Dartford_Cable_Tunnel
Dartford Cable Tunnel
Tunnel under the river Thames in London, England
The Dartford Cable Tunnel is a 2.4 km utility tunnel beneath the Thames, upstream of the Dartford Crossing. With a diameter of ~3 m (10 ft), it carries a 400 kV National Grid electrical transmission cable. It is accessible by foot as a crossing of the Thames, but by authorised personnel only.[1][2][3] It was built in 2003–04 at a cost of £11 million (equivalent to £22 million in 2023).[4][5]