A load-bearing frame structure for a maritime vehicle includes two support plates, a deck plate structure, a front bulkhead structure, and a back bulkhead structure. Each of the support plates has a front edge, a back edge, a top edge, and a bottom edge. The support plates can be angled relative to each other and connected to each other at the top edges thereof forming an inverted V-shape. The support plates can alternately be parallel to each other in a vertical orientation. The support plates each have one or more cut-out sections. The deck plate structure connects the two support plates proximate the bottom edges of the support plates. The front bulkhead structure connects the front edges of the support plates, and the back bulkhead structure connects the back edges of the support plates.

Disclosed is a method for stiffening plates for ship walls. At least one elongate profile member of laminated composite material and having a transverse cross-section of a predetermined shape over the length thereof is pre-manufactured, the profile member being rigid. Then, a panel including laminated composite materials at least on the surface of at least one of the two main surfaces thereof is used, and the at least one pre-manufactured profile member is assembled and attached together onto one of the main surfaces of the panel. The main surface of the panel receives the profile member including laminated composite material. The profile member has a transverse cross-section with three continuous portions: two flanges having substantially straight cross-sections and interconnected by a web. The flanges and the web in transverse cross-section are supported by separate planes, the plane of the web intersecting the two planes, supporting the flanges, at 90.

Two watercraft are connected together using a hinge system. A knuckle in one watercraft is placed in a corresponding space therefore in a second watercraft. Similarly, a buttress in the second watercraft is placed in a corresponding space in the first watercraft. An axle is placed within the buttresses as well as within the knuckle to attach the hinge device to attach the two watercraft together. This axle is also attached to a rear transom and to a forward bow connector. A second axle adds further rigidity to the system as it attached through a first watercraft passageway to both the transom and to the bow connector.

Two watercraft are connected together using a hinge system. A knuckle in one watercraft is placed in a corresponding space therefore in a second watercraft. Similarly, a buttress in the second watercraft is placed in a corresponding space in the first watercraft. An axle is placed within the buttresses as well as within the knuckle to attach the hinge device to attach the two watercraft together. This axle is also attached to a rear transom and to a forward bow connector. A second axle adds further rigidity to the system as it attached through a first watercraft passageway to both the transom and to the bow connector.

A floating connection assembly of a bulkhead to at least one element of constraint includes a projection integral to the element of constraint and at least one first longitudinal sealing bead. At least one projecting element protrudes from the bulkhead. The assembly has at least a second flexible seal and at least one closure plate, arranged in such a way that the bulkhead and the element of constraint are separated along an edge of the bulkhead. The one first longitudinal sealing bead is interposed between the bulkhead and the projection, on which is present at least one through hole through which passes the projecting element, integral with a respective closure plate, so that the bulkhead remains cantilevered on the protrusion, avoiding a different support, and so that the projecting element is free to oscillate inside the hole.

A floating connection assembly of a bulkhead to at least one element of constraint includes a projection integral to the element of constraint and at least one first longitudinal sealing bead. At least one projecting element protrudes from the bulkhead. The assembly has at least a second flexible seal and at least one closure plate, arranged in such a way that the bulkhead and the element of constraint are separated along an edge of the bulkhead. The one first longitudinal sealing bead is interposed between the bulkhead and the projection, on which is present at least one through hole through which passes the projecting element, integral with a respective closure plate, so that the bulkhead remains cantilevered on the protrusion, avoiding a different support, and so that the projecting element is free to oscillate inside the hole.

Hull structure made of composite material that includes a hull with high thickness single skin monocoque plating without reinforcements and an internal stiffening structure (1) formed by a deck (2), two opposing transverse bulkheads (3) and more cradle-shaped load-bearing elements (5) to support components or machinery intended to be housed on board said hull structure. Advantageously, the above-mentioned cradle-shaped load-bearing elements (5) are supported at the respective internal portions of said opposite transverse bulkheads (3) only at their opposite head ends (5b).

Hull structure made of composite material that includes a hull with high thickness single skin monocoque plating without reinforcements and an internal stiffening structure (1) formed by a deck (2), two opposing transverse bulkheads (3) and more cradle-shaped load-bearing elements (5) to support components or machinery intended to be housed on board said hull structure. Advantageously, the above-mentioned cradle-shaped load-bearing elements (5) are supported at the respective internal portions of said opposite transverse bulkheads (3) only at their opposite head ends (5b).