Hi-Rail Trucks Don't Activate Crossing Signals - Trains Magazine

Fairmont, Mitchell and the others use air actuated "shunts" to set the current to short the signal circuit. They either use brushes (steel cable cut to length & then bound togeter to look like a funky paint brush or they use a round rotary cup bru***hat you would use with a buffer or power drill. Some brushes have constant contact with the rail and have to be adjusted constantly because they wear out. Most hi-rail wheels have a 1/2inch hard rubber tire to help smooth the ride. The hi-rail gear is insullated often to protect the truck electrical system from stay current in the rail wiping out voltage regulators, alternators, fusible links, etc. (it works BOTH ways!) from things other than normal signal cicuitry (like lightning)......

Power operated shunts can be pneumatic, hydraulic or electrical/solenoid controlled.

Down there at "Death-by-Water" (I know it well), the San Diego Northern, SANDAG or whatever they call themselves this week , has a ballancing act to perform in dealing with the public and/or getting out and maintaining a busy track.

What gets nuts is the shunts not working properly or not working at all. (In most states, the hi-rail/motor car operator is liable in a grade crossing collision)

Mudchicken Nothing is worth taking the risk of losing a life over. Come home tonight in the same condition that you left home this morning in. Safety begins with ME.... cinscocom-west