Section: 11 CARGO OPERATIONS - Univan

Univan Ship Management Limited Issue 1 REV 0 Page
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FLEET OPERATION MANUAL Date 01.01.2005
CONTAINER TYPES AND ASSOCIATED PROBLEMS
Copyrights: Univan Ship Management Limited, Hong Kong. All rights reserved
Any unauthorized reproduction of this manual, in any form is prohibited
SECTION 11.7
at the time of stuffing, and accordingly, they are incapable of freezing a cargo which is not already
in a frozen state. Pre-cooling of the container, and indeed the cargo, to the required temperature
is usually critical, but it is often thought that setting the container temperature at a lower
temperature than that required for carriage will give speedier cooling. This is not the case, the
rate of cooling will not be significantly different and there is the risk that the lower temperature will
result in frosting damage to cargo. The ventilation openings on reefer containers can also be a
source of problems, and it is often the case that these are not in the correct position for the cargo
being carried. Most refrigerated loads (especially fruit), with the exception of frozen goods, fresh
meat, and non-organic goods such as photographic film, require air exchange to reduce carbon
dioxide (CO2) build up and remove enzymes which speed up ripening. For frozen cargoes the
ventilation openings should always be closed.
The actual functioning of the reefer equipment is also a source of many problems. There are
numerous accounts of units not being plugged into their power/cooling source correctly, or at all,
or being inadvertently unplugged. This is as much a problem off the ship as it is on, and carriers
should be aware of their period of responsibility for the goods and in any case ensure that a
supervised regime of manual inspections is rigidly enforced. Reefer system failure is also a
problem and pre-trip inspections (PTI) should be thorough. Appropriate spares and knowledge
should be available on board to effect repairs. The interior fitness of reefer containers is essential,
and there are numerous instances where cargo has been contaminated or otherwise damaged
due to improper or insufficient cleaning and/or removal of previous cargo remnants including
odours.
Other common sources of problem lie with temperature setting, recording devices and stowage
arrangements. Incorrect temperature setting is a common occurrence and even when this has
been done by the shipper, the carrier’s responsibility may become involved if the set temperature
is not checked against bill of lading and shipping/booking instructions. Temperature records are
invariably of great importance and enormous difficulties can arise when recording devices are not
working. Partlow charts are in common use, and each individual chart can record for up to 31
days. It is often the case that the charts are not replaced or filled in correctly, i.e., with start time,
container number, set temperature, etc., or that the clockwork mechanism is not activated.
Temperature monitoring is not so much a problem but a burden and a necessary one. The
problem arises when monitoring has not been done and/or records are not kept. As to stowage, it
is often found that arrangements within the container are not suitable for the type of refrigerated
cargo concerned.
11.7.8 Bulk Containers.
These general purpose type containers can carry dry powders and granular cargoes in bulk. Top
loading is via hatches fitted in the roof and discharge (which requires a tipping trailer) is via a
hatch fitted in the door. Mild steel floors are commonly fitted to enable easy cleaning. Tank
containers for dry bulk cargoes are also in use, but give lower payload capacities than the box
design (for a TEU, around 33.1 cbm for the former and 19.3 cbm for the latter).
The main problems these units encounter are water ingress and condensation. Care must be
taken particularly with fine powders, where the inadvertent opening of hatches has been known to
cause product loss, especially in windy conditions.