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Specifications for Building Exhibition Model Ships

Durability of Materials

As part of the permanent collection of the Department of the Navy, it is reasonable to expect a new ship model to last one hundred years before deterioration is visible. Therefore, resistance of models and parts to the actions of temperature, humidity, and light is essential. Extreme care must be given to select materials which are known to be compatible and will not, in time, interact chemically.

Although only a few materials are prohibited in "Specifications for Construction of Exhibition Models of U.S Naval Vessels," some recently developed model-building materials and techniques should be avoided until sufficient time has passed to properly evaluate their longevity. Though some of these recently introduced materials may ultimately test superior to more traditional techniques, substances of unproven longevity should not be employed in models built under these specifications. It is advised that fiberglass resins, styrene, expanding foams, casting resins, and cyanoacrylate glues be avoided when other materials can possibly be used.

Workmanship
Workmanship shall be in accordance, in every respect, with the best model-building practices. Hulls shall be smooth, fair, and symmetrical; without blemishes, sap pockets, or tool marks, and shall be scraped and sand-papered to smooth surface. Machined parts shall bear no tool marks. Castings shall bear no visible mold marks. In no case shall glue alone be deemed sufficient to hold deck houses, fittings, or other appurtenances in place. Mechanical fastenings such as screws and pins shall be used in addition to adhesives.

Range
Models shall be museum quality and shall consist of the whole exterior of the vessel from keel and appendages to the top of the highest antenna or fitting, and shall include interiors of such enclosures, conning stations, deck house topside stations, gun and missile stations, hangars and bays as are accessible to weather without opening watertight doors or ports. Generally, all items on the prototype twelve inches or larger for 1:96 scale (six inches or larger for 1:48 scale) will be reproduced.

Rigging
Running and standing rigging and cable antennas shall be represented. Windlasses shall be wound with appropriate cable or line.

Ports and Windows
Large windows shall be indicated on the model by clear acrylic plastic. Ports shall be transparent, and shall have a hole bored behind them to give an appearance of depth.

Gun Turrets
Gun turrets shall have the openings in face plates required for elevation of the guns. Where required, gun shrouds shall be represented.

Aircraft and Vehicles
Where appropriate for the mission of the actual vessel, and visible on the model, scale aircraft or vehicles will be provided. Landing pads shall be provided with at least one representative scale aircraft.

Small Boats
Small boats shall be mounted on davits or otherwise as actually carried and shall show all details, motors, and equipment twelve inches or larger in actual size. If represented with weather covers, gripes and all fastenings visible are to be shown. Landing craft and whale boats shall be without covers and shall show all exposed details and equipment.

Special Features
Special functional features peculiar to the vessel (for example: stern doors, towing devices, special antennas, fire fighting gear, etc.) shall be shown.

Materials

Rigging
Layed rope shall be represented with first-quality, twisted, linen line. Wire cable will be used to represent wire cable. Wire will be used to represent wire. Care shall be given to insure the proper color of all rigging. Knots and seizings may be secured with thinned white glue.

Flags
Flags shall be such material that a natural appearance as in a calm is achieved.

Deck Covering
Deck covering shall be represented as installed on the vessel, including safety treads and nonskid areas. Decks which are bright shall show planking, seams, scarfs, butts, and miters, and shall be rubbed to a dull finish. Paper shall not be used to represent deck coverings.

Hull
Hulls shall be built up in lifts of clear, first-grade mahogany or basswood; doweled and glued together with water-resistant glue. The wood shall be completely free of knots, checks, and sap pockets and shall be thoroughly seasoned. Models over 12 inches beam must be hollowed for reduction of weight The hull shall be composed of the least number of parts necessary to achieve the proper shape. An excessive number of glue joints shall be avoided. On models less than 12 inches beam, hull lifts shall be cut to the full body shape: lifts shall not be cut in halves, thereby creating a glue seam along the vertical centerline of the model. The lifts shall conform accurately to lines of the vessel as shown by the plans. A stable, durable, flexible body putty may be used in moderation to fill gaps.

Hull Inspections
Prior to applying any sealer or primer to the hull, the hull shall, at the builder's expense, be crated and sent to the Curator of Models, Code 301, Naval Surface Warfare Center, Carderock Division, West Bethesda, Maryland 20817-5700 for inspection and testing.

The Curator of Models will inspect the hull for wood-type, grain, seasoning, putty, glue-type, checks, excessive glue joints, and conformity to plans. Samples of wood, glue, and glued pieces may also be required for destructive tests. The Curator of Models shall return the hull, collect freight, as certification of compliance.

Hull Fittings
Propeller shafts, struts, bearings, bilge keels, etc. will be made from brass, aluminum, or stainless steel.

Propellers
Propellers should be cast in bronze. If another material is used it shall first be copper plated and then brass plated. Plastic propellers are not permitted.

Ship Fittings
Fittings and accessories shall be of metal or other suitable material which will permanently hold its shape and will not deteriorate from temperature, humidity, light or chemical reaction with other parts, paint, or the atmosphere. Lead or lead-bearing compounds are not suitable for any component. No ferrous materials shall be used.

Masts, Antenna Masts, Yardarms, etc.
All masts, antenna masts, shafts, yardarms, booms, etc. less than 3/16" diameter shall be metal.

Solder
All solder points shall be silver soldered wherever possible.

General Requirements

General Requirements
Painting of models shall receive careful attention. Special care shall be given to select compatible paints that demonstrate the best resistance to color changes, cracking, peeling, and fluctuations in temperature and humidity. All parts of the model shall have a surface treatment representing the appearance of the actual vessel if reduced in scale. The Curator of Models, NSWCCD, may provide paint chips upon request. In all cases, the models shall be spray painted with opaque lacquer. Paint shall be applied thinly and evenly so that fine detail will not be obliterated. The use of metallic paints such as silver or gold is discouraged. The use of white enamel or natural varnish is not permitted. See also "Schedule of Materials."

Painted Wood
Wooden parts shall be sufficiently filled, sealed, and primed so that when rubbed down, the wood grain is not visible.

Painted Metal
Metal parts shall be well-cleaned and then primed before painting.

Stripes and Markings
Hull numbers, ship's names, flight deck and draft markings, as well as any other prominent signage, shall be carefully applied in paint. Tape, paper, or decals are not permitted.

Inspection

Beyond the hull inspection required in section 2.4.1, the model may be inspected by the Curator of Models or his designate during construction and upon completion at the contractor's plant.

Delivery

Schedule of materials
The contractor shall provide, at the time of delivery of the model, a schedule of materials and brand-name products employed in the construction of the model. The schedule of materials will be added to the historical file retained for each model.

Sample schedule of materials
The schedule of materials written in tabular form by the contractor should include, but is not limited to, the following data:
 

  • Type of wood used for hull.
  • Type of wood filler used. Include brand name.
  • Type of primer used. Include brand name.
  • All paints used. Include brand name and color designation.
  • All glues used. Include brand and areas where employed.

Any other significant materials. Include clear sprays, stains, waxes, and the types and application areas of any sheet, cast, foam, or resinous plastics (if any).

Transportation
The contractor shall be responsible for delivery of the model and exhibition case in good condition to the location designated in the contract.

Deviations
Desired deviations, if any, from these specifications will be enumerated on a case-by-case basis through the normal contract process.

Model specifications are published here for general interest and are not to be referenced regarding official Navy contracts.