A wireless position sensing device is provided for monitoring railyard
equipment status. The device comprises a gravity sensing mechanism for
sensing an angular displacement with respect to a substantially vertical
line, and for generating a displacement signal upon sensing a change in
angular displacement exceeding approximately 40 degrees. A processing
mechanism, operatively coupled to the gravity sensing mechanism, receives
the displacement signal. A radio frequency transmitter, responsive to the
processing mechanism, transmits a data signal indicative of the angular
displacement. The processing mechanism is programmed to activate the
radio frequency transmitter upon receipt of the displacement signal. The
gravity sensing mechanism is affixed, attached, or mechanically coupled
to railyard equipment comprising at least one of a manually operated rail
switch or a safety indicator.