Don't know about other airlines but the one I work has following rules:
Straps are allowed to be used max 5 years - manufacturing month and year is printed on them.
Maximum weights are;
1300Kg upwards (3g) and
2600Kg forward and backward (1.5g)
Presume the vehicle + ULD + other loading material weighs 16tons it would need minimum 27 straps to hold it in place; 7 for forward forces + 7 for backward forces + 13 for upward forces.
