The Cougal Spiral is a

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

single track Single may refer to: Arts, entertainment, and media * Single (music), a song release Songs * "Single" (Natasha Bedingfield song), 2004 * "Single" (New Kids on the Block and Ne-Yo song), 2008 * "Single" (William Wei song), 2016 * "Single", by ...

railway tunnel Rail transport (also known as train transport) is a means of transport using wheeled vehicles running in railway track, tracks, which usually consist of two parallel steel railway track, rails. Rail transport is one of the two primary means of ...

and

spiral In mathematics, a spiral is a curve which emanates from a point, moving further away as it revolves around the point. It is a subtype of whorled patterns, a broad group that also includes concentric objects. Two-dimensional A two-dimension ...

in Australia. The feature is located on the North Coast railway line in Australia that connects

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

with

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

under the Border Ranges near Richmond Gap. 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 The New South Wales State Heritage Register, also known as NSW State Heritage Register, is a heritage list of places in the state of New South Wales, Australia, that are protected by New South Wales legislation, generally covered by the Heritag ...

on 2 April 1999. The railway line needs to climb at a steady

ruling gradient In railroading, the ruling grade is steepest grade on the rail line between two locations. Climbing the steepest part of the line dictates the minimum motive power needed, or how light the train must be, in order for the run to be made without ...

from

Kyogle Kyogle () is a town in the Northern Rivers region of northern New South Wales, Australia. It falls within the Local government in Australia, local government area of Kyogle Council. At the 2016 Australian census, 2016 census, Kyogle had a popu ...

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.

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 In classical geometry, a radius (: radii or radiuses) of a circle or sphere is any of the line segments from its Centre (geometry), center to its perimeter, and in more modern usage, it is also their length. The radius of a regular polygon is th ...

. 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 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

South Brisbane South Brisbane is an inner southern suburb in the City of Brisbane, Queensland, Australia. In the , South Brisbane had a population of 14,292 people. Geography South Brisbane is on the southern bank of the Brisbane River, bounded to the nor ...

. 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

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 States and territories of Australia, state of New South Wales and the List of cities in Australia by population, most populous city in Australia. Located on Australia's east coast, the metropolis surrounds Syd ...

and

Brisbane Brisbane ( ; ) is the List of Australian capital cities, capital and largest city of the States and territories of Australia, state of Queensland and the list of cities in Australia by population, third-most populous city in Australia, with a ...

. 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