Prefabrication experiments - 202 - master industrialists - 03 - Henry Grey's rolled beam

Nearly all buildings produced in North America today combine some form of industrialized timber, concrete or steel construction method. The evolution from earthen, masonry or notched timber to skeletal systems to balloon or skeletal steel frames altered building culture and its logistics. In a relatively short time frame these two iconic building systems reinvented urbanit, sprawling horizontally (the balloon frame) and vertically (the skeletal steel fame), which globalized these efficient and flexible construction methods. Contributing to this development, the I-Beam is arguably the single most iconic building component that sustained the development of frame structures and still symbolises tall steel building construction. The I-Beam has been used in construction since the 1850s, its shape closely mimics the letter «I» with top and bottom extensions joined together by a central web portion. All through modernity architects used lightweight profiled metal sections to represent a new architectural language. 

The H-beam or the wide-flange beam also known as the Grey beam after its inventor industrialist Henry Grey, is an optimized structural shape. Loosely mimicking a rotated «H» its composing matter is extended from the beam’s centre of gravity increasing its inertia. Top and bottom plates or flanges resist compressive and tensile forces while the beam’s vertical web optimizes vertical reaction and shear resistance. Grey’s rolled structural shape was stronger than the previous built-up I-beams. 

Grey’s innovation is not the structural shape as beams of this nature were be riveted from plates to achieve similar results. Grey invented the continuous rolled beam shaping it directly from hot rolled steel ingots which made it cheaper, faster and stronger as it was a continuous shape; Further, simply adjusting the rollers could adjust height, steel thickness and flange dimensions. A large diversity of profiles could be mass-produced, cut and delivered and a greater rate. Controlling a simple industrial process, Grey developed the beams in 1902 while working for the Ironton structural Steel company of Duluth Minnesota.  Bethlehem steel gained the rights to the Grey beam’s production in 1908. The mass-produced profile established skeletal construction as an efficient scheme for building, is still produced in steel mills and remains an icon of  industrialized building culture.

technical drawing from Grey's patent application from 1904