| Line: | Guangzhou-Shenzhen-Hong Kong |
| Construction: | China Railway Group China Railway 12th Bureau Group |
| Length: | 5.3 kilometres 5.5 kilometres |
| Notrack: | 2 |
| Speed: | 250km/h (350km/h designed) |
The Shiziyang Tunnel is a high-speed railway tunnel under Shiziyang, the northern part of the Pearl River estuary in China.[1]
The 10.8 km long tunnel is part of a 140km (90miles)-long high-speed line from Guangzhou to Shenzhen and Hong Kong. It is designed for speeds of up to 350 km/h (usually 250 km/h in operation) - the fastest underwater tunnel in the world.[2] as well as being China's longest underwater tunnel.[3] This allows rail journeys between Guangzhou and Hong Kong to take only 40 minutes – much faster than the previous 2-hour journey. The Guangzhou-Shenzhen-Hong Kong express rail link is part of a broader expansion of high-speed rail in China; journeys from Beijing to Hong Kong will take only 8 hours.[4]
Construction began in November 2007, with a budget of CNY2.4 billion;[5] the tunnel was completed in 2011, and passenger services began on 26 December 2011.[4] Unusually, the tunnel boring machines were designed to be dismantled inside the tunnel.[5]