Here is a pic of the interiors of the 1400 HP HHPDEMU that was being tested between Chennai and Gummidipundi around 2 years back. The coaches are loaded to 200% of the design limits using sand bags (loaded the previous day at Doravarichatram near Naidupettah - this place almost skirts the sea, hence plenty of sand!) The wiring, etc. you see are the ones laid by the RDSO who were observing the acceleration, load, speed and oscillation trials. The large black item on the right is a loudspeaker. This was part of an intercom system between the RDSO gang in the driving cab and the recording crew "Mishraji, jara reading note kariye...". Photo by Apurva, 2001