The word “chainsaw” It brings to mind images of lumberjacks cutting down tree trunks, but what not everyone knows is that the tools from which chainsaws were derived were invented to facilitate childbirth. In the 1780 two Scottish doctors, John Aitken And James Jeffraythey designed a prototype of hand crank chainsaw to perform the so-called “symphysiotomy”a surgical procedure that involved widening the pelvis by resecting the joint between the two pubic bones to facilitate childbirth in the most complicated cases. This machine, as disturbing as it may seem when placed in an operating room, gave rise to the modern chainsaw, used not only in the medical field but also in the lumber industry.
Childbirth in the 18th century
In the 18th centurychildbirth was a critical and sometimes life-threatening moment for future new mothers. Complications were frequent, especially when the mother had difficulty dilating the cervix (the lower part of the uterus), with the consequence that the baby was unable to pass through the exit canal. One of the solutions was the cesarean section (which however was highly risky due to the haemorrhages) and the craniotomya procedure that involved breaking the fetal skull to save the mother, but at the cost of sacrificing the unborn child.
Another widespread practice was the symphysiotomywhich consisted of cutting the pubic symphysisor the joint between the left and right pubic bones. Before the invention of the chainsaw, this operation was performed with a scalpel, but it was imprecise and often caused damage to nearby organs such as the bladder and urethra.
It was in this scenario that Aitken and Jeffray introduced their innovation. Their device was equipped with a chain with serrated teeth and cranks on both sides, designed for cut the bone more effectively and less invasively compared to the scalpel. The saw, flexible and easy to handle, could reach difficult areas without damaging the surrounding tissue too much. However, this solution was not without its flaws: the chain could break or get caught in the bone, making the entire procedure complex and risky. Despite this, the operating principle of this instrument was one of the bases on which subsequent surgical chainsaws were developed.
The evolution of the chainsaw over time
The chainsaw soon found other applications, both medical and otherwise. After seeing its effectiveness in cutting bones, it began to be used not only in obstetrics, but also for theexcision of diseased joints and the removal of compromised bone tissue. In the 1830 the german surgeon Bernard Heine developed a mechanical version called osteotomewhich accelerated the cutting process thanks to a manual gear. This device was used during the American Civil War to quick and precise amputations and, as you can appreciate from the following photo, it was closer to the concept of the chainsaw we know today, since it was characterised by a continuous chain that facilitated the cutting of hard fabrics.
As the years went by, the use of the chainsaw reached fields far from the medical one. A milestone was set in 1918 from the Canadian mill builder James Shandwho patented the first portable chainsaw for outdoor use. According to what was declared by the British Columbia Provincial Museum «The idea came to him while he was fencing off his quarter of land and discovered that the barbed wire, pulled by horses, had sawed through a seven-inch oak post.». The first chainsaw with an internal combustion engine, however, made its appearance in 1927when the German inventor Emil Lerp he mass-produced it.
