The 25C tunnel Jet Fans are provided with Larsen & Toubro Soft Starter units model PM 12 to ensure that the motor starts gently while accelerating the rotor. The lamps on the panels were not lit, making us suspect that the Jet Fan system was not working. A system of Infra Red sensors is apparently used to start and stop the Jet Fans – provided they are working in the first place and not wind milling in the extreme slipstream of a passing train.