Sangster was born in Aberdeen and was named after his godfather, fireworks manufacturer Charles Thomas Brock.
He attended school in Aberdeen before continuing his education at King's College London.
Fellow employees included William Chater Lea, who would become noted for his Chater-Lea bicycles, motorcycles, and automobiles, J.G.H.
He worked with the New Howe Cycle Co., of Glasgow, and then with the Coventry Machinists Company a predecessor to the Swift concern.
For more than thirty years Sangster was managing director of Components, Ltd., and occupied a similar office in the Ariel Company.