Foot-way manhole cover for stiffened steel plate construction - has horizontal top and bottom plates fixed apart by longitudinal Z=sections and U=sections

摘要

The manhole cover is for use in footways and is of a cellular stiffened steel plate construction. In detail the cover may comprise horizontal top (1) and bottom plates (2) with an infill of parallel interspaced 'Z' (3) and channel sections (4). The construction combines light weight with high strength characteristics. The cover may be rectangular in plan with the infill sections (3, 4) aligning parallel to a major size, extending over the length of the plates (1, 2), and locating at equal transverse intervals. The interior (3) and exterior (4) infill sections may be of 'Z' and channel section respectively and may be fixed to the plates by welding (5, 6) or bolting or combinations. The external 'U' sections (4) may be installed with the webs (W) innermost.