Stan Stewart worked for A. Reyrolle and Co. Ltd for over 20 years. In 1979 he joined Brush Switchgear Ltd as Chief Designer, later joining the board as Technical Director. Mr Stewart moved to East Midlands Electricity in 1990 and then joined GEC ALSTOM Distribution Switchgear Ltd as Technical Director in 1991 before retiring in 1998. During his career, Mr Stewart served for total of 18 years as a member of the BEAMA Switchgear Technical Committee and was responsible for leading the design team which produced the UK's first indigenous SF6 circuit breaker, the 145kV type SPL in 1977, followed by the 245kV SPL.