Work on refurbishing a key transport route is now due to end next year after a new contract was awarded.
Officials behind the work refurbishing the Tyne pedestrian and cyclist tunnels between Howdon and Jarrow, say they will now re-open in June 2015.
This comes following the awarding of additional contracts to deal with asbestos removal and corrosion.
The free, scheduled shuttle bus and a night service for shift workers will continue to operate during the closure.
Paul Fenwick, project director for the Grade II-listed tunnels, said: “Once we decided to fully address the asbestos and corrosion issues, we believed the works could be completed by February or March.
“When bids came back from prospective specialist contractors it became obvious the works would take longer than we had originally hoped.
“The alternative transport measures we put in place – providing a free replacement shuttle bus and a night service – have proved highly successful and will continue until the tunnels re-open.”
One of the features of the refurbishment will be the replacement of two of the original wooden-step escalators with inclined lifts.
The tunnels opened in 1951 and were the first purpose-built combined pedestrian and cyclist tunnels ever built.
The wooden-tread escalators were once amongst the longest in the world, equivalent to the height of the Angel of the North.