The present invention relates to an arrangement for containment of liquid natural gas (LNG) in a hull compartment of a marine construction, comprising a self-supporting primary barrier, a second barrier surrounding the self-supporting primary barrier, and an access space between the self-supporting primary barrier and the secondary barrier. The self-supporting primary barrier is a liquid-tight self-supporting LNG tank and is connected with the hull compartment by support devices penetrating the secondary barrier. The secondary barrier is a liquid-tight thermal insulation connected with the interior surface of the hull and is sealed to the support devices by a flexible liquid tight seal, so that the self-supporting primary barrier and the secondary barrier are separately connected with the hull compartment to prevent transfer of forces between the primary barrier and the second barrier.