for the carriage of cargo in non-operating reefer containers were launched by TT
Club, Container Owner Association (COA), and Cargo Incident Notification System
(CINS) on 15th August. Refrigerated containers (known as
reefers) are designed to be used to transport temperature controlled cargo.
Since there may be insufficient temperature controlled cargo for a ‘return’
leg, reefers would normally be positioned empty to a demand location.
In order to
minimise empty repositioning costs, container operators may use reefer
containers in a non-operating mode to carry approved dry cargo on a return leg.
Such cargo is described as non-operating reefer cargo (NOR cargo). NOR
cargo is defined as a cargo that is approved for packing into a refrigerated
container to be transported without operating the refrigeration machinery.
Transporting NOR cargo enables the carriage of additional cargo in busy trade
lanes where reefers need to be positioned for their next cargo move, but are
competing for slot space with revenue earning dry cargo.
containers differ from General Purpose (GP) containers in both design and
materials. This must be taken into account in relation to the approval of and
packing requirements for NOR cargo. These guidelines are intended to help
container operators and shippers in making decisions that appropriately protect
both cargo and containers. The design of reefer containers enables cargo
that is sensitive to temperature to be transported in an insulated container
with its own refrigeration machine that circulates air, controlled at a set
characteristics of a reefer container are:
of accurate control of temperature and air flow, within specified technical
parameters. Satisfying hygiene and similar standards, for example related to
food cargo, pharmaceuticals or flowers. The design is complex and
reefers are seven times more costly than GP containers to purchase. The
internal construction materials used are susceptible to damage if cargo packing
techniques are not adjusted. Repairs to reefers are more difficult and costs
are seven times higher than for GP containers.
Dry Cargo in
Reefers: Issues to Consider
There are a
number of issues to be considered concerning the characteristics of a reefer
container before approving it to carry a NOR cargo or commencing packing cargo.
internal dimensions than a GP container require increased awareness and
attention when preparing the packing plan. Front-heavy weight
distribution from refrigeration machinery should be taking into account in
planning cargo distribution. In planning appropriate cargo distribution, the
packer should take account of front-heavy weight distribution in the container
from the refrigeration machinery. Materials used for construction are
less robust and particularly susceptible to piercing or stress. Unpainted
metal surfaces are susceptible to corrosion from cargo and improper cleaning
various causes for the type of corrosion that are presented in reefer
container. Although the most common cause is the cargo itself, including
treatments (e.g. residues of fumigation) that might be applied to the cargo,
cleaning with caustic materials will also cause corrosion or oxidation to the
interior of the unit.
Say no to
fumigation is not allowed in operating reefers; shippers should ensure
fumigated cargo is adequately ventilated before packing the container. It is
difficult to treat and permanently repair this corrosion as the surface of the
aluminium has had its protective oxide layer contaminated. In addition to
corrosion, the aluminium T Floor sections are susceptible to mechanical damage,
such as caused by fork or pallet truck wheels. Most reefer interior
sidewalls are protected by aluminium scuff liners. Aluminium is a softer
material than the steel used in GP containers, so can be more easily cut by
forklifts used during the packing/unpacking process or by the sharp edges of
packaging, such as pallets. Some reefers use Fibre Reinforced Plastic (FRP) as
lining material, which is more resistant to damage. Cuts in the scuff liner or
sidewall, as shown in Picture 6, allow moisture into the insulating foam that
needs to be repaired before the insulation deteriorates. The thin panel
aluminium ceilings are significantly easier to damage than the Corten steel
used in the roofs of GP containers. Such damage exposes the insulation foam and must be
repaired to prevent moisture absorption. It is not operating, the
refrigeration machine is exposed to the atmosphere inside the container.
Gases released from
cargo can corrode and 1 50% of a reefer container’s new value is the complex
refrigeration machinery at the front of the unit. Half of this machinery
is located inside the container. Corrosion to the coil can result in
the coil area reducing, air resistance increasing or refrigerant pipes being
corroded through. Such damage will affect the cooling performance of the
machinery and its ability to maintain temperature settings for future
temperature controlled cargoes. In some cases, corrosion and corrosion products
may also compromise the quality of certain cargo types, although not generally
NOR cargo. There are detailed maintenance guidelines for machinery that
need to be followed in order to prolong optimal performance and avoid damage to
future temperature controlled cargoes, adds TT Club advisory.