Undetectable submarine of composite construction - involving fibre reinforced resin laminates, expanded resins and impregnated fabrics

摘要

An undetectable submarine for e.g. attack or surveillance purposes down to 500 m has a hull of which the rigid members are of a non-magnetic glass reinforced resin laminate covered with composite layers to absorb external acoustic (sonar probe) signals and contain internal noise. Propulsion units (linear, hydraulic, volumetric or mechanical drive) are contained within longitudinal tunnels also lined with acoustic absorbants. Communication signals are received or transmitted via (carbon fibres) antennae wires laid up within the structure of the skin of the hull or its (retractable) conning tower. External ballast tanks with flexible walls allow buoyancy to be adjusted by internal fluid transfer-silent and without involving expulsion of tell tale air bubbles. Specific constructions may involve hull panels of glass reinforced polyester laminates supported on ribs of elastomeric matl. with interstices packed with sound absorbant expanded polyurethane or polystyrene. The outer skin may be a flexible, permeable fabric of PVC coated polyamide or polyester enclosing an open-celled foam impregnated with a slurry of sand or mud and pref. various sizes of trapezoidal diffractors also made of reinforced polyester resin. Opt., the reinforcing fibres of the structural panels may be of polyimide resin or carbon and the open celled foam complemented by longitudinal or transverse hoops of expanded epoxy or polyester resin.