How the I-Beam Got Its Iconic Shape

A key aspect in any modern steel building.

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There are few things more emblematic of construction and architecture than the iconic I-beam. The distinctive beam has been around for while, developed in 1849 by an engineer named Alphonse Halbou. If you're a savvy student of engineering, you probably already know that this isn't just a matter of style; it has a functional purpose as well.

Real Engineering explains how the concept took over the world:


Despite its clear innovations over previous beams, many of which were shaped like the letter Z, the I-beam took a few decades to really catch on. The world's first steel building, the Rand McNally building of 1889, gave the I-beam the perfect moment to show its strength.

Halbou invented the I-beam, but an English engineer named Henry Grey perfected it. Early I-beams could only hold around twenty stories, but Grey developed a new rolling method that allowed him to control the distribution of steel within the beam. Alleviating internal stress within the beam, the new distribution methods allowed for I-beams to be strengthened and made in bigger sizes. The first building that used Grey's method was a factory for more I-beams.

Source: Real Engineering

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