Special Hull Treatment

Last updated

Special Hull Treatment was the process, devised in the 1980s, by which defense contractors coated the outsides of the hulls of submarines with a rubberized tile that was designed to deaden noise, redirect sound waves, and absorb or contain hull noise.

The tiles, measuring about 12 inches square resemble an octopus tentacle. They are actually constructed in a quadrahedral formation, in which the bottom sides have an array of holes. The holes connect to a central port in the center of the tile. This port is where a vacuum source is applied to pull a vacuum once the hole tile has been laid on the hull and glued with an epoxy. The epoxy takes about 1 day to harden, after which the vacuum is removed to make sure the tile has a good seal indicated by the vacuum not dissipating.

The tiles' shape is like the facets of a diamond or gemstone. It has four angles, and the construction of the tile is a soft black rubber with lead shavings impregnated in it. Each tile is fitted on the hull, and a caulk is applied in the seams between the tiles. The hull has to be sandblasted to bare metal and then re-coated with a special paint. The epoxy is applied to that paint. During the process, the hull is maintained above the dewpoint and in a controlled environment so that condensation does not occur during the process.

The first sub to receive this hull treatment was the USS Batfish, c. 1980.

Related Research Articles

Anode Electrode through which conventional current flows into a polarized electrical device

An anode is an electrode through which the conventional current enters into a polarized electrical device. This contrasts with a cathode, an electrode through which conventional current leaves an electrical device. A common mnemonic is ACID, for "anode current into device". The direction of conventional current in a circuit is opposite to the direction of electron flow, so electrons flow out the anode into the outside circuit. In a galvanic cell, the anode is the electrode at which the oxidation reaction occurs.

Printed circuit board Board to support and connect electronic components

A printed circuit board (PCB) mechanically supports and electrically connects electrical or electronic components using conductive tracks, pads and other features etched from one or more sheet layers of copper laminated onto and/or between sheet layers of a non-conductive substrate. Components are generally soldered onto the PCB to both electrically connect and mechanically fasten them to it.

Flooring is the general term for a permanent covering of a floor, or for the work of installing such a floor covering. Floor covering is a term to generically describe any finish material applied over a floor structure to provide a walking surface. Both terms are used interchangeably but floor covering refers more to loose-laid materials.

Epoxy family of two-part adhesive resins

Epoxy refers to any of the basic components or cured end products of epoxy resins, as well as a colloquial name for the epoxide functional group. Epoxy resins, also known as polyepoxides, are a class of reactive prepolymers and polymers which contain epoxide groups.

Varnish transparent, hard, protective finish or film used in painting

Varnish is a clear transparent hard protective finish or film. Varnish has little or no color and has no added pigment as opposed to paint or wood stain which contains pigment. However, some varnish products are marketed as a combined stain and varnish. Varnish is primarily used in wood finishing applications where the natural tones and grains in the wood are intended to be visible. It is applied over wood stains as a final step to achieve a film for gloss and protection. Varnish finishes are usually glossy but may be designed to produce satin or semi-gloss sheens by the addition of "flatting" agents.

Vacuum energy is an underlying background energy that exists in space throughout the entire Universe. Its behavior is codified in Heisenberg's energy–time uncertainty principle. Still, the exact effect of such fleeting bits of energy is difficult to quantify. The vacuum energy is a special case of zero-point energy that relates to the quantum vacuum.

Stitch and glue

Stitch and glue is a simple boat building method which uses plywood panels stitched together, usually with copper wire, and glued together with epoxy resin. This type of construction can eliminate much of the need for frames or ribs. Plywood panels are cut to shape and stitched together to form an accurate hull shape without the need for forms or special tools. This technique is also called "tack and tape", or "stitch and tape". Seams are reinforced with fiberglass tape and thickened epoxy.

Wood preservation Treatment or process aimed at extending the service life of wood structures

All measures that are taken to ensure a long life of wood fall under the definition wood preservation.

Boat building construction and engineering of boats

Boat building is the design and construction of boats and their systems. This includes at a minimum a hull, with propulsion, mechanical, navigation, safety and other systems as a craft requires.

Anti-fouling paint Specialist paint that greatly inhibits bio-fouling

Anti-fouling paint - a category of commercially available underwater hull paints - is a specialized category of coatings applied as the outer (outboard) layer to the hull of a ship or boat, to slow the growth and/or facilitate detachment of subaquatic organisms that attach to the hull and can affect a vessel's performance and durability. Anti-fouling paints are often applied as one component of multi-layer coating systems which may have other functions in addition to their antifouling properties, such as acting as a barrier against corrosion on metal hulls that will degrade and weaken the metal, or improving the flow of water past the hull of a fishing vessel or high-performance racing yachts.

Plating is a surface covering in which a metal is deposited on a conductive surface. Plating has been done for hundreds of years; it is also critical for modern technology. Plating is used to decorate objects, for corrosion inhibition, to improve solderability, to harden, to improve wearability, to reduce friction, to improve paint adhesion, to alter conductivity, to improve IR reflectivity, for radiation shielding, and for other purposes. Jewelry typically uses plating to give a silver or gold finish.

Saltillo tile

Saltillo tile is a type of terra-cotta tile that originates in Saltillo, Coahuila, Mexico. It is one of the two most famous products of the city, the other being multi-coloured woven sarapes so typical of the region. Saltillo-type tiles are now manufactured at many places in Mexico, and high-fire "Saltillo look" tiles, many from Italy, compete with the terra-cotta originals.

Gelcoat or 'Gel Coat' is a material used to provide a high-quality finish on the visible surface of a fibre-reinforced composite. The most common gelcoats are thermosetting polymers based on epoxy or unsaturated polyester resin chemistry. Gelcoats are modified resins which are applied to moulds in the liquid state. They are cured to form crosslinked polymers and are subsequently backed with thermoset polymer matrix composites which are often mixtures of polyester resin and fiberglass, or epoxy resin which is most commonly used with carbon fibre for higher specific strength.

Anechoic tile

Anechoic tiles are rubber or synthetic polymer tiles containing thousands of tiny voids, applied to the outer hulls of military ships and submarines, as well as anechoic chambers. Their function is twofold:

Powder coating is a type of coating that is applied as a free-flowing, dry powder. Unlike conventional liquid paint which is delivered via an evaporating solvent, powder coating is typically applied electrostatically and then cured under heat or with Ultraviolet light. The powder may be a thermoplastic or a thermoset polymer. It is usually used to create a hard finish that is tougher than conventional paint. Powder coating is mainly used for coating of metals, such as household appliances, aluminium extrusions, drum hardware, automobile, motorcycle, and bicycle parts. More advanced technologies allow other materials, such as plastics, composites, carbon fiber, and MDF, to be powder coated using different methods that require less heat and time. The powder coating process was invented around 1945 by Daniel Gustin US Patent 2538562.

Friction stud welding

Friction stud welding is a solid phase welding technique involving a stud or appurtenance being rotated at high speed while being forced against a substrate, generating heat by friction. The metal surfaces reach a temperature at which they flow plastically under pressure, surface impurities are expelled and a forged weld is formed.

Carbon fiber reinforced polymer, Carbon fibre reinforced polymer, or carbon fiber reinforced plastic, or carbon fiber reinforced thermoplastic, is an extremely strong and light fiber-reinforced plastic which contains carbon fibers. The spelling 'fibre' is usual outside the USA. CFRPs can be expensive to produce but are commonly used wherever high strength-to-weight ratio and stiffness (rigidity) are required, such as aerospace, superstructure of ships, automotive, civil engineering, sports equipment, and an increasing number of consumer and technical applications.

Corrosion in Ballast Tanks is the deterioration process where the surface of a ballast tank progresses from microblistering, to hydroscaletric electration, and finally to cracking of the tank steel itself.

According to EN 13523-0, a prepainted metal is a ‘metal on which a coating material has been applied by coil coating’. When applied onto the metallic substrate, the coating material forms a film possessing protective, decorative and/or other specific properties.

Boat building uses many common house tools such as hammers, crosscut saws, power drills, benches and vises.

References