The history and subsequent evolution of the chainsaw began in 1830 by the German orthopaedist Bernhard Heine. The osteotomeman as it was called was essentially a hand cranked bone saw used in surgical operations which rapidly gained in popularity after the advent of anesthetics.
Later a patent was granted to Samuel J. Bens of San Francisco in January 17, 1905 for “the endless chainsaw.”
By 1918 a portable chainsaw was developed and patented by Canadian millwright James Shand. Although they were still far from portable. They were big electric two man saws powered by generators mounted on crawlers or tractors. The size made them cumbersome and only allowed limited access to standing timber.
In 1930 the original patent expired only to be further developed by the German company Festo in 1933. Along with Andreas Stihl who patented and developed an electric chainsaw for use on bucking sites in 1926 and a gasoline-powered chainsaw in 1929. Later to become the company Stihl that we still know today.
Once WWII broke out the race for better technology to replace shrinking labor pools jumped into full swing. Chainsaws still hadn’t changed much by then and were still huge two man tools. Eventually, the development of aluminum and magnesium alloys, combined with improved engine design, gave way to lighter single man chainsaws. With Mercury being the first American company to capitalize on the new technology immediately after the war ended.
From there all sorts of weird and wonderful design were dreamed up. After a few decades, the design was standardized into what we recognize today.