6.1.3   Securing of the coils
The coils are secured according to the principles in chapter 5. The friction coefficient is taken as 0.4 due to the form locking to the skids. Thus, a residual securing demand remains against longitudinal accelerations of 0.6 g and transverse accelerations of 0.4 g.

The residual longitudinal securing effort of 28 · 0.6 · 9.81 = 165 kN should be partly achieved by lashings, because securing by pressure elements alone would overcharge the end walls, as they are rated for 0.4 g only.

Figure 22 shows the arrangement of such lashings in a container with 10 securing points in the bottom area. Due to the layout of the securing points only four of them are loaded simultaneously to fore or aft in this example.

Figure 22: Longitudinal lashing of the coils

Figure 23 shows the additional longitudinal pressure elements. They consist of three upright timbers of 10 x 10 cm in the space between the coils in the middle, secured against falling loose. To the end wall on the left, the coils are braced by means of two cross beams in a height of 0.5 and 1 m. At the door end this is done by 8 short scantlings of 10 x 10 cm cross-section being braced to the corner posts.

Figure 23: Longitudinal and transverse bracing of the coils

The residual transverse securing effort of 28 · 0.4 · 9.81 = 110 kN is exclusively achieved by pressure elements of four timbers of 10 x 10 cm cross-section to each side wall with the coils in the middle. The coils resting side by side at the ends of the container are braced against each other by two scantlings of 10 x 10 cm cross-section.

The arrangement is checked by a balance:

 Longitudinally: 1 · 9.81 · 28 ≤ 0.4 · 28 · 9.81 + (4 · 10 + 8 · 100 · 0.3) / 1.5
 (to the door end) 275 ≤ 110 + 187
 275 < 297 Balance is met!

 Transversely: 0.8 · 9.81 · 12 ≤ 0.4 · 12 · 9.81 + (4 · 100 · 0.3) / 1.5
 (3 middle coils) 94 ≤ 47 + 80
 94 < 127 Balance is well met!

 Transversely: 0.8 · 9.81 · 4 ≤ 0.4 · 4 · 9.81 + (2 · 100 · 0.3) / 1.5
 (each 1 Coil at the ends) 31 ≤ 16 + 40
 31 < 56 Balance is well met!

Notice: The bracing between the coils stowed longitudinally at the ends of the container must transfer the load from one coil only at a time.

The shown securing effort may appear rather extensive. But it must be necessarily installed because in a case of failure the damage may become immense and may also impact neighbouring containers on a sea going vessel.

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