Patent ID: 7503249

Claim:
A rail gun barrel having a bore through which a projectile may be accelerated, which barrel comprises: an outer rigid tube; a pair of spaced apart rails disposed within said tube; a pair of spaced apart insulators which separate said rails in a central region within said outer tube, said rails and said insulators being elongated and having side faces that are juxtaposed with one another to form a generally annular composite structure having a defined interior bore; a surrounding prestressed shell which is in contact with and applies compressive stress to said composite bore-defining structure, which shell is a filament-wound tubular structure wherein filaments having a high tensile strength and an elastic modulus of not greater than about 5 Msi are wound under tension about said composite bore-defining structure in predominately hoop orientation, with a hardened polymeric resin impregnated in said wound filaments; and a pressure medium positioned adjacent the exterior surface of said prestressed shell and within said outer rigid tube, which pressure medium is operative to apply compressive stress to the surface of said prestressed shell at least at locations generally radially outward of said rails, whereby the resultant compressive stresses applied by the combination of said prestressed shell and said pressure medium are additive and effective to preload the rails to adequately resist bursting forces that include electromagnetic repulsion forces and axisymmetric pressure if a plasma armature is employed.