Ideally, you have the contingency to carefully prepare for securing the load, in which all weights and dimensions are taken into consideration. However, frequently an assessment must be made quickly on site in order to decide about suitable measures.
What forces must I anticipate?
The graphic on the right shows the size of the forces that normally occur during transportation. Multiply the weight of the load by the associated acceleration "g" and you obtain the force that wants to move the load away from the trailer.