The origin of the chainsaw is one of those historical facts that surprises most people, because the powerful timber-cutting tool familiar today was developed from a surgical instrument designed for a very different purpose.

The Medical Origin

The chainsaw was invented in the late 18th century, with credit given to two Scottish surgeons, John Aitken and James Jeffray, who developed a small hand-cranked chain saw device around 1780 to assist with a surgical procedure called symphysiotomy. Symphysiotomy involved cutting the symphysis pubis, the cartilaginous joint at the front of the pelvis, to widen the birth canal during difficult labours where the baby could not pass through the pelvis. Before this innovation, the procedure was performed with a knife, which was slow and imprecise in the confined space involved.

The early chainsaw was a small, hand-operated device with a serrated chain loop driven around a guide bar, similar in mechanical principle to modern chainsaws but much smaller in scale. The teeth cut through cartilage and bone more quickly and with greater control than a knife or saw blade of the time.

Development into a Timber-Cutting Tool

The application of the mechanical chain cutting principle to timber work came later, in the 19th and early 20th centuries. In 1830, the German orthopaedic surgeon Bernhard Heine developed an osteotome, a surgical bone-cutting instrument, based on the chain principle. The adaptation of this concept to cutting larger timber was gradual, with various mechanical and eventually powered chain-cutting devices patented through the 19th century.

The electric chainsaw was patented by a Canadian millwright named James Shand in 1926, and the petrol-powered chainsaw was developed in the 1920s and 1930s. Early petrol chainsaws were heavy two-person tools; lighter single-person chainsaws became available from the 1950s onward and transformed forestry and timber work.

Summary

Chainsaws were originally invented in the late 18th century as surgical instruments to assist with symphysiotomy, a procedure for widening the birth canal in difficult deliveries. The mechanical chain-cutting principle was adapted for timber work in the 19th and early 20th centuries, leading to the development of electric chainsaws in the 1920s and lighter petrol-powered models from the 1950s. The original medical application is now obsolete; the timber-cutting chainsaw is the lasting product of this surprising origin.