HS2 viaduct weighing 1,300 tonnes slides into place

Temporary bearings were installed on the concrete pillars for the deck to lie on

A 1,300-tonne viaduct deck has been slid into place for the HS2 project after four years of work.

The 220m (722ft) steel and concrete deck has been installed near the Northamptonshire village of Thorpe Mandeville.

HS2 said the "russet-coloured weathering steel" had been designed to match the "natural" tones of the surrounding countryside.

The sliding operation, which took three days to complete, involved pads made from the same material used on non-stick frying pans.

The viaduct deck was put together at the side of the concrete pillars and then moved into place

The positioning of the viaduct deck is the latest in a series of major engineering projects to be completed for the new fast London to Birmingham rail link.

It was assembled to one side of its final location and then slid into position.

Five concrete pillars were constructed for the deck to sit on, with temporary steel bearings placed on top.

Pads made from the non-stick compound PTFE were used to reduce friction between the deck and the bearings.

The next part of the operation will involve lowering the deck by 60cm (24in) onto the permanent bearings

The deck is one of the 15 major viaducts being produced by HS2's main contractor, EKFB, and is the last of five being built using the sliding technique.

HS2 said it would "help manage flood risk by ensuring that rainwater can continue to run off into existing watercourses".

Sam Arrowsmith from HS2 said getting the viaduct deck into position was the "culmination of four years work"

HS2 Ltd's project manager, Sam Arrowsmith, said: "The slide may only have taken three days, but it was the culmination of four years of work – developing the design, completing the groundworks and the piers and assembling the enormous steelwork."

The russett-coloured steel is designed to match the "natural tones of the surrounding countryside"

EKFB's technical director, Janice McKenna, said: "The philosophy was to design the viaducts with architectural input to 'blend' the structures into their respective landscapes and reduce the visual impact on the environment."

The government announced last week that the 2033 deadline for completion of the London to Birmingham railway would be missed, but did not provide a new date.