Sydney extend the system through the CBD by 2024. At the time the Sydney Harbour Bridge opened in 1932, the city's ferry service was the largest in the world. Patronage declined from 37 million passengers in 1945 to 11 million in 1963 but has recovered somewhat in recent years. From its hub at Circular Quay the ferry network extends from Manly to Parramatta. Sydney Airport, officially "Sydney Kingsford-Smith Airport", is located in the inner southern suburb of Mascot with two of the runways going into Botany Bay. It services 46 international and 23 domestic destinations. As the busiest airport in Australia
Sydney Harbour Tunnel to Sydney Harbour. A trench was dredged before the arrival of the IMTs and then the IMTs were lowered into the trench by a system of pontoons and control towers. After the IMTs were in place the trenches were backfilled and then a rock armour was placed over the top to protect the units against marine hazards, such as anchors or sinking vessels. The land tunnels were constructed by a combination of driving and cut-and-cover techniques, designed to be strong enough to withstand the impact of earthquakes. The northern end pylons of the Sydney Harbour Bridge were altered to allow