A practical, calculator-first playbook to plan a 40’ high-cube reefer of Indonesian vannamei or black tiger to the U.S. We cover floor-load vs pallets, carton counts, airflow, and the safe weight window that keeps you out of axle-overweight trouble.
If you’ve ever been hit with an overweight fee or opened a container to find frozen cartons choked the airflow, you know load planning isn’t a “nice to have.” It makes or breaks a shrimp shipment. We ship Indonesian vannamei and black tiger every week, and this is the exact, field-tested way we plan a 40’ HC reefer so you maximize cartons without triggering U.S. axle problems or airflow issues.
We’ll focus on the container, not the paperwork. If you also need supply, see our Frozen Shrimp (Black Tiger, Vannamei & Wild Caught).
Step 1: Know your box and the weight window
Here’s the thing. You can “fit” far more cartons by volume than you can legally move by road in the U.S. So we plan by U.S. axle weight first, then confirm cube and airflow.
Typical 40’ HC reefer internals and limits (brand-to-brand varies slightly):
- Internal L × W × H: about 11.58 m × 2.28 m × 2.54 m
- Door width × height: about 2.29 m × 2.48 m
- Tare (container only): 4.4–4.9 MT
- Max gross (on the CSC plate): 34.0–34.5 MT. That’s not your road limit. U.S. axle rules are.
What’s a safe max gross weight for a 40’ reefer to avoid U.S. axle overweight fines?
In our experience, a good nationwide target cargo weight is 19,000–21,000 kg. You can sometimes push to 22,000 kg with the right drayage setup, short hauls, or tri-axle chassis, but 19.5–21.0 MT keeps most customers out of trouble across ports and states.
Why: U.S. federal axle limits are 12,000 lb (steer), 34,000 lb (drive), 34,000 lb (trailer). By the time you add tractor, driver, reefer gen-set fuel, chassis, and container tare, your practical payload for a reefer narrows to around 41,000–46,000 lb of cargo. If your inland run is long or through strict states, stay closer to 42,000–44,000 lb (19.0–20.0 MT). Confirm with your drayage provider for the delivery ZIP before you lock your plan.
Practical takeaway: Plan your carton count by gross carton weight to hit 19–21 MT total cargo weight. Then check airflow and cube.
Step 2: Floor-load or palletize?
We’re blunt about this. If your goal is maximum cartons per 40’ HC reefer, floor-loading almost always wins for shrimp. Pallets cost you cube and add weight.
Should I floor-load or use pallets for frozen shrimp to maximize capacity?
- Floor-load: Best for maximizing cartons. Lower weight, better use of length, and easier to keep a continuous “brick” with aligned airflow channels.
- Palletize: Best when the consignee needs quick cross-dock or retail DC handling. Expect fewer cartons and more dunnage/air gaps to maintain airflow.
How many pallets fit in a 40’ HC reefer and what pallet pattern works best for shrimp?
- 40"×48" pallets (1,016×1,219 mm): 20 pallets single-stacked is common. Two across, ten deep. Keep a rear air return gap.
- 1,000×1,200 mm pallets: 18–20 depending on orientation and your airflow gap discipline. We recommend 18–19 to maintain side and top clearance.
- Don’t block the front bulkhead or rear return. Use ventilated pallets when possible. If you’re near your weight limit, pallets can add 25–40 kg each fast.
Practical takeaway: If receivers accept floor-load, do it for shrimp. If you must palletize, lock the count with your pallet dimensions, keep two-across, and protect airflow.
Step 3: Build the math for your cartons
We always start with your specific carton’s external dimensions and gross weight. Not net. Not drained weight. Gross carton weight is what the highway cares about.
Key allowances for airflow:
- Top clearance: target 8–10 cm below the ceiling
- Sidewalls: 5–8 cm each side
- Rear door return: 20–30 cm clear
- Front bulkhead face: never block the supply/return openings
How many 10×1 kg vannamei cartons fit in a 40’ HC reefer?
Short answer we see in the U.S.: 1,750–2,050 cartons when floor-loaded. The spread depends on your gross carton weight and whether you prioritize the 19–21 MT target.
Example you can copy:
- Assumptions: 10×1 kg master case, external 40×27×15 cm, gross 11.2 kg per carton
- Weight cap first: 20,500 kg ÷ 11.2 kg ≈ 1,830 cartons
- Cube check: With disciplined gaps, a 40’ HC reefer can volumetrically hold well above this count, so you’re weight-limited, not cube-limited
- Final plan: 1,800–1,900 cartons often hits the weight sweet spot and keeps rear/top clearance intact
Does glaze percentage change how I plan container weight and carton count?
Yes. Plan by the gross carton weight as packed, which includes water glaze and packaging. If you move from 10% to 20% glaze on a 10 kg net pack, the gross carton can jump by 1 kg or more. Across 1,900 cartons, that’s roughly 1.9 MT extra. We’ve seen this alone turn a “legal” plan into an overweight one. Get confirmed gross weight on the final spec sheet before you finalize the count.
How does my carton size change how many fit?
Bigger footprints reduce how many you can brick per layer and how neatly stacks interlock.
- Common 10×1 kg master: 40×27×15 cm stacks efficiently
- Common 6×2 kg master: 49×29×15–16 cm. Heavier gross per carton, fewer total cartons before weight cap
Quick weight-led estimate for 6×2 kg:
- If gross is 12.5 kg per carton and you target 20,000 kg cargo weight, you’re around 1,600 cartons. We generally see 1,500–1,700 cartons in practice for this SKU.
Practical takeaway: Confirm external carton dimensions and gross weight for each SKU lot. Then run the weight-first calculation, and only then refine the stack plan to respect airflow.
Step 4: Airflow, dunnage, and stacking that protect the cold chain
Air wants a clean loop: supply at the ceiling from the front unit, through the cargo, and back via the floor and rear return.
How should I stack cartons to keep airflow channels open in a reefer?
- Build a tight brick. Stagger cartons to avoid continuous vertical seams but keep the outer face straight so you preserve a uniform side gap.
- Maintain a rear air-return gap of 20–30 cm. Use a dunnage board or corner posts so cartons can’t slump into the door space in transit.
- Respect the top line. Keep stacks 8–10 cm below the ceiling. Don’t “crown” the center higher than the sides.
- Don’t block the front bulkhead. No cartons or dunnage against the air outlets or returns.
- Use slip sheets sparingly. Overusing plastic sheets can create vapor barriers and cold spots.
- Securement. For floor-loads, use air bags or honeycomb dunnage in the last bay to hold the brick. Shrink-wrap bundles in the final row if needed, but avoid sealing the whole wall.
Practical takeaway: Most thaw incidents we troubleshoot trace back to blocked returns, crowned stacks, or carton slumps at the rear door. Set the gaps before you set the count.
A simple worksheet you can copy
- Confirm U.S. delivery profile. Will dray be port-only or inland? Ask the trucker for a max cargo weight target. If unsure, use 19.5–21.0 MT for reefers.
- Lock carton specs. External L×W×H and gross weight, including glaze and packaging.
- Weight-first carton count. Cargo weight target ÷ gross carton weight = target carton count.
- Floor-load vs palletize. Floor-load for maximum cartons. If palletized, re-run the weight with pallet mass and recalc your count.
- Airflow check. Hold 8–10 cm top, 5–8 cm sides, and 20–30 cm rear. If your count pushes you to crown the load, reduce cartons.
If you’re buying shrimp from us, we’ll run this math with you and share a draft load map for the exact carton. Need help with your specific carton size and U.S. ZIP? Contact us on whatsapp and we’ll send options within one business day.
Real-world examples from our team
- 10×1 kg vannamei, gross 11.4 kg. Portland delivery with standard chassis. We capped at 1,820 cartons for 20,750 kg cargo and kept a 25 cm rear air gap. Zero overweight and clean temps.
- 6×2 kg vannamei, gross 12.8 kg. Chicago rail ramp delivery with strict axle enforcement. We targeted 1,560 cartons (≈19,970 kg) and palletized 18× 1,000×1,200 mm skids for DC handling. The receiver wanted pallets, so we dropped count and used ventilated deck boards.
When to break these rules
- Ultra-short drays from port to cold store with tri-axle equipment can sometimes support 21.5–22.0 MT cargo, but confirm in writing with your trucker.
- Mixed loads. If you’re capped by weight but still have cube, we sometimes balance with lighter whitefish IQF portions to stabilize the stack without pushing axle weights. If that’s useful, explore compatible items like Grouper Bites (Portion Cut) or Mahi Mahi Portion (IQF) alongside shrimp.
The reality is that most shrimp moves are weight-limited in the U.S. Plan for 19–21 MT cargo, and your airflow and count decisions get much easier.
Looking for Indonesian supply with the load plan baked in? See our Frozen Shrimp (Black Tiger, Vannamei & Wild Caught) or browse more options here: View our products.