Green Switch Innovations
Innovation in railroad signal systems
















The SIM - Switch Indication Maintainer is a handheld device used to simulate normal switch correspondence while the switch is handthrown or handcranked to perform periodic maintenance or testing.

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 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 can allow a
maintainer to take only one track out of service greatly decreasing
the impact switch maintainance has on train operations.

This means:

  • The dispatcher can clear signals on adjacent tracks.
  • Prevents "tumbledown" on the track out of service.
  • Track time required only on one track
  • Reduces "wait time" for maintainers

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 is connected to the pre-wired cable which allows the maintainer to simulate normal correspondence.

Features include:

  • Lightweight, durable case
  • High visibility yellow case
  • Normal switch indication LED
  • Requires 2 actions to simulate normal switch position
  • Easy setup and removal
  • Keyed cable connectors
  • Works with most model switch machines

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