Loading of Reefer Containers – Fruit

Contents

1. Pre-season Planning
   a. Crop Projections
   b. Cooling
   c. Shipping Space
2. Training
   a. Product Knowledge
   b. Process Knowledge
3. Packaging
   a. Cartons
   b. Other Items
4. Pallets and Palletisation
   a. Pallet Base
   b. Palletisation
5. In-Season Planning
   a. Cooling
   b. Ambient Loading
   c. Booking Shipping Space
   d. Inventory Control
   e. Order Picking
   f. Pre-Tripping of Containers
   g. Booking Containers
   h. Stack Times
   i. Transportation
   j. 21 Pallets
   k. Slipsheets
   l. Dual Loads
   m. Cargo Mass
   n. Mixed Loads
   o. Airlocks
   p. Docking Station
   q. Loading Ramps
   r. Humidity
   s. Horizontal Airflow Cooling System
6. Loading the Container
   a. The Cold Chain
   b. Container Types
   c. Checking the Container
   d. Vent Settings
   e. Drainage Plugs
   f. Pre-Cooling of the Container
   g. Selecting the Pallets
   h. Checking the Pallets
   i. Placing the Pallets
   j. Temperature Recorders
   k. Void Plugs
   l. Airflow
   m. Air Bags
   n. Seal
   o. Documentation
   p. Gensets
   q. 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 sealed, the container is transported to the port and shipped overseas, where it arrives two to three weeks later with fruit in prime condition.
However, this process is not simple.
It requires meticulous planning and critical decisions to ensure only quality fruit reaches consumers. Like a high-rise building needs 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 before harvesting.
• Infrastructure must cool fruit according to PPECB 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 affects shipping line accountability.

c. Shipping Space

• Arrange shipping space based on crop projections well in advance.

2. Training

a. Product Knowledge

• All personnel must understand cold chain principles and fruit sensitivities.
• Exporters/growers must ensure agents understand the handling chain.

b. Process Knowledge

• Define the entire process from planning to load-out, assigning clear responsibilities.
• Every team member should understand their role for efficient 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 on 1070x1000mm pallets.
• Cartons must support a 2.4m pallet load under high humidity, preventing sagging and bulging.
• Provide adequate horizontal and vertical ventilation for cooling.
• Carton structure must accommodate ventilation holes.
• Non-telescopic cartons should interlock for stability; use securing strips or sheets.

b. Other Items

• Internal packaging (trays, punnets, bags, wrappers) must not obstruct ventilation and cooling.

4. Pallets and Palletisation

a. Pallet Base

• ISO pallets: 1000mm x 1200mm.
• Citrus Research International recommends 1010mm x 1210mm for citrus.
• Pallet slats are unevenly spaced to support carton edges and prevent sagging.
• Only high-quality pallets should be used.
• All pallets must bear the ISPM15 mark (burned into at least two corner blocks).
• Avoid pallets treated with SOPP (anti-fungal), as residues may exceed limits.

b. Palletisation

• Stack cartons tightly and securely.
• Use specified securing strips/sheets to interlock cartons.
• Secure corner pieces with adjustable plastic straps.
• Place pallet ID stickers in designated positions.

5. In-Season Planning

a. Cooling

• Use forced air pre-cooling to reach prescribed temperatures.
• Apply delivery air with consideration for cultivar sensitivities; avoid too low or rapid cooling.
• Inspect pallet bases for damage or poor palletisation before pre-cooling.

b. Ambient Loading

• Reefer containers maintain optimal fruit temperatures by dissipating fruit and ambient heat.
• Ambient loading is standard for hard citrus (excluding Navels) for non-EU markets.
• Super Vent cartons enhance cooling efficiency.
• Non-climacteric citrus can be shipped at +4°C or higher; pome and stone fruit require strict temperature control and are not ambient loaded.

c. Booking Shipping Space

• Book containers well in advance to ensure availability.

d. Inventory Control

• Use a stockkeeping system to track pallet locations.
• Store pallets in block positions to speed up loading.
• Conduct daily age analyses to follow FIFO.

e. Order Picking

• Identify pallets per consignment order.
• Designate replacement pallets in case of issues during loading.

f. Pre-Tripping of Containers

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

g. Booking Containers

• Inform PPECB as per procedures (online Q67 Export Notification).
• Provide specifications for container preparation (temperature, vents, vessel, discharge port).

h. Stack Times

• Confirm terminal stack times before arranging transport.

i. Transportation

• Book reliable transport 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 pallets are unsuitable for 21-pallet loads.
• No pallet should extend beyond the T-bar floor.
• Adjust carton and pallet dimensions for safe shipping.
• The stacking pattern for 21 pallets differs from 20; gaps at corners must be closed to prevent air short-circuiting.
• Maintain a 100mm gap between the last pallet and container doors.
• Not all containers can accommodate 21 pallets.

k. Slipsheets

• Slipsheets can replace wooden pallets if equipment is available.
• Plastic sheets allow for an extra layer and reduced freight costs.
• The receiver must have compatible equipment or be prepared for manual unloading.

l. Dual Loads

• Dual loads (loading 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 or road axle regulations.
• For heavy loads (e.g., citrus), sometimes only 19 pallets are loaded.

n. Mixed Loads

• Assess compatibility when mixing fruit types (aromas, temperature, packaging, ventilation, ethylene sensitivity, vent settings).
• PPECB provides compatibility rules.

o. Airlocks

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

p. Docking Station

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

q. Loading Ramps

• Used where loading docks are absent; take precautions to minimize cargo damage.
• Ramps must allow forklifts to enter horizontally.
• Loading ramps are used outside cold stores, where ambient conditions can affect loading.

r. Humidity

• Maintain RH above 85% to prevent fruit moisture loss.
• Use shrivel sheets for sensitive fruit types.

s. Horizontal Airflow Cooling System

• Horizontal Cooling (RAFT) covers the floor with a sheet, forcing air below the floor to the door end.
• Gaps above pallets are blocked to optimize airflow.
• Other airflow techniques include Ottflo and Airflow floor coverings.

t. Cold Sterilisation

• Used to eliminate insect pests for certain countries.
• Protocols are strictly monitored and not covered in this document.

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).

b. Container Types

• 12m Hi-Cube Container: Most common for fruit exports. Internal width ~2,285mm; length varies by refrigeration unit. Leave a 150mm gap above pallets for air return. Max pallet height is marked by the red load line.
• 12m Standard Container: Rarely used for fruit.
• 6m Standard Container: Not common for fruit.
• 6m Port-Hole Container: Phased out in 2005.
• Controlled Atmosphere (CA) Container: Fully sealed, used mainly for avocados.

c. Checking the Container

• Inspect condition and temperature settings on arrival.
• Ensure power is available to verify settings.
• Check drainage plugs as per loading instructions.

d. Vent Settings

• Confirm vent settings per booking and check at loading.

e. Drainage Plugs

• Four drainage plugs remove excess water; open/close as per instructions.
• Special seals may be required.

f. Pre-Cooling the Container

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

g. Selecting the Pallets

• Select pallets per consignment order and pre-stack near the container bay.
• Use mobile racking for direct access.
• Pre-stack only in a cooled airlock once the container arrives.

h. Checking the Pallets

• Repair any pallet damage and tighten straps before loading.

i. Placing the Pallets

• 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.

j. Temperature Recorders

• Place recorders as per market/exporter instructions, ideally in pallets before loading.
• PPECB handles probe placement for cold sterilisation.
• New recorders may transmit data via cellular networks.
• Recorders are vital for cold chain tracking and insurance.

k. Void Plugs

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

l. Airflow

• The T-bar floor cools cartons via channels; palletised cargo increases risk of airflow short-circuiting.
• Load warmer, high-respiration fruit first.
• Use floor covers for airflow equalisation, especially for cold sterilisation.

m. Air Bags

• Place air bags between last pallets and doors to prevent collapse (especially for open-top citrus cartons).

n. Seal

• Close doors immediately after loading and affix customs seals.

o. Documentation

• Complete all required documentation.

p. Gensets

• PPECB mandates a max of 6 hours (deciduous) or 16 hours (citrus) from loading to terminal power connection (Time Temperature Tolerance, TTT).
• If TTT will be exceeded, use a genset.
• Supervisor must ensure genset is fitted and started before departure.

q. PPECB TempLog System

• Delivery and return air temperatures are reported daily to PPECB.
• Shippers are encouraged to register for TempLog access.

7. Arrival Condition Reporting

• Retrieve temperature data from recorders to assess transit conditions.
• Analyse data for issues during loading or equipment failures.
• Document any pallet damage during loading, transit, or destuffing.

8. Conclusion

• The loading process is critical to export success; fruit condition on arrival depends on process integrity.
• Every link in the handling chain is essential; deviations have consequences.
• Conduct post-season evaluations to identify improvements 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 their use.

10. Hortgro Webpage Link

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