Conventional calculation methods
distinguish between direct lashing and tie-down lashing and apply both kinds of
securing to the aims of securing items against sliding and tipping. Virtually
no account is taken in the calculations of compaction, which is often
encountered in road freight transport in the form of strapping or bundling.
Conventional calculation methods are
briefly presented below, with emphasis on the general conditions and
simplifying assumptions which apply. In order to clarify the most recent
trends, the calculation conventions from three regulatory texts will be
presented and, if necessary, compared:
Source [1] VDI 2700, Sheet 2, November 2002,
Source [2] DIN EN 12195-1, April 2004,
Source [3] DIN EN 12195-1, January 2009.
The systems of
notation for the operands in the formulae vary between the stated regulatory
texts. In order to facilitate comparability, the following standard system is
used for the purposes of this presentation:
F = force in the securing device assumed in the calculation [kN]
Fx, Fy, Fz
= force components in the system of coordinates of the loading area [kN]
L = length of the securing device [m]
X, Y, Z =
geometric components of length L [m]
m =
cargo mass [t]
fx,
fy = coefficients of acceleration in the longitudinal and transverse directions
m = coefficient of friction
n = number of parallel securing devices
Figure 10: Spatial coordinates of a securing device
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