These signals are used at grade crossings to warn automobiles and pedestrians of passing trains.  Earlier signals use standard 8 3/8 inch diameter lenses.  More modern signals use larger more visible 12 inch diameter lenses.

Each light unit has a background and visor assembly which is hinged at the bottom and tilts down to allow access to the lens, bulb and mirrored reflector.  This assembly is held upright by a single bolt located on the front directly above the lens visor.  Each unit also has a small window on each side commonly referred to as a “side light” which indicate to the crew on an approaching train that the crossing signal system has been activated.

Light units usually are found in groups of four - two facing forward and two facing to the rear - to enable warning of traffic approaching in each direction.

The mast holding the light units usually has two “Railroad Crossing” cross bucks (one for each side) as well as a top mounted crossing bell.

Crossing Bell Details

LED Signals

Above.  Side of signal showing side light window and bulb.

Above.  Crossing signal with 8 3/8 inch diameter lenses and top of mast bell.  Normally the cross bucks visible at the bottom would be mounted above the light units.