3.28 CARGO SAMPLING

Cargo starting and tank bottom samples are described in section 3.16.
In some cases, it is advisable to take bottom samples even when not required by the shore terminal. Bottom samples should be taken when one to two meters of cargo is in the tank, to retain proof of the quality of the cargo at that point in the loading. It is also advisable to take additional samples from the loading manifold following any shore interruption of loading.

3.28.1 Composite samplers
If the ship or dock is fitted with a composite sampler, the chief officer and independent petroleum inspector must attend the opening of the (sealed) sampler cabinet, removal and sealing of the sample container(s) and labelling of the sample. The chief officer should note any apparent irregularities in the sample or sampler operation.

3.28.2 Tank samples after loading
Cargo tanks should be sampled at top (1/6 depth), middle (3/6 depth), and bottom (5/6 depth). It is not unusual for a case of sample bottles to be consumed in this process, so the ship should be well supplied with them. For some crudes, an average (running tank) sample may be sufficient. Follow the owner's sampling instructions.
Sampling should be witnessed by a ship's officer, who should sign any labels affixed to sealed samples retained by the terminal or consigned to the shipper. Under no circumstances should sample labels be signed and handed over to the sampling crew for application 'after the bottles have been cleaned up'. Should the cargo surveyor refuse to jointly seal and mark the samples, an entry to that effect should be made in the deck logbook and the master should submit a protest regarding the refusal.
Samples drawn by the independent inspector are for the inspector, shipper and consignee/receivers. If the ship wishes to retain a sample for their own purposes, the chief officer must persuade the independent inspector to draw a fourth sample, or else have the crew draw a sample.
Because of the size of cargo tanks and the fact that the samples may be drawn from only one location, ship tank samples will never be as representative of the cargo as a sample obtained by a properly functioning automatic or composite sampling unit.

3.28.3 Sampling IGS vessels
On crude carriers and other inerted vessels, tank samples should be drawn through vapour lock fittings, without reducing IGS pressure. If suitable vapour locks are not fitted, then the IGS pressure may be
reduced to a minimum and tanks sampled one at a time, under close supervision, with the ullage hatches being closed tight immediately after. Advise the engine control room to be prepared to top up the IGS pressure as soon as sampling is completed.

3.28.4 Sample labels
The labels on sample containers should include, at a minimum:
- Vessel's name, date and port.
- Sample container seal number.
- Cargo name and other description.
- Cargo destination and shipper.
- Sampling witness names.
- Sample quantity.
- Tank number.
- Tank ullage and temperature.
- Sample type:
• Manifold.
• Bottom sample.
• Composite (automatic).
• Top/middle/bottom/running.

A record book should be maintained of all samples taken.

3.28.5 Storage
Cargo samples should be stored in a cool, well ventilated space, away from light. The space must be protected by a fixed fire extinguishing system.
Samples should be retained for one year after the discharge of the cargo if no protest of contamination is received in that time. If a protest of contamination is received, owners must immediately instruct the vessel to remove the corresponding samples to locked, fire-protected storage until they are shipped to the designated testing laboratory.