Knapsack Viaduct

This video is of some cheeky people making use of the old Knapsack Viaduct. Constructed between 1863 and 1867 the viaduct was built to carry rail traffic across Jamisons Creek and into the “little zig zag” which climbed the eastern side of the Blue Mountains to Glenbrook.

The beautiful structure stands at 130 feet (40m) tall, is 388 feet (118m) long with 7 sandstone arches rising imposingly above the gully. It was built at a width of 30 feet (9m) to accommodate a single railway line. The second Engineer-in-Chief for Railways John Whitton designed and built the viaduct which was the largest in Australia at the time. A special call out to @chillitriffids2 who’s great grandfather was involved in construction and who suggested I feature it as a post. Thank you.

The line up Lapstone Hill was a major engineering feat at the time. A few other ideas had been proposed including horse drawn tram and simply asking people to walk but authorities settled on the zig zag despite its steep inclines. Stories are told of the difficulties in using the zig zag including when in 1886 a train lost control on descent injuring 15 people. Despite this, the line served to revolutionise transportation from Sydney, to the Blue Mountains and then the agricultural regions beyond.

The bridge continued in use for approximately 40 years before the Glenbrook Gorge deviation to the south was completed in 1913. The bridge was modified slightly then began being used for road traffic in 1926 as a section of the Great Western Highway. The extension of the M4 motorway up Lapstone Hill in 1993 meant that it was closed to traffic and has now stood idle for over 20 years, aside from a few bushwalkers, cyclists and daredevil bridge swingers.

Note: I try to be as accurate as possible but make no guarantees. Please use this information at your own risk.


Knapsack Viaduct Emu Heights

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