page_title: FS Class E.424
section_title: Technique
hierarchical_section_title: FS Class E.424 / Technique
caption_attribution_description: Cabina di guida della E.424.075
context_page_description: The FS E.424 is a class of Italian railways electric locomotives. They were built in 1943-1951 and have been decommissioned in 2008.
context_section_description: Class E.424, having DC type motors like all the Italian locomotives of the time, is a rheostatic-type locomotive; on start, a rheostat is connected in series to the motors and is gradually excluded as speed builds up allowing more current to flow to the motors; unlike other rheostatic locomotives of that time, this is not achieved via the characteristic lever (Maniglione), but through an automatic system, called Avviatore Automatico, derived from contemporary first-generation ALe 790/880/883 EMUs.
  The driver simply selects the combination (series or parallel), and the relative rheostat contactors are automatically and gradually closed by this system; in case of failure, the driver can manually rotate an apposite wheel (that also usually rotates automatically as the system advances) to proceed with the exclusion.
  When the rheostat is completely excluded for the series combination, field shunts can be inserted, or the driver can proceed to parallel combination, making a transition, which is handled by a device called "CEM" that automatically combines the motors (closing various contacts) accordingly.
  Originally more than one unit could be coupled and be controlled remotely by the first locomotive using a system called Comando Multiplo; on the central part of the cab there also was a door that enabled the crew to pass from one locomotive to another in case of problems. However, because of safety issues and the imperfect reliability of this system (there were no instruments indicating the status of the slave locomotive, so it was not certain if it correctly made a transition or not, for example), it  was abandoned and then disassembled.
  Eleven units received compound-type motors, enabling a very fine speed control, in a range included between 25 and 50 km/h (16 and 31 mph) in series combination, and 50–100 km/h (31–62 mph) in parallel.
caption: Original E.424 driver console.
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