Abstract: The invention relates to a device for measuring the shearing action in the core of a sandwich structure, for instance a hull. The device comprises a sensing means, e.g. a cylindrical rod, and a measuring instrument. The rod is adapted to be inserted into a cylindrical hole which is bored in the hull preferably perpendicular to the surface thereof so as to extend a distance into the core and which has a diameter corresponding to that of the rod. By means of the measuring instrument, an angle between the rod and a reference plane is measured, which is determined by three points on the surface of the hull or the change of this angle when the hull is subjected to a change in load. This angle can be converted into a measure of the current shearing load.

Abstract: The invention relates to a boat or ship's hull, which is shielded against electronic radiation and comprises a cover (2) or the like for closing a hatch (3) in e.g. the deck (1) of the hull, and a sealing device for electric sealing of the closure of the cover at that part of the hull which surrounds the hatch. The hull and the cover comprise a composite (7, 9) containing fibers of an electrically conductive material, such as carbon fibers. The fibers reach the surfaces of the hull and the cover at the closure, where two sealing members (14, 15) included in the sealing device are fixed by lamination. The sealing members comprise flexible layered elements including fibers of the same kind of material as the fibers of the composite, for instance, textile bands of carbon fibers. The electric seal is kept closed by preferably non-laminated parts (20) of one of said sealing members being pressed against parts (21) of the second sealing member, e.g.