When securing cargo, choosing the right lashing strap and understanding its strength is crucial for safe transport. In this guide, we’ll walk you through how to calculate lashing strap strength, covering key concepts like breaking strength, lashing capacity, and safety factors.
Key Definitions
- Breaking Strength (BS): Breaking strength is the maximum force a lashing strap can withstand before breaking. Manufacturers often list this value in kilograms (kg) or kilonewtons (kN) on the strap’s label.
Example: A lashing strap with a breaking strength of 2,000 kg can withstand up to that load before failing.
- Lashing Capacity (LC): Lashing Capacity is the safe working load, which is typically half of the breaking strength. This value ensures that the strap operates within a safe range.
- Safety Factor: A common safety factor of 2:1 or 3:1 is applied to lashing straps, meaning the strap is designed to handle twice the working load to ensure additional security.
Safety Example: Using a strap with a 1,000 kg lashing capacity, the 2:1 safety factor means it can withstand up to 2,000 kg in extreme conditions.
Example calculation
Breaking strength(BS): 9,000lbs
safety factor (SF):3
LC=9,000lbs/3=3,000lbs
What factors should I consider when calculating the load capacity of a lashing strap?
When calculating the load capacity (LC) of a lashing strap, several factors must be considered besides BS, and SF to ensure safety and effectiveness
- Material Condition:
- Definition: The physical state of the strap, including wear, damage, and age.
- Consideration: Inspect straps regularly for fraying, cuts, abrasions, or other signs of wear. Damaged straps should be replaced, not used.
- Environmental Factors:
- Definition: Conditions such as temperature, UV exposure, moisture, and chemicals.
- Consideration: Environmental factors can degrade the material of the strap over time, reducing its strength.
- Load Characteristics:
- Definition: The nature of the load, including weight, shape, and stability.
- Consideration: Ensure the load is evenly distributed and securely fastened to prevent shifting.
- Angle of Use:
- Definition: The angle at which the strap is applied relative to the load.
- Consideration: Straps used at angles other than straight (90 degrees) can experience reduced strength due to increased tension.
- Type of Strap and Hardware:
- Definition: The specific type of strap (e.g., polyester, nylon) and any associated hardware (e.g., hooks, ratchets).
- Consideration: Different materials and hardware have varying strengths and durability. Ensure compatibility and check ratings for all components.
- Regulatory Standards:
- Definition: Compliance with local, national, or international safety standards and regulations.
- Consideration: Follow relevant standards (e.g., OSHA, ANSI) to ensure legal compliance and safety.
Conclusion: Choosing the Right Lashing Strap
Understanding these parameters ensures you choose the correct lashing strap for your load. Always inspect the strap for wear and tear before each use and follow manufacturer guidelines to ensure safety.
