Have we ensured that the cargo is shipped
in apparent good order and condition? In this article, we will look at best
practices that members can follow to ensure they have a good defense when facing
alleged contamination claims.
What’s the problem?
One of the functions of the bill of lading
is that it is the evidence of receipt of the goods on board. It is the duty of
the master to ensure that the information shown on the bill of lading is accurate,
including that regarding cargo quality.
However, in most cases, the ship’s staff
are not able to assess the condition of the cargo on a tanker, due to loading
via a closed system and limited resources on board to check the quality of the
cargo. Also,
although the master has every right to
clause the bills, we have seen that most charterparties require a clean bill of
lading.
As a result, bills of lading may not be an
accurate reflection of the quality of cargo on board. Most cargo contamination
claims are brought against the member at the discharge port.
In most cases, the onus lies on the
shipowner to prove that the contamination did not occur on board. Given the
difficulties identified above, the ship becomes an easy target even if she was
not at fault and the cargo was contaminated before it was loaded. Under these circumstances,
sampling becomes vital as it can provide the shipowner with an important means
of confuting any alleged cargo contamination claims.
When to take samples
It is very important to take samples at
each of the stages of loading and discharging so that they can be compared, to
identify the source of the contamination. The stages are:
1. Shore tank sample prior to loading.
2. Manifold sample at the start of loading,
preferably with the manifold valve closed if possible; thereafter, spot checks should
be carried out during the whole loading operation.
3. Manifold samples during loading whenever
there is a change in the shore tank.
4. First foot samples from the cargo tank once
cargo is received in the tanks.
5. Final cargo tank samples after completion
of loading.
6. Cargo tank samples prior to commencement of
discharge at the discharge port.
7. Manifold samples at the start of discharge.
8. Shore tank sample at the discharge port if
there is any pre-existing cargo in the tank.
Who should take the samples?
Cargo surveyors attending at load and
discharge ports are more often
than not attending on behalf of the shipper
and the consignee, and are
not obliged to provide samples to the ship.
The ship might be handed a sample at the load port for delivery to the receiver
at the discharge port.
This sample is not the property of the ship.
Whether samples are provided to the ship or not, it is recommended that the
ship’s crew draw samples to protect the interest of the shipowner.
Every effort should be made to get the cargo
surveyor to sign and seal these samples; however, if the surveyor declines,
then a senior officer should sign and seal the sample, and keep it in their
safe custody. It is recommended that a ship’s officer always supervises the
sampling on board to check that the correct and safe sampling procedure is used
based on the material safety data sheet (MSDS) of the cargo and that
the sampling equipment and bottles are in a
good and clean condition
appropriate to hold the sample.
Sampling procedure
It is difficult to generalise the sampling procedure
for the various liquids which are carried in bulk because of the diversity of
the cargoes, the variety of loading procedures and the differing effects on
human health and the environment.
Safety is vital and utmost care should be
taken to avoid any exposure at the time of sampling.
Certain chemical cargoes might also require
antidotes to be carried on
board in case there is exposure to the
chemical. The MSDS should be
reviewed and the crew should have appropriate
training before they undertake any activities where the risk of exposure is
high.
Hazards must be mitigated by the correct
use of personal protective equipment and other safety equipment.
Samples should be drawn in compliance with
the industry best practices as set out in publications such as:
· ASTM
D 4057 – Standard Practice for Manual Sampling of Petroleum and Petroleum
Products;
·
ASTM
E 300 – Standard Practice for Sampling Industrial Chemicals;
·
BS
3195 – Methods for Sampling Petroleum Products;
·
BS
5309 – Methods for Sampling Chemical Products;
· API
Manual of Petroleum Measurement Standards, Chapter 8 – Standard Methods of
Sampling Petroleum and Petroleum Products;
·
ISO
5555 Animal and Vegetable Fats and Oils – Sampling.
In general, a ‘running’ sample taken by use
of a bottle and sample cage is the preferred method; however, for non-homogenous
cargoes, zone sampling is required to produce a representative composite sample.
The properties of some chemical cargoes require that special sampling
procedures be adopted such as excluding air, using specialist sample valves or
-‘closed’ sampling methods due to the toxicity or flammability of the cargo.
Appropriate safety procedures must be observed and the person taking the
samples should always be protected from exposure to the cargo
Sampling equipment
Sampling equipment and bottles come in a
variety of shapes, materials and sizes. Selection of the equipment and the
container should be based on the product to ensure that there will be no interaction
between the product and the container, which could affect the integrity of
either.
The following should be considered as a
general guide:
· Internal surfaces should be designed to
minimise corrosion, encrustation and clinkage.
· Inspection cover/cap should be of sufficient
size to facilitate filling, inspection and cleaning.
· Sample containers should be clean and free
from all substances (such as water, dirt, lint, washing compounds, naphtha and
other solvents, soldering fluxes, acids, rust and oil) that might contaminate
the cargo sample. Reuse of containers should be avoided; however, if necessary,
the containers should be cleaned by a method that has been determined as
acceptable for the intended use, for example, by rinsing with a suitable solvent.
· The equipment should be designed to allow
safe transfer of the product both from the tank to the container and from the
container to the analytical apparatus without affecting the sample product or
the safety of the person handling the sample.
·
The
sampling equipment should be cleaned using a method that has been determined as
acceptable for the intended use, for example, by rinsing with a suitable
solvent.
·
The
sample container should be large enough to contain the required sample volume
and have sufficient ullage space for expansion and mixing of the sample.
·
Glass
containers are suitable for many test and storage requirements. Clear glass
bottles can be easily examined visually for cleanliness, and allow for visual inspection
of the sample. Dark glass bottles offer protection to cargo samples that are
affected by light.
·
Plastic
bottles may be used for certain liquids after ensuring that the sample would
not be affected by problems such as solubility, contamination or loss of light components,
or would not lead to failure of the sample bottle.
·
Certain
products can be stored in metal (tin, aluminum or stainless steel) cans.
However, it is difficult to check the cleanliness of the cans prior to use.
Certain products might become contaminated due to oxidation and corrosion on
the can surface.
·
Sample
bottle closures/caps vary in their chemical resistance depending on the sealing
insert. Appropriate sealing caps should be used. Waxed cardboard disc inserts are
suitable for most petroleum products. Aluminum disc inserts are unsuitable for
acids and alkalis.
·
The
master should ensure that adequate and appropriate sampling equipment and
containers along with labels and seals are available on board, especially when
the ship carries different grades of cargo.
Checking of samples
Ship staff might not have the means to
analyse the sample, but should be able to check for:
è general physical appearance;
è colour and brightness;
è presence of water (if apparent);
è odour and taint (for non-toxic cargoes –
refer to the MSDS for the cargo);
è other physical impurities visible to the
eye; and
è the approximate pour point of the cargo if
it is heated cargo.
Loading of cargo should be stopped immediately
if the manifold samples show such apparent deviations.
Further investigation should be carried out
and the master should note protest. We recommend the member to also notify the
club.
Labelling and storage of samples
All samples drawn should be sealed, labelled,
retained and recorded.
The following information should be
recorded on the labels and the sample log for easy cross reference and
traceability:
1.
Ship’s
name and operational status before loading, after loading and before discharge.
2.
Product
name.
3.
Sample
source – tank number, manifold number.
4.
Sample
type – top, middle, bottom, dead bottom, running, composite.
5.
Identity
of sampler – surveyor, crew member.
6.
Date
and time.
7.
Location
– port, berth, anchorage.
8.
Seal
number.
Sample bottles should be sealed in order to
preserve the sample in the
event of a dispute. Ship staff should ensure
that the correct seal numbers are recorded in the sample log and other cargo
documentation. Marked samples should be retained in a dedicated sample locker,
ideally for at least 12 months. Samples should not be
exposed to extreme temperatures and should
be kept in darkness. When no longer required, disposal should be by the
appropriate means in accordance with MARPOL requirements. Samples of cargoes
that are known to react should not be stowed together.
Conclusion
It is very important that a strict and diligent
sampling procedure is adopted and included in the ship’s operations manual and that
the staff are trained appropriately to follow the best practices required to
carry the various grades of cargo that the ship transports.
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