Non-metallic Materials

Non-metallic materials--structural plastics, extrusions, moldings, single-skin and sandwich structures--are finding increasing use, and consideration for further use, in the field of Naval Engineering. Although smallboat hulls have been fabricated from reinforced plastics for many years, the application of these materials to equipments and components for large ships is a fairly recent development. The unique combination of properties obtainable in non-metallic materials provides an opportunity and a challenge for the naval engineer to reach new goals in the areas of corrosion resistance, electromagnetic interference (EMI) reduction, decreased maintenance, improved habitability, and lessened weight. However, since these non-metallic materials have different properties and are produced and assembled differently from their metallic counterparts, the Naval Engineer who designs equipment and components using non-metallics must adopt a fresh viewpoint. This poses a challenge to the Naval Engineer to redesign his equipments and components in the light of these properties and production and assembly techniques, so that advantage can be taken of the non-metallics' unique combination of properties. Examples are given of non-metallic materials and items already fabricated and service tested and found satisfactory; and of other items now under consideration for fabrication and testing, with applicable criteria which led to the selection of these items for consideration.