. Pre-inspect to a higher standard than for gasoil.

Common causes of jet contamination complaints

• Colour or haze traced to residue in lines or pumps
• Water from inadequately dried tanks
• Particulates from rust scale or coating breakdown
• Trace components from a previous cargo the charterer did not accept

The commercial side

Fixing a ship for jet after a dirty history without checking the previous cargo rules first can lead to rejection at the load port, with all the cost and delay that brings. It is far cheaper to confirm acceptability, plan the intermediate cargoes and prepare properly than to argue about it at the terminal.

How Cleanship helps

We plan and carry out changeovers from our Fujairah and Indian bases, with tank, line and coil preparation, manual finishing, drying and pre-inspection. See the DPP to CPP changeover guide, our DPP and CPP tank cleaning service, or send us the cargo history and next nomination for advice before fixing.