Лапстон зигзагы: Австралия тарихындағы алғашқы теміржол серпілісі

The Lapstone Zig Zag was a zig zag railway built between and stations on the Main Western Line of New South Wales in Australia. Constructed between 1863 and 1865 to overcome an otherwise insurmountable climb up the eastern side of the Blue Mountains, the zig zag and associated Knapsack Viaduct, a sandstone arch viaduct, were designed by John Whitton, Engineer in Charge of New South Wales Government Railways, and were built by William Watkins. The zig zag was listed on the Blue Mountains local government heritage register on 27 December 1991;

The zig zag closed in 1892 when the Main Western line was diverted via the Glenbrook Deviation and subsequently sections of the line were repurposed as the Great Western Highway, and later use as a walking track.

The contract to build this railway from Penrith as far as Valley Heights, which included building the Knapsack Viaduct and the Lapstone Zig Zag, was awarded to William Watkins in March 1863 but was completed eighteen months behind schedule in December 1865. It opened for traffic in 1867. Once the westbound train had crossed Knapsack Viaduct, it entered the Bottom Road of the Zig Zag. There were points where the Middle Road cut backwards and sharply upwards to form the middle stroke of the Z. Beyond the points, Bottom Road extended an additional 532 feet (162 m) to a dead end. It was in this area that the train stopped before it reversed direction to climb Middle Road. Similarly at the junction of Middle and Top Roads, Top Road continued some distance to buffers on the edge of Knapsack Gorge. Here the train again reversed its direction to resume the journey over the Blue Mountains. Lucasville Station was completed in 1877 on the extension section of Top Road. In 1886 the line of the Top Road extension was remodelled with a new parallel, more steeply sloped line to the west. Both of the lines of the Top Road extension are clearly legible. but the Lapstone Zig Zag, which included Lucasville station, soon ran into problems: the length of the top points and bottom points limited the length of trains and the single track meant that trains travelling in opposite directions had to stop at crossing points. The first crossing point after Lapstone Zig Zag was at Wascoe's Siding at what is now Glenbrook station. The Lapstone Zig Zag was the first Zig Zag constructed on any main line railway anywhere in the world. The idea on which Whitton built came from the Indian railways. A friend of his, Solomon Tredwell, had in 1859 started the construction of half a Zig Zag (with a reversing line and stone viaducts) at Bhore Ghat on the Bombay to Poona line. Although Tredwell died in 1859, his widow saw the half Zig Zag to completion in 1863, employing 42,000 men, and this feat was reported at some length in The Sydney Morning Herald on 3 July 1863. Whitton knew of the conquering of the Bhore Ghat, which posed problems very comparable to the Lapstone Monocline, both from personal and public communications. The way in which he adapted the Indian experience into a full Zig Zag, approached over an exquisite, and very cheap, sandstone viaduct, was a substantial feat in world terms of railway engineering. The single track contributed to a fatal accident at Emu Plains in 1878 where eastbound and westbound goods trains collided.

Commissioner of Railways, E. M. Eddy, decided that the ZigZag should be replaced by the deviation including a tunnel, both built around 1890. The Lapstone Zig Zag and Lucasville station were officially closed on 18 December 1892 and the rails were raised, after the completion of the Glenbrook Tunnel Deviation.

By 1910, the line as a whole was being duplicated (made into double track) and the "rathole" tunnel was replaced on a different deviation with a gentler alignment with 1 in 60 (1.67%) grades and the new Glenbrook Tunnel at Bluffs point on the Glenbrook Creek escarpment. From then on the lower section of the track, including the historic Knapsack Gully Viaduct, was converted into a road, the Great Western Highway, the main road up the Lapstone hill until the M4 motorway replaced it in 1993. The older tunnel was converted for mushroom growing but was also used by the RAAF for storage during World War II. During 1943 to 1946 the Glenbrook tunnel stored chemical weapons, mainly of bulk drums of mustard. Today the Zig Zag, Knapsack Viaduct, The Old Glenbook Tunnel, and Lucasville station can all be accessed by walking tracks.

The line of the old track and cuttings (including the long abandoned platform of Lucasville station), and the old Knapsack Gully bridge is now a popular bushwalking track. Often a cacophony of birdsong and insects can be heard where the gully is deep at the viaduct and it would tend to echo these sounds, especially that of the bell miner. Although the original tunnel is closed there is also a bush walk that will take you close to its entrance.