A299 Thanet Way - Chestfield Tunnel
A contraflow is currently in place on the London-bound lane along the length of the Chestfield Tunnel on the A299 Thanet Way.
We identified safety critical faults with the jet fans in the ventilation system during a routine inspection in June 2024. The jet fans are one of the primary safety systems in the tunnel. They are critical to ensuring fire crews can safely evacuate people in the event of a fire in the tunnel. As well as safely venting away traffic pollution.
About the works
The jet fans are specialist pieces of equipment. They are manufactured and reconditioned to order and need specialist teams to deliver and install them.
Emergency works were undertaken in June to repair some of the fans. This allowed for a lane in each direction in contraflow through the westbound tunnel to be used safely by the public.
Our priority is to get the ventilation system working safely, so all lanes of both the west bound and east bound tunnels can be opened in the autumn. This means the contraflow system can be removed.
Once the tunnel is fully open, we will work with a specialist company to redesign and install a new and efficient ventilation system during 2025. This will ensure continued service for many years to come.
Latest updates
15 October 2024
Chestfield Tunnel on the A299 Thanet Way near Whitstable is set to fully reopen on 20 October.
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 between 8pm and 5am on the following dates so that highways crews can safely remove the contraflow:
| Date | Description of closure |
|---|---|
| 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. And a 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. And a 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. And a night-time full closure in both directions to remove the temporary safety fencing (8pm to 5am). |
| 20 October | The tunnel will be fully reopened in both directions |
While the contraflow has been in place, we have 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
- clearing up litter and other debris.
29 August 2024
A specialist contractor has inspected the broken fans. They checked which parts can be salvaged and which need replacing.
We've sourced replacements for the faulty parts. A specialist contractor will be appointed in the next few weeks to refurbish the fans on site.
After refurbishing the fans, we will test them for safety. Specialists will then install the fans and remove the contraflow.
Also, on the eastbound road between the Chestfield Tunnel and the Herne Bay slip road, lane one had an uneven surface and it was unfortunately unsafe to use. We resurfaced the road to smooth it overnight and finished in the early hours of Thursday, 29 August. The road has returned to the original contraflow system.
Repairs to the westbound carriageway took place overnight from 26 August.