The bridge was opened in 1887 and named after HRH Louise Margaret, the Duchess of Connaught, who opened it.
IRFCA  records that :-
“The first railway link to Quetta was inaugurated in 1886 via Bolan Pass. A year later another rail route to Quetta was opened via Harnai, Khost, Chappar Rift and Bostan. This route through Chappar Rift, though non-existent today, has been considered one of the most revered engineering projects in this part of the world ....The Railway line served as an alternate route to Quetta for about 55 years. On the night of July 10, 1942 there was a flash flood in the area which swept away the scree bank in the Chappar Rift. With the scree slope washed away there was nothing left for the railway to be laid upon.”
- The Chappar Rift irfca.org
- "Chhappar: born of an earthquake" by Salman Rashid April 18, 2013
- Photographs: Railways of the Raj Balochistan Archives on flickr.com. Originally from the Library of Congress USA
- IRFCA I’Indian Railways Fan Club’ ; Retrieved 18 Dec 2020