At just before 7pmT on Tuesday 1 March, the train was travelling by Old Mill Road, Cambuslang, when an object was thrown at the side window of the driver’s cab.
The window smashed, and glass covered the driver as a result.
Officers are keen to speak to anyone who was in the area at the time of the incident or anyone with information that could assist their enquiries.
Witnesses, or anyone with information, can contact BTP by texting 61016 or calling 0800 40 50 40 quoting reference 484 of 01/03/22.