Found my self under some bridges tonight, (not done that for a while lol)
The western bridge carries High Speed 1 (HS1), the high speed rail link that connects London with the Channel Tunnel.
The rail bridge is 1.3 km long, making it the longest high-speed rail span in the world. The viaduct is a multi-span structure, with typical approach spans of 40.5 m, spanning the River Medway with a central navigation span of 152 m. The viaduct substructure is of reinforced concrete pier columns supported on bored piles. A unique feature of the columns is that they are in a “V” shape. This is to provide greater lateral support and stability in the event of two high-speed trains using their emergency brakes. (More orthodox vertical supports could, in a worst-case scenario, topple like dominoes.)
The bridge deck was pushed out from each bank of the river during construction, using hydraulic pistons.
On 4 September 2007, Eurostar 9021 driven by Neil Meare crossed the viaduct at up to 200 miles per hour, during the record breaking inaugural run from Paris Gare du Nord to London St Pancras