Cafodd y cynllun hwn ei ddefnyddio ym mis Gorffennaf 2011 yn sgil tân yn y twnnel i’r gorllewin. Er gwaethaf y difrod a achosodd y tân ailagorodd y twnnel o fewn tri diwrnod.
This plan was used in July 2011 when a fire occurred in the westbound tunnel, where despite the damage caused, the tunnel was fully opened within three days.