Emu Plains Underbridge facts for kids
Quick facts for kids Emu Plains Underbridge |
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The railway bridge at Penrith, c. 1920 – c. 1927, from the Broadhurst collection of postcards
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| Coordinates | 33°44′45″S 150°40′54″E / 33.7459°S 150.6818°E |
| Carries | Main Western line |
| Crosses | Nepean River |
| Locale | Off Bruce Neale Dr, 1.3 kilometres (0.81 mi) west of the Penrith railway station, Penrith, City of Penrith, New South Wales, Australia |
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| Owner | RailCorp |
| Preceded by | Victoria Bridge |
| Characteristics | |
| Design | Pratt Truss railway underbridge |
| Material | Steel |
| Pier construction | Brick |
| Longest span | 58.8 metres (193 ft) |
| Number of spans | 5 |
| History | |
| Designer | James Fraser |
| Contracted lead designer | New South Wales Government Railways |
| Constructed by | Labourers |
| Fabrication by | R. Tulloch & Co. |
| Construction end | 1907 |
| Replaces | Victoria Bridge (converted to motor vehicle use) |
| Official name: Emu Plains (Nepean River) Underbridge; Penrith (Nepean River) Underbridge | |
| Type: | State heritage (built) |
| Designated: | 28 June 2013 |
| Reference #: | 1830 |
| Type: | Railway Bridge/ Viaduct |
| Category: | Transport - Rail |
| Builders: | Fabrication by R. Tulloch & Co.; erection by day labour |
The Emu Plains Underbridge is a special railway bridge in Penrith, Australia. It is built from steel and is known as an "underbridge" because the railway tracks run on top of its main structure. This bridge crosses the Nepean River and is a very important part of the Main Western railway line. It was designed by James Fraser and built in 1907. The bridge is also called the Emu Plains (Nepean River) Underbridge or Penrith (Nepean River) Underbridge. It is so important that it was added to the New South Wales State Heritage Register in 2013.
Building the Emu Plains Underbridge
The Main Western Railway Line connects Granville to Bourke. It was finished in 1885. By 1900, some parts of this railway were getting very busy. The single track could not handle all the trains. This included the section from Emu Plains to Bathurst. More tracks were needed to make train travel smoother.
What is a Pratt Truss?
The Emu Plains Underbridge uses a special design called a Pratt truss. This type of bridge design came from the United States in 1892. It became very popular for main railway lines in Australia. Pratt trusses are strong and efficient. They use steel rods or bars that are good at handling pulling forces. This made them much better than older bridge designs, especially for long spans. The New South Wales Railways used steel Pratt trusses for big bridges until the 1970s.
Why a New Bridge Was Needed
The first railway bridge over the Nepean River was built in 1867. It was made of iron and designed for two tracks, but only ever used one for trains. The other side was used for road traffic. As trains became heavier and more frequent, this old bridge was not strong enough. Also, a single track was causing too much traffic.
Instead of adding more piers in the river, which could cause problems, the decision was made to build a brand new, stronger bridge for the railway. The old bridge was then fully converted for road traffic. This is still how they are used today.
The Designer: James Fraser
The new railway bridge was designed by James Fraser. He was a very important engineer who later became the Chief Railway Commissioner. Fraser joined the New South Wales Government Railways in 1881. He designed the new bridge to be extra strong. It could handle trains that were twice as heavy as those at the time. This was a smart move, as it meant the bridge would not need replacing even as trains got bigger.
Fraser's bridge, built in 1907, is still used today. It carries modern, heavy diesel trains and wagons full of coal and wheat. The bridge was built by R. Tulloch & Co., a local company. This showed that local steelworks could handle very large projects.
How the Bridge Was Built
Building a bridge over a flood-prone river can be tricky. Instead of using lots of temporary supports in the water, James Fraser chose a clever method. The bridge sections were built continuously from one river bank to the other. They went over the main piers and some temporary wooden supports. Once the whole structure was complete, the linking parts over the piers were removed. This turned the bridge into five separate, strong sections. This method helped avoid delays from floods.
Bridge Features
The Emu Plains Underbridge has five sections, called spans. It is a double-track bridge, meaning two railway tracks run across it. The bridge is made of steel and has brick piers (supports) in the river. One span is about 36.6 meters (120 feet) long, and the other four spans are about 58.8 meters (193 feet) long. The older Victoria Bridge from 1867 is right next to it.
Condition of the Bridge
The bridge is in good condition, even after more than 100 years. There are some small cracks and minor rust, but overall, it is very strong. The bridge still looks much like it did when it was first built.
Changes Over Time
- 1961: Service pipes were added to the bridge.
- 1995: A safety platform and walkway were added for maintenance workers.
Why This Bridge is Important
The 1907 Nepean River Underbridge is one of the biggest steel truss bridges in New South Wales. It is also the oldest truss bridge still used by trains in the Sydney area, having been in use for over 100 years. It is a striking landmark over the river.
The bridge is important because it shows how railway bridge design changed over time. It stands next to the 1867 Victoria Bridge. Together, they show the shift from older British bridge technology to newer American designs in the early 20th century.
The bridge is also linked to James Fraser, a key figure in the NSW Railways. His design was very forward-thinking, making the bridge strong enough for future, heavier trains. The way it was built was also innovative. It used special techniques to avoid problems from floods during construction. The fact that a local company, R. Tulloch & Co., built it showed that Australian steelworks could handle huge projects. This bridge became a model for other railway bridges built in New South Wales.
Historical Significance
This bridge is important because it was part of making the Main West Line bigger. It has been used for trains for over a century. The local company that built it proved that Australian factories could handle big projects. This helped them get more work, like building all the bridges for the North Coast Railway.
Association with James Fraser
The bridge is strongly connected to James Fraser. He designed it when he was the chief engineer for existing railway lines. Fraser's idea was to build things strong enough for the future, which made this bridge very long-lasting and cost-effective.
Design and Technical Achievements
The Nepean River Underbridge looks impressive because of its length and long spans. Its location next to the older Victoria Bridge makes both bridges stand out. It is one of the largest truss bridges in New South Wales.
The way the bridge was built was a clever technical trick. Instead of using many temporary supports in the flood-prone river, the builders put the truss sections together continuously. This meant they could build it without worrying too much about floods interrupting their work.
Research Value
These two bridges, side by side, offer a great chance to study how railway bridge design changed from the late 1800s to the early 1900s.
Example of Bridge Type
The Nepean River Underbridge is a great example of a Pratt truss railway bridge. This design was a new technology introduced to the NSW railway network in 1892, coming from American bridge building ideas.
