The Critical Nature of Steel Coil Transportation

Inherent Risks: The "Rolling Pin Effect"

The primary danger in transporting steel coils stems from their mass and shape. A key concept is the "rolling pin effect": if a coil breaks free from its restraints, it can start to roll, accumulating immense kinetic energy and becoming a highly destructive force.

"Once the mass starts to move and roll, there is no stopping it, and the coil will leave a trail of devastation."

This uncontrolled force can breach standard container walls, which are not designed for such concentrated impacts, leading to catastrophic accidents. These can include vehicle rollovers, loss of cargo, and significant damage to infrastructure. The potential for serious injury or fatality is a grave concern, underscoring why strict adherence to securing guidelines is non-negotiable.

Understanding Forces and Securing Principles

Dynamic Forces in Transit

All cargo is subjected to dynamic forces during transport, including acceleration, braking, turning, and rolling.

• Longitudinal forces act forward (braking) and backwards (accelerating). The forward force from braking is typically the most significant in road transport.
• Lateral forces act sideways during turns or swaying.
• Vertical forces result from bumps or, at sea, the vessel's heaving motion.
• Rotational/Rolling forces are especially critical for cylindrical cargo, such as steel coils, particularly during sea transport.

A securing plan must be robust enough to resist the combined effect of all anticipated forces for the specific mode of transport.

Fundamental Principles of Cargo Securing

Two core principles guide all effective cargo securing practices:

1. Unification of Cargo with Transport Unit: The goal is to make the coil "one with the transporting unit," eliminating any possibility of movement through tight lashing, blocking, and bracing.
2. Sufficient Securing System Strength: The securing system must be strong enough to hold the cargo in place against all dynamic forces. This involves using a sufficient quantity of materials with adequate strength.

Adhering to these principles is a critical safety imperative that protects the cargo, the transport unit, and public safety.

Container Selection and Floor Integrity

Suitable Container Types

Selecting the correct container is a critical first step.

• Only 30-tonne, 20-foot containers that have been proof-load tested should be used.
• GRADE B containers, which are structurally sound despite potential cosmetic wear, are recommended. The structural integrity of the understructure, cross-members, and lashing points is paramount.

Container Floor Structure and Limitations

A container's floor is often its most vulnerable component. It typically consists of plywood sheets screwed onto steel cross-members. The plywood between these supports has limited strength. A container's maximum payload rating assumes the weight is distributed evenly, which is not the case with steel coils that concentrate their entire mass on a small footprint.

ISO 668 Standard: Floor Loading Capacity

The ISO 668 standard provides guidelines for maximum loads per linear meter of container length. Shippers must know both ISO standards and any specific carrier requirements.

Principles of Weight Distribution for Steel Coils

No Direct Coil-to-Floor Contact

A non-negotiable rule is that the steel coil must have NO CONTACT WITH THE FLOOR of the container. Placing a coil directly on the plywood floor will almost certainly cause damage.

Use of Supports and Cradles

A support system, such as timber or steel beams, is mandatory to bridge multiple floor cross-members and distribute the load. For heavy coils placed with their axis running lengthwise ("Eye Fore and Aft"), heavy-duty cradles made of wood or steel are required to support the weight and prevent rolling.

Calculating Load Spread

Personnel must ensure the load does not exceed the floor's limits. A practical method to determine the required support is:

1. Find max weight per cross-member: Divide the container's max payload by the number of cross-members (e.g., 28 tonnes ÷ 18 cross-members ≈ 1.56 tonnes/cross-member).
2. Determine required cross-members for the coil: Divide the coil's weight by the max weight per cross-member (e.g., a 5-tonne coil ÷ 1.56 ≈ 3.2).
3. Round up and implement: The result must be rounded up. In this case, the coil's weight must be spread over at least four cross-members using appropriate supports.

Approved Coil Placement and Orientation

"Eye to Sky" (Coil axis vertical)

The coil rests on a flat face. Small coils can be placed close together and bound with steel straps. If on pallets, the coils must not protrude and must be secured to the pallet, which is then secured to the container.

"Eye to Side" (Coil axis transverse)

The coil rests on its curved surface with its axis across the container's width. Coils must be distributed to keep the cargo's center of gravity in the middle of the container. This orientation requires extensive blocking and lashing to prevent rolling.

"Eye Fore and Aft" (Coil axis longitudinal)

The coil rests on its curved surface with its axis along the container's length. Heavy steel coils in this orientation must be packed on heavy-duty cradles to prevent rolling and distribute the load.

Securing Techniques and Strength Requirements

Lashing, Shoring, and Chocking

• Lashing: Using steel straps or synthetic webbing to prevent movement.
• Shoring: Using timber to fill voids and brace the cargo.
• Chocking: Using correctly sized timber wedges to prevent rolling.

Strapping and System Strength

Two critical rules apply to securing materials:

1. The total breaking strength of the primary restraint straps should be at least five times the weight of the coil.
2. The breaking strength of each individual lashing strap must be less than the breaking strength of the container's lashing rings. This creates a "fuse" system, ensuring a replaceable strap fails before a structural anchor point is damaged.

Always inspect lashing points for damage or corrosion and use certified products (e.g., CTU Code Compliant) where possible.

Loading Operations: Forklift Safety

When a forklift operates inside a container, its concentrated wheel loads can damage the floor. ISO standard 1496/1 specifies limits to prevent this.

Non-Acceptable Securing Practices

Understanding what not to do is as important as knowing the correct methods. Common mistakes include:

• Loading a coil without any support bedding.
• Improperly transferring pressure to the container walls.
• Using weak or poorly fastened bracing timbers.

The consequences are severe, often resulting in cracked floorboards and bent cross-members, leading to costly repairs. For example, replacing multiple cross-members and floor sections can easily cost over £1,000.

Shipper's Responsibilities and Liabilities

The shipper is ultimately responsible for the correct and safe loading of their cargo. Contracts typically require the shipper to indemnify the carrier for all damages, including: fully

• Repair costs for damaged equipment.
• Replacement value for equipment damaged beyond repair.
• Consequential damages, which can include damage to other cargo, the vessel, port infrastructure, environmental cleanup, and business interruption losses.

The potential financial repercussions are enormous, making proper securing a critical risk management function.

Key Recommendations for Safe Transport

The safe transport of steel coils demands meticulous planning and execution. The following control points are critical:

• ✅ Container Selection: Use only appropriate, structurally sound, and tested containers.
• ⚖️ Weight Distribution: Never allow direct coil-to-floor contact. Use robust supports like beams or cradles to spread the load across multiple cross-members.
• 📏 Linear Load Limits: Strictly adhere to the container's maximum load per linear meter.
• 🔒 Coil Securing: Use the correct orientation and securing methods, including cradles, blocking, and lashing.
• 💪 Material Strength: Use certified materials and ensure the securing system's total strength is at least five times the coil's weight.
• 🚧 Forklift Operations: Comply strictly with ISO 1496/1 limits.

A detailed loading plan developed by knowledgeable personnel and continuous training for all staff are essential. Prioritising safety and compliance is an investment that protects assets, personnel, and the public.