Chord line is defined a straight line connecting the leading and trailing edges of an airfoil which should then mean chennai and trichy is connected by straight line through virudachalam hence the name chord. The other line through cuddalore takes slightly more distance of around 40 km. Until 1927, Viluppuram Junction and Tiruchirappalli Junction were only connected by Main line that traversed through Kumbakonam and Mayavaram, which was 240 kilometres (150 mi). Hence, the need for shorter route arose and construction began on 22 August 1927 for a new railway line via Virudhachalam Junction in phases. Initially, the stretch between Viluppuram Junction and Virudhachalam were completed and opened on 1 December 1927, the Srirangam - Golden Rock stretch on 22 August 1927, Bikshandarkoil - Srirangam stretch on 12 December 1927 and the entire stretch began its operations since 1 February 1929. One of the popular train in main...
more... line is Cholan express. The grandpa boat mail exp also travels in main line. I have traveled numerous time in chord line and only once in main line some 20 years back. The super star of chord line is vaigai exp. Like TN exp vaigai is also known rather controversially for speed since its inaugration 40 years ago. Main line opened up in 1880 and chord line in 1929. Though it is stated that main line opened up in 1880 actually it opened up more before in 1862. This history says like this - In 1861 the Great Southern Railway of India built the 125 km (78 mi)-long 1,676 mm (5 ft 6 in) wide broad-gauge line between Nagapattinam and Tiruchirapalli (then known as Trichinopoly) and the line was opened to traffic next year. It was a new development south of Chennai. Spectacular and colourful history indeed for Trichy which was second largest town as per 1871 census taken by Madras presidency next only to Madras ! Trichy which is now part of SR was once indian HQ of south indian railway company which was registered in 1890 at London !!! Before 1964 people used to travel in boat mail exp till rameshwaram, cross the sea in streamer to talaimannar, continue journey then into ceylon in their train. After 1964 danushkodi cyclone which destroyed part of tracks there this practice was discontinued and now it runs up to rameshwaram :( Many of you must be aware of places in chord line only. FYI the following important towns are located in main line after Villupuram and they are Panruti, Tirupadripuliyur, Cuddalore port jn, Chidambaram, Sirkazhi, Vaithiswaran koil, Mayiladuthurai, Aduthurai, Kumbakonam, Papanasam, Thanjavur, Budalur and finally Trichy ! Tirupadripuliyur also serves cuddalore besides pondicherry also which is just 23.4 kms away !! Trichy is 336 kms in chord line and 401 kms in main line, just see the difference !
