The Zig Zag Heritage Railway - opening again this winter. скачать в хорошем качестве

The Zig Zag Heritage Railway - opening again this winter.

The Lithgow Zig Zag was constructed as part of the Main Western line and opened on the 19 October 1869. Between Lithgow and Clarence, the Main Western line needed to climb the western flank of the Blue Mountains, overcoming a vertical distance of 550 ft (170 m). The alternative eventually decided upon required the use of two railway zig zags where all trains had to reverse. The line had a ruling grade of 1:42 (~2.38%) on three inclines known as the Top Road (above Top Points), Middle Road (between the two zig zags) and Bottom Road (below Bottom Points). The line included several short tunnels and some viaducts. The steep gradients and need to reverse trains proved to be a serious bottleneck to traffic on the line, and there were several accidents with runaway trains at the reversing points. Attempts were made to mitigate this by realigning the track and relocating and extending the reversing stations, but the problems continued. As early as 1885 plans for alleviating the Zig Zag problem involved the construction of a 2 mi (3.2 km) long tunnel. This was said to provide little gain for the cost proposed. In 1908, work began on the Ten Tunnels Deviation, a double-tracked route that by-passed the two reversing stations and the upper two inclines, although retaining the Bottom Road with its 1:42 gradient. Once this was completed, the by-passed section was closed in October 1910.