HS2 has thanked passengers after closing the railway south of Aylesbury for critical viaduct preparation over Easter.

The four-day closure enabled engineers to operate safely on two vital viaduct piers supporting the Small Dean viaduct, south of Wendover.

This work involved the construction of 49m deep piled foundations for a pier adjacent to the railway, as well as the positioning of a 42-tonne 'Y' shaped pre-cast segment onto another pier.

Unique to the Chilterns, the viaduct is one of the only two spots where the HS2 route will surface, with the rest being underground.

With its bottom just 6m above the road, this huge structure is supported by six massive piers.

The viaduct's long expanse of 345m will comprise large girders, made from weathering steel that naturally ages into a rich, russet tone, complimenting the surrounding landscape.

In reverence to Victorian era infrastructure, the viaduct's design will include prominent deck stiffeners.

This construction is set to be finalised by next year, following a 'slide-out' method over the completed piers. The Small Dean viaduct is one of 50 major viaducts for the HS2 project.

The railway is an effort to improve transportation between major cities like London and Birmingham and the North while also creating space for more local trains at the already busy southern end of the West Coast Main Line into London Euston.

HS2 Ltd’s Senior Project Manager, Ben Sebastian-Green, said: "It’s great to see the first piers for Small Dean viaduct coming together.

"Once complete, this striking viaduct will carry HS2 services between Britain’s two largest cities, improving journeys and freeing up space for more trains on the congested west coast mainline.

"I’d like to thank passengers for their patience and our contractors for all their hard work over the bank holiday weekend."

The project is overseen by EKFB, comprising Eiffage, Kier, Ferrovial Construction and BAM Nuttall, along with design partner ASC.

Martin Gamble, EKFB’s Project Manager, added: "The Small Dean Viaduct Team is delighted to have successfully and safely completed all planned works over the Easter weekend.

"The closure has allowed us to deliver vital works adjacent to the existing railway which will now enable the next phase of the viaduct build."

Besides the viaduct, revisions to Small Dean Lane and the A413 are in order, including landscaping to manage structural elevation shifts.

A foot and cycle path is also in the pipeline along the main road under the viaduct.