The Cougal Spiral is a

heritage-listed This list is of heritage registers, inventories of cultural properties, natural and man-made, tangible and intangible, movable and immovable, that are deemed to be of sufficient heritage value to be separately identified and recorded. In many ...

single track railway tunnel and

spiral In mathematics, a spiral is a curve which emanates from a point, moving farther away as it revolves around the point. Helices Two major definitions of "spiral" in the American Heritage Dictionary are:North Coast railway line in Australia that connects New South Wales with Queensland under the Border Ranges near

Richmond Gap Richmond most often refers to: * Richmond, Virginia, the capital of Virginia, United States * Richmond, London, a part of London * Richmond, North Yorkshire, a town in England * Richmond, British Columbia, a city in Canada * Richmond, California, a ...

in the

Kyogle Council Kyogle Council is a local government area in the Northern Rivers region of New South Wales, Australia. The council services an area of and is located adjacent to the Summerland Way and the North Coast railway line, within two hours drive from ...

local government area of New South Wales, Australia. It was built during 1930. It is also known as the Border Loop railway formation and landscape, Cougal To Border Loop and Railway Spiral and Landscape. The property was added to the New South Wales State Heritage Register on 2 April 1999. The railway line needs to climb at a steady

ruling gradient The term ruling grade is usually used as a synonym for "steepest climb" between two points on a railroad. More simply, the steepest grade to be climbed dictates how powerful the motive power (or how light the train) must be in order for the run to ...

from

Kyogle Kyogle () is a town in the Northern Rivers region of northern New South Wales, Australia. It falls within the local government area of Kyogle Council. At the 2016 census, Kyogle had a population of 2,751 people. Kyogle is known as a "gateway" ...

to the summit at a tunnel at the border between the two states. The border is also at the watershed. The rail spiral and associated facilities are located between from

Sydney Central railway station Central is a heritage-listed railway station located in the centre of Sydney, New South Wales, Australia. The station is the largest and busiest railway station in Australia and serves as a major transport interchange for NSW TrainLink inter-c ...

Description

Climbing almost non-stop at the ruling grade of 1 in 66 or 1.5% ( compensated) the line has almost continuous curves of radius. Near Cougal, the alignment finally runs out of valley, and has nowhere to go. Fortunately a convenient hill allows the line to circle back on itself so that it climbs without having to make any forward progress. The common name of 'Border Loop' for the Cougal Spiral has itself led to ambiguity in descriptions of the feature itself. The single rail line heading north makes a spiral round this hill, mostly comprising surface track plus two short curved tunnels (one where it passes under itself, the other through a small spur in the hillside). The surface line travels a further north to cross the state border under the Border Ranges by passing through a longer, straight summit tunnel. Soon after the Border Tunnel under the watershed is reached the line curves westward and descends on the other side. A lower summit, perhaps without the spiral, would have been possible with a considerably longer and more expensive summit tunnel, with the possibility of problems with fumes for both the original steam locomotives and the replacement diesel engines. The Cougal Spiral is easily viewed from parts of the

Lions Road The Lions Road is a section of the road running between the Summerland Way in New South Wales and the Mount Lindesay Highway near Rathdowney, Queensland at Running Creek. It joins two pre-existing sections of rural road, namely Gradys Creek Ro ...

. The structure has been heritage listed due to its historical, scientific and architectural rarity. It opened on 29 August 1930 as part of the extension of the North Coast line from

to South Brisbane. The Cougal Railway Spiral and Landscape consists of the following elements: *a concrete tunnel, located from from Central; *a concrete tunnel, located from from Central; *an underbridge, constructed of five steel spans RSJ on concrete

piers Piers may refer to: * Pier, a raised structure over a body of water * Pier (architecture), an architectural support * Piers (name), a given name and surname (including lists of people with the name) * Piers baronets, two titles, in the baronetages ...

, located at from Central; *the Border Loop crossing, located at from Central (no longer extant); and *a tunnel on the border with Queensland, located from from Central. The heritage feature is formed by the whole section of line from Cougal to the Border Tunnel.

History

The 'Border Loop' opened on 29 August 1930, connecting New South Wales and Queensland by rail beneath Richmond Gap.

Heritage listing

As at 19 July 2013, the Cougal to Border Loop section of the North Coast Line was a notable engineering achievement, revealing a twentieth century engineering solution that allows trains to pass through the steep topography at the NSW/Queensland border. The 'Border Loop' railway formation and landscape was listed on the New South Wales State Heritage Register on 2 April 1999 having satisfied the following criteria. The place is important in demonstrating the course, or pattern, of cultural or natural history in New South Wales. The completion of the Cougal Spiral to Border Tunnel section of the North Coast Railway was a major engineering feat in the first half of the twentieth century, being one of several major engineering projects in NSW that allowed continuous railway access between

Sydney Sydney ( ) is the capital city of the state of New South Wales, and the most populous city in both Australia and Oceania. Located on Australia's east coast, the metropolis surrounds Sydney Harbour and extends about towards the Blue Mountain ...

and Brisbane. The place is important in demonstrating aesthetic characteristics and/or a high degree of creative or technical achievement in New South Wales. The combination of tunnels, crossing loops, the underbridge and spiral together form a technically significant example of an innovative and successful railway engineering solution. The place possesses uncommon, rare or endangered aspects of the cultural or natural history of New South Wales. The railway spiral at 'Border Loop' is one of only two railway spirals in NSW.

References

Attribution

External links