Seven graceful sandstone arches rise before you. This is the New Knapsack Viaduct a marvel of engineering. It wasn’t always a pedestrian walkway.
The New Knapsack Viaduct’s story begins in the 1860s. John Whitton the Engineer-in-Charge of NSW Government Railways designed it. William Watkins built it. They needed a way to get trains over Knapsack Gully. This was part of the Lapstone Zig Zag railway. A zig zag railway is a series of switchbacks to overcome steep inclines.
The viaduct carried the Main Western railway line. Construction took from 1863 to 1865. Local sandstone was used. The single rail line allowed trains to cross Knapsack Gully. For early travelers it was an inspiring sight. A testament to human ability.
The New Knapsack Viaduct wasn’t always so peaceful. It was a busy part of the railway line. Hundreds of people worked on the project. Many others worked on the railway after its completion. The viaduct was vital. It helped improve travel through the Blue Mountains. It opened up the area for settlement and tourism. Even a station was built nearby called Lucasville. This was for the Minister for Mines who had a holiday home nearby.
But times changed. The increase in freight and limitations on train length made the Zig Zag inefficient. A tunnel was built around 1890. This didn’t initially affect the viaduct. But in 1913 a larger deviation was completed. This new route went through Glenbrook Gorge. A newer viaduct was built. The original New Knapsack Viaduct was no longer needed.
In 1926 the Main Roads Board took over. They widened the viaduct for cars. It became part of the Great Western Highway. The highway was improved again in 1939. More widening was required because of increased traffic. In 1993 the M4 motorway opened. This ended the viaduct’s use as a highway.
Finally the New Knapsack Viaduct found new life. In 1995 it reopened. It’s now a part of the historic Lapstone Zig Zag walk. The echoes of trains are gone. But the sounds of birds and insects now fill the air. Walk across this iconic structure. Feel the history beneath your feet. The New Knapsack Viaduct stands as a reminder of the past. A testament to ingenuity and perseverance. A symbol of progress. And now a tranquil place for a stroll.