HOW DO YOU PROTECT AGAINST UPWARD FORCES?
LASHING DOWN, FORM-FIT SECURING OR VERTICAL TOP LASHING?
Several values are important when it comes to calculating and securing a load correctly. That is why every book or training course on load securing explains that the STF value (standard tension force of a lashing strap) is only intended to be used when lashing down a load. This can lead to confusion in practice. Our load securing specialist Niels Bouwmeester explains this in more detail in his blog below.
Lashing down is the most commonly used non-positive method of load securing. When lashing down, you pull the load down towards the loading floor using lashing aids such as lashing straps or chains. This creates downward pressure and increases the friction between the load and the loading floor. The purpose of lashing down is to prevent a load from moving!
FORM-FIT SECURING AND VERTICAL TOP LASHING
Lashing down is the least effective way of securing a load. You are better off using the method of form-fit securing, where the load is fully enclosed so that it is unable to move. However, combined load securing works best because standards specify that you should also prevent oscillations and vibrations. The possible shifting of a load.
Here is an example of form-fitting in practice:
Steel coils are being transported using a special coil trailer. The steel coils are firmly fixed in a coil duct and are then secured using the form-fit method with the help of stanchions, chains and/or lashing straps.
As you can see from the picture below, two lashing straps have been placed over the load. According to all the theory books, you should now use the STF value. But as explained above, the purpose of lashing down is to prevent movement. That is not necessary here as the coil is already enclosed by the form-fitting duct, which will prevent the coil from moving. So the purpose of the two lashing straps is not to increase friction and create additional downward pressure, but rather to protect against upward forces. So you have vertical top lashing. In this case, the LC value is sufficient in the strapping.
(Bron: Fahrzeugwerk Bernard KRONE GmbH & Co. KG)
CHECK AND ASK MORE QUESTIONS
This example clearly shows that you should look at more than just laws and standards when securing a load. So my advice is: take a good look at the situation and what you are dealing with. During an inspection it is also advisable to ask for the calculations carried out. Inspections are often carried out using apps, but they are not always the be-all and end-all. Specialist training on load securing can also provide a solution.