Mr ALISTER HENSKENS (Wahroonga) (13:33): We are all familiar with the famous Zig Zag Railway in Lithgow, but an often-forgotten hidden gem is being brought to the public's consciousness in our community in Thornleigh. It is one of Sydney's little-known mysteries. Details are now emerging about the Thornleigh Zig Zag Railway, which ran from the Thornleigh railway station to a nearby quarry in the late nineteenth century. Nestled deep in the bush of Sydney's north, the line operated from 1883 to 1892 and was described as an engineering marvel by the former railway chief, Howard Collins, OBE. While a short-lived line, the railway played a crucial role in building the historic Great Northern Railway in New South Wales, linking Sydney and my birthplace of Newcastle, and eventually the north shoreline.

The Great Northern Railway ultimately led to the establishment of Hornsby, which is a local government area that covers a little under half of the Wahroonga electorate that I represent. The railway played a vital role in the social, technological and industrial progress of the nation by connecting two of the most populated cities in New South Wales: Newcastle and Sydney. It began when the contractors who started to build the Meadowbank to Hornsby section of the railway line needed to source ballast to form the bed of the railway sleepers. Large deposits of sandstone were discovered in the new suburb of Thornleigh and the clever engineering solution was found in the planned Thornleigh Zig Zag Railway, with this being considered the best way to reach the quarry safely and effectively.

After completion, the Zig Zag stretched 1.2 kilometres long and was the only one in the Sydney metropolitan area. The railway wound from the northern end of Thornleigh station by today's platform 3, through to the top end of what is now a commuter car park and to a lever-frame for signals controlled at the junction of what is now Eddy Street and The Esplanade. The Zig Zag passed a narrow reserve, crossing what is now Lovett, Wells, Eddy, Tillock and Pritchard streets, and Janet Avenue, across two timber bridges crossing the creek and down to the quarry.

After the Zig Zag closed, a sandstone cobbled road was installed to provide better access to the quarry, which was valuable during World War II when it became a firing range. By the 1950s, use of the site and most of the Zig Zag route was built over by new land and gradual recognition of the history began only in the 1960s. However, it was not until the 1990s when the Zig Zag would emerge in public consciousness again, being added to the Hornsby Shire Council's heritage listing in 1994 as an archaeological site. The creek near the quarry was then renamed Zig Zag Creek in 1994 and, at the turn of the millennium, a detailed historical and archaeological study was commissioned.

Currently only three pieces of this rail are in existence, one of which was handed to the Hornsby Historical Society, located in Normanhurst in the Wahroonga electorate, and two others discovered near existing bushwalks along Zig Zag Creek and the quarry. As part of the Thornleigh station upgrade, which was undertaken by the former New South Wales Liberal Government, the Hornsby Historical Society wrote a submission to Transport for NSW calling for greater recognition of the history and proposing that new physical markers be installed to mark the local area's history. I am pleased that Transport for NSW said it was excited to incorporate Thornleigh station's heritage into the station upgrade and has celebrated the railway within The Esplanade space through sandstone blocks and a zig-zag walkway approach to the station. This marked a major victory for local history in our area. The society also worked to develop a new plaque so that future generations would know the big story behind this little railway.

Recently I was introduced to this fascinating piece of local history when author and local resident, Tim Sowden, a member of the Hornsby Historical Society, generously sent me a copy of his new book entitled Zig Zag Away: Thornleigh's Little Railway with a Big Story, published by the society. I thank Tim and the society for their dedication to raising awareness of our important local history. Our area has had a major impact on New South Wales and it is wonderful that Tim has ensured that this important story is not forgotten. I was able to see the history of the Thornleigh Zig Zag Railway incorporated in the upgrade of the station while I was campaigning for the March 2023 election. The station upgrade is absolutely outstanding. It is part of six railway upgrades that have occurred in my electorate and is a wonderful augmentation to public transport.