The high-speed rail line linking London with the Channel Tunnel is High Speed 1, commonly abbreviated HS1. Officially known during development as the Channel Tunnel Rail Link, it runs from London St Pancras International through Kent to the Channel Tunnel.
HS1 was built in two sections. The first opened in 2003, while the complete route and the rebuilt international station at St Pancras opened in November 2007. The railway is about 109.9 kilometres long and carries international Eurostar services as well as domestic high-speed trains operated by Southeastern.
A frequent mix-up is treating HS1 and Eurostar as interchangeable names. HS1 is the infrastructure—the railway line—whereas Eurostar is a train operator using that line for services to mainland Europe. HS2 is a separate, largely planned high-speed project intended to connect London with major cities in the Midlands and northern England. Trains on HS1 can reach 300 km/h.