Abstract: A method and system for fabricating molded composite support members for use in climbing structures, which molded composite support members comprise variable performance properties along a longitudinal length thereof. The variable performance properties are achieved or provided by selectively reinforcing one or more regions determined to be subject to greater stress, thus allowing a minimum amount of material to be used in other areas that will subject to less structural stress. Selective reinforcement is accomplished by adapting one or more regions of a primary composite material composition with a supplemental composite material composition, wherein the supplemental composite material composition increases the amount of composite material fibers within that particular region.

Abstract: A molding process, other than pultrusion, is used to manufacture composite ladder rails of non-uniform cross-sectional area and non-uniform strength throughout their lengths. Each ladder rail includes a structural fiber preform embedded in a cured polymeric resin. Fiberglass preforms are preferred because they are electrically non-conductive. Resin transfer molding processes, using either polyester or epoxy resins, are ideally suited for such manufacture. Vacuum-bagged, open-mold processes may also be used, as may be compression molding processes. Regions of the rails subject to greater stress during usage are strategically reinforced with additional structural fibers, and have greater cross-sectional area than regions subjected to lesser stress. The differential cross-sectional area permits the construction of ladders which are optimized for both strength and lightness of weight. Ladders of all types may be constructed with rails incorporating the invention.