Originally St Pancras station was built in four years (1864-1868) by William Barlow, the eminent Victorian Railway engineer. Work started at St Pancras in 2001 with the completion date set for 14 November 2007. St Pancras will be the “Jewel in the Crown” of High Speed 1 connecting the centre of London to the European high speed rail network, it is the UK's largest ever construction project and the first new section of railway for over a century. The route of HS1 uses over 150 bridges, including the longest high speed rail viaduct in the world and the largest ever tunnels under London. HS1 is costing £5.8bn and as well as being delivered on time and within budget is an active catalyst for over £10.5bn investment in regeneration.
The Barlow train shed is the largest enclosed space of its kind in the world (689ft long, 243ft wide and 118ft high). There are 850 cast iron pillars that raise the train deck 18ft above ground level. The undercroft area below the train deck was originally used to store beer barrels and will now be converted for use as Eurostar departures and arrivals lounges as well as The Arcade shopping area.
The ironwork of the roof has been painted in 25,000 litres of ‘English Heritage Barlow Blue’ (an exact match to the original colour of the station), all of the 300,000 Welsh slates on the roof have been replaced with new slates quarried from the same quarry as the originals, the station uses over 60 million bricks, several million of which have had to be replaced and over 250,000 km of cabling and extensive wi-fi systems will make this among the most technologically advanced stations in the world.
The renovation and modernisation of St Pancras International has cost £800m and it is expected that up to 50 million people per year will use and visit the station. The original station clock was broken and an exact replica, made by Dent Clock will be installed.