Mitsubishi Bank Head Office (1916)
[Structural diagram from 100 years ago]

The blueprints for Mitsubishi Bank's head office were drawn up in 1916 (Taisho 5), about 100 years ago, and they vividly illustrate the thinking behind structures and construction at the dawn of modern Japanese architecture. The structural drawing for the ground floor shows a steel frame with reinforced concrete columns and steel beams, and it is interesting to note that the design is comparable to modern drawings.
Looking more closely, one notices that two different units of measurement were used in one drawing. One is shaku and sun, and the other is inches, represented by the suffix " ". What is interesting is that inches are only used on the periphery of the steel frame. During the Taisho period, Japan had little experience with steel frame construction, and the dimensions were heavily dependent on Western standards. The inches written here are thought to be "units of measurement exclusively for steel frame components."
Let's look at another detailed cross-sectional view in relation to the steel frame construction. We can see that each steel column had a joint near the third floor, and was constructed in pairs, 31.2 shaku (approximately 10 m) above ground level. If the maximum length that steel frames could be transported and delivered from the factory was approximately 10 m, this size has not changed much between 100 years ago and today.
But was there anything like a trailer capable of transporting a 10m-long steel beam 100 years ago? And where was this steel beam manufactured and transported in the first place? Japan's first blast furnace, the Yawata Steel Works, was lit in 1901 (Meiji 34), just 15 years before this blueprint was drawn.