A 175-year-old tunnel has reopened following a major ten-week repair programme.
Blackheath Tunnel in southeast London received £10 million of essential repairs, which were delivered by Network Rail along with its partner the Southern Integrated Delivery (SID).
The mile-long tunnel, which opened in 1849, required extensive work to its lining, with leaks and water damage causing around 1000 minutes of delays to Southeastern services over the last year.
The cause of the leaks was damage to brickwork caused by the freezing and thawing of rainwater that filtered through the ground above. In turn, track and electrical equipment in the tunnel had incurred damage over time that led to unreliability and delays.
To solve this fault, more than 10,000 bricks were used to patch up the tunnel lining. Engineers also used a specialist industrial vacuum to clean soot from the tunnel lining which built up over the years that steam trains operated on the line.
Southeastern will resume its normal timetable following the reopening of the tunnel earlier this week, with the line connecting Dartford and Connon Street via Charlton, Blackheath and Lewisham.
Engineers also performed detailed structural and ground surveys ahead of further work next year.
David Davidson, Network Rail’s Route Director for Kent, said: “We’re in the process of renewing everything within the tunnel, which includes replacing the track.
“That means we’ll need to return to Blackheath to complete this work over the next few years so that we can keep this Victorian-era structure in the best possible condition. We will now assess the further repair work needed for next year.”
The repairs to the tunnel form part of the South East Upgrade, a package of £1.35 billion invested by Network Rail to improve the railway in Kent and South East London during CP7. The funding will tackle historic under-investment in Kent, replacing ageing equipment with new and more reliable technology.
Image and video credit: Network Rail
