Abstract :
The authors discuss the stages of approval for the Class 365 Networker Express trains-dual voltage (AC/DC) multiple units-by the S&T Safety Assessment Panel. The key issues discussed are transformer inrush, third rail gapping, and pantograph performance. The difficulties that arose were generally in the realm of Physics and Electrical Engineering proving that “traction electricity” (particularly the return current) would not interfere with “signalling electricity”. In many cases, it was demonstrated that there is less risk of electrical interference from Class 365 than there is from traditional units which, in practical terms, have been shown to pose a negligible risk of accident