Blackheath Tunnel Reopens After Major Repairs to Boost Rail Reliability

Train services are now running again through the Blackheath Tunnel following the completion of a major £10 million engineering project designed to improve performance and reduce delays for thousands of passengers.

The one-mile-long Victorian tunnel between Charlton and Blackheath reopened on Monday, 28th July, after a 10-week full closure, with trains now travelling through a safer and more resilient structure. The reopening marks the successful delivery of essential infrastructure work by Network Rail and the Southeastern–Network Rail Alliance.

What’s Been Done

As part of the upgrade, engineers:

• Repaired damaged brickwork

• Installed a new waterproof lining

• Rebuilt drainage systems

• Removed waterlogged sections of track (known as ‘wet beds’)

• Cleared decades of soot and debris from the tunnel lining

These improvements are expected to significantly cut delays, particularly during wet weather, and reduce the need for speed restrictions.

What This Means for Passengers

Passengers travelling between Dartford and London Cannon Street via Charlton, Blackheath, and Lewisham will now benefit from a more reliable service. The standard timetable has resumed, with up to four trains per hour running through the tunnel.

The repairs also mean fewer disruptions, smoother journeys, and improved infrastructure resilience for years to come.

Long-Term Benefits

Although the tunnel was structurally safe before the work, long-standing water damage had led to performance issues. Last year alone, leaks and damaged tracks in the tunnel were responsible for nearly 1,000 minutes of delays.

Now, with the tunnel reconditioned and weatherproofed, services through this critical part of the network should see fewer faults and more consistent travel times.

Looking Ahead

This summer’s project is part of a wider multi-year programme to modernise and future-proof the tunnel. While further phases of work may be needed—potentially including another 10-week closure in summer 2027—officials are optimistic about the positive impact of this year’s upgrade.

What Network Rail and Southeastern Say

David Davidson, Network Rail’s Kent route director, commented:

“The successful reopening of Blackheath Tunnel is a major milestone. These repairs ensure the tunnel remains safe and reliable, benefiting passengers now and for decades to come.”

Scott Brightwell, operations and safety director for Southeastern, added:

“We’d like to thank our customers for their patience. The work carried out over the past 10 weeks will result in a much better and more reliable service.”