The winning bidder on the Sydney Airport will have its work cut out contending with the giant Airbus A380. Not only is the mammoth aeroplane too big to safely pass other planes on the runway, but it is also too heavy for the busy road tunnel under the airport. The tunnel was built in 1968 when planes weighed no more than 340 tonnes. The A380, however, is 566 tonnes fully loaded. One possible solution is to thread steel cables through the walls and the ceiling of the tunnel to act as reinforcement.