The DC motor was the mainstay of electric traction drives on both electric and diesel-electric locomotives, street-cars/trams and diesel electric drilling rigs for many years. The introduction of DC motors and an electrical grid system to run machinery starting in the 1870s started a new second Industrial Revolution.
One acre is 43,560 sq ft. One half acre is 21,780 sq ft. However, that doesn't help most people much when trying to picture how large a lot is. Half acre lot is roughly:
A half acre is 21,780 square feet. There are various combinations of length and width that would amount to this area. One possibility is 110 x 198 feet. Another is 55 x 396. Iâ¦f it were square, each side would be approximately 147.58 feet.