Why underground?

The Airport Line is a new rail line connecting the railway east of Bayswater Junction to High Wycombe with 8.5 kilometres of new tracks, 8km of it in tunnels.

The use of underground tunnels reduces the project’s impact on the environment and the community during both construction and operational phases. It also avoids any interference with vital aviation infrastructure at Perth Airport.

Before tunnels were selected as the best way to achieve project goals, other potential options were investigated, particularly in relation to the rail line between Bayswater and Perth Airport. Options considered for this area of rail line included:

• elevated structures such as a series of bridges
• cut-and-cover structures located just below ground level
• deep bored tunnels.

Ultimately, it was determined that bored tunnels would provide the best solution. This approach reflects similar rail projects around Australia and overseas, where the trend is to locate key transport infrastructure below ground where possible.