Context

• Railway flagman became a new profession when the railroad network expanded across the United States in the 1800s. The role of the flagman consisted of staying informed about train schedules and waving a red light to alert all persons by the tracks of the danger of the coming train. Cattle presented a greater problem than humans, since the animals couldn't react to the signs and sometimes could not be removed from the tracks in time. In the mid-1860s, the idea to use a gate to physically block the crossing surfaced.
  
  

History

• The first gates represented mechanical wood structures that extended the width of the road and protected both sides of the crossing. The heavy weight made it difficult to move them in a timely manner. This problem led to a series of new concepts with weight balancing mechanisms and eventually mechanical gates that were automatically closed. The closure presented some danger because the automated gates closed too abruptly and at times trapped persons or animals under them.
  
  

Electric Gate

• The Watson concept attempted to address this issue and supported a progressive closure of the gate, giving plenty of time for anyone to avoid the gate and clear the tracks. The design called for placing electrical wires on the rail tracks ahead of the crossing to detect the approach of the train and trigger the activation of a wooden arm that lowered slowly across the road. Similarly, some wires placed downstream relayed that the train had cleared the space and gates could open again.
  
  

Evolution

• Subsequent inventions followed for more than two decades with new combinations of electric activations of the gates. Watson did not engage in this journey past his first patent. With the arrival of the "horseless carriage" in the late 1890s, the livestock gave way to the automobiles, and the gates shortened and acted more as a visual indicator of an upcoming train. The invention of cattle grids helped contain the cattle away from railroad tracks.
  
  

Anecdote

• One of the 19th century railway gate patents belongs to Mary J. Riggin (1889). Because female inventors were rare back then, Riggin is frequently mentioned as one of the 19th century female patent owners. Her design involved a series of pulleys to activate mechanically wooden gates.