The Original Ghan Crossing of the Leigh Creek
The remains of the Ghan narrow gauge bridge show just what living in this remote area was all about! The map (link above) shows the bridge location in the top right hand corner.
The enormous task facing the early railway construction crew becomes apparent when one sees this one crossing as part of the Ghan route heading north across out back Northern Australia. A copy of the original rout planning map will be displayed in the rail precinct at Farina sometime soon.
The whole area North or Lyndhurst and to the West of Marree is a sandy flood-plain, (and incidentally nearly 10 metres below sea level!), and part of the Lake Eyre basin. As a result, this whole area was not only subject to flooding after rain, but when dry, subject to huge dust storms and moving dunes. Not ideal for a railway track route!
All three of the Leigh’s Creek crossings North of Farina were originally built on steel tresles, carrying 16 spans, each 22 foot 7 inches long.
During the 1920s, with locomotives and loads becoming increasingly heavier, extra supports of heavy cross-braced timbers were installed on the bridge.
Unfortunately, as the line grew older and traffic became heavier, speeds were forced to be steadily lowered because of frequent danger of de-railments. Maximum speeds were often down as low as 15mph. This continual lowering of speeds not only decreased the amount of stock that could be moved, but forced some rather unusual shunting requirements.
A number of gradients out of Farina were sufficient to require that the locos take a “run-up” at them to pass the high spot (called “momentum grades”). One in particular in the Wangianna/William Creek/Bundooma area (near Marree) finally forced the splitting of the train. Half of the train would be taken to Marree, uncoupled, and then the loco would return to collect the second half of the trucks, taking them also to Marree where the first batch were again connected and the train would continue on.
This situation became so bad that the line finally closed in 1957. Not only because of the (now) poor load carrying ability of the track, but the trains were frequently almost empty on the way North, and full on the way South – thus only earning revenue for half the time.
On the Rail route map (below). The creek crossing is right at Farina.
The images (below) were captured on June 24 during an exploratory hike through the bush in the Leigh’s creek.
The first indication that we had of being on the right track (no pun intended), was a star dropper with a heavy steel base, favoured by the railways for driving in to heavy soil. A little further into the bush (following the star droppers) we found the first timber sleepers.
The thick bush in the creek crossing could cause folks who are un-used to bush trekking to lose their way, so since our walk on the 24th, Dr. Bob and Kevin Dawes have cut an initial walking track into the undergrowth adjacent to the track. This will enable our work parties to complete the track, with appropriate signage in the 2016 season.
The track will also enable walkers to see the artefacts that we found without disturbing them, and so get a better idea of the task that the railways constructors had set themselves and still allow others in the future to see the remains.
It’s interesting to note that nearing the Northern end of the crossing, we found a number (up to 3 at one stage) of heavy pipes – some steel, and others a cement composite, which carried water from the very large railways dam a few miles to the North to the overhead storage tank at Farina. It appears that when a pipe failed, instead of repairing it, a completely new pipe was laid!