A BRIDGE has won concrete evidence of its achievement. The UK's first high-speed railway viaduct, the 1.25km Medway Viaduct, won this year's Concrete Society Civil Engineering Award.

From next September, Eurostar trains will speed across the completed bridge at up to 300km/h (186mph).

The Medway Viaduct was completed just over a year ago. It was built by the Eurolink Joint Venture--

Morgan Est, Vinci Construction Grands Projets and Beton und Monierbau GMBH - in partnership with Rail Link Engineering.

Each push-launched concrete deck section--most are 40.5metres long--was assembled and cast in a specially-built launch area on either side of the river, then slid out on stainless steel bearings fixed on top of the piers. A pair of 900-tonne capacity hydraulic jacks pushed them into place.

Each subsequent concrete section, weighing around 1,000 tonnes, was then cast, stressed together with its predecessor and pushed out by the jacks over the piers.

The central spans are made up of two cast-in-situ balanced cantilevers each measuring around 160m long, the longest of any European high-speed railway bridge.

When complete in 2007, the £5.2 billion CTRL will halve journey times from central London to the Channel Tunnel. Journey times from central London to the Channel Tunnel will be halved. Paris will be around 2 hours 15 minutes and Brussels just 2 hours from St Pancras by non-stop Eurostar.