Relay working operations typically require two crews of train drivers to work a totating 8-h schedule for two or more days. While one crew is driving, the other has the opportunity to sleep onboard the train. The current study investigated the impact of relay work on drivers sleep quantity and quality. Fourteen drivers wore wrist wactivity monitors and completed sleep/wake diaries for 3 d prior to and during short (<48 h) relay trips. Drivers obtained and average of 7.8 h sleep per night while at home, and an average of 4 h sleep per opportunity during the relay trip. Sleep obtained in the relay van was associated with lonnger sleep onset latencies, lower efficiency and poorer subjective quality than sleep at home. During the relay trip, drivers obtained significantly more sleep during opportunities that occurred in the evening, than those that occurred early morning or during the day. These findings suggest that while drivers are able to obtain sleep during short relay operations, it is of poorer quality than sleep obtained at home. Further, the timing of the sleep opportunities during the relay trip impacts on the quantity and quality of sleep obtained.