Yamamoto Rock Machine (Former Yamamoto Iron Works) Former Head Office and Main House

Yamamoto Rock Machine Former Head Office: The Company's Face on Shinmachi-suji

The Yamamoto Rock Machine (Former Yamamoto Iron Works) Former Head Office and Main House (ヤマモトロックマシン（旧山本鉄工所）旧本社事務所兼主屋) is an early Showa-period (1926 to 1945) combined office and residence of a rock drill maker, facing west onto Shinmachi-suji in Tojo-cho, Shobara City, Hiroshima Prefecture, and it was registered as a Registered Tangible Cultural Property on 3 December 2024. The 2-story timber building has a tiled roof and a building area of 259 square meters. The street side served as the office, while the rooms at the back remained a Japanese-style home, an arrangement familiar from Japanese merchant townhouses, with the shop in front and the household behind.

From the street, though, it looks nothing like a townhouse. The tiled roof is hipped at one end and gabled at the other. The walls are scraped mortar, a gritty stucco finish, over a base clad in stone. A bay window projects from the upper floor, and round windows and other geometric details dress the facade. Among the older townhouses of Tojo, this is the one building that puts early-Showa modern taste on show.

The official record gives its date as the prewar Showa period, with alterations in the mid-Showa years; the street side has since been converted into an office.

Why the Former Head Office and Main House Was Registered

It was registered for contributing to the historic landscape. The Agency for Cultural Affairs notes that its distinctive exterior shapes the look of the street. Most of the Yamamoto Rock Machine buildings stand back inside the site, so that from outside only their roofs show. The old head office sits right on Shinmachi-suji and is the first of the company's buildings anyone walking through town meets.

Its second value is that office and home share one roof. Turning the front into an office while keeping tatami rooms behind can be read as a trace of a time when an ironworks in a provincial town was run much like a local shop, with the business at the front and the family behind. The facade was modernized, but the plan kept the pattern of town life. It is a modest, honest portrait of a regional firm in the years it was building a national market for its drills.

It was registered together with the former research laboratory directly to its east. Both have the same scraped-mortar walls, which suggests the public office and the laboratory behind it were planned as a pair.

What to Look For at the Former Head Office

The west front is the thing to see. A bay window juts out from the upper floor, surrounded by round windows and other geometric openings and ornament. Circles and straight edges are cut sharply into the rough mortar, and the stone base at street level gives the lighter upper design something solid to stand on.

Look up at the roof as well. With one end hipped (a form related to Yosemune-zukuri) and the other gabled, the two ends of the building finish differently when seen from the street. The side facing the road was dressed up, while the end running back into the site was kept plain, a typical compromise for a building in a narrow town lot.

One of the Agency's record photographs shows the entrance hall of the old ground-floor office, where visitors stepped up from the earthen entry. If an event gets you inside, that doorway is worth a close look.

Visiting the Former Head Office and Main House

Of the ten buildings, the Yamamoto Rock Machine former head office is the easiest to see. It faces west onto Shinmachi-suji, so the whole front is visible from across the street. Because the facade faces west, it catches the light best in the afternoon.

The building belongs to the company and is not open on a regular basis. Workshops and small concerts have been held in the former head office and the old dormitories, and the interior can be entered only on such occasions. Do not step onto the property without permission, and photograph from the public road. Cars use the street, so pick your spot with care.