A system for support of a vertical cargo tank resting on an insulation layer against the hull of a vessel is arranged such that vertical forces are supported through the base of the tank. Horizontal forces are supported by support point pairs. These pairs are designed to direct applied forces generally through the middle of the shell of the tank in order not to apply bending moment to the shell of the tank. The base of the tank is flexible to generally distribute transferring forces from the tank directly to the bottom of the vessel in order not to apply bending moment to the shell of the tank or to the bottom of the vessel.