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Risk Focus: Temperaturecontrolled cargoManaging risk throughout the cool supply chain

CONTENTS

1. Introduction 3

2. The Reefer Cargo Transport Unit (CTU) overview 3

3. Equipment selection, maintenance, pre-trip inspection and cleaning 5

4. Maintenance – Why run the risk of equipment breakdown? 6

5. Cargo packing 8

6. Packing cargo into reefer CTUs 9

7. General principles of packing 10

8. Reference guide to common commodities and temperatures 13

9. Importance of in-transit instructions 15

10. Final mile delivery 16

11. Post-incident investigations 17

12. Operational check list 18

Glossary of terms 19

AcknowledgementsThe information contained in this Risk Focus briefing has been formulated from the UK P&I Club’s and TT Club’s insurance experience. However, the Clubsgratefully acknowledges the advice and support in the preparation of this guidance of Mark Bennett, Bennett Consulting Associates, Bill Brassington, ETSConsulting, Carsten Jensen, Jensen Associates and Mark Edwards, Modalis.

DisclaimerThe information contained in this briefing has been compiled from various sources. We do not accept responsibility for loss or damage which may arise fromreliance on the information contained herein.

Copyright 2019 © Jointly held by Thomas Miller P&I Ltd and Through Transport Mutual Services (UK) Ltd. All rights reserved. Users of this briefing may reproduceor transmit it verbatim only. Any other use, including derivative guidance based on this briefing, in any form or by any means is subject to prior permission in writingfrom the copyright holders.

3Temperature Controlled Cargo

1. Introduction

The temperature controlled cargosupply chain can present operationalchallenges for all stakeholders, thesecargoes being amongst the moresensitive transported. Through analysisof claims experience from UK P&I Cluband TT Club there are a number ofcommon errors and misconceptionswhich can result in deterioration or totalloss of the cargo, as well as damage tothe carrying equipment.

This document is intended to be apractitioner’s good practice guidecovering all stakeholders throughout thesupply chain whether operating, packing,unpacking or handling temperaturecontrolled, ‘refrigerated’ or ‘reefer’ cargotransport units (CTUs). The document isstructured in such a way that it followsthe chronology of the supply chain.

The IMO/ILO/UNECE Code ofPractice for Packing Cargo TransportUnits (CTU Code)1 is mentionedthroughout this document. Chapter 2of the CTU Code defines variousstakeholders in the supply chain whilstChapter 4 provides details of theresponsibilities for each; the due diligenceelements between stakeholders areexpanded in MSC.1/Circ.15312. Furtherperishable cargo advice can be found

within the CTU Code Informative Materialsection IM8. The table below illustrateshow, in today’s supply chain, sometraditional stakeholders may assumeseveral roles as defined in the CTU Code.

The stakeholders mentioned throughoutthis document are consistent with thosestakeholders identified in the CTU Code.A glossary defining these roles is on theinside back cover of this document.

In addition to the guidance andinformation contained in this document, allstakeholders need to be aware of national,regional and international regulationsconcerning the preparation and transportof certain commodities, including thecapability to provide data records.

2. The Reefer Cargo Transport Unit(CTU) overview

The reefer containerWhen the first refrigerated containerswere introduced during the 1960s, the

cooling was initially provided by acentral refrigeration plant, which meantthat the containers had to be connectedthrough pipes or air ducts before anytemperature control could take place.These units were referred to as‘porthole’ containers.

The next development was to producedemountable refrigeration (clip-on) unitsthat were attached to the front (porthole)end of the insulated container, whichallowed the cargo to be cooled evenduring road or rail transport. This quicklyled to refrigeration machinery that couldbe incorporated into the containers, andso by the mid 1970s the integratedrefrigerated (reefer) container was inoperation. An integrated reefer container,as the name suggests, houses its ownrefrigeration machinery and essentiallyonly requires an electrical supply tooperate. The two designs of insulatedcontainers (porthole and reefer)operated in different trades for manyyears but the reefer quickly became thepreferred standard in new trade routesowing to its ease of operation.

Developments in refrigeration technologyand the efficiency of container insulationmean that today reefer containers are areliable and highly cost effective modeof transport for temperature controlledor sensitive cargoes.

Managing risk through the cool supply chain

Stakeholder responsibilities under the CTU Code

1 www.unece.org/trans/wp24/guidelinespackingctus/intro.html2 www.imo.org/en/OurWork/Safety/Cargoes/CargoSecuring/Documents/MSC.1-CIRC.1531%20(E).pdf

Maintenance/ Cleaning Selection Packaging Cargo Passing DeliveryPTI packing instructions

CTU operator � � � �

Consignor � � �

Packer � �

Shipper � � � �

Road haulier � �

Rail haulier �

Intermodaloperators

Carrier � � � �

Consignee � � �

� � � �

Demand for the carriage oftemperature controlledcargo continues to increase

4 Temperature Controlled Cargo

Common reefer containers have anoperating range between -30°C to +30°C(-22°F-86°F). In response to shipperdemands for protecting high value cargosuch as sashimi-grade swordfish andtuna, machinery manufacturers have nowdeveloped specialised super-lowtemperature containers with the capacityto maintain temperatures down to -60.°C(-76°F). Common for all is that they aredesigned to maintain the carried cargowithin a given temperature range, withthe cooling air provided constantlymonitored and regulated by thecontainer’s refrigeration unit.

It remains the case that reefer containersfor intermodal transport – despitemodern ones being able to decreasetemperatures over time – are designedto maintain a pre-set temperature only,not lower the temperature of the packedproduct. Consequently, any frozen productpacked for shipment should always bepre-cooled to the desired carriagetemperature and any fresh product shouldbe pre-cooled prior to loading to providethe best quality on delivery to the receiver.

The main cargoes carried within reefercontainers are fruits, vegetables, fish,meat and poultry. However, there aremany other commodities carriedincluding flowers and pharmaceuticals.

Shippers or consignees may request thatthe cargo is transported throughout thesupply chain under active refrigeration.That means that the machinery must beconnected to a power source at all times.Such a requirement may also bestipulated where there is a long road or

rail element to and from the maritimeterminals. To achieve this, it is essentialthat a mobile generator (gen-set)accompanies the container(s). Thegen-set may be mounted on the front ofthe container (nose mounted), fittedunder the chassis or trailer (underslung)or, for rail transport, fitted into acontainer (generator container). Activerefrigeration is essential where theaverage ambient temperature is high,taking account of the entire transportmovement from point of loading todelivery, and each leg of it.

Some reefer containers are used in anon-operating state within certain tradelanes where empty re-positioning wouldnormally be required. CTU operatorsshould be aware of this practice astransporting other types of cargo canresult in increased damage, whichincreases the risk of inefficient operation,and of contamination. For furtherinformation, we have produced

Guidelines for the Carriage of Cargo inNon-Operating Reefer Containers3.

The reefer trailerRefrigerated trailers are understood tohave been widely commerciallyintroduced from the 1930s, as a moretime efficient alternative to rail cars. Thereefer trailer was designed in numerousvariations to accommodate differingtrade volumes and restrictions.

Reefer trailers are far less standardisedwhen compared to reefer containers.There are a vast number of differentoptions from which to select in relationto size, shape, weight, volume andcapabilities. Furthermore, it is possiblefor trailers to be compartmentalised,therefore having more than one climaticzone, allowing a single trailer to carry bothchilled and frozen cargoes concurrently.These trailers may have a movableinsulated wall that, when not required, canbe hoisted up and secured flat against theceiling of the trailer. Dual compartmenttrailers would generally have asecondary evaporator/refrigeration unitpermanently mounted in the ceilinginside the doors. Dual temperaturetrailers may have an additional accessdoor on one side to facilitate directaccess to the front compartment.

The Agreement on the InternationalCarriage of Perishable Foodstuffs andon the Special Equipment to be used forsuch Carriage (ATP)4 sets the standardsregarding the specification of reefertrailers; all reefer trailers must conformto the specifications set, in all of thecontracting countries5.

3 www.ttclub.com/fileadmin/uploads/tt-club/Publications___Resources/Document_store/COA-CINS-TT_Club_Guidelines_NOR_Containers_2017.pdf4 www.unece.org/trans/main/wp11/atp.html5 https://treaties.un.org/Pages/ViewDetails.aspx?src=TREATY&mtdsg_no=XI-B-22&chapter=11&clang=_en

…any frozen productpacked for shipment shouldalways be pre-cooled tothe desired carriagetemperature and any freshproduct should be pre-cooled prior to loading toprovide the best quality ondelivery to the receiver

Potential airflow patterns in a dual compartment reefer trailer


Whilst the refrigeration machinery maydiffer in design compared to the reefercontainer, the principles of its operationare the same; indeed manymanufacturers produce units for bothtrailers and containers.

Reefer trailers are primarily powered byeither an inbuilt power pack orconnection to the tractor unit, althoughwhere longer periods of storage arerequired they are capable of beingplugged into fixed power sources.

In the case of dual compartment trailers,the main refrigeration machinery at thefront is larger and has a higher coolingcapacity than the secondaryrefrigeration unit. It is, therefore,generally recommended to transport themost temperature sensitive cargo in thefront compartment.

When using dual compartment trailers, itis also important that due care is takento ensure that the split wall is properlyinstalled and that the gaskets around theedges (sealing the wall against the sidewalls and floor of the trailer) are intactand provide a true airtight barrierbetween the two compartments. Wherethere is significant variation in thetemperature requirements for the twocompartments (e.g. frozen cargo in onecompartment, chilled cargo in the other),leakage from a defect or improperlyinstalled split wall may cause damage toone or both the cargoes carried.

Reefer trailers have two primary optionsin terms of cooling, either a continuousfeed of cool air for chilled/fresh produceor a start/stop system used for frozencargoes and to some extent non-livechilled cargoes.

Where cargo type is concerned there areno differences between the use of areefer container or a reefer trailer. Thechoice in this regard will be influencedby seasonality and market demand.

Generally reefer trailers are utilised forshorter land based journeys.

3. Equipment selection, maintenance,pre-trip inspection and cleaning

SelectionThis section explores the various optionsavailable and considerations to be takenwhen selecting the most appropriatereefer transport unit for the shipment.

The selection of the correct equipment isof importance and the key factors arethe volume and mass of the cargo to beshipped, the nature of the journey andthe required transport temperature.

Integrated reefer containers generallycome in 20ft, 40ft or 45ft length and8ft 6in and 9ft 6in (known as high cubeor ‘HC’) height configurations. Very few45ft reefer containers exist, with atendency for use in domestic andintra-regional operations. The vastmajority of the global fleet is comprisedcurrently of 40ft HC.

The table below provides a guide to thetypes of reefer container commonlyavailable and the approximate volumeand payload capabilities. Thisinformation should only be used as aguide and for specific information youshould consult the provider of theequipment being used, as eachoperator’s equipment is likely to differ inprecise specification.

The standardisation of reefer containershas been driven by the desire tooptimise ship operation and efficiency ofspace utilisation on-board ships. Trailerson the other hand come in manydifferent sizes and capacities, themaximum sizes dictated by the nationaland transnational limitations forweight/axle pressures and dimensionsallowed, as provided by the road safetylaws applicable in the countries wherethe trailers operate.

It is common for both trailers and reefercontainers that each equipment providerwill offer a selection of equipment andservice levels to suit industry needs onall trade routes. Below is a list of themore common options:

• The majority of reefer CTUs will havesome form of reefer monitoring toprovide running information. However,some providers will be able to offeradditional remote temperature andcondition monitoring potentiallyaccessible by the shipper or consignee;this form of monitoring is becomingmore common.

• Specialist reefer CTUs adapted totransport cargoes that need to be hung– for example meat carcasses.

• Specialist dual refrigeration unitswhich are particularly useful in theshipment of sensitive chemicals andpharmaceuticals.

• Specialised reefer CTUs capable ofsuper-low temperature cargoes whichneed to be transported at temperaturesdown to -50°C (-58°F).

• Controlled atmosphere CTUs wherethe interior atmosphere is managed todelay respiration and to extend storagelife for fruits and vegetables. Spoilingand moulds are thus minimised.

Where there is a requirement totransport cargoes with differenttemperature specifications within thesame CTU, a dual refrigeration CTU willbe required. A dual refrigeration CTUprovides two entirely separate cargospaces in a single unit (generally trailer)and allows, for example, a fresh and afrozen cargo to be carried concurrently.

It is possible to utilise a dualcompartment trailer as a conventionalsingle compartment trailer. When doingthis, there are some key points that needto be taken into consideration:

• The split wall must be properly stowed;when not in use, it is important that thesplit wall is locked in place completelyflat against the ceiling. If the wall isloose or slanting downwards, this cancause blockage or restriction of theproper airflow through the trailercompartment. There is also risk ofbodily injury or damage to cargo.

• Only the primary refrigeration unit mustbe operated; the primary refrigeration

Common types of reefer container

Common ISO Description Est volume PayloadReefer size codes capacity

45R1 40' High Cube 67-68.7cbm Approx. 29,900-30,500kgs(65,918lbs-67,240lbs

42R1 40' Standard 56cbm Approx. 28,500kgs(62,831lbs)

22R1 20' Standard 29cbm Approx. 26,000-27,500kgs(57,320lbs-60,627lbs)


unit at the front of a dual compartmenttrailer has the same capacity as in aconventional, single-compartmenttrailer, capable of providing therequired temperature control for thewhole compartment when the trailer isnot split. If the two refrigeration unitsare operated simultaneously in onecompartment, then they will bedistributing cool air towards each other,which will hamper the natural airflowthrough the cargo compartment andcause uneven temperature conditions.

• Potentially lower stacking height; boththe secondary refrigeration unit andsplit wall take up space at the ceiling,meaning that the maximum stackingheight of the cargo is less than forsingle-compartment trailers. This mustbe taken into consideration whenconfiguring the cargo to be shipped.

Greater consideration must be given tothe volume of cargo to be shipped whenselecting a reefer trailer. Too little cargoin a large unit can have a detrimentaleffect on the efficiency of the airflowand thus affect the quality of the cargoon arrival.

Consideration must also be given to thefact that there is generally a higherpropensity to transport consolidated

cargoes in trailers. Where this is thecase, the reefer trailer doors will beopened more frequently, which willimpact the ability to maintain set pointtemperature.

Where carriage overnight is concerned,the driver will need to ensure that thereefer equipment remains operationalthrough the entire rest period.

4. Maintenance – Why run the risk ofequipment breakdown?

Even the newest, most sophisticatedmachines require maintenance; reeferCTUs are not an exception.To ensure the efficient operation of thereefer CTU, it is essential to keep theequipment in a sound state of repair.Improper maintenance can causeinconvenient downtime, costly repairsand potential loss of cargo. Establishinga preventative maintenance schedulecan prove extremely valuable.

Under the CTU Code, the CTU operator,generally the shipping line or leasingcompany, is responsible to provide areefer CTU which is fit for purpose.

The structure of all containers, includingreefers, should be examined and

maintained within the parameters of theoperator’s maintenance scheme asrequired by the International Conventionfor Safe Containers (CSC6) as a matterof course. It should be noted, wherereefer containers are concerned, thatwhilst general damage (for example tothe side walls) to the container may beacceptable within the parameters ofthe CSC, such damage may bedetrimental to the effective operation ofthe reefer container and must, therefore,not be overlooked.

The refrigeration machinery will, inaddition, require regular maintenance andservicing in line with the manufacturer’srecommendations and guidelines. Whilstthe recommendations for each model willvary, the service manual will state howfrequently specific components, such asthe compressor and evaporator, shouldbe fully serviced, and how often filtersand other wear and tear componentsshould be routinely replaced.

The reefer container has its own powercable which, when not in use, should becoiled in the designated area at the frontof the unit. Failure to do so may result inthe cable and plug being damaged duringtransport that may in turn compromisethe electrical integrity of the refrigerationmachinery. Refrigeration machines require

6 www.imo.org/en/About/Conventions/ListOfConventions/Pages/International-Convention-for-Safe-Containers-%28CSC%29.aspx


several kilowatts of energy to operate,which is generally provided by threephase electrical supply. Therefore, if theinsulation or conductors within the cableor plug are damaged, there is a seriousrisk of injury to persons operating thereefers or a fire. Regular checks shouldbe made before connection and whilst inoperation to ensure that the power cableis in sound condition and not showingany signs of discolouration.

Pre-trip InspectionsOne of the objectives of the pre-tripinspection (PTI) carried out on everyreefer CTU prior to release for packingwith cargo is to ensure that therefrigeration machinery is in workingorder. Many reefer CTUs will have anautomatic pre-trip mechanical testcompleted by the machinery controller.However even though the machinery hasbeen tested before packing, there areinstances when the machinery failsduring transport. If this takes place onboard ships the engineering staff mayseek to rectify the problem byundertaking urgent repairs, however thisis not always possible due to weatherconditions or the container’s location.

Most controllers for the refrigerationmachinery will include one or morediagnostic routines within the software.Each of these routines may be referredto as a PTI in some format, for example“Brief PTI Test” or “Full PTI Test” or justundertake function tests. They are,however, diagnostic procedures to checkthat the components are operatingwithin the normal parameters and shouldnot be considered as a replacement fora correctly undertaken PTI. Whilst not anexhaustive list, below are a number ofimportant checks which should beundertaken during the pre-trip inspection.

A “before power on” inspection wouldseek to ensure that the CTU andrefrigeration equipment where applicable,satisfy the following conditions:

• Free from physical damage and ingood condition.

• Are not missing components which arekey to the operation of the equipment.

• The reefer CTU is sufficiently clean,including ensuring that the CTU is freefrom signs of mould, plants, pests andother invasive species.

• Any debris such as old labels, placardsor remnants of previous cargoes isidentified.

• The refrigerant and lubrication levelsare sufficient.

• Condenser coils/evaporator andevaporator drain are clean and freefrom debris.

During the “power on” inspection theefficient operation of the refrigerationmachinery should be checked. Asdescribed above this is normally initiatedby the inspector by selecting theappropriate diagnostic routine on themachinery controller display. The choiceof routine selected will determine thediagnostic checks undertaken and oncompletion of the automatic checks thecontroller will illuminate either a pass ora fail. Whilst this is being undertaken theinspector should ensure that there areno abnormal noises from componentsand that the rotation of the condenserand evaporator fans is evident and in thecorrect direction. The inspector may alsoinitiate a manual defrost routine.

In the event that a reefer CTU fails thePTI, the unit should be marked for repairor maintenance immediately and notreleased into use.

A CTU operator should determine anddocument the period of time that apre-trip inspection is deemed valid; apre-trip inspection would normally beconsidered valid for a period of 30 days.

CleaningAs part of the PTI, the cleanliness of theCTU should be checked to ensure that itmeets the requirement of the shipper.However, and in addition, the presenceof pest or pest contamination shouldalso be checked visually (see also theJoint Industry Guidelines for Cleaning ofContainers7). The CTU Code providesthat “all persons involved in themovement of CTUs also have a duty to

ensure, in accordance with their rolesand responsibilities in the supply chain,that the CTU is not infested with plants,plant products, insects or other animals”.It should be noted that pests and otheranimals can take residence within thehousing of the reefer machinery as wellas the loading space.

There are generally three levels ofcleanliness in this context.

Physically clean – which could beconsidered as the surface areas appearclean to the naked eye. This could beachieved through sweeping and washingwith cold or hot water.

Chemically clean – whereby all surfaceresidues which could supportmicroorganisms are removed. This couldbe achieved through the use ofappropriate soaps/chemicals applied tointernal surfaces, left for a period andthen rinsed clean.

Microbiologically clean – where surfaceresidues are free from viablemicroorganisms including food bornepathogens. There is a need to use moreaggressive disinfectants to achieve adeeper clean.

Under the CTU Code, the CTU operatoris responsible for providing a reefercontainer, which is clean and free ofdebris, cargo residues, noxious materials,plants, plant products and visible pests.

The general design features of the reeferCTU can give rise to some challenges inrespect of cleaning activities includingnon-welded joins in and between theinternal side wall panelling and – forcontainers – the T-bar flooring.

7 www.worldshipping.org/industry-issues/safety/joint-industry-guidelines-for-cleaning-of-containers8 www.imo.org/en/OurWork/Safety/Cargoes/CargoSecuring/Pages/CTU-Code.aspx (see Chapter 8, Annex 5, Annex 6 and IM4)

All stakeholders involved inthe movement of CTUsalso have a duty to ensure,in accordance with theirroles and responsibilities inthe supply chain, that theCTU is not infested withplants, plant products,insects or other animals8

Specifically for pharmaceutical use,but applicable to other productscarried, the temperature sensorshould be calibrated at least annuallyand a certificate to this effectexamined as part of the pre-tripinspection process.


The use of reefer CTUs to transportgeneral cargo in a non-operating statefor re-positioning purposes can also giverise to unexpected contaminants beingpresent after use.

Some cargoes, for example, tuna carriedin bulk or other dried fish products, canleave the CTU with significant taint/smell,which may still remain after cleaning.This can subsequently cause taintdamage to other cargoes, especially ifthe next load is fresh fruit or vegetables.Certain fatty cargoes, such as chocolateand butter, are particularly prone toabsorbing odours.

Each customer will have their ownrequirements and expectations in thisregard and it is important to ensure thatthese are clearly communicated to thereefer operator when booking theequipment and transport.

Technology in respect of inspections andcleaning of reefer units continues toprogress. Advanced techniques,including inspections under ultra violetlight, can assist in readily identifyingproblem areas in terms of cleanliness9.

During the cleaning process, whereapplicable, operators should ensure that:

• The floor drains are opened.

• There are no obvious signs of damageto non-welded joins (breaks in sealant)

that could allow water ingress into theinsulation.

• Any debris collected in or blocking thedrains is removed.

• There is no evidence of the presenceof pest or pest contamination.

• The equipment is thoroughly rinsedand, if washing liquids or soaps areused, ensure that there are no residuesremaining.

• The equipment is dry following thecleaning process – there is a risk,otherwise, of freeze damage, iceblockages being formed and corrosiondamage when turned on.

Certain cargoes and fumigants, such asSulphur Dioxide (SO2) where permittedfor use can give rise to corrosion of thereefer container components whenmoisture is also present. In particular,aluminium corrosion of the internalsurfaces of the reefer CTU can beproblematic. Evidence of this oxidationcan be identified visually and manifest asan accumulation of white powder. Thisby-product of oxidation is mainlycosmetic, although a potential risk existsof transfer to the cargo itself, which canresult in rejection by the consignee. Theeffects of such corrosion are irreversible.

If corrosion is identified, it should benotified to the CTU operator immediately.

5. Cargo packaging

PackagingThe correct packing of cargo is one ofthe more important factors in all typesof transport and is particularly affectedby the packaging of the commodity,whether it be carton, pallet, net bag orhanging meat. The stow should bestable to avoid damage during handlingand in transit, yet it should alsopromote the desired air circulationthrough and around the commodity.Incorrect selection of the packagingdesign can result in damage to, or lossof the cargo.

Under the CTU Code the consignor isresponsible for ensuring that thepackaging is sufficient to withstand therigours of transit, which can becategorised into the following risks:

• Rough handling during packing andunpacking the transport unit.

• Compression from cartons stackedupon one another due to the physicalmass of the cargo.

• Humidity during the transit period,compromising the structural integrity ofthe packaging.

The natural rolling movement of the CTUparticularly during carriage by sea andthe vibration settling associated withroad and rail vehicle transport can resultin stack collapse.

It is important to recognise that paperor cardboard based packaging canabsorb moisture over time, such cartonsgradually get weaker during transport.This process may also lead to stackcollapse. For this reason, specialistpackaging such as wax impregnatedcardboards are sometimes used forchilled products, but with the movetowards more environmentally friendly,degradable packaging, the use oftreated cartons is decreasing. Hence,it is imperative that a solid cartondesign is chosen, using multi-plycorrugated cardboard.

If palletised, the cartons should besquared to the pallet to ensure thatthe pallet supports the cartons and thatthey are properly secured to thepallet using strapping and corner piecesas appropriate.

9 CTU Code provides further general information in respect of cleaning and cleanliness at Chapter 8.2.4


Pharmaceuticals are required by law to show the temperature range withinwhich they should be stored and transported, often referred to as the labelclaim. Industry regulators police this on a strict basis; pharmaceuticalmanufacturers should demonstrate that the label claim has been met beforetheir products can be released to market and used by healthcare practitioners.

It has been recognised that reefer transportation presents risks in this area andmitigating action must be taken. The particular risks are when the reefer is notpowered, typically during receipt at the port, movement to the reefer stack andship loading during export operations, then the same points during import.Consequently, various insulation protection products are available to maintainproduct temperature during those times when the reefer is not powered.

These various solutions each have their own processes, which must be followedas defined by the manufacturer.

Chilled productChilled products such as fruit andvegetables are living organisms andproduce heat, moisture and ripeninggasses as they respire (or breathe), all ofwhich need to be removed during transit.The quantities of heat etc. generateddepends on the variety of fruit orvegetable and usually varies with theproduct temperature. To ensure thatthese respiration elements are removed,it is essential that a large proportion ofthe circulating air passes through, ratherthan around the stow, to give goodcontact with all parts of the product.

Without sufficient airflow, there is a riskthat the correct temperature will not bemaintained within the entire consignment,despite the refrigeration unit providingadequate cooling and operating asintended. Furthermore, build-up of ripeninggasses from respiration can causeaccelerated ripening of the cargo, therebyshortening the storage life of the cargo,and increasing the risk of mould and decay.

Where chilled or fresh cargo is concernedthere are variants as to the packagingrequirements, dependant on whether youare intending to ship by reefer trailer orby reefer container, as the airflow withineach behaves very differently.

As all reefer containers used for seatransport have bottom air delivery/verticalairflow, the packaging for fresh fruit andvegetables being shipped in reefercontainers requires ventilation holes in thetop and bottom so that when the cartonsare stacked, the holes align allowing aclear path for the air to flow through themass of cargo. The number, size and

placement of the holes within thepackaging are usually cargo specific sowill vary from commodity to commodity.

In reefer trailers, the air is pumped in atthe top of the cargo compartment,resulting in a more horizontal airflow.Therefore, packaging for fresh fruit andvegetables being shipped in reefertrailers also requires ventilation holes inthe sides so that when the cartons arestacked, the holes align allowing a clearpath for the air to flow through the massof cargo. The number, size andplacement of the holes within thepackaging are usually cargo specific sowill vary from commodity to commodity.

If the packages are stacked and securedon a pallet and where covers are used inthe shipment of chilled cargoes it mustbe ensured that sufficient ventilation ismaintained through the pallet and that thecovers are properly secured to the pallet.

Shrink wrapping should not be usedsince it prevents airflow.

Frozen cargoesAs frozen products do not produce anyheat or respiration gasses that need tobe removed, there is no need forventilation holes in cartons used.

It is imperative that the product isproperly pre-cooled to the requiredcarrying temperature before packinginto the CTU takes place.

Cartons should be stacked directly ontop of each other in a ‘block stow’(one which has no deliberate spacingbetween the cartons and pallets),indeed it is preferable that there is noairflow through the block stow, as thecore temperature will assist inmaintaining the overall temperature ofthe cargo.

6. Packing cargo into reefer CTUs

Pre-checksUnder the CTU Code the packer isresponsible for ensuring that the reeferhas been checked and verified as fitand clean for use before packingcommences. Given the complexities ofthe supply chain, the shipper or a freightforwarder may be performing the roleof the packer.

Where appropriate, the packer shouldconfirm that:

• The reefer CTU is in cargo worthycondition.

• The cargo has been correctlypre-treated. Even with the correcttemperature, ventilation and humiditysettings, carriage in a reefer CTU willnot improve the quality of the cargo.

The cargo needs to have been pre-cooledto the required transport temperature.

Chilled cargoes cangenerate their own heatdemonstrating theimportance of sufficient airflow through the packaging

Ventilated carton

Blocked air passageFree passage of air

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Generally speaking, the earlier thetransport temperature of the cargo isachieved, the better the quality and thelonger the storage life of the productduring transport. Remember; a reeferunit is designed to maintain thetemperature of the cargo being carriedand not lower it.

The reefer unit should be set at thecorrect transport temperature. Verificationshould be sought regarding °C and °Fand also + or – temperature values.

Ventilation should be set at the correctlevel in cubic metres per hour (cmh) orcubic feet per minute (cfm) (attemperatures below 0°C (32°F) theventilation setting must always be closed).

The humidity setting should be at thecorrect level (at temperatures below-3.0°C (37.4°F) this must always be off).

7. General principles of packing

Under the CTU Code the consignor isresponsible for providing all informationrequired for the proper packing of thesubject cargo. The packer is responsiblefor ensuring that the transportinstructions are adhered to and that thecargo is sufficiently secured.

PlanningIt should be highlighted that there are anumber of critical differences betweenthe packing of cargo into a reefercontainer and the packing of cargo intoa reefer trailer, which are addressed inthe coming paragraphs.

Packing guidance applicable to bothcontainers and trailersNo fumigants should be used in reeferCTUs such as sulphur dioxide (SO2).SO2 can react with moisture in the CTUto produce acids which attack theinternal aluminium components,including the T-bar floor (containers),scuff liner and the evaporator coil of themachinery. SO2 induced corrosion hasbecome a significant cause of damageto reefer CTUs in recent years whereshippers have used this fumigant in anattempt to control mould growth orinsect infestation.

When preparing the stowageconfiguration prior to the actual loadinginto the CTU, it is essential that dueconsideration is given to the cargo to becarried, and its volume.

For frozen cargoes, subject to proper pre-cooling of the consignment, the purposeof the refrigeration unit is to maintain thetemperature of the external faces of thecargo stow to counter the heattransferred through the doors, walls, roofand, to a lesser extent, the floor. This isachieved by cooled air circulating aroundthe stowage (peripheral circulation).

Certain commodities, such as fish, aresometimes transported in bulk (notpackaged) and it is imperative that thecargo is sufficiently pre-cooled to therequired carriage temperature. Thisensures that the cargo maintains itsshape and does not deform duringpacking or in transit; where containersare used the T-bar floor poses that risk.Any deformation of the cargo afterpacking may reduce the airflow aroundthe cargo stow.

When palletising cargo for shipment, thecargo must be positioned to avoid anyvertical voids such as chimney stacking,where unavoidable, spaces should becovered with dunnage.

Packing guidance for reefercontainersWhere reefer containers are to be used,whenever possible the cargo should be

evenly distributed across the entire floorof the container to ensure the mostefficient airflow.

Reefer containers are generally designedand operated with bottom delivery, i.e.that the cooled air is delivered out of thebottom of the refrigeration machineryand directed into the T-bar flooring. It isessential that the channels in the T-barfloor remain clear otherwise the cooledair cannot be delivered to the rear of thecargo as shown below.

Placing all the cargo evenly as a blockright from the front of the containerimmediately adjacent to the refrigerationunit all the way to the end of the T-barfloor at the doors will ensure that thecooled air is circulated around the backof the cargo and presents the least riskto the product during transport.

There are obviously occasions where thecargo is not sufficient in volume to fillthe entire load space, where this is thecase, the packer should seek to avoid:

• Block stacking to the red load lineimmediately adjacent to therefrigeration unit as this may result in aseriously asymmetrical load with aneccentric centre of gravity.

Efficient airflow pattern in a reefer container

Cargo

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Block stacking adjacent to the refrigeration machinery creates airflow inefficiencies

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Cargo Cargo

Creating air gaps in the cargo stow will create airflow inefficiencies


• Block stacking the cargo to the red loadline in the centre of the load space,thus leaving a large gap between thecargo and the refrigeration unit as thiswill result in short circuits in the airflow.

• Creating air gaps in the stowage, whichwould cause an air short circuit anduneven cooling through the cargocompartment during transit. Gaps inthe stowage, as well as a largevariation in stacking heights, alsorenders the load more prone todamage from movement during transit.

It is essential that proper planning isundertaken prior to packing to maximisethe area covered and to minimise theexposed T-bar floor. Where it isnecessary to position the cargo withvoids above the T-bar floor, these shouldbe covered with dunnage and air bags toprevent an air circulation short circuit.

Packing guidance for reefer trailersWhilst many of the same principlesapply, where reefer trailers are to beused, greater consideration needs to begiven to the weight distribution of thecargo to ensure that axle weight limitsare not exceeded.

In a reefer trailer, the airflow is designedto take a very different path from therefrigeration machinery. Reefer trailers donot have a T-bar floor and are generallydesigned and operated with top delivery,i.e. that the cooled air is delivered out ofthe refrigeration machinery across thetop of the cargo stow, and is then pulledback through return air ducts placedcentrally on the front wall, creating amore horizontal airflow through thetrailer as illustrated below.

Cargo

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Efficient airflow in a reefer trailer

For transport in reefer trailers, nationalroad safety laws may stipulate that thedriver is responsible for the cargobeing securely packed inside the trailerand unable to shift dangerously duringroad transport. The driver is responsiblefor lashing inside the trailer afterstuffing, which is commonly achievedthrough the use of metal bars that canbe installed vertically and/or horizontallywhere required.

Packing guidance forconsolidated cargoesThere is a greater propensity to loadconsolidated cargoes in reefer trailerswhere several consignments may bedelivered in one trip. When planning topack consolidated cargoes thought mustbe given to how the stow will behave aftereach delivery is made, especially regardingairflow, ventilation and how the remainingcargo will be secured for onward transit.

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Due consideration must also be given toconsider whether all intended productsto be transported together are fullycompatible. In this regard, the followingpoints should be considered:

• Do all products have same temperaturerequirements?

• Are ventilation and humidityrequirements compatible?

• Will all products be properly pre-cooled?

• Ripening gasses such as ethylene andCO2 produced by one commodity may

cause accelerated ripening or taint ofother commodities.

• Possible tainting of smell or taste (e.g.chocolate transported together withgarlic can cause taint of the chocolate).

• Packaging compatibility (for example,non-live product in fully closedcartons stowed next to ventilated fruitcartons in a trailer would block thehorizontal airflow).

• Have some products been fumigatedor received any treatments that couldcause taint to other products?

Good practice regarding airflowThe way the cargo is packed within thereefer CTU has a direct impact on theairflow and therefore, the efficientdistribution of cooling air andmaintenance of temperature conditionsthroughout the cargo compartment duringtransit. It is vital to adhere to the followinggeneral guidance where applicable:

• Do not run the reefer unit with thedoors open or not closed properly.

• Where containers are used do not blockthe channels at the end of the T-bar floor.

• Where containers are used do not packcargo beyond the end of the T-bar floor;there may be a rear loading line beyondwhich the cargo should not be placed.

• Ensure that cargo is not packed abovethe red maximum height load line.

• Ensure that the airflow is not restrictedby the cargo or any packing materials.

• Do not leave any areas open oruncovered on the floor, the frontbulkhead or the side walls.

• Ensure that the airflow encapsulatesfrozen cargoes.

Cargo

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Efficient airflow for a frozen cargo stow

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Efficient airflow for a fresh cargo stow

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decisions and cargo care required:

• routing, modes and duration of the transit

• the ripeness and related characteristicsof the commodity

• the seasonal or regional climate in thegrowing areas.

All such factors may require slightlydifferent temperature settings tomaintain the quality of the produce.

As can be seen, transposing °C with °For vice-versa would have a major effecton the cargo. For example milk, thatshould be transported at 0.5°C would befrozen if the refrigeration machinery wasset to 0.5°F (-17.5°C)

• It is important that cartons are notforcibly pressing against the side wallsor doors of the reefer container as thiswill restrict the efficient flow of airduring transit.

• Ensure sufficient airflow through thepackaging for chilled cargoes and thatthere are no blockages to the airflow.

Good practice for packing reefer CTUs

• Ensure that the cargo is packedaccording to any producer ormanufacturer guidelines which may beavailable for that particular commodity.

• Ensure that the cargo is stable on thefloor of the CTU.

• Ensure that the total cargo mass doesnot exceed the maximum payload ofthe reefer CTU and where appropriatethe respective axle weight limitations.

• Ensure that the total gross mass of thereefer container (cargo + container +dunnage) does not exceed themaximum permissible operating grossmass of the container or any road orrail limitations in any country passedthrough during the planned transit.

• Close the doors of the unit immediatelyonce packing has been completed.

• Where mandated, or specified by thecustomer, seal the CTU.

8. Reference guide to commoncommodities and temperatures

Common cargoesIt is important for all stakeholders in thecool supply chain to have a basicknowledge of common temperature


Temperature reference guide for commonly carried cargoes

Commodity Celcius Fahrenheit

Sashimi-grade swordfish and tuna -50.0 -58.0

Frozen fish -28.0 -18.4

Ice cream -26.0 -14.8

Frozen butter -18.0 -0.4

Frozen meat -18.0 -0.4

Frozen fruit -18.0 -0.4

Garlic fresh -2.0 28.4

Chilled meat -1.0 30.2

Peaches 0.0 32.0

Kiwi 0.0 32.0

Grapes 0.0 32.0

Milk pasteurised (chilled) 0.5 32.9

Butter 1.0 33.8

Apples 2.0 35.6

Avocado 5.5 41.9

Chocolate (chilled) 8.0 46.4

Bakery products (chilled) 10.0 50.0

Lemons 12.0 53.6

Bananas 13.3 55.9

Frozen

Chilled

For pharmaceutical products, thereefer should be pre-conditioned i.e.it should arrive at the loading facilitywith the internal temperaturealready at the set point. Typical labelclaim temperature ranges forpharmaceuticals are 2°C (35.6°F) to8°C (46.4°F) and 15°C (59°F) to25°C (77°F) with set points at 5°C(41°F) and 20°C (68°F) respectively.The loading should take place in atemperature controlled facility so thereefer should remain operationalduring loading.

ranges for various cargo types. Thus,for example, if instructions are receivedto transport a consignment of frozenfish at +25°C, the instructions shouldbe questioned, thus potentiallypreventing a loss.

The following chart provides guidance asto the common temperature ranges andsettings for a selection of commoditieswhich may assist an operator to validatethe instructions presented. The datacontained within this chart should be usedas a guide only and should not supersedethe data provided by the shipper.

Where chilled and fresh produce are beingtransported, each specific consignmentwill be unique. Whilst not exhaustive thefollowing factors will impact the


Set point temperatureThere are several factors which need tobe considered when carrying cargo inreefer CTUs; temperature is perhaps themost obvious. Ensuring the correcttemperature setting is critical to thequality of the cargo being carried.

There are a number of commonoperational errors made aroundtemperature selection which can beeasily avoided, including:

• the choice of degrees Celcius (°C) ordegrees Fahrenheit (°F) or selecting a“-” value rather than a “+” value.

• confusion between the unit ofmeasurement at certain levels, forexample; 0°C (a common chilled value)and 0°F (a common frozen value).

Recognising that each and every cargowill have its own requirements, there aresome commonalities which can be ofgeneral assistance.

The data opposite should be used as aguide only and should not supersede thedata provided by the shipper.

Celcius °C Fahrenheit °F

-60 -76.0

-58 -72.4

-56 -68.8

-54 -65.2

-52 -61.6

-50 -58.0

-48 -54.4

-46 -50.8

-44 -47.2

-42 -43.6

-40 -40.0

-38 -36.4

-36 -32.8

-34 -29.2

-32 -25.6

-30 -22.0

-28 -18.4

-26 -14.8

-24 -11.2

-22 -7.6

-20 -4.0

-18 -0.4

-16 3.2

-14 6.8

-12 10.4

-10 14.0

Celcius °C Fahrenheit °F

-8 17.6

-6 21.2

-4 24.8

-2 28.4

0 32.0

2 35.6

4 39.2

6 42.8

8 46.4

10 50.0

12 53.6

14 57.2

16 60.8

18 64.4

20 68.0

22 71.6

24 75.2

26 78.8

28 82.4

30 86.0

32 89.6

34 93.2

36 96.8

38 100.4

40 104.0

42 107.6

Reference conversion chart from Celsius to Fahrenheit


9. Importance of in-transit instructions

InstructionsEach stakeholder in the supply chainhas a responsibility to pass all theappropriate information regarding thecargo and transport requirements to thenext stakeholder so that the cool chain ismaintained, and the cargo remains at therequired transport temperature andsettings. Careful scrutiny of theinstructions at each stage isfundamental to the successful shipmentof temperature controlled cargoes.

Under the CTU Code the consignor isresponsible for ensuring that the cargois correctly described and to notify thepacker/freight forwarder of anyspecific instructions in relation to thepending shipment.

Cool supply chains are often complexwith multiple stakeholders involved.When claims arise, it is often due tosimple instructions between the variousstakeholders highlighting the need forthe reefer container to be plugged in andunder power which have been overlooked,which can have a devastating impact onthe quality, or total loss of the cargo

Haulier

Maritime Terminal Operator Maritime Terminal Operator

Carrier

Pack House

Meat Works

Cold Store

Un-packer Cold Store

Retailer

Wholesaler

Consumer

Haulier

Consignor

Consignee

The complexities of a modern cool supply chain

when it reaches its destination.

Poorly worded notations can also bean attributing factor, ambiguity whereinstructions are concerned should beavoided. Where instructions appear tobe less than certain, the stakeholdershould seek clarification prior toproceeding.

Each stakeholder taking delivery of areefer container and cargo shouldundertake a number of checks such as:

• Pause to consider whether theinformation received is complete andmakes sense.

• Ensure that the required set pointtemperature on the shippingdocuments corresponds with thesetting on the reefer container itself.

• Ensure that the receiving stakeholderconfirms that the reefer is operatingand under power after interchange.

• Ensure that, where used, generatorsare properly connected and havesufficient fuel for the entireremaining journey.

• For frozen cargoes, ensure that theventilation, humidity and controlledatmosphere settings are in the offposition with ventilation closed

• For chilled cargoes, ensure that therequired ventilation, humidity andcontrolled atmosphere settings arecommunicated and strictly followed.

When transferring the reefer CTUbetween stakeholders, for examplebetween the port and the road haulier,each party should keep EquipmentInterchange Receipts (EIRs), stating thetime the reefer CTU was transferred (i.e.picked up and left the port). Thisdocument should also includeconfirmation of the transport instructionsand settings.

Where a dual compartmentreefer trailer is used extracare is required to ensurethe correct settings areselected


Where appropriate, each stakeholder inthe supply chain should consider thepotential language barriers faced bysubsequent stakeholders. There may bea requirement to provide translatedinstructions, therefore avoiding apotential loss through misunderstanding.

Where particularly sensitive cargoes areconcerned, additional communicationsmay be appropriate betweenstakeholders. It is good practice todevelop a procedural audit trail to verifyinstructions have been passed.

Practical checksIt is critical that the reefer CTU is checkedthroughout the journey along the supplychain. The care, custody and control of areefer CTU will likely pass to severalstakeholders in any given transport. Thereefer CTU should be checked to ensurethat the set temperature is correct andthat the reefer is operational at eachinterchange through the supply chain byboth stakeholders. Where a single stake-holder has the reefer CTU in its care,custody and control for an extended period,checks should be undertaken periodicallyat intervals of not more than12 hours.

As a general rule, a reefer CTU should notbe left off power for any prolonged periodthrough the supply chain. In particular,ship to shore or shore to ship operationscan give rise to delays in this contextand should be managed carefully toensure that the reefer CTU remainsunder power wherever practicable.

10. Final mile delivery

Final mile delivery to the consigneeAt the time the reefer CTU is picked upfrom the port or depot for delivery tothe consignee, the following checksshould be carried out by the collectingdriver, regardless of whether the inlandhaulage is arranged by the carrier orthe consignee:

• Visual check that the reefer CTUappears structurally sound.

• The security seal remains intact anddisplays the correct seal number.

• Temperature setting on the reefermachinery is the same as the transportdocumentation.

• Ventilation setting on the reefermachinery is the same as the transportdocumentation.

• Humidity setting (if used) on the reefermachinery is the same as the transportdocumentation.

• Controlled atmosphere settings (ifused) on the reefer machinery is thesame as the transport documentation.

Upon arrival at the delivery point, theconsignee should always carry out thesame initial checks of the reeferCTU structure, seal and settings aslisted above, to the extent this ispractically possible.

Under the CTU Code the consignee isresponsible for:

• Ensuring that the floor of the reeferCTU is not overstressed during theunpacking process.

• Reporting any damage to the reeferCTU after unpacking.

• Returning the reefer CTU completelyempty and clean.

The reefer CTU doors should be openedcarefully to avoid injuries if the cargo hasmoved in transit and spills out with theopening of the doors. If the interior had ahigh humidity, or was not at the requiredtransport temperature before packing, orif the cargo was not at its transporttemperature, there is a risk that thedoors may be frozen shut. Extra caremust be taken to open the doors withoutdamaging the structure.

Allow time for the interior atmosphere toequalise with the cold store or exteriorbefore entering the container. Only oncethe interior atmosphere has equalisedwith the outside should any person enterthe container. This is to ensure that theair within is breathable.

When the reefer CTU doors are opened,the consignee, from outside thecontainer, should firstly check whetherthe consignment appears to be correctlystowed inside the container and palletsor packaging are still intact.

In the event that any quality irregularitiesare noted immediately upon opening thedoors, or in connection with unloadingthe first cartons, the consignee shouldstop further unpacking, notify the carrierand arrange for a surveyor to attend,prior to completing the unloading.

In cases where quality irregularities areonly noted after the reefer CTU hasbeen fully unpacked, the consigneeshould endeavour to notify the carrieras soon as possible, and anindependent survey should be arranged.There may be a number of insurancestakeholders interested at this stageand they should be notified and askedfor instructions.

The consignee should initially visuallycheck the subject cargo for compliancewith expected specifications and qualityand is in sound condition. Further probetesting may be required:

• Chilled cargoes should be subjected todestructive probing (temperature probepushed into the produce).

• Frozen cargoes should be subjected toapplying a temperature probe betweenthe cartons. However if the readingsshow temperatures slightly above theset point temperature then destructiveprobing should be consideredsacrificing one of the cartons.

Temperature at the core of the cargo islikely to be different than that betweenlayers of packaging.

Tem

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Time

Time

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Edge orCorner

Temperatures fluctuate differently depending on the position of the carton in the stow

Pharmaceutical products will havededicated portable temperaturerecorders placed within the productby the shipper and these will beused for the purposes of releaseas described in the packagingsection above.


Where the reefer CTU is not unpackedat a conditioned unloading bay, it isimportant to transfer the cargo from thereefer CTU to the cold store withoutdelay. Exposing the cargo to ambienttemperature and humidity level may resultin the loss of or damage to the cargo.

11. Post-incident investigations

The data loggerAlmost all reefer CTU used in internationaltrade today are fitted with data loggers.The data logger is an integrated part ofthe reefer control unit, and is basically acomputer record of the unit’s operationalhistory. Data concerning the unit’soperation is collected and stored as adatabase on the controller hard disk.This can be downloaded by connecting alaptop or other external device via aspecial download connection placed onor near the controller unit at the front ofthe CTU (in containers, an additionalconnection is located inside the CTU,behind the left front panel). For newerreefer units which are prepared forremote monitoring and control, this datacan be accessed wirelessly via GPS orthrough closed networks.

The reefer container data logger recordstemperatures on an hourly basis and willnormally keep records for a period of 12-24 months, depending on the frequencyof use, since more memory is used whenthe container is running than when it isoff. For reefer trailers, the recordinginterval is often set between 5 to 15minutes, whereby the records kept areshortened to a period of 1 to 6 months.The data logger continues to collect dataeven when the reefer is not connectedto a power supply, as long as theintegrated back-up battery is charged.Once the memory is full, the data loggerwill delete the oldest data whenevermore space in needed for new data.

Usually the data logger is configured torecord the temperature setting and theactual supply and return air temperaturereadings. For voyages where humiditycontrol, integrated controlledatmosphere or additional cargo probesare in use, the actual readings for theseare also recorded.

Other events, such as turning the poweron and off, start and end of defrostcycles, active alarms or changes to thesettings, are recorded and time stampedat the exact time they happen. All of thisdata provides an audit trail of the

operation of the refrigeration machineryduring transport, from pre-packing to un-packing. This data should always bedownloaded and retained in case of aclaim resulting from a loss of, or damageto, the cargo.

When perusing data logger printouts, itshould be noted that the time is normallyconfigured to show Greenwich MeanTime (GMT) or Coordinated UniversalTime (UTC), regardless of geographicalposition of the container. Hence no timezone adjustments are applied, but willneed to be taken into account inidentifying the time of any discrepancy.

In addition to these, an extensive list oftechnical operational data concerningthe running of the compressor,evaporator and other key componentsare recorded. This information isprimarily used by reefer techniciansproviding a detailed account of thecondition of the reefer machinery inconnection with service and repairs.

In the event of a claimIn the unlikely event that therefrigeration machinery should fail, areefer CTU is designed to continue toprovide thermal insulation to a certaindegree but will not be able to preventthe internal temperature rising over time.

The insulation of modern reefer CTU isdesigned specifically to prevent heattransfer from the ambient air, even underextremely warm conditions. Even thoughthe insulation capabilities decrease

slightly over time, the heat transferpotential in a unit less than 10 years old,and in a good general state of repair, isvery low. Subject to the doors remainingclosed, any actual increase intemperatures inside the unit duringunavoidable off-power periods, e.g.during loading and discharge from shipsand intermodal handling, will not havesignificant effect on the actual cargotemperatures, even if such off-powerperiods persist for several hours. Evenso, any unavoidable off-power periodsshould always be kept as short aspractically possible.

Furthermore, errors or discrepancies tothe settings or operation are often timecritical and may result in loss of ordamage to the cargo. Therefore, ondiscovery, through checks undertaken atany point through the supply chain, areport should be made immediately tothe contractual party highlighting theerror or discrepancy.

Common issues include:

• An off-power period• Incorrect temperature setting selected• Contamination• Theft• Unplanned human interference

Where an issue is discovered the twokey elements in the initial investigationare temperature and time. Once known,an expert should be consulted as towhat the best course of action to takeshould be.

In such circumstances, it is goodpractice to involve your liability insurer atthe earliest opportunity.

It is also good practice to scrutinise thecontractual chain to identify (if possible)where the error has occurred with a viewto holding the responsible party liable atan early stage.


Whilst the earlier chapters consider each stage of the cool supply chain in detail,below is a 12-point check list, which can serve to provide a reference to anintended shipment. If the answers to the 12 questions beloware positive, thenwhilst it doesn’t cover every eventuality, the risk of loss through the supply chainwill be greatly reduced.

12. Operational checklist

1. Has the cargo to be shipped been clearly identified?

2. Does the subject cargo have any special requirements?

3. Have clear instructions been received regarding the requirements ofthe transport?

4. Have you selected the most appropriate CTU for the cargo and transport?

5. Has the pre-trip inspection been undertaken and the CTU passed?

6. Is the CTU clean and free from debris and pests?

7. Has the cargo been appropriately packaged for the intended transport inthe intended reefer CTU?

8. Has the subject cargo been pre-cooled, where appropriate?

9. Has the reefer CTU been correctly set in terms of temperature, ventilation,humidity and controlled atmosphere, where appropriate?

10. Has the subject cargo been packed and secured correctly within the CTU?

11. Has the CTU been sealed?

12. Have all received instructions been passed accurately to all stakeholdersthrough the intended supply chain?

Cargo transport unit (CTU)A freight container, swap body, vehicle,railway wagon or any other similarunit in particular when used inintermodal transport.

CarrierThe party who, in a contract of carriage,undertakes to perform or to procurethe performance of carriage by rail,road, sea, inland waterway or by acombination of such modes. Can befurther classified as:

• Road haulier

• Rail operator

• Shipping line

ConsigneeThe party to whom a cargo is consignedunder a contract of carriage or a transportdocument or electronic transport record.Also known as the receiver.

ConsignorThe party who prepares a consignmentfor transport. If the consignor contractsthe transport operation with the carrier,the consignor will undertake the functionof the shipper and may also be known as:

• The shipper (maritime)

• The sender (road transport)

ConsolidatorThe party performing a consolidationservice for others.

CTU operatorThe party who owns or operates theCTU and provides empty CTUs to theconsignor/shipper/packer.

Freight forwarderThe party who organises shipments forindividuals or other companies and mayalso act as a carrier. When the freightforwarder is not acting as a carrier, itacts only as an agent, in other words asa third-party logistics provider whodispatches shipments via carriers andthat books or otherwise arranges spacefor these shipments.

Intermodal operatorThe party who provides a service totransfer and/or stow CTUs. May besubdivided into:

• Maritime terminal operator

• Rail terminal

• Inland waterway port

PackagingReceptacles and any other componentsor materials necessary for the receptacleto perform its containment function.

PackageThe complete product of the packingoperation, consisting of the packagingand its contents as prepared for transport.

PackerThe party that loads, places or fills thecargo within or on the CTU; the packermay be contracted either by theconsignor, by the shipper, by the freightforwarder or by the carrier; if theconsignor or the shipper packs a CTUwithin his own premises, the consignoror the shipper is also the packer.

Set pointTemperature setting on the controller ofthe refrigeration unit.

ShipperThe party named on the bill of lading orwaybill as shipper and/or who concludesa contract of carriage (or in whose nameor on whose behalf a contract ofcarriage has been concluded) with acarrier. Also known as the sender.

Glossary of terms

The glossary of terms has been sourced from the CTU Code – Chapter 2

SM/CD 03/19

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