6.1.1 The securing devices on non-standardized
portable tanks and on the ship should be arranged in such a way as
to withstand the transverse and longitudinal forces, which may give
rise to sliding and tipping. The lashing angles against sliding should
not be higher than 25° and against tipping not lower than 45°
to 60° (figure 1).
Figure 1 Securing of Portable Tanks with Favourable Lashing Angles
6.1.2 Whenever necessary, timber should be used
between the deck surface and the bottom structure of the portable
tank in order to increase friction. This does not apply to tanks on
wooden units or with similar bottom material having a high coefficient
of friction.
6.1.3 If stowage under deck is permitted, the
stowage should be such that the portable non-standardised tank can
be landed directly on its place and bedding.
6.1.4 Securing points on the tank should be of
adequate strength and clearly marked.
6.1.5 Lashings attached to tanks without securing
points should pass around the tank and both ends of the lashing should
be secured to the same side of the tank (figure
2).
Figure 2 Securing of Portable Tanks having No Securing Points
6.1.6 Sufficient securing devices should be arranged
in such a way that each device takes its share of the load with an
adequate factor of safety.
6.1.7 The structural strength of the deck or hatch
components should be taken into consideration when tanks are carried
thereon and when locating and affixing the securing devices.
6.1.8 Portable tanks should be secured in such
a manner that no load is imposed on the tank or fittings in excess
of those for which they have been designed.