Impermeable and thermally insulating tank comprising prefabricated panels

Impermeable and insulating tank built into a load-bearing structure of a ship, the said tank having two successive sealing barriers, one a primary barrier (19, 119) in contact with the product contained in the tank and the other a secondary barrier (6, 106) placed between the primary barrier and the load-bearing structure (1, 101), these two sealing barriers being alternated with two thermally insulating barriers, the primary sealing barrier consisting of thin metal sheets (19, 119) held mechanically against the primary insulating barrier, the secondary barriers and the primary insulating barrier essentially consisting of a set of prefabricated panels (2, 102) which are mechanically fastened to the load-bearing structure but not adhesively bonded to it, each panel comprising, in succession, a first rigid board (3, 103) forming the bottom of the panel, a first thermal insulation layer (4, 104) supported by the said bottom board and constituting with the latter a secondary insulating barrier element, a second thermal insulation layer (8, 108), which partially covers the first aforementioned layer, and a second rigid board (9, 109) forming the cover of the panel and covering the second thermal insulation layer which constitutes with the said second board a primary insulation barrier element, the junction regions between the primary insulating barrier elements of two adjacent panels being filled with insulating tiles (14, 114) each consisting of a thermal insulation layer (15, 115) covered with a rigid board (16, 116), the rigid boards of the insulating tiles and the second rigid boards of the panels constituting an approximately continuous wall capable of supporting the primary sealing barrier, the junction regions between the secondary insulating barrier elements being filled by means of a joint (150) made of thermally insulating material, characterized in that the continuity of the secondary sealing barrier is provided in the junction regions of two adjacent panels by flexible strips (20, 120) which are impervious to gas and to liquid and may include at least one deformable continuous thin metal sheet, each strip being hermetically bonded, on its side facing the secondary insulating barrier, on the one hand, to a secondary insulating barrier element of one panel by a lateral marginal region (120a) of the said strip and, on the other hand, to a secondary insulating barrier element of the adjacent panel by an opposite lateral marginal region (120b) of the said strip so that the central region (120c) of the said strip, which covers the junction region between the two aforementioned secondary insulating barrier elements is free to deform elastically and/or to elongate with respect to the insulating tiles and to the insulating joint, the panels being held against the walls of the load-bearing structure with a limited freedom of movement in the planes parallel to the said walls.