Outer Circle Line (EDR)
The Outer Circle Line (外寰綫, mngwats-gwrin-stsin) is a circular route on the Exchequer and District Railway, being completed in 1997 in its current form. The line has a length of 26.7 km and girds the lines of the EDR network that radiate towards Kien-k'ang suburbs.
The Outer Circle Line stands in contrast to the original Circle Line, which is on the Metropolitan and Market lines of the KRT network, rather than the regional/suburban-oriented EDR network. The (Inner) Circle has a length of 5.7 km and is nested within the Outer Circle.
History
Included within the plan of the original Super Metro System, as proposed in 1961 and revised in 1964, is a relief line that incorporates parts of the right of way of the Kim-mar freight line that crosses the southern reaches of central Kien-k'ang and Lats-lin (annexed by Kien-k'ang in 1957). The line would serve the triple purposes of:
- Storage for more numerous upbound trains that arrive in the morning from the suburbs
- Cross-city service in the developing south, which lacked a service in this direction
- In case of blockage or need to operate trains between lines, a bypass between them
This would eventually form the southern half of the Outer Circle and was completed in 1971 shortly following the central sections of the Super Metropolitan in 1969 – 70. Platforms on the line were built with both the Super Metropolitan and Red lines in mind and enable cross-platform transfer. At the time of completion, it was called the South Link.
At the same time the Green line was under planning in the 1980s, it was proposed to transform the South Link into a circular line to provide lacking transit options in the city's north, which was exclusively oriented to the city-centre. Unlike the South Link, the North Link was mostly built elevated, as there was no pre-existing right-of-way to utilize; it goes into a tunnel across the Kaung to meet with the South Link at Pran-rang station.
Stations and route
The Outer Circle is 22.7 km long and comprises 20 stations. All sections of the line are double-track.