Abstract: An equipment mounting rack is composed of a seismically sound skeleton structure having spaced vertical uprights supplemented by distinct spaced equipment mounting structures attached to that skeleton structure and extending along these vertical uprights and constituting side wall structures of a mounting rack interior space. The distinct spaced equipment mounting structures may have elongate first sections extending along the spaced vertical uprights, and elongate second sections extending along these first sections and constituting side wall structures of a mounting rack interior space. Cabinet walls may be attached to the skeleton structure, and the equipment mounting structures may constitute inside such cabinet walls side wall structures of a mounting rack interior space. The vertical uprights advantageously are reinforced by elongate partial enclosures that may avoid the need for a large number of weakening mounting holes in these uprights.