Historical information
This photograph documents the construction of the Jacana Underpass Tunnel, a landmark infrastructure project undertaken to allow Melbourne’s Western Ring Road to pass beneath a complex transport corridor. The corridor included Pascoe Vale Road, Electric Street, and four active railway lines—two broad gauge, one standard gauge, and one commuter line—making traditional tunneling or bridging methods impractical.
The tunnel was constructed using a pioneering hydraulic jacking technique, where precast concrete tunnel segments, each weighing approximately 1200 tonnes, were pushed into place through pilot tunnels. This method minimised disruption to the busy transport corridor above, which carried tens of thousands of vehicles and multiple rail services daily.
The Jacana Underpass Tunnel was constructed between 1992 and 1993 as part of Melbourne’s Western Ring Road project, a major infrastructure initiative aimed at improving traffic flow and connectivity across the city’s northern suburbs. The underpass was designed to carry the freeway beneath a complex transport corridor that included Pascoe Vale Road, Electric Street, and four active railway lines—two broad gauge, one standard gauge, and one commuter line.
Due to the shallow depth of cover—less than one metre in some areas—and the need to maintain uninterrupted road and rail services above, engineers employed an innovative hydraulic jacking technique. This involved pushing precast concrete tunnel segments, each weighing approximately 1200 tonnes, through pilot tunnels using hydraulic rams. The method was one of the largest of its kind in Australia at the time and allowed for the safe and efficient installation of the tunnel without open excavation.
The photograph captures a key stage in the construction process, showing the dual tunnel portals, heavy machinery, and construction materials on site. It reflects the scale, complexity, and ingenuity of late 20th-century civil engineering in Victoria and provides valuable insight into the evolution of Melbourne’s transport infrastructure.
Significance
This photograph documents a pivotal moment in the construction of the Jacana Underpass Tunnel, part of Melbourne’s Western Ring Road infrastructure project undertaken in the early 1990s. The image features two tunnel entrances under construction, surrounded by heavy machinery, construction materials, and temporary fencing, with a dirt access road leading into the site.
The Jacana Underpass was constructed using a hydraulic jacking technique, a method that allowed large precast concrete tunnel segments—each weighing approximately 1200 tonnes—to be installed beneath a live transport corridor without disrupting traffic or rail services. This innovative approach was one of the largest of its kind in Australia and addressed significant engineering challenges, including shallow cover and complex geological conditions.
The photograph is significant for its documentation of advanced civil engineering practices and the transformation of Melbourne’s northern suburbs through major infrastructure development. It provides insight into the construction techniques, site logistics, and material use typical of large-scale tunneling projects in the late 20th century.
As part of an archival collection, this image contributes to the historical record of urban growth, transport planning, and engineering innovation in Victoria. It holds enduring value for researchers, historians, and infrastructure professionals studying the evolution of public works in the state.
Physical description
Colour photo. Construction Site. Jacana underpass tunnel.
Inscriptions & markings
(Back - blue pen)
'Underpass/Jacana'
