Former Hokuriku Line Tunnels

What the Former Hokuriku Line Tunnels Are

The Former Hokuriku Line Tunnels (旧北陸線トンネル群, Kyū Hokurikusen Tonneru-gun) are a chain of railway structures in Tsuruga City and Minami Echizen Town, Fukui Prefecture, built between 1893 and 1896 for the original Hokuriku Main Line between Tsuruga and Imajō; thirteen of them became Registered Tangible Cultural Properties in 2016.

Eleven are tunnels, all bored to a single-track profile. The shortest is the 64 m Funagaya Tunnel and the longest the 1,170 m Yamanaka Tunnel. The other two are the Wanayamadani Culvert, which lets a mountain stream pass beneath the old track bed, and the Yamanaka Rock Shed, a prestressed concrete canopy added in 1953 to keep falling rock off the line. All thirteen were registered on 25 February 2016 under the same criterion, as structures that contribute to the historic landscape of the country.

After the rails were lifted, the old alignment became a local road. That is what makes the Former Hokuriku Line Tunnels unusual: they are not fenced off for display. Bores dug in the Meiji era still carry everyday cars and people, some 130 years after the first trains ran through them.

How the Former Hokuriku Line Crossed the Kinome Mountains

Once the railway linked Nagahama on Lake Biwa with Tsuruga, the Hokuriku Line was extended north, and its first section, Tsuruga to Fukui, opened in 1896. The stretch as far as Imajō was the hard part. It had to climb over the Kinome mountains that separated the old provinces of Echizen and Wakasa, and it did so with a string of tunnels and switchbacks. The Japan Heritage story published by the Agency for Cultural Affairs says that about 30 km of line needed 12 tunnels, that every brick and stone was laid by hand, and that floods and landslides during construction left workers carrying repair materials up to the sites on their backs.

The gradient shaped the line's working life too. Heavy trains needed a second engine pushing from behind, and every train stopped at Tsuruga and Imajō while the banking engine was coupled or released. On the Imajō side of the Yamanaka Tunnel, a switchback passing point called the Yamanaka signal station was added in 1919.

When the long Hokuriku Tunnel later opened deep beneath the mountains, the old line was closed and its bed handed over to road traffic. The Japan Society of Civil Engineers named the Former Hokuriku Line Tunnels Selected Civil Engineering Heritage in 2014, and the thirteen structures were registered in 2016. They also belong to the Japan Heritage story Umi o Koeta Tetsudō, roughly "the railway that crossed the sea", which ties together railway sites in Nagahama, Tsuruga and Minami Echizen.

The Former Hokuriku Line Tunnels in Order, Tsuruga to Imajō

Heading north out of Tsuruga, the first structure you meet is the Kashimagari Tunnel, about 3.7 km northeast of Tsuruga Station. A gap of roughly 6 km follows before the Habara Tunnel. The Funagaya Tunnel comes about 1.1 km after that, and the Sorojidani Tunnel some 200 m farther on.

Another 1.3 km brings you to the Wanayamadani Culvert, and beyond it the spacing tightens abruptly. The First Kannonji Tunnel lies about 400 m north. After it come the Second Kannonji (about 80 m on), Magaridani (about 50 m), Ashitani (about 100 m), Iradani (about 90 m) and Yamanaka (about 90 m) tunnels, separated only by short open stretches. No other part of the climb packs its tunnels so closely.

About 1 km northeast of the Yamanaka Tunnel stands the Yamanaka Rock Shed, and the northern end of the Former Hokuriku Line Tunnels is the Yunoo Tunnel, about 1.6 km north of Imajō Station. Most of the thirteen are in Tsuruga City. The Yamanaka Tunnel straddles the municipal boundary, and the rock shed and the Yunoo Tunnel lie in Minami Echizen Town.

Brick, Stone and Many Builders on the Former Hokuriku Line

Part of the value of the Former Hokuriku Line Tunnels lies in how differently they were made. They went up in the same few years on the same stretch of line, yet the commentary Tsuruga City prepared for the Japan Heritage listing points to a range of methods in the portals and linings, and reads the group as a record of Japanese civil engineering in transition, learning to stand on its own and moving toward standard designs.

Materials are the easiest difference to spot. The Kashimagari, Iradani and Yamanaka tunnels are brick right out to the portals, which the city treats as a special design in a group that otherwise relies heavily on stone. Tunnels such as Sorojidani, Funagaya and First Kannonji have stone side walls and portals, with brick kept for the arch. Where brick does line the walls, it is laid in English bond, with the arch above in stretcher bond.

The contractors varied as well. Kashimagari went to Ōta Rokurō, who had studied civil engineering at the Imperial College of Engineering; Ashitani was built by a consortium of local Hokuriku firms; and the troubled Iradani Tunnel was finally completed by Kajima-gumi working directly. Walk from portal to portal comparing the dressing of the stone and the run of the mortar joints, and it becomes clear that the line was the work of many hands, not a single design office.

Visiting the Former Hokuriku Line Tunnels

The old alignment is now an everyday local road, open to vehicles and pedestrians, with no admission fee and no ticket office. By modern standards the bores are narrow and dark. Because they are only one lane wide, some tunnels have signals at the portals that let traffic through in one direction at a time, so drivers should switch on their headlights and follow the signals and signs. There is no dedicated parking.

By car, the Minato Tsuruga Tourism Association gives about 10 minutes from the Tsuruga Interchange on the Hokuriku Expressway to the Kashimagari Tunnel and about 20 minutes to the Habara Tunnel. It also lists the expressway's Suizu Parking Area, about 30 minutes from the Tsuruga Interchange on ordinary roads or about 10 minutes on the expressway toward Fukui. Around Suizu the view opens over the Sea of Japan and Tsuruga Bay.

Without a car, take the Tsuruga City Community Bus Tōgō Line from JR Tsuruga Station to the Kashimagari stop, a ride of about 12 to 24 minutes, then walk about 5 minutes to the Kashimagari Tunnel. The Habara Tunnel is about a 25-minute walk from the Habara stop. The Tōgō Line must be booked in advance. A taxi from Tsuruga Station takes about 10 minutes to Kashimagari and about 20 minutes to Habara.

Tsuruga City has reported bear sightings around the Former Hokuriku Line Tunnels and asks visitors to take care. A tourism council formed by Nagahama, Tsuruga and Minami Echizen also hands out collectible cards with a photo and notes for each tunnel, in limited numbers, at places such as the visitor facility at Tsuruga Station and the souvenir shop at Imajō Station.