由 caicai8478 Introduction: Why is securing oversized cargo so special?
Standard cargo is secured by stacking and squeezing. However, oversized cargo is often isolated within the container, unable to leverage support from other cargo. It independently withstands various forces throughout the voyage:
Longitudinal gravity: Lifting and forklifting during loading and unloading.
Lateral impact: Sudden braking and turning of trucks and ships.
Continuous vibration: Long-term vibration caused by road transport and sea waves.
Twisting force: Minor deformation of the container hull in wind and waves.
The purpose of reinforcement is to safely direct these forces to the solid structure of the container through artificial means, integrating the cargo and container.
Part 1: Core Principles – Understanding the Essence of “Reinforcement”
Eliminate space for movement: Any small gap between cargo and packaging, or packaging and container, is a safety hazard. All gaps must be securely filled.
Minimize the center of gravity: Ensure the cargo’s center of gravity is as low as possible and falls in the center of the pallet or base. Excessively high or unstable cargo must be transported “lying down” or on a dedicated base.
Strength over weight: The tensile and compressive strength of the packaging and reinforcement materials must significantly exceed the cargo’s weight and potential impact forces.
Easy loading and unloading: Clear markings and reserved operating space are inherently safe.
Part 2: Material Selection – Choosing the Right “Armor and Ropes”
Material Application Selection Key Points
Wooden Pallet/Base Load-bearing foundation, connecting the cargo to the container floor. Solid wood is preferred, with thickness and number of crossbeams customized according to cargo weight. Cheap, rotten, or cracked pallets are strictly prohibited.
Wood (lumber, strips) Primary material for support, reinforcement, and filling gaps. Lumber must be dry, bark-free, and insect-free. The dimensions (e.g., 10cm x 10cm lumber) must be sufficient to support the load. Wire ropes/nylon straps pull cargo against the container walls, providing lateral restraint. Ties must have sufficient breaking strength (LC), typically ≥5 tons. They should be equipped with a tensioner (ratchet) and corner protectors to prevent damage to cargo.
Air bags/air bladders fill the gap between cargo and the container walls, absorbing vibration and shock. They are suitable for filling irregular spaces. Ensure reliable quality and prevent air leakage.
Stretch film/PE film protects against moisture and dust, and secures small components. For oversized items, vacuum lamination is far superior to hand-wrap film and provides additional securing force.
Edge boards protect cargo edges and distribute the pressure of tie straps. Made of paper or plastic, they are crucial to prevent tie straps from cutting into cargo or packaging.
Screws/bolts permanently secure the bottom of the cargo to the pallet. For heavy equipment, screws must be directly screwed through the equipment’s feet (or base) and secured to the wooden base.
Part III: Operation Guidelines – Build a “Steel Fortress” Step by Step
Step 1: Build an Indestructible Base
Custom Pallet: Avoid using standard European or American pallets. Customize a reinforced solid wood pallet based on the dimensions of the cargo’s base. The pallet’s length and width should be at least 10-15cm smaller than the cargo’s base to facilitate forklift access.
Align the Center of Gravity: Place the cargo precisely on the pallet, ensuring the center of gravity is centered. If necessary, use a jack or other tool for fine-tuning.
Mechanical Securing: For machinery and equipment, directly secure the equipment’s foot holes to the wooden base with high-strength screws/bolts. This is the most effective and fundamental method for preventing movement.
Step 2: Main Body Protection and Padding
Internal Securing: Secure moving parts of the machine (such as doors and robotic arms) with internal wooden planks to prevent them from shaking.
Moisture-Proofing Treatment: First, wrap with bubble wrap or pearl cotton for cushioning, then vacuum-wrap the entire pallet to prevent moisture and ensure a secure fit.
Edge Protection: Secure all edges that come into contact with straps and forks. Install corner guards at corners where the truck arm may come into contact.
Step 3: Final Reinforcement—Integration with the Container
This step is usually performed by a professional after the cargo is loaded into the container.
Gaps Caulking: Use square timbers to firmly wedge and hammer down the gaps between the cargo and the container’s side and end walls. The timbers should be positioned to effectively resist forward and backward, left and right movement.
Lateral Lashing:
Use heavy-duty nylon straps (or wire rope) and ratchet tensioners.
Wrap the straps around the cargo (with the corner guards in place) and hook them onto reinforcement structures such as ladder posts and ground bells on both sides of the container.
Tighten downward in an “eight” pattern to create a downward force component on the cargo and increase stability.
The number of straps required depends on the weight and size of the cargo; generally, at least 2-4 are required.
Top Support (if necessary): For very tall cargo, vertical support can be provided between the top of the cargo and the container roof with wooden planks to prevent jumping.
Part 4: Marking and Acceptance The Last Line of Defense
Clear markings serve as operator instructions:
Center of Gravity & Lifting Points: Clearly mark “CENTER OF GRAVITY” and “SLING HERE” in English and with icons.
Forklift Pockets: Mark “LIFT HERE” or “FORK POCKETS” with arrows.
Weight and Dimensions: Paint “GROSS WEIGHT: …KGS” and “Dimensions: L x W x H” on all four sides of the packaging.
Warning Signs: Post “HEAVY,” “DO NOT STACK,” and “FRAGILE” and other markings.
Final Inspection:
Push Test: After loading, try to push the cargo vigorously. Ideally, the cargo should remain motionless, without any shaking or movement.
Photo Evidence: Take high-definition photos and videos of the loading process and internal reinforcement details (wooden supports, strapping points). This is crucial evidence for claims in the event of damage and can also guide safe unpacking at the destination port.
Summary: The Ultimate Self-Checklist
Base: Are custom-made solid wood pallets with sufficient load-bearing capacity used?
Security: Are the cargo bolted to the base?
Security: Are the Is the container vacuum-laminated and corner protection installed?
Padding: Are the gaps between the cargo and the container walls securely wedged with wooden planks?
Lashing: Are sufficient straps (≥5 tons) used and tightened in a figure-eight pattern around the container’s reinforcement structure?
Marking: Are markings such as the center of gravity, lifting points, weight, and dimensions clearly visible?
Documentation: Have photos and videos been taken of the completed container loading and reinforcement?
Remember: In cross-border logistics, every penny saved on reinforcement can mean a hundredfold cost in a cargo damage claim. Safety first is always the most cost-effective option.