Wikipedia will not tell you, but the Indian Railway History Book will. Sutlej Express, introduced in 1921 originally ran from Ludhiana to Samasata (Lodhran) via Phillaur-Nakodar-Lohian Khas-Firozpur-Kasur-Burewala-Maisli-Lodhran until 1947. After partition of Punjab in 1947, the route of Sutlej Express was changed via Moga-Firozpur-Kasur-Maisli-Lodhran. At first until 1947, this train used to cover 552 kms in 11 hrs 45 mins & was a overnight train. But from 1947-65 period the route got changed via Moga & the train started covering the distance of 533 kms in 11 hrs 40 minutes & was made into day train. After India Pakistan War of 1965, train services to Pakistan were permanently closed & Sutlej Express route lost 409 kms running distance between Samasata & Ganda Singhwala. The Stanford Bridge, the 1600 mtrs long road cum rail bridge on Sutlej River in Hussainiwala was blown up in the war & was never remade. Sutlej Express...
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was confined to run between Firozpur & Ludhiana via Moga until it got extended to Chandigarh in 2015.
Pictures below
1. Indian Railways a Visual Journey History Book Cover Page.
2. 1444 mtrs long Sutlej Bridge in Pakistan between Lodhran & Samasata.
3. Remains of Stanford Bridge in Hussainiwala.

The Railway Route forcefully vanished. A Story of Firozpur-Kasur-Khem Karan-Amritsar Railway line. (From Indian Railway History book)
A. Introduction:- Its been 74 yrs since the last train services ran on Jammu-Sialkot-Narowal-Dera Baba Nanak-Amritsar, Faridkot/Ludhiana-Raiwind-Lahore, Amritsar-Khem Karan-Kasur-Firozpur/Lodhran & Muktsar/Bhatinda-Bahawalpur-Samasata routes. But partition changed everything.
Partition in 1947:- The partition line drawn, planned & recommended by Sir Radcliff, had many important places of Punjab in India. Details as follows:-
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On the Faridkot/Ludhiana-Raiwind-Lahore line, Ganda Singhwala & Kasur Jn. was slated to be part of Indian Punjab. 2. On the Amritsar-Khem Karan-Kasur-Firozpur/Lodhran railway line, Kasur Jn. was inside India. Kasur was slated to be part of Indian Punjab. 3. On the Jammu-Sialkot-Narowal-Dera Baba Nanak-Amritsar railway line, Sialkot, Narowal, Jasar, Kartarpur, Shakargarh & Chak Amru was slated to be part of Indian Punjab. 4. On the Muktsar/Bhatinda-Bahawalpur-Samasata railway line, Amruka, Mandi Sadiqganj, Qasamwala & Bahawalnagar were slated to be part of Indian Punjab.
B. Partition Went Wrong:- Alas, when the partition line was implemented it was found that Ganda Singhwala, Kasur, Sialkot, Narowal, Jasar, Kartarpur, Shakargarh, Chak Amru, Amruka, Mandi Sadiqganj, Qasamwala & Bahawalnagar were given to Pakistani Punjab rather than Indian Punjab. This snapped important legendary trains, running before the partition & short terminating the routes. Trains like Punjab Mail from Peshawar/Lahore to Kolkata via Amritsar-Lucknow-Varanasi & Punjab Mail from Peshawar/Lahore to Mumbai via Faridkot-Bhatinda-Delhi, Frontier Mail from Peshawar/Lahore to Mumbai via Amritsar-Saharanpur-Delhi, The Grand Trunk Express from Peshawar/Lahore to Mangalore via Amritsar-Delhi-Chennai & The Chenab Express from Jammu to Lodhran via Sialkot, Narowal, Dera Baba Nanak, Amritsar, Khem Karan & Kasur were stopped. Although Punjab Mail to Kolkata, Punjab Mail to Mumbai & Frontier Mail to Mumbai from Lahore ran till 1965, their importance plummeted greatly. Only the Bahawalpur Express from Bhatinda to Samasata via Muktsar-Fazilka-Mandi Sadiqganj-Bahawalpur, the Bahawal Express from Delhi to Bahawalnagar via Bhatinda-Abohar-Hindumalkot-Mandi Sadiqganj, Satluj Express from Ludhiana to Lodhran via Moga-Firozpur-Kasur & Ravi Express from Shorkot Cantt. to Pathankot via Nankana Sahib, Sheikhupura-Lahore-Amritsar-Gurdaspur were successfully running until 1965 war permanently closed the journey in Pakistan soil.
Post 1965 War:- Punjab Mail to Howrah & Frontier Mail to Mumbai had their terminal points changed to Amritsar. Punjab to Mumbai had its terminal changed to Firozpur Cantt. Bahawalpur Express permanently became a Pakistani Train running from Bahawalnagar to Sialkot via Lodhran-Khanewal-Raiwind-Lahore-Narowal. Bahawal Express was permanently withdrawn from service with Satluj Express becoming the only train running between Firozpur & Ludhiana(Now Chandigarh). Ravi Express was confined to run between Pathankot & Khem Karan, later in between Amritsar & Pathankot only.
Conclusion:- Just the blunder during implementing partition of Punjab, which happened not as per the plan & recommendations of Sir Radcliff, but as per Indian Political leaders wishes ruined Firozpur-Kasur-Khem Karan-Amritsar Railway forever.

Member No. 226565 got this Book as a Birthday Gift from his Sis yesterday.