Abstract: A portable structure which consists of a plurality of I beams placed side by side and hinged together in a parallelogram fashion such that adjacent I beams may be folded together.

Abstract: This invention is for a light-weight bridge floor and the like in which spaced parallel structural sections with top flanges and vertical webs are connected by cross braces threaded through openings punched through the webs of the structural sections at intervals along their lengths and at a level spaced below the top flanges of said sections and thereafter deformed in such manner that the cross braces cannot move relatively to the webs through which they pass and integrate the structure whereby loads are distributed from one structural section to the others and welding is unnecessary. Subsequently deck strips with skid-resistant surfaces are applied lengthwise over the flanges of the structural sections which are wider than the tops of the sections to such strips being wide enough to cover a single section, or of a width to cover a plurality of sections. The assembly may be made in situ on the bridge structure or preferably prefabricated in transportable panel sections.

Abstract: A skid-proof gangway element in the form of a metal sheet having large holes with upwardly pressed edges and small holes arranged between the large holes and having downwardly pressed edges. The sheet material between the large holes is inclined toward the small holes so as to allow oil to be drained off. The upwardly pressed edges of the large holes provide skid-proof zones.