Lashing
Why lashing
The purpose of lashing is to prevent the cargo from sliding or tipping when it is exposed to forces during transport. This prevents accidents and damage to the cargo during transport. Depending on the application, either webbing or chain lashing is used.
Determine the number of lashing straps needed
On each lashing strap you will find, among other things, the values LC and STF. LC stands for Lashing Capacity and means the maximum working tension. This is the maximum direct tensile force that a system can withstand when in use. The LC will be doubled if the strap is used for round pull (instead of straight pull). STF stands for Standard Tension Force and represents the standard tension force transmitted to the strap. This value is used for tying down the load, i.e. when the strap covers the load from above and thus keeps the load pressed down. In this case the LC-value is not taken into account, only the STF-value counts.
Let us take for example a truck carrying a 10000kg load (or 10 tons or +- 10000daN) with a tie down lashing and with the centre of gravity in the centre of the load. How many lashing straps are needed to hold the cargo with a standard lashing straps with LC 2500daN and STF 350daN? And how many with ERGO lashing straps with LC 2500daN and STF 500daN? For this you have to determine the most important force. For a truck, it is the braking, with a force of 80% of the load. There is a coefficient of 0.2 for metal against metal or 0.6 for metal against rubber (e.g. if you use our anti-slip mats). Here is the calculation for this case:
10 tonne load - metal on metal floor
10000daN load with 80% braking force = 8000daN
Coefficient of friction of 0.2 = 10000daN x 0.2 = -2000daN due to friction
So 8000daN - 2000daN = 6000daN = maximum load to hold in place
And 6000daN / STF of 350daN = 17.14 or 18 standard straps to prevent the load from moving
10 tonne load - metal on metal floor and ERGO lashing straps
10000daN load with 80% braking force = 8000daN
Coefficient of friction of 0.2 = 10000daN x 0.2 = -2000daN due to friction
So 8000daN - 2000daN = 6000daN = maximum load to hold in place
And 6000daN / STF of 500daN = 12 ERGO straps to prevent the load from moving
10 tonne load - metal on non-slip mat floor
10000daN load with 80% force = 8000daN
For a coefficient of friction of 0,6 = 10000daN x 0,6 = -6000daN due to friction
So 8000daN - 60000daN = 2000daN = maximum load to hold in place
And 2000dN / STF of 350daN = 5.71 i.e. 6 standard straps to prevent the load from moving
10 tonne load - metal on non-slip mat floor and ERGO lashing straps
10000daN load with 80% force = 8000daN
For a coefficient of friction of 0.6 = 10000daN x 0.6 = -6000daN due to friction
So 8000daN - 6000daN = 2000daN = maximum load to hold in place
And 2000dN / STF of 500daN = 4 ERGO straps to prevent the load from moving
In this case, you will only need 4 ERGO straps and an anti-slip mat as opposed to 16 standard straps and without an anti-slip mat.
Some tips
Protect the lashing system against rubbing, abrasion and damage by using protective sleeves and/or corner protectors. Use only one lashing system (e.g. do not mix chain and lashing straps). After a thorough initial check by a competent person, frequent regular checks should be carried out and a visual inspection made before and after use. Never tie the straps together. Polypropylene is suitable for temperatures from -40° to 80°C and polyester and polyamide up to 100°C. These properties change in a chemical environment. If in doubt, contact us.
