Abstract: The invention relates to a vessel (1) provided with a deck (2) and with a device (3) for removing and/or installing a sub-structure (4) of a drilling or production platform, wherein said device comprises a supporting structure (5) which is capable of tilting movement in a direction transversely to an edge (6) of the deck (2), hoisting means (7) connected to said supporting structure for hoisting said sub-structure, and supporting means for supporting said sub-structure mainly during tilting movement of said supporting structure, wherein said supporting means are provided separately from the supporting structure and capable of tilting movement with respect to the edge of the deck.

Abstract: A method for removing a jacket of a drilling or production rig using a vessel provided with a deck includes manoeuvring the vessel close to the jacket, hoisting the jacket, and tilting the jacket relative to a tilting point located close to an edge of the deck of the vessel until the jacket lies on the deck, wherein the side of the jacket directed toward the vessel is supported during the tilting, such that the jacket can be removed in one operation and carried away using the vessel. A vessel with a deck and a device for removing a jacket of a drilling or production rig is also disclosed.