High rigidity vertical column member and structure and hoist platform system

A high-rigidity modular scaffolding or tower structure comprising:

• a plurality of stacked units, each unit comprising;
• a plurality of vertical column members, forming a rectangular scaffold structure each vertical column member comprising a hollow cylinder, a cross-section of the cylinder having an uninterrupted circular inner contour and a circular outer contour interrupted by four equally-spaced radially-projecting flanges integrally joined to each cylinder of each vertical column member, at the outer contour of the cylinder, at 90 degree intervals about the circumference of each cylinder, wherein the flanges have a plurality of holes that are regularly spaced along the axial length of the flanges;
• and
• a support structure having a plurality of substantially horizontal beam members, each horizontal beam member affixed to an upper most hole of a radially-protecting flange of two adjacent vertical column members, the horizontal beam members spanning between and attaching adjacent vertical column members;
• a rectangular floor platforms supported by the support structure;
• and
• diagonal bracing members at only upper ones of said plurality of holes affixed to the vertical column members, spanning between and attaching adjacent vertical column members, the diagonal bracing members being arranged substantially immediately below the support structure, the vertical column members below the diagonal bracing members being free of attachment therebetween, forming an open frame work providing unencumbered access to the floor platform on all sides of the scaffold structure;
• the plurality of vertical column members each being joined end-to-end one above another by a column end joint member to form said plurality of stacked units.