Blue Mountains City Council engaged MTS Heritage to prepare a Conservation Management Plan (CMP) for the Lapstone Hill Tunnel, located in the lower Blue Mountains NSW. The CMP aimed to guide the tunnel’s future use, conservation and maintenance.

The Lapstone Hill Tunnel was constructed in 1892 as a deviation to the Lapstone Zig Zag, to create a more efficient route for trains ascending the eastern escarpment of the Blue Mountains. The tunnel is listed on the NSW State Heritage Register (SHR) as the ‘Glenbrook Railway and World War II Mustard Gas Storage Tunnel’. The listing recognises the tunnel’s historical heritage values and rarity for its use to store chemical gas during World War II. Its historical association with the 1891 painting, ‘Fire’s On’ by eminent landscape artist, Arthur Streeton, is also recognised. The tunnel is also listed as a heritage item in Schedule 5 of the Blue Mountains Local Environmental Plan 2015. This listing highlights the significant labour and funds required to construct the tunnel and its importance as the first rerouting of the initial ascent of the Blue Mountains by rail.

The CMP followed the established guidelines of The Conservation Plan by Dr James Semple Kerr published by Australia ICOMOS, and the Australia ICOMOS Charter for the Conservation of Places of Cultural Significance (Burra Charter). It also takes into consideration the Statement of Best Practice for Conservation Management Plans published by the Heritage Council of NSW.

The report builds on a previous CMP by incorporating a recent condition assessment and the results of additional heritage surveys. Eighteen (18) heritage elements were identified within the study area. Except for Arthur Streeton’s viewing platform, all the identified heritage elements highlight the significant human effort required to construct the 1892 rail deviation. They include significant cuttings, rubble embankments, a large sandstone culvert and remnants of a former sandstone bridge. Detailed survey of the tunnel and its portals confirm that they are in relatively good condition, despite the addition of the concrete floor and later modifications associated with mushroom farming and ammunition storage during World War II.

Re-assessment of the heritage significance of the tunnel and a comparative analysis confirm that it is typical and representative of its type. Unlike other comparable railway tunnels, construction of the Lapstone Hill Tunnel was particularly labour intensive due its crossing of the eastern escarpment. As documented by Arthur Streeton, the scale and intensity of the operation was impressive and captivating, as was its landscape and setting.

The CMP presents conservation policies to ensure the tunnel and its heritage values, setting and significance are retained for future generations. Given the structural integrity of the Lapstone Hill Tunnel, no impediment to allowing public access was identified. The continued use of the tunnel and its approaches is considered vital to its ongoing conservation.