Durian Container Loading: How to Fit 18,000kg in a 20ft Reefer Without Crushing Product
A poorly loaded durian container wastes 15-20% of available capacity, costing you $6,000-8,000 in lost product opportunity per shipment. You're already paying $6,000-9,000 for ocean reefer freight regardless of whether the container is efficiently packed or wastefully loaded. Efficient loading maximizes the expensive freight you're paying for anyway, letting you import more product for the same shipping cost and improving your per-kilogram landed economics dramatically.
The difference between amateur and professional container loading is substantial. Amateurs achieve 14,000-15,000kg in a 20ft reefer because packaging doesn't stack efficiently, weight distribution is poor, or cube utilization leaves gaps. Professionals consistently load 18,000-20,000kg through smart packaging choices, proper stacking patterns, and understanding the interplay between weight limits and volumetric capacity. Here's how to optimize your container loads like the professionals do.
Understanding 20ft Reefer Container Capacity
A standard 20ft refrigerated container has internal dimensions of approximately 5.4 meters length × 2.3 meters width × 2.2 meters height, giving you roughly 28 cubic meters of usable volume. The reefer refrigeration unit mounted on the container front reduces usable space compared to dry containers – you're losing perhaps 0.5 cubic meters to the equipment bulkhead.
Weight capacity is around 27,000kg maximum payload, but frozen durian shipments rarely approach this limit because you hit volumetric constraints first. Typical durian loads run 18,000-20,000kg where you've filled the available volume before maxing out weight capacity. Frozen whole durian with its bulky husk takes more space per kilogram than dense frozen pulp packs – the format you choose affects whether you hit volume limits or weight limits first.
The optimization challenge is balancing weight and cube utilization simultaneously. You want heavy, dense packaging that maximizes weight within available cube. But you also need packaging that stacks efficiently without wasting space in gaps between cartons or pallets. This is where packaging dimensions and format selection matter enormously.
Why Packaging Format Affects Loading Efficiency
Frozen whole durian is volumetrically inefficient. The round, spiky husk creates gaps between units that can't be filled. Even vacuum-packed whole durian in cartons doesn't stack as efficiently as uniform rectangular boxes of frozen pulp. You might fit only 14,000-16,000kg of whole durian in a container where you could load 18,000-20,000kg of pulp format.
Frozen seedless pulp in rectangular cartons stacks like building blocks – minimal wasted space, efficient palletization, maximum density per cubic meter. A 10kg pulp box measuring 40cm × 30cm × 15cm stacks perfectly on standard pallets and creates stable layers. Twenty boxes per pallet layer, four layers high, gives you 800kg per pallet in a stable configuration that won't shift during ocean transit.
Discuss packaging dimensions with your supplier before ordering. Some suppliers offer multiple carton size options – 5kg boxes versus 10kg boxes versus 20kg bags. The configuration that loads most efficiently depends on your specific container dimensions and whether you're palletizing or floor loading. Suppliers experienced in container exports can recommend optimal packaging for efficient loading based on your destination and handling preferences.
Palletized Loading Versus Floor Loading
Palletized loading provides easier handling, more stable stacking, and faster loading/unloading at both origin and destination. Standard pallets measuring 1.0m × 1.2m fit two across the container width (2.3m) with small gaps for air circulation. You can fit roughly 20-24 pallets in a 20ft container depending on exact pallet dimensions and how tightly you load.
Each pallet loaded with 600-800kg of frozen durian (depending on packaging format and stack height) gives you 12,000-19,200kg total container capacity for 20-24 pallets. The lower end reflects conservative stacking, the higher end reflects maximum efficient loading. Palletized loading costs slightly more (pallet costs, forklift handling fees) but the handling efficiency usually justifies the expense.
Floor loading eliminates pallets, letting you pack product directly from floor to ceiling. This can increase density by 10-15% compared to palletized loading because you're not "wasting" space on pallets themselves and you can pack more tightly against walls. The tradeoff is significantly more labor-intensive loading and unloading – you're hand-stacking every carton rather than moving pallets with forklifts.
For most durian shipments, palletized loading makes more sense unless you're absolutely maximizing every kilogram for some reason. The handling efficiency, reduced labor costs, and faster loading/unloading outweigh the slight reduction in maximum capacity compared to floor loading.
Stacking Strategy and Weight Distribution
Stack height should reach approximately 2.0 meters maximum, leaving headroom below the 2.2m ceiling height. Product settles and shifts slightly during ocean transit. Stacking to absolute ceiling height risks crushing top layers as settling compresses the stack. The air gap also ensures refrigeration air can circulate properly – blocking air flow creates temperature variations within the container.
Weight distribution requires heavier, denser cartons on lower layers to prevent crushing. If you're mixing different products or packaging formats, place the heaviest on the bottom. A 20kg box of frozen whole durian should sit below lighter 5kg retail pulp packs. This prevents bottom layer compression that can damage packaging and product.
Balanced loading side-to-side prevents container shifting during ocean transit. Don't load all heavy product on one side and light product on the other – the weight imbalance can cause handling problems at ports and during vessel loading. Distribute weight evenly across the container length and width for stable transport.
Leave small gaps between pallets or carton stacks and container walls for air circulation. Packing completely against all walls blocks refrigeration air flow, creating warm spots where product nearest walls may partially thaw. A 5-10cm gap around the perimeter ensures proper cold air circulation throughout the container.
Loading Mixed Varieties in One Container
You're not limited to single-variety container loads. Combine multiple varieties – perhaps 40% Musang King, 40% D24, 20% Black Thorn in a single shipment. This lets you test market response to different varieties without committing full containers to each, and it gives you product mix flexibility for customers who want variety.
Clear marking and separation by variety is essential for inventory management. Use color-coded cartons: yellow for Musang King, blue for Black Thorn, white for D24. Or clearly marked sections in the container: pallets 1-10 are Musang King, pallets 11-20 are D24. Without clear organization, mixed loads become nightmares during receiving when you can't tell which cartons contain which variety.
Document the loading plan in detail: packing list showing exactly which cartons contain which variety, how many cartons of each, and where in the container they're positioned. Container loading photos provided by the supplier help verify the loading matches the packing list. This documentation prevents disputes about what was actually shipped versus what arrives.
Protecting Quality During the Loading Process
Pre-cool the container to -18°C before loading begins. Don't start loading frozen product into a warm container and expect the reefer to cool everything down. Pre-cooling ensures product enters a proper cold environment immediately, maintaining the cold chain without interruption.
Fast loading minimizes temperature exposure. The longer frozen product sits at ambient temperature during loading, the more surface warming occurs. Professional loaders complete container loading in 2-4 hours, not all day. This speed protects product quality and reduces the risk of partial thawing during the loading process.
Temperature sensors should be placed strategically within the load – not just relying on the container's built-in sensor near the refrigeration unit. Place a data logger in the center of the load where product is furthest from cold air sources. This monitors whether the interior of your tightly-packed container maintains proper temperature throughout transit, not just the edges near air flow.
Documentation and Verification Before Shipping
Demand a detailed packing list showing variety, carton count, net weight, gross weight, and container position for each product type. This becomes your verification tool when the container arrives – you can confirm what was loaded versus what you receive.
Request container loading photos from the supplier showing the loading pattern, stacking stability, and that your mixed varieties are properly separated and marked. Many container quality issues trace back to poor loading that you could have caught with photos before shipment departed.
Verify total weight matches what you ordered and what the container can legally carry. Overloaded containers trigger penalties at ports, potential shipment refusal, or forced partial unloading at your expense. Underloaded containers mean you paid for shipping capacity you didn't use. Target weight should be 18,000-20,000kg for efficient utilization of a 20ft reefer.
The Bottom Line on Container Loading
Efficient loading puts 18,000-20,000kg in a 20ft reefer container versus 14,000-15,000kg for poorly optimized loads. That 3,000-5,000kg difference represents $9,000-15,000 in additional product capacity per container using the same freight cost you're paying anyway.
Packaging format matters enormously. Frozen pulp in rectangular cartons loads far more efficiently than bulky whole durian. Discuss packaging dimensions with suppliers before ordering to optimize for container loading rather than accepting whatever packaging they use by default.
Palletized loading provides the best balance of efficiency and handling practicality for most operations. Floor loading squeezes slightly more product in but costs more in labor and time. Mixed varieties in one container work well if properly organized and documented.
Take Action
Work with suppliers experienced in optimizing container loads for maximum efficiency. Submit an RFQ on CommoditiesHub specifying your container loading preferences and capacity targets – we'll connect you with suppliers who understand freight economics and load containers professionally for maximum utilization.