The Zig Zag Railway was built between 1866 and 1869, as a part of the Western Main Railway, from Sydney to Bathurst. It was constructed to enable produce to be taken to Sydney from the prosperous farming areas beyond the Blue Mountains, to develop the coal and iron ore deposits in the Lithgow Valley, and the shale deposits in the area by anabling their products to be taken to Sydney.

When the railway reached Clarence, the highest railway station on the mountains at 3658 feet above sea level, a way of descending 209m (687 feet) down the Lithgow Valley had to be found. There was a choice of cutting a 2 mile long tunnel, using about 10 million bricks, or to build a Zig Zag. The Zig Zag was the easiest and most economical method with the materials and technology then available.

The Zig Zag is a giant "Z" carved in the side of the mountain. Trains travel down each part of the "Z" at a gradient of 1 in 42 which can safely be negotiated by a loaded train. The train travels a distance of 8 km (5 miles) to make the descent. The Railway was designed by John Whitton, Engineer-in-chief of the New South Wales Government Railways. The contractor was Patrick Higgins. The Resident Engineer was George Cowdery. The Lithgow Zig Zag  was the earliest ever built, the one at Bhore Ghat near Bombay in India was only half a zig zag or single switchback with a single reversing station.

The Zig Zag Railway today operates trains on the Top, and Middle Bars of the "Great Lithgow Zig Zag", between Clarence and Bottom Points, about 45 minutes walk from Clarence. There are 3 stops: 1) on Top Road at no. 1 Viaduct, for the best view of the whole Zig Zag, 2) at Top Points to see the site of the 1901 runaway and reverse direction, and 3) at Bottom Points for a tour through the workshops, where locomotives and rolling stock are maintained and repaired.

After leaving Clarence Station the train passes through the 493m. (1617' - 539 yards), sandstone lined, Clarence Tunnel.

Outside the Tunnel

By the late 1890s rail traffic across the mountains had so grown that the Zig Zag could not handle loads sufficiently quickly, even though the track had been doubled at the reversing stations at Top and Bottom Points. The limiting factor was the length of the reversing stations. In 1907 work started on the Ten Tunnel deviation, using technology not available in the 1860s. The deviation starts about 3 km. east of Clarence at Newnes Junction, forming big semi circle underground, crossing underneath the Zig Zag site with over 3 miles of tunnel. This deviation opened in 1910.

On the right as the train is descending is the Lithgow Valley. Through the trees can be seen some Zig Zag railway wagons in a siding on Top Road.

The Zig Zag Railway runs on the same track bed as the original railway in 1869 except for the part on the west (Lithgow) side of Clarence Tunnel where both the railway track and the road were modified to accommodate both. The road was built during World War II, on part on the railway old track bed.

The gauge of the Zig Zag railway was originally the New South Wales Railways standard gauge of 1435 mm (4’ 8 1/2"). When the Zig Zag Railway Co-op was formed, the NSW railways would not sell rollingstock because they were forming their own railway museum at Thirlmere. Zig Zag therefore looked elsewhere for rollingstock.  It bought mostly from Queensland Railways, but some came from South Australia, Western Australia, and Tasmania. The track was therefore laid 1067mm (3’6") gauge.
The 2000 class railmotors came from Queensland where they were used for the Brisbane commuter service 1960s - 1994. They enable the railway to run trains daily, on days when a steam train would be uneconomic. 

Edgecombe Siding

To the right can be seen the earth embankment outside Clarence Tunnel already travelled. It can be seen how far the line has descended. In the 19th century there was only one brake on the train and one on the engine, so trains travelled very slowly and it took 3 hours to cross the Zig Zag. The line was doubled here in 1901 to allow trains to cross and therefore speed up the journey. There used to be a signal box here at the Sydney end, which was removed when the 10 Tunnel deviation came into use in 1910.

At No 1 Viaduct

From here can be seen the 3 levels of the railway: Top Road with No 1 viaduct in front, below is Middle Road with nos. 2 and 3 viaducts, the double electric line across the bottom is the original Bottom Rd, still the main line west to Broken Hill in NSW, Aidelaide in South Australia and Perth in Western Australia.

It took 600 - 700 men, about 2.5 years to build the Zig Zag; they lived in tents, in 20 different locations, at temperatures down to -10 degrees Celcius during winter, there were only 2 permanent buildings on the Zig Zag, a bakery, and a gunpowder store. Each worker was paid 1 shilling & 3 pence a day, or 1 shilling 9 pence if he brought his own horse, that is 15 or 19 cents a day, good money then, particularly as they had nowhere to spend it.

The railway was mostly hand built, all of Middle Road, and most of Top Road consisted of ledges hand carved from the mountain side. The workers used hand augers for drilling, which were filled with gunpowder for blasting. It took 3 men to drill each hole, 2 to hold the auger and turn it, while another hit it with a hammer. After each blast if the material thrown out was not where required, workers hand loaded the rock into wheelbarrows or carts and took it where it was needed as fill.

When the line was surveyed, the surveyors were placed in large wicker baskets, and lowered over the cliff side, in order to shoot the line in. During construction, the chief engineer, John Whitton, sat on a stone seat carved in the cutting next to no. 2 viaduct, where he sat and supervised the work. He sent instructions by runners on foot or horseback, or signalled by semaphore or mirrors. This is called Engineer's Lookout.

Everything used on the railway was obtained locally, sandstone for the viaducts was hand carved, transported by horse drawn dray. The stone came from Baker's quarry about 1 km away to the north as the stone close by was of poor quality. The stones were measured in metric scale, because the stonemasons came from Italy and brought their own measuring equipment. The viaducts are inspected every 5 years; on the last inspection, the engineer said they were better than when they were built as they are designed so that settlement makes them stronger.

From the time of construction and for much of the railway's use in the 19th century there were no trees on the Zig Zag. As rock was blasted away on each level it slid down the side of the mountain, taking anything that got in its way with it. The other side of the valley gives an indication of what it must have looked like before the railway was built.

In December 1997, severe bushfires swept through the reserve. Looking at it now it is hard to realise that so much damage was done, nature has repaired it well.

Between No. 1 and Top Points

The Zig Zag was originally planned with 5 sandstone viaducts, and 3 tunnels. Only 3 viaducts were built, the other 2 were replaced with stone removed from cuttings. The first electrically detonated blast took place here in January 1867 on Middle Road.

Only 2 tunnels were completed, the 3rd developed cracks during construction, and was blown up to form a cutting. It was the second electrically detonated explosion in the southern hemisphere. In September 1868 the Countess of Belmore came out from Sydney by train to push the plunger, she did not think that much of the occasion, in fact the only mention it got in her diary, was the fact that the train had broken down on the way back to Sydney.

Blowing up the tunnel was the only ceremony that the Zig Zag had. After completion 18 October 1869, the railway immediately started operations. The NSW Government was so proud of the achievement that the site was gazetted a Reserve in 1881, one of the first in the State.

Much the same happened in 1910 when the ten tunnel deviation was completed; the morning train came down the Zig Zag and returned to Sydney through the tunnels. All railway line was removed and the formation lay abandoned until the 1970’s. It remained a tourist attraction with many visitors.

Top Points

Top Points is the first reversing station, where the locomotive is moved from one end of the train to the other so that it may be at the front of the train travelling the next section. It is the second yard that was built here in 1907-8. Its altitude is 1025.4 m. (3362 ') - a difference of 88.8m. (296') between Top Points and Clarence. It was built to ease congestion. It could handle trains twice as long, and could cross trains, that is accommodate one train from Top Road and another from Middle Road, and each go out on a different line. The engine that brought down a train from Clarence could return with the one that had come up from Bottom Points.

Originally both reversing stations had only a single track, which limited the amount of traffic carried. Top Points was altered to twin track with a runaround in 1895. Bottom Points had various modifications between 1878 & 1895 to end with twin track and runaround. After the Top Points accident in 1901 both reversing stations were altered to accommodate longer trains. The line at Bottom Points was lengthened but that at Top Points was swung inland and considerably lengthened to allow for longer trains to cross.

Spanning the two lines is the Cooerwull Footbridge built 1941, relocated from Lithgow in 2002. This provides an excellent spot for photography.

This yard ends in a solid wall. The first yard did not, only a sheer drop. In 1901 a train coming down the Zig Zag lost control of its brakes, crashed through the wooden bufferstop, and stopped half suspended over the cliff edge. The driver and fireman were uninjured, as, when they realised that the train could not stop, they jumped out. The day after the accident the train was pulled back on the track, and allowed to continue on its way, remaining in service until the mid 1950s. The driver and fireman booked onto work the next morning, with a small fine, no stress counselling, just straight back to work!

At Top Points Lookout

The site of the 1901 accident is at the lookout. A concrete block was put here after the accident, to prevent a repetition. Below is Ida Falls Gully, where there were a number of small coal mines, with their own railway branch lines. The original 3rd level of the Zig Zag can be seen below, still at 1 in 42 gradient. Heavy trains out of Lithgow still have extra locomotives to push the train up and over the steepest part of the hill, when they get onto easier grades the extra locomotives used to be detached and returned to Lithgow. In latter years this is no longer the case as there are no service facilities in Lithgow.

Oakey Park is below to the right, originally a mining town, now a suburb of Lithgow, with the Zig Zag school and the Zig Zag brewery named after the railway. The mines supplied most of the coke for the Lithgow steelworks. Nearby is the water treatment works where they pump water out of flooded mines, treat it and put it into the water supply. Lithgow was particularly known for coal mining, but also had many other industries, including the first Australian steel works, before it was moved to Port Kembla. The Lithgow area mines provide a lot of coal, a major export industry, as well as supplying the local power stations servicing both the local area and Sydney.

Beside No. 2 Viaduct

Just before reaching No. 2 viaduct there is a stepped pyramid rock with a pointed end, where the Engineer in Chief, John Whitton, sat to control the works. This is Engineer's Lookout. He could set out his plans on the rocks, and signal to the various work groups by means semaphore or heliograph, or send runners or men on ponies.

Bottom Points Station

At the approach to the station is Bottom Points Signal Box. This signal box was formerly beside the main line not far from the main line Zig Zag Platform. It was gradually leaning towards the main line because of vibration from heavy coal trains. NSW State Rail sold the signal box to Zig Zag Railway for a dollar in the early 1990s and it was moved to the present site. Previously it had been moved from an earlier site to its site beside the main line.

Bottom Points Station is at an altitude of 994m. (3260'), the difference between Bottom Points and Top Points being 31m. (102'), and the difference between Bottom Points and Clarence being 121m. (398').

Down the hill is the Zig Zag Railway Depot where engines and carriages are maintained and overhauled. Visitors are welcome to walk around the Depot but are asked to remain on the designated paths, and not climb on any of the equipment.

Zig Zag Railway Co-op

The railway is a Co-operative is owned and run by its volunteer members, with a small number of employed staff. The railway is always looking for volunteers, anyone interested in joining can do so, any assistance is always welcome, either in person, or financial.

It came into being through a group of young men in the 1970s who wanted to run steam trains again on the Great Lithgow Zig Zag. In 1972 they formed the  Co-operative; the first train ran 18 October 1975, 106 years after it was originally opened. The current General Manager was one of those founder members.