# Chord Line, Tamil Nadu

The Chord Line connects Viluppuram Junction and Tiruchirappalli Junction, via Virudhachalam Junction in Tamil Nadu. It is the shortest, busiest and most vital route connecting Chennai Egmore and Southern Tamil Nadu.

## History

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. This line gradually reduced the Madras - Colombo journey by around four hours.

## Gauge conversions

The conversion from metre gauge to broad gauge was effected during 1992-93 and completed during September 1998.

## Introduction of EMD diesel locomotives

10 years post the gauge conversion, in 2008, Southern Railway decided to introduce new advanced hi-tech state-of-the-art EMD GT46PAC aka WDP-4 diesel-electric locomotives, powered by a record-breaking 4,000-horsepower (3,000 kW) 16-cylinder EMD 710G3B diesel engine, equipped with a 3-phase AC Traction with a top speed of 180 kmph, to haul some of their top Express services, another reason being the electrification on the Viluppuram-Vriddhachalam-Trichy section was still pending as well. With Krishnarajapuram (KJM) & Hubballi (UBL) diesel loco sheds belonging to South Western Railway zone (SWR) getting more of these locomotives, the then General Manager of SR, Shri V. Anand, took the initiative to speak to SWR, to allot WDP-4 links to the Chord line express services, starting with the pristine Pandian Express, followed by Guruvayur Express, Nellai Express, Pothigai Express and since 2009-10, even Vaigai Express, to train the Piloting Crew of Chennai, Trichy and Madurai railway divisions with EMD locomotives. 4-5 Pairs of WDP-4 locomotives (8-10 locos totally) worked on the Chord Line per day, Individually, with WDP-4 Multiple Units as "twins" supplied occasionally, making it up to 9-11 locos in a day. 2-3 trains on the Electrified Bangalore-Chennai Main Line, including the Sanghamitra Superfast Express (which then ran from Bangalore to Patna via Reversal at Chennai Central), ran on WDP-4 (or WDP-4 Twins occasionally), to supply them to Chennai division. This practice happened till late 2011, until SR's own diesel loco shed at Golden Rock Ponmalai (GOC), belonging to Trichy Division, got its own passenger hauling EMD WDP-4B locomotives to haul many more further passenger and express services since then.

## Electrification

This stretch was proposed for electrification phase by phase by CORE. The electrification was completed during 2010.

## Operations
### Passenger services

The line experiences a heaviest traffic handling about 30 passenger and 56 express trains passing through every day in addition to goods train, particularly during night.

### Freight services

The line has a number of Industrial establishments which utilises their nearby railway stations for their logistics and transports such as Central Workshop (Golden Rock), Cement and gypsum factories at Trichy, Perambalur and Ariyalur, and the Sugar factories at Villupuram and Vridhachalam,