Historical Engineers: George Westinghouse and the AC Power Grid

October 21, 2017 by Tim Youngblood

Learn about the man who helped Nikola Tesla propel the adoption of the AC electrical grid in the United States.

Learn about the man who helped Nikola Tesla propel the adoption of the AC electrical grid in the United States.

George Westinghouse is often remembered for his work improving railroads, the Westinghouse Company, and his mutton chop beard. For electrical engineers, however, he is remembered as the financial backer for many of Nikola Tesla's inventions.

Tesla and Westinghouse are well known for their battles with Thomas Edison and Westinghouse might have been the only person Edison despised more than Tesla. His contributions to the improvement of the essential distribution systems of railroads, natural gas, and electricity helped to propel the infrastructure of modern society. 


Our favorite engineer Nikola Tesla and George Westinghouse. Since Westinghouse was not one for photo ops, some photoshop had to be used to get them together in a picture.

Early Career

Some may think of Westinghouse as merely the money behind the great inventions, but he did a fair amount of inventing in his own right.

Westinghouse created his first invention, the rotary steam engine at the age of 19. At 21, he invented the Westinghouse farm engine (a steam-powered tractor), a "car replacer", and a frog switch (a type of railroad track switch).

His greatest contribution to the railroad industry was the air brake for trains, which he invented at the ripe old age of 22. Before air brakes, individual railcars had a person in each car who would pull a brake lever and do their best to pull their levers at the same time. This had a high margin of error and resulted in many train wrecks. Westinghouse's system used a compressor on the locomotive, which allowed the train's engineer to hit the brakes on every car simultaneously. This invention saved many lives and cut down on the crew size needed to operate a train safely.


A section from Westinghouse's air brake patent.

After Westinghouse moved on from railroads, he settled in Philadelphia where he drilled a natural gas well at his new home. This gave him the perfect place to test his next invention, a valve that allowed for natural gas to be distributed safely.

At the time, natural gas had to be highly pressurized in order to travel over distance. When the gas reached its destination, it was still under too much pressure to be used safely in homes. Westinghouse invented a reduction valve that allowed natural gas to come out of their pipes in low-pressure bursts, which allowed for natural gas to be accessed safely from homes.

AC Versus DC

After making natural gas distribution safe, Westinghouse set his eyes on the distribution of electricity. At the time, Thomas Edison's DC electrical grid was a popular model that was thought to revolutionize modern society. Edison's grid had a major flaw in it, however. The DC electrical grid could only distribute electricity about 2 kilometers away from its power source.

Westinghouse was almost the complete opposite of Edison in personality. While Edison was a showman who loved to talk himself and his inventions up, Westinghouse didn't even like to be photographed and was much more open to incorporating the ideas of other inventors. Even when Nikola Tesla worked for Edison, Edison went out of his way to discredit Tesla's alternating current. Westinghouse, however, made Tesla a central figure in the Westinghouse Electrical Company.

Seeing the limitations of the DC electrical grid, Westinghouse purchased the patent Gaulard and Gibbs' AC transformer, along with Tesla's AC induction motor, to create an AC electrical grid to transfer power up to thousands of miles using a concept similar to his natural gas valve system. The transformer served as a reduction valve for electricity.

In Edison's defense, the DC electrical grid worked. It just wouldn't get its missing component until well after his death—localized power sources like solar and wind energy. DC electrical grids are making a comeback in the form of microgrids and nanogrids, which are small-scale electrical grids that are usually powered by solar panels. These grids are finding use in extent and emerging industries alike.

Edison's battle with George Westinghouse and Nikola Tesla is finally getting a feature film called "The Current War" which comes to theatres on November 24th. It will certainly be interesting to see how Hollywood depicts such an important period in history for engineers and the evolution of American infrastructure.

This article is by no means a complete documentation of Westinghouse's life or the war of currents. If you know of any good articles, books, or documentaries on the topic, please share in the comments!