Visualising the Invisible: The Original Sydney Harbour Tunnel

Sydney Environment Institute Research Assistant Brett Morgan dives into the elusive history of Sydney Harbour’s first tunnel. 

Image by Dan Freeman, via Unsplash

For the past few months, I have been undertaking some research on Sydney Harbour, and was fortunate enough to present some of my findings at the recent Enlarging the Harbour View workshop hosted by the Sydney Environment Institute, in conjunction with the Power Institute. My research explores how the under-Harbour is represented, visualised or imagined, and documented, using the resources at the State Library of New South Wales. Going into a project like this, there are numerous obstacles to overcome, the most pressing being the problem of visualisation and representation. There is also an inherent unknowable-ness to that which lies beneath the surface of the Harbour, as it is a space that humans are rarely able to occupy. How, then, are we to properly conceptualise the under-Harbour, when it is a place that eludes visualisation?

My research has so far uncovered a range of intriguing records, including 18th Century watercolour paintings of Harbour marine life, 19th Century poetry about Harbour shipwrecks, and 20th-century maritime archaeological surveys that detail some of the cultural heritage sites that lay at the bottom of the Harbour. The under-Harbour can thus be understood as an assemblage of social, cultural, and environmental phenomena that spans both distance and time. There are many fascinating narratives pertaining to the under-Harbour, and this is one relatively unknown, but particularly interesting tale — the story of Sydney’s first Harbour Tunnel.

Throughout the late 19thand early 20th centuries, Sydney’s tram network was growing rapidly, and it had been extended to the north shore of the Harbour. The electricity for the tram network was being generated in Ultimo at the time, and in order to deliver the energy to this newly-established north-shore network, cables were run across the floor of the Harbour at the narrowest point closest to Ultimo, which happened to be a distance of a little under 300 metres between Long Nose Point at Birchgrove and Mann’s point at Greenwich. However, running electricity cables across a Harbour floor doesn’t come without certain risks, and in several instances, these cables were badly damaged—even severed—by the anchors of nearby ships as they were dragged across the Harbour floor during strong winds. In 1912, NSW Government Railways—the department responsible for rail transport at the time—decided to build a tunnel beneath the Harbour floor (across that same expanse between Birchgrove and Greenwich) to house the cables needed to power the tram network on the north shore. This was a very bold decision to make, at this scale, no similar projects had ever been attempted in Australia, and the NSW Government didn’t reach out to any international consultants to help. After all of the planning and mapping had been done, construction on the tunnel began in 1913, and was initially estimated to take two years and cost around £11,000. However, the project encountered many, many problems.

The first problem was a  presumed fissure in the Harbour floor that the workers tunnelled straight into, which flooded the tunnel and halted work for an extended period of time. After sealing this fault from the surface and blocking off the leak with a bulkhead door, the scope of the project had changed drastically, as the workers now had to tunnel deeper beneath the Harbour floor in order to avoid the fault they had encountered. This didn’t prevent further leaks and other complications, however, as they hit this same fault once more. The roof collapsed several times, and, eleven years on and a massive £173,000 later, the workers at last broke through to the other side. The final fit-out (which included pulling the cables through the tunnel) took the project through to 1926, and, after another four years of battling with constant leaks, the tunnel was left to flood. It was, however,  still able to carry electricity and it was used up until 1969.

Though this is a very interesting aspect of the Harbour’s history, there isn’t a whole lot of information available on this subject within the archives at the State Library of New South Wales. James Dargan’s Sydney’s First Harbour Tunnel (1992) is the only source I can find that tells this story, and one of very few that mentions the tunnel’s existence.1 There are two newspaper articles within the archives—one published in 1921, the other, in 1924—that mention the tunnel, and it is Dargan’s belief that this lack of media attention is because the tunnel was being built during the First World War, and so there was a political incentive not to publish any articles about a two year project that ended up taking over a decade. Percy Stephenson’s 1966 book, The History and Description of Sydney Harbour, gives a very detailed account of the Harbour’s history, and not even this well-researched book mentions the tunnel.2

The fact that there are so few sources on this tunnel is perplexing. Of Dargan’s sources, one third are oral histories, which is a clear indication of how few publications there are on this subject. Why is the tunnel’s history so poorly documented? Perhaps Dargan is right to suggest that international politics may have had an influence Or perhaps there is simply just not enough historical nor economic interest in the tunnel. Whatever the case, the State Library’s archives do house this fragmented tale , but it is a place that is difficult to access, difficult to visualise, and therefore, it is a story that remains difficult to tell.

1. Dargan, J. (1992) ‘Sydney’s First Harbour Tunnel’ Lane Cove Public Library: Local Studies Monograph, no. 5
2. Stephenson, P.R. (1966) The History and Description of Sydney Harbour, Rigby: Adelaide

Brett Morgan is a research assistant for SEI’s The floor of Sydney Harbour research project. Brett completed a Bachelor of Arts (Honours Class I) in 2017 from the University of Sydney, where he majored in Gender & Cultural Studies (Hons) and Philosophy. His thesis titled ‘Think Global, Reconfigure the Local: How Intermediaries Articulate Pro-Environmental Values and Practices’ explored the concept of the ‘pro-environmental intermediary’ within contemporary environmental discourse.