GWR petrol-electric railcar
The GWR petrol-electric railcar was a 4-wheel motorised coach ordered by the GWR in 1911 from British Thomson-Houston, who designed it and supplied the electrical fittings. It was powered by a 35–45 horsepower (26–34 kW) Maudslay petrol engine driving a dynamo which supplied two electric motors, one on each axle.
Source: Wikipedia — GWR petrol-electric railcar (CC BY-SA 4.0)