Abstract: The present invention provides a containment integrity system for application in a vessel carrying bulk materials such as liquid petroleum products. The containment integrity system comprises a flexible liner having an inner composite fabric portion and an outer fiber-reinforced rubber skin portion, a fastening system for rigidly securing the flexible liner to the walls of the vessel, an anchoring system for releasably securing and conforming the flexible liner to and about all coverable features of the hull of the vessel, and a self-sealing flange assembly for insertion into all flow holes connecting the cargo compartments of the vessel. The present containment integrity system insures the necessary containment integrity of the hull of the vessel without significant reduction in the carrying capacity of the vessel.