There were 37 tunnels on this stretch. Near Jatinga, there was also the steepest railway gradient in the world. As the train zigged and zagged, those steam engines had a system of catching, which meant another engine at the rear for pushing. As a child, because my father worked in that part of the world, I recall travelling quite a bit along the hill section. You watched out for tunnels, dark and forbidding. As soon as the train entered a tunnel, there were howls, not from passengers, but from other creatures, residing in the tunnels. I was told these were "ullukas". Until much later, I never quite figured out what 'ullukas' were. They couldn't have been owls ('ullu' in Hindi or 'uluka' in Sanskrit). These were Hoolock gibbons, found all over the northeast. (If you want to see one, your best chance is in Balpakram National Park in the Garo Hills.) If I remember right, the hill section then had the longest railway tunnel in India, between Haflong and Jatinga and well over 3 km, probably closer to 4 km. If I remember right again, it was famous as tunnel no 10. You leant out of the window, heard the gibbons, smelt the smoke and got coal dust and soot in your hair.
Those were the days. But after Independence, those weren't quite the days. This metre gauge line was the only means of railway access for Tripura, Mizoram and parts of Manipur and Assam's Barak Valley, as connections through Bangladesh had been severed. The Agartala-Akhaura railway project has now been revived and once that is completed, the Agartala-Kolkata railway distance will become 515 km, compared to the present 1,650 km. To return to Lumding-Badarpur, from metre gauge, this was to be converted to broad gauge, under Indian Railways' unigauge project. This isn't just about Lumding-Badarpur, it is about the entire 210-km-long Lumding-Silchar stretch, with additional lines that connect other northeastern states. By 2020, all northeastern states are projected to be connected through railway networks. For example, Meghalaya was connected in November 2014. Arunachal Pradesh was connected in February 2015 and so on. The Lumding-Silchar gauge conversion was thought of in the 1980s and formally sanctioned in 1996. Because of this, the train between Lumding and Lower Haflong, Hill Queen Express, had its last run in September 2014, amidst a lot of nostalgia. Other than northeastern connectivity, the Lumding-Badarpur metre gauge portion had become a bit of an anomaly, as Guwahati-Lumding-Dibrugarh-Tinsukia had become broad gauge by 1997.
The years 1996 to 2015 is a long time. Let's not get into post-mortems of why it took so long. There was opposition, seeking to ensure that the heritage status of hill section was preserved. There were law and order issues. In the 1890s, the British faced much worse. To celebrate 150 years, Indian Railways commissioned a book. This was by Arup Kumar Datta and titled Indian Railways: The Final Frontier. This was released in 2002 by the then railway minister and documents what the British had to go through in the Northeast. All problems were sorted out and in March 2015, the current railway minister inaugurated the broad gauge Lumding-Silchar line by flagging off a goods train, via a video conferencing link. But there is a catch. There is a Commission of Railway Safety, independent of the railway ministry and under the administrative control of the civil aviation ministry. Having inspected the line (specifically the Lumding-New Halfong section), the commissioner of railway safety said this bit was unsafe for passenger traffic. After having taken such a long time and spent an estimated Rs 5,500 crore on upgrade, how can there be nine derailments and 14 instances of track-subsiding in the four months that this line has been opened for goods traffic? As far as I can understand, Indian Railways has promised that these problems will be sorted out by November 2015. But questions about quality of construction remain.