Green Switch Innovations
Innovation in railroad signal systems



















The SIM-Plus - Switch Indication Maintainer Plus is a handheld device used to simulate normal switch correspondence while performing periodic maintenance or testing. The SIM-Plus also provides the ability to power the switch machine using local switch battery or, if battery is not available, provide a temporary source of power from an optional power pack.

With the large number of trains moving today, it has become
difficult for signal maintenance forces to perform required FRA
tests and switch maintenance at control points. To test a switch
in a crossover now requires the maintainer to take two tracks
out of service.
The SIM-Plus is designed to allow a maintainer to
perform testing on a switch without adversely affecting the adjacent
tracks by simulating normal switch correspondence. The SIM-Plus
can allow a maintainer to take only one track out of service
greatly decreasing the impact switch maintainance has on
train operations. The SIM-Plus will also provide a means for
operating the switch machine under power as opposed to hand
operation, reducing the time and effort required to perform switch
maintenance and testing.

This means:

  • The dispatcher can clear signals on adjacent tracks.
  • Prevents "tumbledown" on the track out of service and the adjacent tracks.
  • Track time required only on one track
  • Reduces "wait time" for maintainers
  • Reduces track time required to perform testing
  • Allows power operation of switch machine under test

A cable is permanently wired into the switch machine or switch junction box. When the maintainer obtains permission to work on the switch, the SIM-Plus is connected to the pre-wired cable which allows the maintainer to simulate normal correspondence and power operate the switch machine to the desired position.

Features include:

  • Lightweight, durable case
  • High visibility yellow case
  • Normal switch indication LED
  • Ammeter for monitoring switch current
  • Designed for both 3 or 5-wire circuits and biased-neutral controllers
  • Requires 2 actions to simulate normal switch position
  • Easy setup and removal
  • Keyed cable connectors
  • Works with most model switch machines
  • Optional Power Pack for operation of switches without control battery at the switch

(an optional cable is available to use the SIM-Plus on any switches with a SIM cable installed)