Chennai Area Gauge Conversion

by Bharath Moro, May 2005

The Chennai area was unique on IR. It was the only section on IR to have electrified MG lines and MG EMU's. However, with the city growing rapidly and the MG lacking sufficient carrying capacity, it was decided that all MG networks around the city will be converted to BG. The article below sheds some light on the conversion process and also the early years of suburban services in the city

Pre 1950's

With the city growing in size and importance, the government of the day felt the need to introduce suburban train services connecting the commercial Northern part to the mainly residential south-western parts of the city. Accordingly in 1928, work begins on constructing two meter gauge lines between Madras Beach and the southern suburb of Tambaram. Initially, the planners seek to run the services using steam locomotives, but in early 1930 a decision is taken to electrify the lines. In addtion, the mainline starting from Madras Egmore is also electrified.

By March 1931 construction of the lines is complete and on May 11, the first MG EMU services are run on 1.5kV DC. These EMU's, built by Metro Camell are wooden bodied and rigid. Later during the year, mainline DC locomotives(YCG) are introduced to haul freight from the harbour to Tambaram.


Madras Beach - Tambaram - Villupuram is converted from 1.5kV DC traction to 25kV AC traction, with the suburban services also switching over. With the change in traction, new ICF built EMU's with motors and electricals from Toshiba/Hitachi are introduced. Additionally, two services per day are extended to Chengalpet. In late 1967, a Toshiba/Hitachi/Mitsubishi combine delivers YAM-1 #21904, the first MG 25kV AC locomotive. In 1969, work begins on laying an additional MG track between Tambaram and Chengalpet. This work is completed by January 1971.

1990 Onwards

In early 1991, with the city growing rapidly, plans are drawn to convert the entire Beach - Tambaram section to BG. The state government proposes a 50:50 joint venture with IR. The first step in the conversion process begins in 1992 with the laying of a BG line between Beach and Tambaram. By February 1993, the work is complete and the section now has three MG lines and a single BG line. Of these, two MG lines are exclusively used for suburban EMU traffic. The additional MG line handles mainline express and passenger trains while the lone BG line is used for suburban purposes.

With work going on steadily in the Chengalpet - Villupuram - Tiruchirapalli gauge conversion project, a decision is taking in 1998 to convert one of the MG lines between Tambaram and Chengalpet. However, large scale protests by commuters over the conversion causes Southern Railway to change it plans. Accordingly, the "down" MG line (easternmost out of Tambaram) is converted to BG and a new parallel MG line is laid. Work on the new BG is completed within a year and by late 1999, there are two MG lines and one BG line between Tambaram and Chengalpet. Electrification on this new BG line doesn't happen until late 2000.

In 2000, SR starts conversion of the MG mainline between Egmore and Tambaram. Mainline passenger and express trains that started and terminated at Egmore are shifted to Tambaram. To cope with the increase in traffic, Tambaram sees two additional MG lines built! With the entire Egmore-Tambaram-Trichy-Dindigul-Madurai gauge conversion complete, SR commisions BG passenger traffic in March 2001. With this, the south western suburban route in Chennai features four lines -- 2 MG and 2 BG. In Dec 2001, work begins on the Chengalpet - Villupuram BG line electrification.

December 2002 - work on conversion of two MG lines between Egmore and Beach is taken up. Heavy rains and tight curves delays the project for about a month but SR manages to complete all works by February 2002. With this, MG EMU's start terminating at Egmore. BG EMU service frequency between Beach and Tambaram is increased. Now isolated, the spur MG lines around Beach, Royapuram and Washermanpet are also dismantled. With this, one of the last few remaining strecthes of gauntleted tracks in IR disappears.

In February 2003, one MG line between Tambaram and Chengalpet is taken up for conversion. After delays over finances, this work is completed by December 2003. Passenger traffic (BG EMU's and mainline expresses) start using the line. At the end of 2003, various lines in the Beach-Chengalpet section were as follows.

  1. Beach - Egmore : 3 Broad Gauge
  2. Egmore - Tambaram : 2 Broad Gauge, 2 Meter Gauge
  3. Tambaram - Chengalpet : 2 Broad Gauge, 1 Meter Gauge

On 1 July 2004, the last MG EMU services between Tambaram and Egmore are run. Work now begins on converting the 30km stretch between these two stations to BG. SR also decides to suspend regular service of the YAM-1 locomotives from this day. All MG mainline trains switch over to diesel traction.

On November 1 2004, BG EMU services are inagurated on the newly converted lines. SR brings in 15 additional new rakes from ICF to service this line.