Exploring the World’s Longest Railway Tunnels
Discover the engineering marvels and global significance of the world's longest railway tunnels, connecting regions and enhancing travel efficiency.
Railway tunnels are engineering marvels that enable trains to traverse challenging terrains and connect distant regions efficiently. These subterranean passages reduce travel times, minimize environmental impact, and foster economic ties between previously remote areas.
Gotthard Base Tunnel
The Gotthard Base Tunnel, beneath the Swiss Alps, exemplifies modern engineering. At 57 kilometers, it is the world’s longest railway tunnel, completed in 2016 to streamline European rail travel through the Alps. The construction involved overcoming geological challenges, requiring innovative tunneling techniques and advanced machinery.
The tunnel features two parallel tubes, each with a single track, enhancing safety and maintenance efficiency. Advanced tunnel boring machines (TBMs) facilitated precise excavation through diverse rock types. The project aligns with Switzerland’s environmental goals by shifting freight transport from road to rail, reducing carbon emissions. A sophisticated ventilation system ensures optimal air quality and temperature control, prioritizing passenger comfort and safety.
Seikan Tunnel
The Seikan Tunnel, beneath the Tsugaru Strait, connects Japan’s Honshu and Hokkaido islands. Spanning 53.85 kilometers, it is the world’s second-longest railway tunnel. Completed in 1988, it addresses transportation challenges, especially during harsh winters when ferry services are disrupted.
Construction involved tackling seismic activity, variable geological conditions, and high water pressure. Engineers used specially designed TBMs and an advanced drainage system to maintain structural integrity. The tunnel facilitates freight and passenger transit, enhancing economic ties and integrating with Japan’s Shinkansen high-speed rail system.
Channel Tunnel
The Channel Tunnel, or “Chunnel,” links Folkestone in the UK with Coquelles in France, running beneath the English Channel. Completed in 1994, it spans approximately 50.45 kilometers and features the longest undersea tunnel section globally. The project realized a long-envisioned dream, enabled by technological advancements.
Engineers bored through chalk marl using advanced TBMs, ensuring minimal environmental impact. The tunnel comprises three parallel tubes: two for rail traffic and a smaller service tunnel for maintenance and emergencies. It revolutionized travel between the UK and mainland Europe, supporting passenger and freight trains and enhancing trade and tourism. The Eurostar high-speed train service exemplifies swift travel between major European cities.
Yulhyeon Tunnel
The Yulhyeon Tunnel, at 50.3 kilometers, is a key component of South Korea’s Suseo–Pyeongtaek high-speed rail line. Completed in 2016, it addresses congestion and improves travel efficiency in the Seoul Metropolitan Area.
Engineers employed the New Austrian Tunneling Method (NATM) for precise excavation in urban settings, integrating the tunnel into the existing rail network. This approach optimized transit times and supported sustainable urban development.
Simplon Tunnel
The Simplon Tunnel, between Switzerland and Italy, is an early example of long railway tunnels. Completed in 1906, it stretches approximately 19.8 kilometers beneath the Alps, establishing a direct rail link between northern and southern Europe.
Construction utilized pioneering techniques, such as compressed air drills and steam-powered machinery. Initially designed with a single track, a second parallel tube was later added to accommodate increasing rail traffic. The Simplon Tunnel’s historical significance lies in its influence on subsequent tunnel projects, showcasing engineering excellence and perseverance.