Wigwag (railroad) - Rationale

Rationale

Soon after the advent of the automobile, speeds were increasing and the popularity of closed cars made the concept of "stop, look, and listen" at railroad crossings difficult.

Fatalities at crossings were increasing. Though the idea of automatic grade crossing protection was not new, no one had invented a fail-safe, universally-recognized system. In those days, many crossings were protected by a watchman who warned of an oncoming train by swinging a red lantern in a side-to-side arc, used universally in the US to signify "stop". This motion is still used today by railroad workers to indicate stop per the General Code of Operating Rules (GCOR) Rule 5.3.1. It was presumed that a mechanical device that mimicked that movement would catch the eye of approaching motorists and give an unmistakable warning.

In July 14, 1925 Alfred S Hoggatt I Patented the Automatic Crossing Guard. The invention relates to improvements in automatic railway crossing gates and has as its general object "to provide a crossing gate and means for automatically elevating and lowering the same in accordance with the passage of trains over the crossing, so that the services of a watchman at the crossing will not be required". Another object of the invention is to provide a simple mechanism, operated by a train approaching the crossing from either direction, for effecting a lowering of the crossing gate or gates before the train reaches the crossing, and likewise effecting an automatic raising of the gate or gates after the train has passed the crossing, the arrangement being such that after a train has passed the crossing, the parts of the mechanism will be automatically reset for subsequent operation. Serial No. 700,306.