Manilla railway underbridges

Manilla railway underbridges
Coordinates	30°38′51″S 150°39′25″E / 30.6475°S 150.6569°E / -30.6475; 150.6569
Carries	Tamworth-Barraba railway line
Crosses	Borah Creek Oakey Creek
Locale	Manilla, Tamworth Regional Council, New South Wales, Australia
Owner	Transport Asset Holding Entity
Characteristics
Design	Howe truss underbridges
Material	Timber
Pier construction	Concrete and timber
Longest span	10.4 metres (34 ft)
No. of spans	7
Rail characteristics
No. of tracks	One
Track gauge	4 ft 8+1⁄2 in (1,435 mm) standard gauge
History
Contracted lead designer	NSW Government Railways
Constructed by	NSW Department of Public Works
Construction end	1908
New South Wales Heritage Register
Official name	Manilla railway underbridges
Type	State heritage (built)
Designated	2 April 1999
Reference no.	1045
Type	Railway Bridges / Viaduct
Category	Transport – Rail
Location

The Manilla railway underbridges are two heritage-listed railway bridges located on the Tamworth-Barraba railway line in the town of Manilla in the Tamworth Regional Council local government area of New South Wales, Australia. The underbridges are owned by Transport Asset Holding Entity, an agency of the Government of New South Wales. The two sites were added to the New South Wales State Heritage Register on 2 April 1999.^[1]

The bridges includes two structures, one located at Upper Manilla across the Borah Creek; and the other across the Oakey Creek.^[1]

The Borah Creek Bridge is a Howe timber truss railway underbridge located at Upper Manilla across the Borah Creek, situated 575 kilometres (357 mi) from Sydney Central station, erected in 1908.^[1] The bridge is seven spans in length, with the three central spans constructed with 10-metre (34 ft) span Howe-Deck timber trusses. The trestles are supported on concrete sills.^[2] Opened in 1908, it has three 10.4-metre (34 ft) timber truss spans and is a good example of the 9.8–10.7-metre (32–35 ft) deck Howe truss. This type of truss bridge was introduced in 1902 and used until 1908. Other examples are across the Murrumbidgee River at Gundagai (1905), and at Oakey Park, 17 kilometres (11 mi) north of the present bridge. The bridge is of considerable technological significance. The bridge carries a single-track 4 ft 8+1⁄2 in (1,435 mm) standard gauge railway on an open deck (with transoms). The spans are 4.3 metres (14 ft), three at 10.4 metres (34 ft), 6.7 metres (22 ft), and 4.3 metres (14 ft), of which the three larger spans are timber trusses and the other timber girders. The trusses are deck-type Howe trusses of the 9.8–10.7-metre (32–35 ft) deck-type, with timber compression diagonals, steel tie rods for the verticals and five bays. The piers are timber, with concrete bases. The bridge was listed on the (now defunct) Register of the National Estate on 18 April 1989.^[3][4][5]

The Oakey Creek Bridge is a Howe timber truss railway underbridge located at Upper Manilla across the Oakey Creek, situated 539 kilometres (335 mi) from Central station, also completed in 1908.^[1][6] The bridge is a significant technical accomplishment. It was opened in 1908 and has five 10.4-metre (34 ft) timber truss spans. It is a good example of the 9.8–10.7-metre (32–35 ft) deck type Howe truss, introduced in 1902 and used until 1908. Other examples are across the Murrumbidgee River at Gundagai (1903) and at Borah Creek, 17 kilometres (11 mi) south of the present bridge. The bridge carries a single-track 4 ft 8+1⁄2 in (1,435 mm) standard gauge railway on an open deck (with transomes). The spans are 7.3 metres (24 ft), five at 10.4 metres (34 ft) and 7.3 metres (24 ft), of which the five larger spans are timber trusses and the others timber girders. The trusses are deck type Howe trusses, of the 9.8–10.7-metre (32–35 ft) deck type, with five bays, timber compression diagonals and steel tie rods for the verticals. The piers are timber. The bridge was listed on the (now defunct) Register of the National Estate on 18 April 1989.^[7][4][5]

The bridges were constructed in timber because of the remote location and constraints on cost, particularly related to branch line construction. They are two of the relatively few surviving timber bridges left in the State and are of considerable significance.^[1]

The Manilla railway underbridges were listed on the New South Wales State Heritage Register on 2 April 1999 having satisfied the following criteria.^[1]

The place possesses uncommon, rare or endangered aspects of the cultural or natural history of New South Wales.

This item is assessed as historically rare. This item is assessed as scientifically rare. This item is assessed as archaeologically rare. This item is assessed as socially rare.^[1]

• Barraba railway line
• William Howe (architect)

• This Wikipedia article was originally based on Manilla railway underbridges, entry number 01045 in the New South Wales State Heritage Register published by the State of New South Wales (Department of Planning and Environment) 2018 under CC-BY 4.0 licence, accessed on 2 June 2018.
• This Wikipedia article contains material from Upper Manilla, Borah Creek Underbridge, entry number 3150008 in the New South Wales Heritage Database published by the State of New South Wales and Office of Environment and Heritage 2016 under CC-BY 4.0 licence, accessed on 28 April 2020.
• This Wikipedia article contains material from Barraba (Ennisdale), Oakey Creek Underbridge, entry number 3150105 in the New South Wales Heritage Database published by the State of New South Wales and Office of Environment and Heritage 2016 under CC-BY 4.0 licence, accessed on 28 April 2020.

• Fraser, Don (1995). Bridges down under: the history of railway underbridges in New South Wales.
• O'Connor, Colin; Australian Heritage Commission; Institution of Engineers, Australia (1983). Register of Australian historic bridges. Institution of Engineers, Australia. ISBN 978-0-85825-231-8.
• O'Connor, Colin (1985). Spanning two centuries: historic bridges of Australia. University of Queensland Press. ISBN 978-0-7022-1798-2.