Sealed and thermally insulating tank

A sealed and thermally insulating tank for transport and/or storage of liquefied natural gas, comprising:

• at least a supporting structure and a storage structure surrounded by the supporting structure, the storage structure comprising at least a first portion and a second portion which are sealed relative to one another, the first portion and the second portion extending at least partially in the same plane parallel to the supporting structure, the storage structure having a thickness from the outside toward the inside of the tank in a direction perpendicular to the plane of the supporting structure, the tank comprising a closure device arranged at least partially in the thickness of the storage structure, the closure device comprising at least a first closure member and a second closure member configured to interact with one another in such a way as to separate the first portion from the second portion, at least one of the closure members comprising a first part and a second part extending in secant planes, wherein at least one of the parts of one and/or the other of the closure members is connected to at least one of the portions by a securing device arranged in the thickness of the storage structure, and wherein the first closing member and the second closing member have an L shaped profile seen in a section plane passing through the closing device.