Trains taking the main line west from Nancha faced easy gradients for the first 35km to Dialing, where the climb over the Dahinggang mountains began in earnest.
QJ 6963 was less than 3 years old when it was caught bowling along the gently graded section east of Wutong with a westbound freight on 7 April 1988. Spring had yet to take hold in China's far north and the river was still largely frozen.