It is recommended that all exporters ensure that they have a defined procedure for the maintenance & carriage of fresh produce in reefer containers. Hence, this paper is based upon the procedures adopted by Perma Shipping Line and aims to inform PSL shipping staff, PSL Depots, Exporters & Packing sheds and assist a common understanding of the various components / actions that form an integrated "cold chain".
The ultimate for a fresh produce exporter is to have its product arrive at its destination in first class condition. This way the buyer is satisfied with what he or she has purchased and can confidently sell the product at optimal profit thereby generating further business for all participants in the "cold chain".
Consequently it is important and in everyone's interest to maintain the cold chain from harvesting right through to delivery to the customer.
Pre Packing Procedures
Much has been published on produce harvesting and post- harvest treatment of products, we will not attempt to add to this, thus it is assumed that all the appropriate measures / procedures have been implemented to ensure the product is at its "peak condition" when being loaded into the container.
The following are some exporter / packing shed recommended Do's & Don'ts to apply during the pre-shipment process.
1.Exporter should ensure the PSL agents are aware of the following details and the details should be provided in the booking format given:
- Name of shipper
- Size & Type of reefer
- Cargo type to be loaded
- Temp. setting required in °F & ° C
- Vent setting required
- Pick up date and time
- Port of delivery and final port of delivery
- Required date at port of delivery
- If IMCO, all necessary details
- Any other remarks
- Exporter instructs his transport contractor to collect the container from the nominated collection depot and ensure that the truck driver sees that the container is internally clean, has no odor, and is not damaged and the pre-trip decal (affixed to the machine casing) is still within the validity date. Under normal conditions the pre-trip is valid for 30 days (from the date shown on decal). Also it is necessary to check that the Part low chart (if applicable for the unit) is in place. If the container does not meet these conditions, the driver should not sign the EIR and he should seek another container.
- When the container arrives at the packing station, exporter to ensure the requirements defined in item have been validated again. Also ensure the drain plugs are not in place and the floor drains are open.
- Exporter to ensure that the product has been "pre-cooled" to the required carrying temperature. It is important to note: "A refrigerated container is designed / manufactured to maintain product temperature – not to reduce the product temperature to the required carrying temperature".
- Exporter to ensure that the cargo weight does not exceed the permissible cargo weight of the container, also ensure the gross weight (cargo and container) does not exceed your road regulations and those of the country of destination, the weight specifications are shown on the container door.
- Should the refrigerated container be held at exporters or his transport premises for some time (days) prior to loading the unit, it is suggested consideration be given to the refrigerated machinery. Storing an operating reefer container with the machinery facing a very hot climate causes problems with the compressor overheating, high head pressure being generated, lower refrigerating efficiency being achieved & higher running costs being incurred by direct exposure to sun light. If the ambient air is at say 40 degrees Celsius, with direct sunlight on the compressor, the compressor temperature can be as high as 50 to 60 degrees Celsius. Compressors are designed to cut out if the compressor temperature or head pressure exceeds preset limits, thus the cool chain can be broken.
- Ensure the product is readily available for loading and is adjacent to the container doors. I.e. ensure the container is located as close as possible to the cool room doors.
- Always load the container as quickly as possible, otherwise ambient temperature will impact on the container and the produce, usually this would be at a higher temperature, which will impact on the product quality if left for prolonged periods. If the product temperature at the time of loading is what is required for carriage during transit, then provided the container is loaded quickly the product temperature will quickly disperse the internal ambient air, therefore the container can operate effectively & efficiently.
- If loading does not occur in a "cold tunnel", do not pre cool the container, it is a waste of power & serves no purpose because the ambient air temperature will invade the container within minutes of the doors being opened. Furthermore if pre cooled, when the ambient air mixes with the chilled air, condensation will occur on the container internal walls. When the container is operational again, the condensation accumulated will force the machinery to more than regularly "defrost", this will result in heat being introduced to take off the ice formed on the evaporator coils – not conducive to maintaining the required chiller temperature. This also adds pressure on the machinery to perform, which with excessive demand, could result in a failure of the machinery. Furthermore, condensation could accumulate on the product cartons, resulting in wet / collapsed packaging.
- Image - Cargo should be stowed below the red line.The cargo must never be loaded above the red line of the container, if cargo exceeds the red line this will impede the air flow which could impact on the quality product out turn and possibly the refrigeration unit.
- Ensure that the weight is evenly distributed throughout the floor space.
- If using forklifts to load the product, ensure that the "T" bar floor grills are protected from damage, as any damage could cause restricted air flow during the transit to the buyer and impact on the quality out turn.
- Ensure that the packages are stowed with adequate spacing between the packages for "good" air flow and that the storing is stable. Do not leave large spaces where the stow could collapse during transit. Palletisation gives a much improved air flow.
- If the container is being held on power at the packing station, before transport to the terminal, ensure:
Carriage temperature is set to the required setting. NB, THIS IS THE SUPPLY AIR TEMPERATURE SETTING.
The fresh air vents are open to the setting required.
The Part low chart is "face up" ready to record & the needle is in the correct position. THIS IS THE RETURN AIR READING, usually slightly higher than the supply air because of produce respiration. When there is a stable temperature, i.e. immediately after being placed on power, the initial Part low chart readings can be much higher than the supply air setting, because the container must disperse the respirated heat & ambient air that has accumulated during the packing of the container. Shippers / Packers are urged to use a bolt seal in addition to any other seals required by the Shipper or Government authorities. However if the container is subject to " PULP TESTING ", please use a strip seal as the bolt seal will be utilized after the pulp testing – as per the pulp testing instructions
Transport & Terminal Receival
- Ensure the vehicle is suitable to transport the container, particularly handling the gross weight and has suitable twist lock fittings – chains are not acceptable. Always ensure that reefer unit power cable is correctly stored within the unit casing, especially if the container was "on power" prior to the transport to the Terminal.
- All appropriate export permits / approvals must be completed before the vehicle leaves the packing station and handed to the driver. The PSL Agent should send an Export Receival Advice (ERA – Ref. appendix 2) to the POL for the acceptance of export reefer. A completed ERA should have all the following information (is clearly written so there is no mis-interpretation of what has been written) – Container no/s, type & size, booking no., seal no., shipper's name, commodity, weight, vessel, voyage number & Eta, POL/POD, set temperature, vent setting, Humidity and IMCO details (if any). Same should be forwarded to the vessel operator and obtain the acknowledgement from vsl. Operator / Chief. Officer for future reference.
- If being transported under refrigeration (i.e. generator), ensure the machinery is set correctly (as per h above). However, ensure the vents are closed during the transport movement to avoid pollutants / contamination i.e. diesel fumes from entering the container via the vents during the transport journey. Usually the container machinery end is loaded behind the transport cabin.
- If not being transported under refrigeration, the transporter must travel directly to the terminal. Transport of more than 2 to 3 hours (without refrigeration) will result in increased product temperature due to the product respiration during the transit. It has been shown in recent exercises that during the transport (during early morning) that the pulp temperature of produce increased by 3 to 4 degrees Celsius during a 6 hour transit – not conducive to a good product out turn!
- Exporter must always ensure that his transport contractor has sufficient time to arrive at the terminal before the final Receival time. Exporter must check with PSL agent office for the final Receival times and if a late Receival is available on that particular day of delivery. Normally the Terminal final Receival times for refrigerated cargo is 1 hour before closure, this enables the container to be placed on power and checked to ensure the unit is operating correctly.
- When the transport arrives at the Terminal, providing the ERA is completed correctly, the transport will be directed to the unloading area – if the ERA is not completed, the transport will be rejected & "turned away".
- PSL agents must collect appropriate deposit from consignee in order to collect damage and cleaning charges (if any).
- On receipt of MT reefers, all depots must thoroughly inspect the reefer unit + the container (as per latest edition of IICL standards) and raise an EIR indicating all missing parts, damages and cleaning requirement and obtain the trucker's signature, identification number and truck registration number for future reference. The Line copy of EIR needs to be submitted to PSL agent along with EOR for recoveries.
Pre Trip & Washing
- PSL agent must keep their reefer technicians and depot operator(s) fully informed of the pre-trip requirements and when the containers are required for clients. It is essential that there is regular dialogue between the Line & exporters.
- Although much of the modern machinery is electronically controlled, the pre-trip procedure must be defined clearly, as any repairs / part replacements are essential to ensure the machinery operates effectively (to ensure the cargo arrives in prime condition). Each port will have interpretations of the length of time that a pre-trip occurs (relative to various costs), consequently the following is the pre-trip procedures for PSL.
- Depot operator and reefer technician are to be advised at least 24 hours in advance of a pre-trip requirement.
- On notification depot should wash the reefer container internally to free from any residue. If the external walls are "dirty", these must be cleaned to ensure a good presentation of the equipment. Depots are to ensure that the floor drain outlets are clear & during the steam cleaning, open the outlets to allow the water / condensation to escape in the correct manner. Once washed, containers should be placed in plugging area for Pre-trip inspection, in a manner that the container could be access easily by the technicians.
- After completion of washing, pre-trip inspection to be carried out by the appointed reefer technicians. If any defect found during pre-trip inspection, PSL agent to be notified immediately with the EOR for repair.
- Upon receipt of EOR from reefer technicians, PSL agent should refer to PSL – DXB (HQ) for approval of repairs. Once the repairs are approved, reefer technicians must carry out repairs and should return all the damaged parts to PSL agent's office.
- The pre-tripped container is then placed in the "available" stack.
- Prior to release of reefer to exporter, depots are required to raise an EIR indicating all necessary parts of the reefer and confirming cleanliness of the interior/ exterior and obtain trucker's signature, identification number and truck number for future reference and Line copy of EIR should be submitted to PSL Agent. Depots can use their own EIR for this purpose.
- On all occasions, the container must be lifted with either an appropriate lift truck fitted with a side frame or straddle carrier. Under no circumstance the reefer container should be lifted with a forklift.
Transport contractors must use trailers fitted with the twist lock fittings to ensure safe transport (there have been serious accidents, unfortunate deaths had occurred where chains have broken during the transport movement)
- The PSL agent must communicate with vessel operator to define the final time for delivery of reefer containers to the terminal (Port), it is essential that this information together with the proposed vessel movements are communicated to the refrigerated cargo exporters and packing stations, preferably in writing i.e. fax or e-mail.
- If the vessel operator has approved "late delivery", PSL agent must liaise with the reefer exporters and packing stations should additional time be required to achieve the delivery to the Terminal. Where necessary appropriate advices are sent to the vessel operator and the Terminal.
- Providing the ERA that is completed correctly, the transport will be directed to the terminal reefer stack where the straddle will off load the unit and place the unit at the sequenced stow point. The temperature and vent settings are then checked (against the ERA information) and if necessary adjusted to the correct (required) settings.
- Ideally the container should remain on power at the terminal for at least 24 hours prior to loading to stabilize the temperature of the produce.
- Until the container is loaded onboard the vessel, the Terminal staff monitors the temperature readings (return air) at least twice daily. Should there be any irregularities, the Terminal will contact PSL agent and they need to inform their nominated reefer technician for immediate action and where necessary repairs are performed to ensure the container is operating correctly. (Many instances the "call out" is because the product temperature was loaded in excess of the required carrying temperature, thus the temperature reading is above the required carrying temperature – poor cold chain practice!). The terminal and reefer technicians must record all "call outs" and temperature readings. It is suggested that the majority of "call outs "are resulting from "hot loads. I.e. the cargo has been loaded at much higher temperatures than the required carrying temperature; sometimes this may be high as 5 times the required carrying temperature.
- he PSL agent needs to make sure that the nominated reefer technicians are available for call out 24 hours a day, 7 days a week.
Loading / On Board to Port Delivery
- When the containers are loaded onboard the vessel, the PSL agent should liaise with the vessel operator and need to make sure that the vessel operator's technicians check all reefers loaded are operating correctly as per the reefer container list. The vessel's chief engineer or electrician must be present during the "pre sail inspection" as they are required to sign the ERA acknowledging receipt of the containers and that they are operating in accordance within the details indicated in ERA, which supplied by the PSL agents at the load ports.
- During the voyage, the vessel's Chief Engineer or Electrician monitor all reefers onboard, generally 3 times per day. Appropriate action is taken when necessary as "spare kits "for each type of container machinery are retained onboard to enable prompt corrective action. The reefer monitoring is based on the reefer container lists supplied by each load port, this is collated from the Exporter's ERA's.
- In port of delivery, PSL agents are required to collect the entire reefer monitoring data from the vessel operator and the port and to keep all the records safely for any future reference.
Procedure for Transshipment Cargo
PSL agents in all load ports should communicate within 24 hours of the vessel's departure, to each final port of discharge and the transshipment departments of all T/S ports with full particulars of each reefer container shipments. Further, PSL agents should make sure to liaise with the transshipment departments of all T/S ports to connect the transshipment containers on 2nd carrying vessels on timely basis. In due course the transshipment departments confirm the 2nd carrying vessel & arrival at the various ports of delivery. This confirmed information is then relayed to the exporter & the port of delivery office confirms to the Notify Party shown on the Bill of Lading.
Gensets are used to power the reefer containers, thereby maintaining the set temperature during rail or road transportation. There are two types of Gensets, one is clip-on type and the other is under slung Gensets that are mounted under the chassis. The use of Gensets is subject to an additional charge.