Jebel Ali is one of the busiest ports in the region, and that intensity shapes every tank cleaning job. Berth windows are tight, surveyors are working to their own schedules, and a vessel that is not ready for the next cargo can lose its slot. The cleaning operation has to be planned before the vessel arrives, not improvised after the gangway goes down.
This guide walks through a practical tank cleaning sequence at Jebel Ali, the documents that matter, the compliance points that often cause delay, and the questions a ship manager should settle before work starts.
1. Pre-arrival assessment
The enquiry should arrive with enough detail to plan the job. Useful information includes:
- Vessel name, IMO number and local agent
- ETA, berth or anchorage
- Tank numbers and capacity
- Previous cargo and cargo history
- Next cargo or inspection standard
- Tank coating type
- Heating, ventilation and access limitations
- Any charterer, terminal or surveyor requirement
From that information, the cleaning team can propose a method, chemical requirement, manning level and realistic duration. If the next cargo is not confirmed, say so. The standard may need to be written around the most likely scenario.
2. Documentation and permits
Before anyone enters a tank, the paperwork has to be in order. Depending on the vessel and the job, this can include:
- Permit to work
- Enclosed space entry permit
- Gas-free certificate
- Risk assessment and method statement
- Chemical safety data sheets
- Waste disposal documentation
- Terminal or port access permits
The vessel remains responsible for its own safety management system. The cleaning provider should work within it, not around it.
3. Gas freeing and atmosphere testing
Tank entry is a controlled operation. Hydrocarbon vapour, oxygen and toxic gas readings must be within the permitted limits before entry. Ventilation may need to run for a considerable period before the atmosphere is acceptable.
This stage cannot be compressed to save time. A rushed entry creates a safety incident and a much longer delay.
4. Washing
The main cleaning phase may use hot or cold water, fixed or portable cleaning machines, chemical injection and manual work in areas the machines cannot reach. The method depends on the residue and the coating.
Practical considerations include:
- Temperature limits for the tank coating
- Chemical compatibility with the previous and next cargo
- Coverage of frames, stiffeners, sumps and pipelines
- Water quality where the next cargo is sensitive
- Drainage to the slop system without contaminating other tanks
For heavy or waxy residues, heating and steam may be needed before washing. For sensitive grades, the final rinse and drying matter as much as the main wash.
5. Slop handling and MARPOL compliance
Washings from oily or noxious cargo tanks are not ordinary waste water. They must be collected, handled and disposed of through an approved route, with records that support the vessel's oil record book or cargo record book.
Ask the provider:
- Where the slops will be received
- How they will be transferred
- What documentation the vessel will receive
- Whether the disposal cost is included in the quotation
Port state control inspectors routinely review these records. Missing paperwork is a compliance problem even when the tank itself is clean.
6. Drying and ventilation
After washing, the tank has to be dried and ventilated to the standard required by the next cargo. Moisture can affect cargo quality, coating condition and inspection results. Forced ventilation and dew point checks may be needed for sensitive products.
7. Inspection and certification
The final step is inspection. Depending on the requirement, this may be an internal check, a charterer's inspection or an independent cargo surveyor. The cleaning team should support the inspection, provide records and be ready to re-clean specific areas if the surveyor identifies a problem.
The best time to agree the acceptance criteria is before washing starts. "Visually clean" and "wall-wash clean" are very different scopes.
Realistic timings
| Vessel / scope | Indicative duration |
|---|---|
| Small product tanker, 2–4 tanks, like-for-like | 12–24 hours |
| Chemical tanker, multiple grades | 18–48 hours |
| Heavy residue or pre-dock clean | 2–5 days |
| Bunker barge or small offshore vessel | 6–12 hours |
These ranges assume reasonable access and a confirmed standard. A vessel with limited ventilation, heavy scale or a surveyor waiting on another job can take longer.
Common causes of delay
- Next cargo or inspection standard not confirmed
- Previous cargo history incomplete
- Slop disposal not arranged
- Gas freeing taking longer than expected
- Coating temperature limits restricting hot washing
- Surveyor availability
- Additional work found during cleaning
Most of these are avoidable with a detailed pre-arrival exchange.
Why coordinate with technical repairs
Tank cleaning often reveals work that needs a technician: a valve that will not seat, a coating defect, a pump issue or a sensor that has failed. If cleaning and repair are handled by separate suppliers, the vessel can end up waiting between them.
RNS Shipping coordinates tank cleaning with technical servicing, engine and machinery work, fabrication and spare parts through one operations desk. That does not remove the need for a drydock or a specialist yard when the scope requires it, but it does reduce the coordination burden on the vessel.
Plan the next Jebel Ali call
Send the vessel particulars, tank details, previous and next cargo, ETA and required standard. The operations team will review the scope and discuss the practical next step.
Questions ship managers ask
How long does tank cleaning take at Jebel Ali?
A single product tanker with two to four tanks may take around 12 to 24 hours. A chemical tanker with multiple grades or a heavy residue can take 18 to 48 hours or longer. The final schedule depends on the standard, access and inspection.
Can tank cleaning be arranged before the vessel arrives?
Yes. Send the vessel particulars, previous cargo, next cargo, tank numbers, coating type and ETA in advance so the method, chemicals and manning can be planned before berthing.
Who handles slop disposal?
Washings and residues should go to an approved reception facility with the correct documentation. Confirm the disposal route and receipts as part of the cleaning scope so the vessel's records are complete.
Do you clean cargo holds as well as tanks?
Yes. RNS Shipping supports tank and hold cleaning scopes for tankers, bulk carriers and other vessel types, subject to the previous cargo and the required next standard.
Which other UAE ports are covered?
RNS Shipping supports vessels in Dubai, Jebel Ali, Dubai Maritime City and Khorfakkan, with wider UAE and Gulf mobilisation discussed through the operations desk.
