A railway practice of switching engines for a smooth change in the direction of a train saved some lives on the ill-fated Kanchenjunga Express, conversations with passengers and railway officials suggested.

Kamal Chowdhury, 52, was on S9 coach of the Kanchenjungha Express. The reserved sleeper coach was towards the end of the train when Chowdhury and his family boarded it in Agartala.

On Sunday evening, at Lumding station in Assam, the engine of the train switched sides. A railway official said it was nothing unusual. The engine was switched because the train reversed its direction — towards NJP — from Lumding.

Chowdhury said his coach now became the fifth coach behind the engine, at the front of the train. Around 14 hours later, a goods train rammed into the rear of the Kanchenjunga Express.

“From when the train left the accident site till it reached Sealdah, we kept thinking about one thing — had the train not changed its direction, we would have been in a rear coach, possibly one of the coaches that derailed after the crash,” said Chowdhury, who lives in Agartala and was headed to a relative’s wedding in Nadia.

After reaching Sealdah early on Tuesday, Chowdhury boarded a Gede local at 4.20am. By forenoon, he had reached his destination.

In railway parlance, the practice of switching the position of the engine is called “end reversal”, officials said. “Initially, the engine of the train was facing Lumding, towards the east. But NJP is towards the west. So, the locomotive was detached from one end of the rake and attached to the other end,” the official said.

Another passenger on the S9 coach, who requested not to be named, echoed Chowdhury. “We would have been in grave danger had the train not changed direction from Lumding,” said the middle-aged man, who was headed to Tamil Nadu. He is spending a night in Calcutta and will take a train from Shalimar on Wednesday.

Chowdhury, who works for a local daily in Agartala, was travelling with his wife, sister, and three nephews.

As the train entered NJP station after 8.30am, Chowdhury got off to buy tea and some snacks. Back in the coach, he barely had the first sip when there was a deafening thud and a massive jerk as the train came to a halt.

The tea spilled on the floor. Chowdhury’s wife fell on his sister and a nephew on the top berth fell down. A minute later, people were shouting outside.

“I rushed out and walked past several compartments. What I saw froze me. The rear coaches derailed. In the mangled coaches, people were writhing in pain and some bodies did not move, laying completely still,” said Chowdhury.

Some local villagers and a group from a nearby mosque were the first to arrive to help the injured, said Chowdhury. Rescue teams from the railways arrived after around two hours, he said.