The train had left Thiruvananthapuram at 17.10 hours and reached Kollam around 18.30 hours.
The two loco pilots were taken for standard medical examination, railway officials said.
Another set of loco drivers was summoned for the onward journey of the train, they said.
The incident comes close on the heels of the derailment of the Thiruvananthapuram-Mangaluru Express at Karukutty near Kochi on Sunday.