Kanonersky Island and the underwater tunnel beneath St. Petersburg
Kanonersky Island in St. Petersburg is an engineered landmass born from a big urban project, the Sea Canal. For many years access to the island was limited to ferries, private boats, or even crossing on ice in winter. The isolation helped shape a distinctive history around this hint of a man-made landscape within the city’s waters.
In 1983 a bold solution was introduced: an underwater car tunnel was laid to connect Kanonersky Island with the surrounding mainland. The structure earned its name immediately, though it was only formally recognized in recent decades. The tunnel’s construction used a notable method called the down section technique. Sections were lowered to the seabed, and then the space around them was pumped dry with water removed gradually to create a dry tunnel interior. Each of the five sections weighed about 8,000 tons, and the overall length of the tunnel stretches to 927 meters. This approach marked a pioneering moment for the USSR in civil engineering, representing a rare and early foray into this tunnel-building method.
Today, the tunnel remains the sole access route to Kanonersky Island. The nearby viaduct of the Western High-Speed Diameter (WHSD) passes above the island, yet there is no direct exit from the WHSD onto Kanonersky Island itself. The legacy of the tunnel endures not only as a critical transportation link but also as a testament to how large-scale city projects can yield lasting subterranean and surface-level infrastructure, shaping movement and access in urban spaces.
Historian and technology enthusiast Mikhail Kolodochkin has long chronicled unusual milestones in the history of technology. He notes intriguing facts about Russia’s engineering feats, including mentions of substantial road tunnels and deep infrastructural projects that reveal the country’s capacity for ambitious, technically demanding work. His observations invite readers to consider the broader context of how transport innovations alter daily life and regional development.
Those with curiosity about industrial history or urban engineering may explore related narratives about transport networks, tunnels, and the ways modern cities intertwine with artificial landforms. The Kanonersky tunnel stands as a concrete example of how a city negotiates water, earth, and mobility to create reliable passage where once there was only surface access or seasonal routes.
For readers who enjoy discovering unusual routes by land and sea, there are other intriguing travel routes and transit stories to explore. And for followers of technology and engineering, periodically revisiting the history of notable feats can reveal how past decisions influence present-day infrastructure and urban planning. The exploration of Kanonersky Island’s tunnel is a reminder that cities continually blend water, rock, and human ingenuity to connect communities and extend possibilities beneath the surface.
- Discover the unique route and cool trolleybus here.
- “Behind the wheel” can also be read in Telegram.