TBM Betty and TBM Dorothy are progressing well on their journey to carve out a section of the twin Sydney Metro West tunnels between Sydney Olympic Park and Westmead, having built 865 metres and 300 metres, respectively, of fully lined tunnels since launching from the Clyde launch box.

The 1,200-tonne machines are tunnelling approximately 180 metres a week and are expected to complete the first 4.5-kilometre leg of their journey and arrive at Sydney Olympic Park in mid-2024.

TBM Dorothy and Betty have made history as the first autonomous TBMs to be used in Australia. 

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

TBM Dorothy has been named in honour of Dorothy Buckland-Fuller who was an Australian human rights and founded the Australian Migrant Women's Association. 

TBM Betty was named after Olympic champion Betty Cuthbert who attended Parramatta Home Science School (now Macarthur Girls High School).

On major tunnelling projects around the world, machines that work underground are traditionally given female names.