A contraflow has been put in place on the London-bound lane along the length of the Chestfield Tunnel on the A299 Thanet Way to repair and replace the jet fans in the coast-bound lane following a safety critical fault being identified in the tunnel.
An emergency closure was introduced on Tuesday 11 June so that specialist engineers could get on site to bring the London-bound lane back up to a safe operational level so at least part of the tunnel can open. The jet fans on the coast-bound side will need to be replaced.
The contraflow will run for approximately 900 metres long (and is shorter than the one in place earlier this year) and will allow one lane to remain open in both directions, where the speed limit will reduce to 40mph.
The contraflow will be in place for at least three months. The jet fans used to ventilate the tunnel are specialist pieces of kit which are manufactured to order and then delivered and installed on site by a specialist crew. It is expected that it will take at least two months dependent on availability to manufacture and deliver the fans, and the contraflow will need to be in place until the specialist crews can safely install the new fans.
The safety critical faults were identified during a routine inspection. The jet fans are one of the primary safety systems in the tunnel and critical to ensuring that fire crews can safely evacuate people in the event of a fire in the tunnel, as well as safely venting away traffic pollution.
(Pic – Kent County Cpuncil)
