Five Arches Between Shore and Launch Pad
The Former Sasebo Naval Arsenal Kawatana Long-Range Torpedo Firing Range Jetty (旧佐世保海軍工廠川棚魚雷遠距離発射場突堤) is a five-arched concrete bridge built in 1918 from Katashima in Kawatana, Nagasaki Prefecture, out to the range's offshore firing platform, and it was registered as a Registered Tangible Cultural Property of Japan on August 15, 2024. It runs 45 meters long and 3.6 meters wide, and its purpose was simple: to carry rails from land to the artificial island about 50 meters out.
Two lines of track are still traced along the deck. According to Kawatana Town's guide materials, one line carried torpedoes heading out to be tested and the other brought back those already fired. Torpedoes were prepared in the machine room on shore and trundled across this bridge to the launch point.
The arches are shallow and never rise far above the water. From a distance the jetty reads as a low line laid across the bay; only up close does the rhythm of the five openings come through.
Arches Made of Concrete Blocks
What sets the Former Sasebo Naval Arsenal Kawatana Long-Range Torpedo Firing Range Jetty apart is how it was built. Like the island it serves, it uses stacked precast concrete blocks, cast in varying shapes and fitted together into piers and arches. The Agency for Cultural Affairs singles it out as a distinctive large structure made by freely shaping concrete blocks.
The piers stand 8 courses deep at their deepest and 4 at their shallowest. Each arch was designed with a span of 27 shaku, about 8 meters, and measurements today come in at almost exactly 8 meters, proof that the builders hit their marks.
The gap between plan and practice survives too. The approved drawing of 1917 called for each arch to be assembled from nine blocks; in reality the central five were cast as one piece. Kawatana's preservation plan reads this as concrete masonry in mid-evolution, and notes that this is believed to be the first five-arch bridge of its kind built by the Sasebo Naval Arsenal.
A Century in Salt Water
The Former Sasebo Naval Arsenal Kawatana Long-Range Torpedo Firing Range Jetty has never had a major repair. Even so, town surveys found no open joints or settlement and rate it in good condition. The cast-in-place concrete on top has chipped in places, but the crane footing and the torpedo rails are well preserved.
The Sasebo Naval Arsenal was working at the time on concrete that could stand up to seawater. That the jetty has sat in the waves for over a hundred years with so little decay is cited in the town's plan as evidence of the quality they achieved.
Look up under an arch and you can see the block joints fanning out along the curve. The way the builders handled that curved surface is as telling as anything on the flat.
Viewing the Jetty
The Former Sasebo Naval Arsenal Kawatana Long-Range Torpedo Firing Range Jetty stands inside Katashima Park and can be viewed free of charge. The arches read best from the north side, the angle the national database uses for its main photograph.
The entrance to the firing platform at the far end is closed by signs. Follow the posted signs on how far you may walk onto the jetty, and take care near the water, where some edges have no railing.
Directions to Katashima Park and general visiting information are gathered on the page for the Former Sasebo Naval Arsenal Kawatana Long-Range Torpedo Firing Range as a whole.
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Q&A
- How big is the Former Sasebo Naval Arsenal Kawatana Long-Range Torpedo Firing Range Jetty?
- It is 45 meters long and 3.6 meters wide, with five arches each spanning about 8 meters.
- What was the Former Sasebo Naval Arsenal Kawatana Long-Range Torpedo Firing Range Jetty used for?
- It carried rails linking the shore to the offshore firing platform so test torpedoes could be moved out and back. Two lines of track are still visible on the deck.
- Can you walk across the Former Sasebo Naval Arsenal Kawatana Long-Range Torpedo Firing Range Jetty to the firing platform?
- No. The platform entrance is closed by signs and the island cannot be visited. Follow the posted signs regarding the jetty deck itself.
- Where is the best place to view the Former Sasebo Naval Arsenal Kawatana Long-Range Torpedo Firing Range Jetty?
- From the north side, where all five arches read clearly. The national database uses a north view for its main photograph.
- When did the Former Sasebo Naval Arsenal Kawatana Long-Range Torpedo Firing Range Jetty become a Registered Tangible Cultural Property?
- On August 15, 2024, together with the firing platform and three other structures.
Basic Information
| Name | Former Sasebo Naval Arsenal Kawatana Long-Range Torpedo Firing Range Jetty |
|---|---|
| Location | Katashima offshore area, Mitsukoshi-go, Kawatana-cho, Higashisonogi-gun, Nagasaki Prefecture |
| Designation | Registered Tangible Cultural Property (Structure) |
| Year Designated | Registered 2024/8/15 (Reiwa 6) |
| Quantity | 1 structure |
| Dimensions | Concrete five-arch bridge, length 45 meters, width 3.6 meters |
| Owner | Kawatana Town |
| Public Access | Inside Katashima Park; exterior viewable freely, no fee. No access to the firing platform |
References
- Agency for Cultural Affairs, Database of National Cultural Properties: Former Sasebo Naval Arsenal Kawatana Long-Range Torpedo Firing Range Jetty
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00015107
- Kawatana Town: Preservation and Use Plan for the Former Sasebo Naval Arsenal Kawatana Long-Range Torpedo Firing Range (Japanese)
- https://www.kawatana.jp/cat03/c3-03/post_732/index.html
- Kawatana Town Tourism Guide: Torpedo Launch Test Site (Japanese)
- https://www.kawatana.jp/kankou/2010/12/post-24.html
Last verified: 2026.09.25
