Loading of Reefer Containers – Fruit

Contents

1. Pre-season Planning
   • Crop Projections
   • Cooling
   • Shipping Space
2. Training
   • Product Knowledge
   • Process Knowledge
3. Packaging
   • Cartons
   • Other Items
4. Pallets and Palletisation
   • Pallet Base
   • Palletisation
5. In-Season Planning
   • Cooling
   • Ambient Loading
   • Booking Shipping Space
   • Inventory Control
   • Order Picking
   • Pre-Tripping of Containers
   • Booking Containers
   • Stack Times
   • Transportation
   • 21 Pallets
   • Slipsheets
   • Dual Loads
   • Cargo Mass
   • Mixed Loads
   • Airlocks
   • Docking Station
   • Loading Ramps
   • Humidity
   • Horizontal Airflow Cooling System
6. Loading the Container
   • The Cold Chain
   • Container Types
   • Checking the Container
   • Vent Settings
   • Drainage Plugs
   • Pre-Cooling of the Container
   • Selecting the Pallets
   • Checking the Pallets
   • Placing the Pallets
   • Temperature Recorders
   • Void Plugs
   • Airflow
   • Air Bags
   • Seal
   • Documentation
   • Gensets
   • PPECB TempLog System
7. Arrival Condition Reporting
8. Conclusion
9. Disclaimer
10. Hortgro Webpage Link

Introduction

Loading reefer containers involves using a forklift to place 20 pallet loads into a 12-meter container. Once the doors are secured, the truck departs for the port. Two to three weeks later, the container arrives at an overseas port, delivering 20 perfect pallet loads of fruit in prime condition, ready for market distribution.

It seems simple, right?
NO, IT’S NOT!
The process begins much earlier, requiring meticulous planning and critical decisions to ensure only quality fruit reaches consumers. Just as a high-rise building requires a stable foundation, successful container loading demands secure pallet loads.

1. Pre-Season Planning

a. Crop Projections

• Realistic crop estimates are essential for effective operational planning.

b. Cooling

• Ensure adequate pre-cooling and cold storage space is arranged before harvesting begins.
• Infrastructure must cool fruit in accordance with PPECB load-out temperature regulations.
• Develop contingency plans for disruptions (load shedding, shipping shortages, labour disputes).
• Avoid using PPECB’s T13 dispensation for higher load-out temperatures, as this impacts shipping line accountability for temperature deviations.

c. Shipping Space

• Arrange shipping space based on expected crop volumes well in advance of harvest.

2. Training

a. Product Knowledge

• All personnel must understand cold chain principles and actively engage in the process.
• Understanding fruit types and cultivars helps recognize unique sensitivities.
• Cargo owners (exporters/growers) must ensure agents understand the total handling chain.

b. Process Knowledge

• The entire process, from planning to load-out, must be clearly defined, with specific responsibilities assigned.
• Every team member should understand their role for efficient and effective container loading.

3. Packaging

a. Cartons

• Carton dimensions (300x400mm or 400x600mm) must allow stable stacking on ISO pallets (1000x1200mm).
• Apples in bushel boxes (500x333mm, 18kg) should be palletised on 1070x1000mm pallets.
• Cartons must be strong enough to support a 2.4m pallet load under high humidity, preventing sagging and bulging.
• Provide adequate horizontal and vertical ventilation for effective cooling.
• Some markets may require ventilation holes to be covered, affecting cooling rate.
• Carton structure must accommodate weakening from ventilation holes.
• Non-telescopic cartons should have interlocking designs for stability; securing strips or sheets are essential.

b. Other Items

• Internal packaging (trays, punnets, bags, wrappers) must not obstruct ventilation to the extent that cooling is compromised.

4. Pallets and Palletisation

a. Pallet Base

• Standard ISO pallet: 1000mm x 1200mm.
  CRI recommends 1010mm x 1210mm for citrus, allowing corner pieces to sit securely.
• Pallet slats are not evenly spaced to ensure carton edges rest on slats, preventing sagging.
• Only high-quality pallets should be used.
• All pallets must bear the ISPM15 mark, clearly burned into at least two corner blocks.
• Avoid pallets treated with SOPP (anti-fungal), as this may cause contamination above residue limits.

b. Palletisation

• Cartons should be stacked tightly and securely.
• Use specified securing strips or sheets to interlock cartons and maintain tight pillar positions.
• Secure corner pieces with adjustable plastic straps, re-tighten before loading.
• Place pallet ID stickers in designated positions for easy identification.

5. In-Season Planning

a. Cooling

• Use forced air pre-cooling to bring fruit to prescribed temperatures.
• Apply delivery air with consideration for each cultivar’s temperature sensitivities.
• Avoid excessively low delivery air temperatures or rapid cooling rates.
• Inspect pallet load bases for damage or improper palletisation before pre-cooling.

b. Ambient Loading

• Reefer containers maintain optimal fruit temperatures by dissipating fruit and ambient heat.
• Cooling capabilities are demonstrated in ‘Dual Temperature’ plums, initially heated to +7.5°C post-loading and then re-cooled to -0.4°C.
• Ambient loading is standard for hard citrus (excluding Navels) for non-EU markets.
• ‘Super Vent’ cartons enhance cooling efficiency.
• Non-climacteric citrus is shipped at +4°C or higher; climacteric fruits (pome, stone) are not allowed ambient shipments.

c. Booking Shipping Space

• Book containers well in advance to guarantee availability.

d. Inventory Control

• Implement a stockkeeping system to track pallet locations.
• Store pallets in block positions to expedite loading.
• Conduct daily age analyses to adhere to FIFO (first-in, first-out).

e. Order Picking

• Identify pallets per consignment order.
• Designate replacement pallets in case of issues (temperature, damage) to avoid delays.

f. Pre-Tripping of Containers

• Empty containers must be cleaned and prepared at the depot before loading.
• The depot is responsible for pre-tripping (cleanliness, damage, functionality); PPECB verifies standards.

g. Booking Containers

• Inform PPECB per prescribed procedures (online Q67 Export Notification).
• Provide essential specs: temperature, vent openings, vessel info, discharge port.

h. Stack Times

• Confirm container terminal stack times before arranging transport.

i. Transportation

• Book transport with reliable contractors.
• Trailers must fit loading docks at the loading point.

j. 21 Pallets

• Loading 21 pallets (vs. 20) is possible with adjustments.
• Standard white block pallet (1000x1200mm) is unsuitable for 21 pallets; can cause cargo damage and airflow issues.
• No pallet should extend beyond the T-bar floor.
• Modify carton and pallet dimensions as needed.
• Stacking pattern for 21 pallets differs; gaps at corners must be closed to prevent air short-circuiting.
• Maintain a 100mm gap between last pallet and doors.
• Not all containers can accommodate 21 pallets.

k. Slipsheets

• Slipsheets can replace wooden pallet bases under specific conditions and require special equipment.
• Plastic sheets are placed on a pallet base; cartons are stacked as usual.
• Special forklift attachment lifts the load with slipsheet into the container.
• Slipsheets provide 153mm extra vertical space, allowing an extra layer and reducing freight costs.
• Receiver must have compatible equipment or be prepared to unload manually.

l. Dual Loads

• Dual loads (container loaded at two locations) are not preferred but sometimes necessary.
• Procedures are outlined by PPECB and in Hortgro’s Handling Protocols.

m. Cargo Mass

• Declare total cargo mass, including palletisation materials.
• Weigh individual pallets or the container before/after loading.
• Do not exceed the container’s gross mass.
• Ensure vehicle does not exceed axle mass regulations, especially with heavy fruit.
• Be aware of destination country weight restrictions; may need to load only 19 pallets for heavy loads.

n. Mixed Loads

• Assess compatibility when mixing fruit types.
• Consider contamination (aromas), temperature settings, packaging (less ventilated cargo first), fruit characteristics, ethylene sensitivity, and vent settings.
• Compatibility rules are available on PPECB’s website.

o. Airlocks

• Cooled airlocks in loadout areas are recommended and mandatory for cold sterilisation consignments.

p. Docking Station

• Docking stations seal containers against ambient temperatures during loading.
• Ramp must be adjustable as container height decreases during loading.

q. Loading Ramp

• Loading ramps may be used where docks are unavailable, but are not ideal.
• Ramp must allow forklifts to enter horizontally.
• Loading ramps are often used outside cold stores in ambient conditions; factors like distance, temperature, speed, and weather can impact loading.

r. Humidity

• Maintain relative humidity above 85% to reduce fruit moisture loss.
• Cold stores and containers are designed for this, but containers may fall short.
• Use shrivel sheets for sensitive fruit types.

s. Horizontal Airflow Cooling System

• Some exporters use a Horizontal Cooling System (RAFT), covering the floor with a sheet to force air below the floor to the door end.
• Gaps above pallet loads are blocked to optimize airflow.
• This system directs air horizontally through pallet loads.
• Other airflow techniques include floor coverings like Ottflo and Airflow.

t. Cold Sterilisation

• Cold sterilisation eliminates insect pests for certain importing countries.
• Each country has strict protocols (pre-cooling, carton marking, temperature limits, duration).
• Separate guidelines exist for cold sterilisation.

6. Loading the Container

a. The Cold Chain

• Maintain cold chain integrity during loading.
• Loading should take no more than 30 minutes, ideally under 20 minutes.

b. Container Types

• 12m Hi-Cube Container:
  • Standard for fruit exports. Internal width: ~2,285mm; length varies by refrigeration unit.
  • Cold air is blown from one end through a T-bar floor; return air passes above pallet loads.
  • Leave a 150mm gap between pallet tops and roof (max height marked by red load line).
  • Temperature settings are configured at the depot, checked by PPECB, and rechecked at loading.
• 12m Standard Container:
  • Height 8’6″, rarely used for fruit.
• 6m Standard Container:
  • Not commonly used for fruit.
• 6m Port-Hole Container:
  • Phased out in 2005.
• Controlled Atmosphere (CA) Container:
  • Fully sealed, nitrogen atmosphere, mainly for avocados.

c. Container Check

• Inspect container condition and temperature settings (inside and outside) on arrival.
• Ensure power points are available to verify temperature.
• Check drainage plugs per loading instruction.

d. Vent Settings

• Vent settings should be included in booking instructions and checked by the loading supervisor.

e. Drainage Plugs

• Four drainage plugs remove excess water.
• Open or close as per booking instructions; affects humidity.
• Apply special seals as per PPECB instructions.

f. Pre-Cooling the Container

• Avoid pre-cooling empty containers in high humidity to prevent condensation.
• Pre-cooling is only specified for cold sterilisation shipments.

g. Selecting Pallets

• Select pallets per consignment order and place in pre-stacking area near the container bay.
• Use mobile racking for direct access and minimal handling.
• Pre-stack only in a cooled airlock once container arrival is confirmed.

h. Pallet Inspection

• Check and repair pallet damage.
• Tighten straps and ensure stability and correct inclusion.

i. Pallet Loading

• Use floor covers if specified; load warmest pallets first.
• Follow a 9/11 stacking pattern for 20 pallets per FEU.
• Load swiftly to limit warming; use forklifts’ side-shift for tight stacking.

j. Temperature Recorders

• Place recorders in designated positions as per market/exporter instructions.
• Preferably place recorders in selected pallets before loading.
• PPECB officials handle probe placement for cold sterilisation.
• Newer recorders use cellular networks for data transmission.
• Recorders are vital for tracking cold chain integrity and insurance claims.

k. Void Plugs

• Cover pallet gaps and floor area at the door to prevent air short-circuiting, but leave a 100mm opening at the T-bar floor.

l. Airflow Management

• T-bar floor system cools cartons through channels; palletised cargo increases risk of airflow short-circuiting.
• Cold air is delivered from the refrigeration end; cooling efficiency decreases toward the door.
• Load warmer, high-respiration fruit first.
• Use floor covers to equalise airflow, especially for cold sterilisation.

m. Air Bags

• For open-top display cartons (citrus), place air bags between last pallets and doors to prevent collapse.

n. Sealing the Container

• Close doors immediately after loading and affix customs seals.

o. Documentation

• Complete all required documentation.

p. Gensets

• PPECB mandates a maximum of 6 hours for deciduous fruit (16 hours for citrus) to load, transport, and connect the container to terminal power (Time Temperature Tolerance, TTT).
• If TTT will be exceeded, use a genset. Confirm availability with the transport contractor.
• Supervisor must ensure genset is fitted and started before departure.

q. PPECB TempLog System

• Air temperature (DAT and RAT) of each container is reported daily by the vessel to PPECB.
• Shippers can register with PPECB to access the TempLog system for cold chain monitoring.

7. Arrival Condition Reporting

a. Temperature Data Collection

• Retrieve temperature data from recorders to assess transit conditions.

b. Problem Identification

• Analyse data to identify issues during loading or equipment failures.

c. Damage Assessment

• Document pallet load damage from loading, transit, or destuffing.

8. Conclusion

• The container loading process is critical to export operations; fruit condition on arrival depends on process integrity.
• Every link in the handling chain is essential; all role-players must understand the consequences of protocol deviations.
• Conduct post-season evaluations to assess effectiveness, identify shortcomings, and improve for the next season.

9. Disclaimer

While every effort has been made to compile these guidelines accurately, neither the author nor Hortgro will be held responsible for any consequences arising from the use of these guidelines.

10. Hortgro Webpage Link

For more information and resources, visit:
www.hortgro.co.za/science-tech-hub/pome-stone-handling-protocols/

JGS/Container Loading/Oct2024