BREAK-BULK & HEAVY CARGO LASHING SPECIFICATIONS

SGS Certified Heavy-Duty Lashing for Vessel, Port, and Oversized Cargo Operations

Why Break-Bulk Cargo Demands Verified Lashing Specifications

Break-bulk cargo — steel coils, machinery, project cargo, timber, construction materials, and oversized loads — is among the most demanding cargo to secure. Unlike containerised freight, break-bulk loads are directly exposed to vessel movement, sea swell, port handling forces, and weather conditions during transport.

The dynamic forces acting on break-bulk cargo during sea transport are significantly higher than those encountered in standard road freight. Vessel roll, pitch, and acceleration can generate forces that exceed several times the cargo weight. This is why break-bulk lashing systems must be specified based on verified, independently tested strength ratings — not estimates or manufacturer claims.

DunLash heavy-duty woven polyester lashing is independently tested and certified by SGS South Africa, providing verified performance data for cargo securing professionals, stevedores, and logistics operators who need to calculate lashing requirements with confidence.

Heavy-Duty Lashing Range for Break-Bulk Applications

For break-bulk and heavy cargo securing, DunLash supplies our highest-rated woven polyester lashing systems. These products are specifically designed for loads where standard strapping or lighter lashing is insufficient.

Understanding the Numbers for Break-Bulk Securing

System Breaking Strength: The DunLash 750 achieves a system breaking strength of up to 13,850daN when combined with a heavy-duty buckle. This is equivalent to approximately 14 tonnes of breaking force, making it suitable for the most demanding break-bulk applications including steel coils, heavy machinery, and project cargo.

Maximum Securing Load (MSL): The MSL is calculated at 50% of the system breaking strength and represents the working load for cargo securing calculations. For the DunLash 750, the MSL is approximately 6,925daN per lashing — roughly 7 tonnes of working securing force. Multiple lashings are applied to achieve the total restraint required for a given cargo weight and transport condition.

Why Elongation Matters for Break-Bulk: Woven polyester lashing elongates under load before breaking. This is a critical advantage for break-bulk cargo because it means the lashing absorbs dynamic forces — vessel roll, sudden acceleration, wave impact — rather than transmitting them rigidly to the cargo. The 10–12% elongation at break in our heavy-duty lashing range provides significant shock absorption while maintaining load stability throughout the voyage.

Related Resources

• Full lashing range specifications
• Polyester cargo lashing systems (parent product page)
• Mining & heavy industry cargo securing
• Lashing versus chains to secure heavy cargo (blog)

Break-Bulk Cargo Types Secured with DunLash Lashing

• Steel coils and steel plate — heavy, cylindrical loads requiring high-strength restraint with surface protection
• Machinery and heavy equipment — irregular shapes with high centres of gravity that demand secure, multi-point lashing
• Project cargo — oversized or one-off loads for construction, energy, and infrastructure projects
• Timber and forestry products — bundled logs and sawn timber requiring flexible yet strong securing
• Construction materials — structural steel, piping, and prefabricated components
• Mining equipment — crushers, conveyors, vehicles, and components being transported to and from mine sites

Why Polyester Lashing Outperforms Chains for Break-Bulk Cargo

Traditional chain and wire rope securing is still used in some break-bulk operations, but woven polyester lashing offers significant advantages for many applications:

• Shock absorption — polyester absorbs dynamic forces from vessel movement rather than transferring them directly to the cargo, reducing the risk of damage and load shifting
• No corrosion — critical for cargo exposed to sea spray, coastal humidity, and extended ocean voyages
• No cargo surface damage — polyester lashing does not scratch, dent, or mark cargo surfaces the way chains and wire rope can
• Lighter weight — easier and safer for stevedores to handle during loading and discharge operations
• Consistent tension — polyester maintains lashing tension over long voyage durations without the loosening that can occur with chain systems
• Faster application — buckle systems are quicker to apply and tension than chain and turnbuckle arrangements

Port Operations in South Africa

DunLash heavy-duty lashing is used at all major South African break-bulk terminals:

• Durban Multipurpose Terminal and Maydon Wharf — South Africa’s highest-volume break-bulk port
• Richards Bay — heavy cargo and bulk commodities for the mining and forestry sectors
• Gqeberha (Port Elizabeth) and Ngqura — automotive, manufacturing, and project cargo
• Cape Town Multi-Purpose Terminal — break-bulk, project cargo, and offshore energy sector loads
• Saldanha Bay — iron ore and heavy industrial cargo

Break-Bulk Cargo Lashing FAQs

What is the strongest lashing DunLash offers for break-bulk cargo?

The DunLash 750 (50mm) achieves a system breaking strength of up to 13,850daN, equivalent to approximately 14 tonnes of breaking force. This is our highest-rated product and is designed specifically for heavy break-bulk and vessel cargo applications. All specifications are SGS certified.

How many lashings do I need to secure a steel coil?

The number of lashings depends on the coil weight, the transport mode, the lashing angles, and the applicable securing standard (such as the CTU Code). The total required restraint force is divided by the MSL of each individual lashing to determine the quantity needed. DunLash provides cargo securing assessments to help you calculate the correct number and placement of lashings for your specific load.

Can polyester lashing replace chains for heavy cargo on vessels?

In many break-bulk applications, woven polyester lashing provides a safer, lighter, and more effective alternative to chains. Its shock-absorbing properties are specifically suited to the dynamic forces of sea transport. However, the suitability depends on the specific cargo, weight, and transport conditions. DunLash can assess your requirements and recommend the appropriate solution.

Is DunLash break-bulk lashing suitable for project cargo?

Yes. Our heavy-duty woven polyester lashing is widely used for project cargo, including oversized equipment, structural components, and one-off loads. The high system strengths (up to 13,850daN) and shock-absorbing characteristics make it well suited to the irregular shapes and demanding transport conditions typical of project cargo shipments.

Are the strength specifications independently verified?

Yes. All DunLash lashing specifications are tested and certified by SGS South Africa. The published figures represent the mean of three separate tests conducted on calibrated tensile testing apparatus, as documented in our SGS Technical Inspection Reports.

Contact DunLash to discuss the right heavy-duty lashing specification for your break-bulk cargo requirements.

Lashing Product Range

Need Assistance? Let one of our specialist consultants get in touch with you today.