In what formations do EMUs run?
Many different EMU formations have been used in different areas. In the 1930’s, Madras suburban service started with 3-car EMUs which were notable in having coupled bogies across cars, thereby making the entire 3-car formation a rigid unit. Later Madras also got some 4-car (non-rigid) EMUs. They were sometimes operated in pairs at rush hours, leading to 6-car (two rigid) and 8-car (two non-rigid) formations, and rarely 7-car formations (one 3-car rigid and one 4-car) In the 1960’s Madras received a couple of 2-car EMUs. Following the conversion of the traction from DC to AC, the 3-car EMUs (which were built for DC) were coupled with a single AC power car to make hybrid 4-car formations. More recently 12-car (4+4+4) formations have been common. In these, the power car is usually one of the middle cars in a 4-car unit. NR uses 12-car formations for some long EMU runs (e.g., Ghaziabad-Mathura). 10-car formations were seen rarely (two 3-car rigid EMUs with a 4-car EMU) in Madras. While the
