A KEY route into the Capital is to be closed to allow a “major milestone” in the Borders Rail project to be winched into place.
The Hardengreen round-about on the busy A7 in Midlothian will be shut for two weekends to allow engineers to crane the beams of a vast bridge over the roundabout.
The construction work on the project has been hailed as “a real piece of history in the making”.
The roundabout will be closed and diversions put in place from 10pm on Friday, February 14, to 6am on Monday, February 17, and again from the evening of Friday, February 28, to the morning of Monday, March 3.
Thousands of commuters use the busy junction each day, but Network Rail is “confident” that the operation will go smoothly with the only possible delaying factors to its 6am reopening being high winds.
A spokesman for Network Rail said: “The bridge over Hardengreen roundabout is the largest new structure to be built on the Borders railway route, so this is a major milestone for the project.
“We have managed to keep the roundabout open while we construct the bridge supports, however the installation of the bridge deck is a major undertaking which will require two weekend closures.
“During the first weekend we’ll be craning in the concrete bridge deck. During the second weekend we’ll be completing the installation.
“We apologise for the inconvenience while we carry out these works but we are trying to keep disruption to an absolute minimum.
“We are working with Midlothian Council to put in place and publicise alternative routes but we’d certainly advise motorists who have to use the A7 during those weekends to allow more time for their journeys.”
Similar work was also recently undertaken at the Gore Glen bridge over the A7, where a number of smaller beams were craned into position.
The bridges are two of the 42 structures to be built along the Borders Rail route, re-establishing a passenger train link from Edinburgh through Midlothian to Tweedbank.
There are 95 existing structures, including the adjacent Lothianbridge/Newbattle Viaduct, all of which will be refurbished before the railway opens in late summer 2015.
Councillor Derek Rosie, cabinet member with responsibility for public transport, said: “It’s an exciting phase of the project, a real piece of history in the making.
“I, for one, will be following the progress of this bridge with great interest. What a spectacle that will be – witnessing the logistics of large beams being manoeuvred into place by an enormous crane and the bridge then running over the top of the roundabout.”