AS commuters and residents prepare for an 11-day blockade on the Twemlow Viaduct, Network Rail have released more details about the £17m repair project taking on numerous historical structures.

From February 13 to 24, those travelling from Holmes Chapel or on the Crewe to Manchester line from other affected stations will be transported by replacement bus services.

Spanning a length of 500m, the viaduct which was built in 1841 and forms part of the Crewe to Manchester line and the Sandbach to Northwich freight line, will be repaired due to extensive damage caused by a lack of drainage.

Joelle Caldarelli, project manager for the viaduct refurbishment, said: “At the time that it was originally constructed they didn’t anticipate that it would be around for as long as it has been.

“At the time, no drainage was installed it may be that they didn’t think it was needed or they just didn’t realise how long it would be here for.

“They might not have known the long term effects of having drainage present. The effect is that it is slowly degrading.

“At first it will stain and then it will start to break down the mortar and push the brickwork apart. Over time that leads to strengthening issues.

“There’s also water at track level which means that you could flood the track so then you can’t run the trains and then slowly it becomes weaker and weaker.

“That’s why we are going in now. We are going to install the waterproofing that is going to protect it all, where it has been degraded over time we are going to repair it, stich it back together put new mortar in, replace the brick and give it a good clean up which establishes waterproofing for the next 125 years.”

From the project’s total costs, the repairs to the viaduct will cost £7m which includes a full suite of masonry repairs to allow the structure to maintain its current capacity, the installation of a new structure to help relieve loading from the parapets and the removal and treatment of all vegetation on and within 3m of the structure.

Network Rail said that the 11-day blockade is a more effective way of getting the work done whilst disturbing less people.

Terry Strickland, area director for Network Rail, said: “If we tried to do these repairs at the weekend we would need 16 or 17 weekends to complete.

“To do it this way means we are not causing all that disturbance and we won’t have to come back for a long time.”

It is estimated that the repair and renovation will last for 125 years, with no intervention needed for between 25 and 50 years.