A Chinese-built tunnel boring machine is currently being used to construct Sydney’s Western Harbour Tunnel, a 6.5-kilometre highway project designed to connect the city’s inner west with the lower north shore. The machine, named Patyegarang after an Aboriginal woman instrumental in early Indigenous-colonial communication, is working deep beneath Sydney Harbour on a tunnel expected to open by 2028.

The Western Harbour Tunnel will feature three lanes in each direction and aims to significantly reduce travel times and alleviate congestion on existing routes such as the Sydney Harbour Bridge and tunnel. The project involves complex underground engineering, including navigating tight, S-shaped curves with a minimum turning radius of 960 metres (3,150 feet), a challenge for typically large and rigid tunnel boring machines.

To address this, the Patyegarang machine is outfitted with a segmented body and precision joint system allowing it to bend and maneuver along curved alignments. The machine, developed by China Railway Engineering Equipment Group (CREG), boasts an excavation diameter of 15.7 metres, making it the largest tunnel boring machine China has ever exported. It marks a significant milestone in Chinese tunneling technology being deployed internationally.

Tunnel boring machines are specialized equipment designed to minimize surface disruption while adapting to local geological conditions. China, known for its rapid infrastructure expansion, historically relied on imported large-diameter machines. However, since developing its first domestic tunnel boring machine in the early 2000s and achieving self-sufficiency in core components by around 2021, China has become the world’s largest manufacturer of these machines.

Manufacturing hub Zhengzhou has emerged as the center of China’s tunnel boring industry, with machines exported to 36 countries. In addition to the Sydney project, the Victorian government in Australia announced orders for four more Chinese-built tunnel boring machines last year to be used on Melbourne’s Suburban Rail Loop twin tunnels. Separately, CREG announced recently the completion of another machine destined for Singapore’s Cross Island Line Phase 2.

This expanding global footprint reflects China’s growing role as an exporter of advanced tunneling technology and infrastructure equipment. The use of Patyegarang in Sydney exemplifies how Chinese engineering is increasingly integrated into major infrastructure projects around the world.