Abstract: An antifouling compound is formed of the esterification product of tributin oxide combined with the copolymer of styrene and maleic anhydride. An antifouling coating formulation is prepared by combining the esterification product with a selected blend of Bisphenol-A and novolac epoxies, fillers, pigment, solvent containing a ketone portion, and an amido amine based accelerator.

Abstract: An antifouling coating for application to submerged surfaces comprises, by eight percent, from about 3-5% fumed silica, from about 60-70% silicone oil, from about 20-30% antifoulant, and from about 0.5-2.0% surfactant.

Abstract: A self-aligning, vibration reducing marine thrust bearing assembly for use ith a propulsion shaft having spaced bearing flanges. The assembly includes a journal bearing sleeve enclosing the shaft and a stationary housing radially spaced from the journal bearing with pivoting means extending therebetween for accommodating any misalignment of the shaft and journal bearing within the housing. An annular fluid containing cavity is formed in the housing adjacent each flange with an annular bearing piston pivotally disposed therein, wherein sealing elements are positioned between the cavity walls and the piston to maintain a fluid seal therebetween. Tapered roller bearings are disposed between each annular bearing piston and each shaft flange raceway.

Abstract: A shaft seal assembly includes a rotor rotationally keyed to a propeller ft; a non-rotating, floating bushing surrounding the rotor; and means for maintaining a fluid seal between the bushing and a housing for the seal assembly. The adjacent surfaces of the rotor and the bushing define a water lubricated bearing interface wherein one of the surfaces is formed of a thin, compliant material and the other surface has axially extending grooves formed therein. The lubrication grooves are arranged in an alternating pattern wherein adjacent lubrication grooves extend from opposite surfaces edges and have portions which axially overlap in spaced apart relationship.

Abstract: A seal structure for an air cushion vessel includes an inflatable bag secd to the hull and a transversely stiffened lobe portion maintained therebeneath. The stiffened lobe portion consists of a membrane with an array of spaced, transverse stiffener members connected thereto. The colinear stiffener members are interconnected in end-to-end relationship.Generally, the end portions of the stiffener members are connected to support stays which are connected either to the bag structure or to the forward portion of the hull. The support stays may comprise cable elements or membranes which form continuations of the stiffened lobe membrane.Additional support for the stiffened lobe portion is provided in the form of a plurality of rear support elements which set the orientation and configuration of the stiffened lobe portion and limit the downward deflection of the stiffened lobe portion.

Abstract: A coating for hulls of ships to be applied underwater to areas of the hull not accessible when ship is in dry dock. The means for applying the coating may take several forms: (1) a multilayered tape system having impregnated in or carrying an antifoulant and having an adhesive tape operable underwater on one side; (2) a sponge like layer having an antifoulant paint or coating liquid which can be squeezed onto the hull; (3) the use of a water soluble sponge having mixed therein microspheres of resin and pigment and microspheres of activator material such that when the microspheres or crushed, the pigmented resin, which may contain an antifoulant, and the activator are mixed and cured to form a coating on the hull while the sponge material will dissolve away when exposed over its surface to seawater.

Abstract: A low infrared emittance coating for use on metal surfaces includes pigme in the form of aluminum, zinc sulfide, antimony trisulfide and blue pigments; filler in the form of aluminum oxide; silicon alkyd resin binder; polarized montmorillite clay; and a diluent.

Abstract: A method and apparatus for replicating the submerged surfaces of ships and other marine structures. One apparatus includes a housing which is partitioned into forward and rear chambers by a membrane and a piston member, which is carried by the membrane. Upon selective flooding of the rear chamber and evacuation of the forward chamber, the piston member is moved toward the submerged surface to form an evacuated molding region therebetween. Liquid molding material is then drawn into the evacuated molding region and the molding device is retained in position until the material solidifies.An alternative molding apparatus includes a housing with peripheral suction elements for releasably securing the housing to the submerged surface so that a molding region is defined therebetween. Upon displacement of water from and subsequent evacuation of the molding region, settable molding material is introduced into the molding region.

Abstract: A steam trap is provided with two paths through which fluid flows from its nput to its output. One path constitutes a control path wherein a small amount of steam or condensate continuously flows through restrictive orifices connected in series between the input and the output. The other path constitutes a main flow path in which a quiet throttling element having a plurality of resistive flow passages and having a moveable valve plug, controls the amount of fluid flowing therethrough. The position of the valve plug and a control piston connected thereto is a function of the fluid flow through the control path between the two orifices; the input and discharge fluid pressures; and a spring connected to the control piston.

Abstract: A wax coating composition capable of underwater application to submerged faces comprises a mixture of from about 2% to about 18% of a polymer having the recurring unit-C.sub.2 F.sub.3 Cl -; from about 20% to about 40% of a microcrystalline wax; from about 40% to about 70% of a chlorinated paraffinic hydrocarbon and up to about 5% of a surfactant. An appropriate biocide may be interspersed into the wax to prevent marine growth.Another wax coating composition comprises a mixture of from about 16% to about 27% of a paraffin wax; from about 22% to about 33% of a microcrystalline wax; and from about 36% to about 58% of a chlorinated paraffinic hydrocarbon. A biocide such as the organotins or cuprous oxide antifoulants may comprise from about 2% to about 10% of the wax mixture.

Abstract: A propeller blade for a multi-bladed propeller comprises a radial inner pion, a radially outer portion and a transition portion extending therebetween. Generally, the leading edge of the blade portions are colinear and the trailing edges of the inner and outer blade portions are offset from each other so that shoulders are defined on the transition portion and the outer blade portion has a higher blade angle of attack than the inner blade portion. The shoulders extend from the leading edge to the trailing edge of the transition for providing flow stability and blade reinforcement.

Abstract: A low infrared emitting coating for use on metal surfaces and compatible with both organic and inorganic binders. The coating is of a color corresponding to the standard Navy haze-gray color and exhibits an infrared reflectance in excess of the standard Navy haze paint.

Abstract: A method of determining the amount of fatigue or stress-corrosion damage occurring in a member includes the step of matching the target material of the x-ray tube with the material of the member such that x-rays from such target material are capable of penetrating beyond the work hardened surface layer of the member. Since the work hardened surface layer extends up to a depth of from about 100 to 200 micrometers in most metallic materials, the x-ray radiation should at least penetrate to a depth of from about 200 to about 400 micrometers to provide x-ray diffraction line intensity profiles from which the excess dislocation density for the material can be determined. The ratio of the average excess dislocation density of the member to the critical excess dislocation density at failure is equivalent to the fatigue or stress-corrosion damage that has occurred to the member.

Abstract: A seal structure for an air cushion vessel includes an inflatable bag secd to the hull and a plurality of juxtaposed, interconnected planer members maintained in operative position beneath the bag by a plurality of support straps. Each planer member includes a transversely reinforced shell portion and a flexible, resilient membrane secured to the longitudinal edge portions of the shell portion to form a flexible planing surface for the seal structure. The planer members may have tapered aft end portions and curved planing surfaces to provide a gradual change of the interface between the planer members and the water.

Abstract: A homopolar machine comprises a stator provided with channel structures caining liquid metal, a rotor concentrically positioned within the stator with circumferential rotor flanges disposed in the channels, and a porous, resilient braided structure slidably positioned in the channels and immersed in the liquid metal to provide a circumferential wetted surface in intimate contact with the peripheral flange surface. The braided structure comprises a longitudinal strip of braided material supported along its longitudinal edge portions by crimped edges of a braid holder such that the central portion of the braided material is resiliently biased toward the peripheral flange surface. The crimped edges of the braid holder are designed to slide into conforming grooves in the stator channel to facilitate easy replacement of the braided structures. Additional resilience is provided by an additional braided element disposed between the braided material and the braid holder.

Abstract: A polyisobutylene based acoustically transparent, camouflage antifouling nt for coating rubber substrates without adversely affecting the chemical stability and sound absorbing characteristics of such substrates. The composition essentially comprises, by weight, non-volatile ingredients including from about 2% to about 23% polyisobutylene polymer of molecular weight from about 81,000 to 99,000; from about 23% to about 29% rosin; from about 45% to about 57% tributyltin flouride and from about 9% to about 11% pigment.

Abstract: In an Air Cushion Vehicle having spaced depending sidewalls, a seal struce which includes an inflatable bag secured to the hull and a plurality of juxtaposed pivotally interconnected planer members maintained in operative position beneath the bag by a plurality of support stays. The support stays are connected to the hull and extend along the longitudinal edge portions of the planer members and are connected to the hinge members, which pivotally interconnect the planer members, to adjustably secure the planer members to the support stays. Fixed length geometry straps and adjustable length retracting straps are connected to the hinge members for limiting the downward deflection of the aft end of the planer members.

Abstract: A method of preventing corrosion of incinerators designed to burn sewage sisting essentially of from about 90 to 98 percent water and from about 2 to 10 percent waste solids by increasing the fusion temperature range of the ash product above the operating temperature of the interior surfaces of the incinerator. The sewage is mixed with additive materials selected from the group SiO.sub.2, CaO, Al.sub.2 O.sub.3, MgO wherein the CaO, Al.sub.2 O.sub.3 and MgO are selected from within the range of 10 to 30 percent of the weight of the waste solids and the SiO.sub.2 is selected from within the range of 25 to 30 percent of the weight of the waste solids.