Coils fastened to wooden skids exhibit, apart from friction locking, also a certain form locking to the skid (see Figure 5). Therefore, a friction coefficient of 0.4 may be attributed to the connection coil to skid. The same coefficient is valid, according to Annex 13 to the CSS-Code, for the boundary between the wooden skid and the wooden floor of the container. Thus a residual securing demand remains against accelerations of 0.6 g longitudinally and 0.4 g transversely.
However, if the coils rest on timber beams or with wooden liners on steel beams, the applicable friction coefficient is only 0.3. Then the residual securing effort must be directed against accelerations of 0.7 g longitudinally and 0.5 g transversely.