The two TBMs, named Betty and Dorothy, have thus far built 865 and 300 metres of tunnels between Sydney Olympic Park and Westmead respectively.

The TBMs are installed with artificial intelligence software, which has the capability to automatically steer, operate and monitor the machine© Sydney Metro

Launched from Clyde at the start of September, the 1,200-tonne machines have made history as the first autonomous TBMs to be put into use for the country, and are tunnelling roughly 180 metres per week.

Betty and Dorothy are expected to conclude the first leg of their journey in Sydney Olympic Park by the end of 2024, and are each installed with artificial intelligence (AI) software with the capability to steer, operate and monitor conditions independent of any operators.