A contraflow has been in place on the London-bound lane since June following the discovery of a safety-critical fault with the jet fans that control ventilation in the tunnel.
The jet fans are the primary safety system for the tunnel, not only venting away pollution from vehicles but also critical for fire crews to be able to safely evacuate people in the event of a fire.
The fans are specialist pieces of equipment and have required specialist teams to repair, refurbish, deliver and install them.
The contraflow will be removed, and the tunnel fully reopened, operating under a 50mph speed limit to reduce likelihood and severity of any potential crash and is in line with other tunnels and underpasses.
The tunnel will need to close overnight on the following dates so that highways crews can safely remove the contraflow:
- 16 October – Night-time full closure in both directions to remove the temporary safety fencing. (8pm to 5am).
- 17 October – Daytime right-hand lane closure in both directions to start re-installing the gates and the permanent safety barrier.
- 17 October – Night-time full closure in both directions to remove the temporary safety fencing. (8pm to 5am).
- 18 October – Daytime right-hand lane closure in both directions to continue/complete the re-installation of the permanent safety barrier.
- 18 October – Night-time full closure in both directions to remove the temporary safety fencing. (8pm to 5am).
- 19 October – Daytime right-hand lane closure in both directions to continue/complete the re-installation of the permanent safety barrier.
- 19 October – Night-time full closure in both directions to remove the temporary safety fencing. (8pm to 5am).
- 20 October – tunnel fully reopened in both directions.
While the contraflow has been in place, Kent Highways has carried out essential maintenance to avoid any further temporary closures, including replacing some corroded guard railing along the escape walkway, resurfacing the carriage way in the tunnel, clearing drains, cutting vegetation, removing graffiti, and clearing up litter and other debris.
“I’m really pleased that we are now able to fully reopen the tunnel.”
Cabinet Member for Highways and Transport Neil Baker said: “I’m really pleased that we are now able to fully reopen the tunnel, which I know has been a huge inconvenience for the travelling public and businesses in the area.
“The jet fans are specialist pieces of equipment and our Highways team has had to source spare parts. We’ve also been reliant on the availability of specialist crews to repair, refurbish and re-install the fans.
“The fans have now been fully tested and are compliant with safety standards, so we can now begin the process of removing the contraflow and reinstalling the safety barrier over the next few days.
“We will operate a 50mph speed limit through the tunnel in the interest of safety.”
The repairs to the existing fans are a temporary measure to fully reopen the tunnel, they will need replacing as they are towards the end of their serviceable life. A specialist company will redesign and install a new and efficient ventilation system during 2025/26 – this will ensure continued service for many years to come.
Updates on the tunnel can be found at A299 Thanet Way - Chestfield Tunnel - Kent County Council
